## GE Energy



# Progress Energy Robinson Unit 1 Furnace Sorbent Injection Demonstration Project

Final Report, Rev. 02 Contract No. 10023-WA169 GE Job Number 6900 25 February 2009

GE Energy and Environmental Research Corporation 1831 East Carnegie Ave Santa Ana, CA 92705Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page ii 

## GE Energy
Table of Contents

Section Page
1.0 Executive Summary...................................................................................................... 1-1 1.1 Project Objectives .................................................................................................. 1-1 1.2 Process Design....................................................................................................... 1-2 1.3 Engineering Design................................................................................................ 1-4 1.4 Field Test Program................................................................................................. 1-5 1.5 FSI System Performance........................................................................................ 1-6 1.6 Recommendations for Permanent Operation at Robinson..................................... 1-8 1.7 Transferability of Results to Other Boilers.......................................................... 1-10 2.0 Introduction................................................................................................................... 2-1 2.1 Furnace Sorbent Injection Technology Overview ................................................. 2-1 2.2 Project Objectives .................................................................................................. 2-4 2.3 Program Overview................................................................................................. 2-5 3.0 Unit Description............................................................................................................ 3-1 4.0 Furnace Sorbent Injection Process Design ................................................................... 4-1 4.1 Overview................................................................................................................ 4-1 4.1.1 Baseline Operating Conditions ...................................................................... 4-1 4.1.2 Boiler Temperature Field............................................................................... 4-2 4.2 Sorbent Injection Process Design .......................................................................... 4-5 4.2.1 Sorbent Injection Requirements and Constraints........................................... 4-6 4.2.2 Computation Fluid Dynamics Studies ........................................................... 4-9 4.2.3 Isothermal Model Studies ............................................................................ 4-10 4.2.4 Thermal Model Studies................................................................................ 4-12 4.2.5 Sulfation Model Studies............................................................................... 4-13 4.3 Sorbent Characterization...................................................................................... 4-14 4.4 Process Design of FSI Injection System.............................................................. 4-16 4.4.1 Baseline Study ............................................................................................. 4-16 4.4.2 Injection Elevation Selection ....................................................................... 4-18 4.4.3 Injection Configuration Selection................................................................ 4-21 4.5 FSI Impact on Boiler Thermal Performance........................................................ 4-28 4.5.1 Coal Firing at 188 MWg.............................................................................. 4-28 4.5.2 Coal Firing at 61 MWg................................................................................ 4-32 4.6 Sulfur Capture...................................................................................................... 4-35 4.7 Design Specification ............................................................................................ 4-36 5.0 Furnace Sorbent Injection Engineering Design ............................................................ 5-1 5.1 General Description ............................................................................................... 5-1 5.2 Silo Fill System...................................................................................................... 5-2 5.3 Silo Discharge and Metering Feeder System......................................................... 5-2 5.4 Injection System..................................................................................................... 5-3 5.5 Controls and Instrumentation................................................................................. 5-7Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page iii 

## GE Energy

6.0 ESP Upgrades ............................................................................................................... 6-1 6.1 Analysis Assumptions............................................................................................ 6-1 6.2 Estimated Electrostatic Precipitator Performance ................................................. 6-2 6.3 Short Term Electrostatic Precipitator Upgrades .................................................... 6-2 6.3.1 Vertical and Hopper Anti-Sneak Baffles ....................................................... 6-2 6.3.2 Lower Frame Stabilizers................................................................................ 6-3 6.3.3 Addition of Four (4) T/R Sets to the Inlet Fields........................................... 6-3 7.0 Field Test Program........................................................................................................ 7-1 7.1 Test Objectives....................................................................................................... 7-1 7.2 Test Plan................................................................................................................. 7-1 7.2.1 Equipment Performance Tests ....................................................................... 7-4 7.2.2 Parametric Tests............................................................................................. 7-4 7.2.3 Long-Term Tests............................................................................................ 7-5 7.3 Measurement Plan.................................................................................................. 7-6 7.3.1 Boiler Operating Data.................................................................................... 7-7 7.3.2 Emissions Data............................................................................................... 7-7 7.3.3 Coal & Ash Sampling .................................................................................... 7-7 7.4 Test Results............................................................................................................ 7-8 7.4.1 Start-Up Performance and Demonstrations ................................................... 7-8 7.4.2 Coal Sample Analysis.................................................................................. 7-13 7.4.3 Baseline SO 2 Emissions............................................................................... 7-15 7.4.4 SO 2 Removal Results................................................................................... 7-17 7.4.5 Impacts of Boiler Operation on Sulfur Capture........................................... 7-19 7.4.6 Impacts of Sorbent Injection on SO 2 Removal............................................ 7-22 7.4.7 Ash Analyses ............................................................................................... 7-23 7.4.8 Mercury Emissions ...................................................................................... 7-24 7.5 Operating Curves ................................................................................................. 7-25 7.5.1 Sorbent Flow Rate........................................................................................ 7-26 7.5.2 Injection Air................................................................................................. 7-28 7.5.3 Diverter Valve Position................................................................................ 7-29 7.5.4 Excess Oxygen Curve.................................................................................. 7-30 7.6 Impact of FSI on Boiler ....................................................................................... 7-31 7.6.1 Ash Deposition............................................................................................. 7-31 7.6.2 Boiler Performance ...................................................................................... 7-36 7.6.3 Opacity......................................................................................................... 7-38 7.6.4 ESP Performance ......................................................................................... 7-44 8.0 Recommendations for System Improvements .............................................................. 8-1 8.1 Sorbent Injection System ....................................................................................... 8-1 8.2 Boiler Deposit Management System ..................................................................... 8-3 8.3 Electrostatic Precipitator........................................................................................ 8-3 8.4 Byproduct Management System............................................................................ 8-5 9.0 Future FSI Application ................................................................................................. 9-1 9.1 FSI Technology Viability ...................................................................................... 9-1 9.2 FSI Performance Projections ................................................................................. 9-2Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page iv 

## GE Energy

9.3 FSI Cost Effectiveness........................................................................................... 9-3 9.4 FSI Schedule .......................................................................................................... 9-4 9.5 Application of FSI to Other Boilers....................................................................... 9-5 10.0 Conclusions................................................................................................................. 10-1 11.0 References................................................................................................................... 11-1 Appendices.................................................................................................................................1Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page v 

## GE Energy List of Figures

Figure Page

1-1. SO 2 reduction as a function of Ca/S ratio for parametric tests....................................... 1-6 2-1. FSI system schematic. .................................................................................................... 2-1 3-1. Robinson Unit 1.............................................................................................................. 3-1 3-2. Side view of Robinson Unit 1......................................................................................... 3-2 3-3. Burner firing angle.......................................................................................................... 3-2 3-4. Burner arrangement. ....................................................................................................... 3-3 3-5. Unfolded view of Robinson Unit 1 ROFA system......................................................... 3-5 3-6. ROFA system plan view................................................................................................. 3-6 4-1. HVT measurement elevations. ....................................................................................... 4-3 4-2. HVT measurements for 188 MW load at Elevation 78 ′ ................................................. 4-4 4-3. HVT measurements for 188 MW load at Elevation 107 ′ ............................................... 4-4 4-4. HVT measurements for 62 MW load at Elevation 78 ′ ................................................... 4-5 4-5. Process design methodology. ......................................................................................... 4-6 4-6. CFD design model geometry........................................................................................ 4-10 4-7. Lab scale isothermal physical flow model of Robinson Unit 1.................................... 4-11 4-8. Schematic of Robinson Unit 1 thermal model.............................................................. 4-13 4-9. Comparison of SO 2 capture for four different sorbents in the BSF.............................. 4-15 4-10. Vertical velocity profiles at the nose plane elevation of 188 MWg load. .................. 4-16 4-11. Robinson Unit 1 upper furnace flow field at 188 MWg load..................................... 4-17 4-12. Upward velocity profile of 62 MWg load at 87'-2".................................................... 4-18 4-13. Average gas temperature profile at a nominal full load injection elevation. .............. 4-19 4-14. Average gas temperature profile at a nominal low load injection elevation. ............. 4-19 4-15. Robinson front wall injection accessibility. ............................................................... 4-20 4-16. Mixing time as a function of sorbent air for various jet diameter sizes. .................... 4-21 4-17. Smoke sketch of 12-double simple jet with LFW-RFW-SW configuration. ............. 4-23 4-18. Smoke sketch of 12-double simple jet with LFW-CFW-SW configuration. ............. 4-23 4-19. Dispersion profiles at nose plane................................................................................ 4-25 4-20. Dispersion profiles at nose plane of various location injection systems. ................... 4-25 4-21. Dispersion profiles at nose plane of various sorbent air flow rates............................ 4-26 4-22. Dispersion profiles at nose plane of various ROFA flow rates. ................................. 4-27 4-23. Dispersion profiles...................................................................................................... 4-28 4-24. Predicted bulk furnace gas temperature at full load. .................................................. 4-32 4-25. Predicted bulk furnace gas temperature at low load................................................... 4-35 4-26. SO 2 Capture as a function of Ca/S at full load operation. .......................................... 4-36 4-27. Front view of the sorbent injector locations. .............................................................. 4-38 4-28. Side view of the sorbent injector locations................................................................. 4-38 4-29. Plan view of sorbent injector locations at the Elevation 87 ′ -2 ′′ (± 6 ′′ ). ...................... 4-39 4-30. Plan view of sorbent injector locations at the Elevation 77 ′ -0 ′′ (± 6 ′′ ). ...................... 4-39 4-31. Conceptual design of an injection box. ...................................................................... 4-40Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page vi 

## GE Energy

4-32. Process flow diagram for Robinson Unit 1. ............................................................... 4-42 5-1. System overview............................................................................................................. 5-1 7-1. Injection labels for upper elevation injectors. ................................................................ 7-9 7-2. Comparison of theoretical SO 2 and measured baseline SO 2 emissions........................ 7-16 7-3. SO 2 removal as a function of Ca/S during the parametric tests.................................... 7-18 7-4. SO 2 removal as a function of Ca/S for all tests. ........................................................... 7-18 7-5. Sorbent removal rate at two different loads during parametric testing. ....................... 7-20 7-6. Sorbent utilization for 158 MWg and 78 MWg loads. ................................................. 7-20 7-7. Impact of ROFA on SO 2 removal and calcium utilization........................................... 7-21 7-8. Impact of sorbent air flow rate on the FSI performance............................................... 7-23 7-9. Loss on ignition during the tests................................................................................... 7-24 7-10. Mercury emissions as a function of unit gross load. .................................................. 7-25 7-11. Mercury emissions as a function of Ca/Hg. ............................................................... 7-25 7-12. Sorbent flow rate as function of steam flow............................................................... 7-27 7-14. Injection air flow rate as a function of steam flow..................................................... 7-29 7-13. Diverter valve position as a function of steam flow................................................... 7-30 7-14. Sketch of ash deposition on secondary superheater and reheat pendants................... 7-33 7-15. Photographs of airheater inspection. .......................................................................... 7-34 7-16. Inspection photographs of A & B airheaters. ............................................................. 7-34 7-17. Primary superheater and primary reheat pendants inspection photographs. .............. 7-35 7-18. Photograph of the ash deposit analysis....................................................................... 7-36 7-19. Boiler efficiency as a function of exit O 2 . .................................................................. 7-37 7-20. Impact of FSI on main steam temperature as a function of the boiler load................ 7-37 7-21. Impact of FSI on NO X emission. ................................................................................ 7-38 7-22. Opacity as a function of SO 2 emission at baseline conditions. .................................. 7-39 7-23. Sample data on September 29, 2008 showing opacity increase................................. 7-41 7-24. Fish bone analysis for causes of opacity increase. ..................................................... 7-42 7-25. Impact of load on opacity. .......................................................................................... 7-42 7-26. Impact of flue gas flow rate on opacity. ..................................................................... 7-43 7-27. Impact of dust loading on opacity. ............................................................................. 7-43 7-28. Impact of exit oxygen on opacity. .............................................................................. 7-44 7-29. Impact of air heater outlet temperature on opacity..................................................... 7-44 9-1. Projected FSI performance as a function of coal sulfur content..................................... 9-3Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page vii 

## GE Energy
List of Tables

Table Page
1-1. Furnace Sorbent Injection Design Basis......................................................................... 1-3 2-1. Failure Modes and Effects Analysis............................................................................... 2-2 3-1. Design Data For Sootblowing Air Compressor.............................................................. 3-7 3-2. Sootblower Design Data................................................................................................. 3-7 3-3. Precipitator Information ................................................................................................. 3-8 3-4. Electrostatic Precipitator Configuration ......................................................................... 3-1 3-5. Electrostatic Precipitator Operating Condition............................................................... 3-1 4-1. Coal Firing Operating Conditions .................................................................................. 4-1 4-2. Furnace Sorbent Injection Design Basis......................................................................... 4-7 4-3. Sorbent Injection System Operating Range.................................................................... 4-8 4-4. Sorbent Particle Size Distribution ................................................................................ 4-15 4-5. Baseline Performance Predictions at Full Load ........................................................... 4-30 4-6. Sorbent Injection Performance Predictions at Full Load............................................. 4-31 4-7. Baseline and Sorbent Injection Performance Predictions at Low Load ....................... 4- 34 4-8. Sorbent Injection System Design Specification ........................................................... 4-41 4-9. Material Balance For Maximum Operation At 5.5% Sorbent Air ............................... 4-43 4-10. Material Balance For Nominal Full Load Operation At 5% Sorbent Air .................. 4-44 4-11. Material Balance For Nominal Low Load Operation At 5% Sorbent Air.................. 4- 45 4-12. Material Balance For Minimum Operation At 4% Sorbent Air ................................. 4-46 5-1. Operation Specifications................................................................................................. 5-4 6-1. ESP Coal Design Specifications..................................................................................... 6-1 6-2. Robinson Unit #1 Stack Test Results for 2006............................................................... 6-1 6-3. Robinson Unit #1 Estimated Stack Emissions w/FSI..................................................... 6-2 6-4. New T/R sETS Specifications ........................................................................................ 6-3 7-1. Progress Energy FSI Test Matrix ................................................................................... 7-2 7-1. Progress Energy FSI Test Matrix (Contd)...................................................................... 7-3 7-2. Emission Measurements Procedures .............................................................................. 7-7 7-3. Clean Air Test Results for Upper Elevation Injections .................................................. 7-9 7-4. Solid Flow Distribution Results for Upper Elevation Injections.................................. 7-10 7-5. Sorbent Feed Rate test sequence .................................................................................. 7-12 7-6. Equipment Performance Test Results........................................................................... 7-13 7-7. Coal Ultimate And Proximate Analysis ....................................................................... 7-14 7-7. Coal Ultimate And Proximate Analysis (Contd).......................................................... 7-15 7-8. Test Conditions For Varying Injection Air Rate .......................................................... 7-23 7-9. Sorbent Flow Rate As A Function Of Steam Flow ...................................................... 7-28 7-10. FSI Excess Oxygen Curve As A Function Of Steam Flow........................................ 7-31 8-1. Compositions of Flyash, Sorbent Byproduct, and Portland Cement.............................. 8-6 9-1. Comparison of Cape Fear and Robinson Coal Properties .............................................. 9-1Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page viii 

## GE Energy

Revision History

Revision Date Author(s) Approver Description of Changes 00 December 30, 2008 Joy Brooks/Pete Maly Wei Zhou First Release
01 January 30, 2009 Joy Brooks/Pete Maly/Santosh Nareddy Wei Zhou Second Release

02 February 25, 2009 Joy Brooks/Pete Maly/Santosh Nareddy Wei Zhou Third ReleaseProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page ix 

## GE Energy
Nomenclature

2DHT Two-dimensional heat transfer and combustion model APH Air preheater Baseline Without sorbent injection Boost Air Injection air BSF Boiler Simulator Furnace Ca/S Calcium to sulfur molar ratio CEMS Continuous emission monitoring system CFD Computational Fluid Dynamics CFW Center front wall COV Coefficient of Variation ESP Electrostatic Precipitator FMEA Failure Modes and Effects Analysis FW Front wall FSI Furnace sorbent injection HHV Higher heating value HVT High velocity thermocouple Injection Air Airflow from the injection air blower for injecting sorbent to furnace LFW Left front wall MWe Net boiler load MWg Gross boiler load PLC Programmable logic controller PSH Primary superheater PM Particular matter RFW Right front wall RH Reheater ROFA Rotating over fire air SH Superheater SR Stoichiometric ratio Sorbent Air Sum of sorbent transport air and injection air SW Sidewall Transport Air Airflow that transport sorbent from silo to injectors WC Water columnProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-1 

## GE Energy

1.0 Executive Summary

This report is organized into 11 major sections, plus appendices. Section 1 is an Executive Summary that provides an overview of project objectives, activities, a nd results. It can be used as a stand-alone summary of the project. Section 2 provides an intr oduction to the project. Section 3 provides a description of the Robinson plant. Section 4 de scribes the process design for the FSI system. Section 5 describes the FSI e quipment. Section 6 describes the recommendations for ESP upgrades. Section 7 descr ibes the test plans and results of the FSI test program. Section 8 provides recommendations for system improvements for potential permanent application of the technology. Sect ion 9 describes implications for applying the FSI technology on a commercial ba sis to Robinson or other coal-fired boilers in Progress Energy’s fleet. Section 10 provides pr oject conclusions. Section 11 provides project references. 

### 1.1 Project Objectives Progress Energy contracted GE Energy (GE) to perform a multi -phase project to demonstrate Furnace Sorbent Injection (FSI) technology for SO 2 control on Unit 1 at the H.B. Robinson plant in Hartsville, South Carolina. From an overall strategic st andpoint, project objectives were to define technical performance and cost-effectiveness of FSI as a potential means of meeting current and pending regulatory emissions control requireme nts. While the project was conducted in South Carolina, Progress Energy also operates boil ers in North Carolina and has a potential interest in implementing SO 2 control methods to comply with the State of North Carolina’s “Clean Smokestacks Act.” This act, officially titled the Air Quality/Electric Utilities Act (SB 1078), requires significant actual emissions reductions from coal-fired power plants in North Carolina. From a Federal regulatory standpoint, w hile proposed Clean Air Interstate Rule (CAIR) legislation was remanded in 2007, it is widely expected that similar regulations for control of SO 2 and other species will be enacted in the near future. The FSI project was designed to provide a basis for technology ev aluation as a potential means of meeting these regulations.
Specific technical objectives of the project were as follows:

• To achieve 40%-50% SO 2 reductionProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-2 

## GE Energy

• To effectively manage furnace and convective pass deposits, allowing the FSI system to be operated for an extended period of time with manageable impact u pon boiler efficiency and without causing boiler shutdown

• To meet air permit requirements for particulate matters (PM) emissions and opacity

• To effectively and safely manage byproduct materials

• To provide process data to allow an accurate assessment of the f easibility of the FSI technology Programmatic objectives were to complete the test work in 2008 and t o provide Progress Energy with summary results in a timely manner to allow the F SI technology to be assessed for potential permanent application to Progress Energy boilers. Environm ental, health, and safety objectives were to manage all project materials and oper ate project equipment in a safe manner, and to meet all plant permit requirements.
To accomplish these objectives, a multi-phase project was conducted. I nitial tasks included conceptual and process design, followed by engineering design, equipme nt procurement and installation (not in GE’s scope), and the FSI test program. 

### 1.2 Process Design The primary objectives of the Process Design task were to chara cterize the operation of the boiler, to define Progress Energy’s objectives and constraints for the sorbent injection technology, and to develop a FSI design basis, including injection l ocation, injector design, sorbent injection air requirements, and required sorbent flow rate. Tool s used to complete the Process Design included pilot-scale sorbent performance tests, phys ical flow modeling studies, and computational modeling, including computational fluid dynamic, thermal, and sulfation modeling. The primary output from the process design task wa s a Design Basis Memorandum [1] summarizing results and conclusions.
The FSI system was designed for a load range from 62 to 188 MWg. R obinson Unit 1 is equipped with a rotating overfire air (ROFA) system for NO X control. The FSI system was designed for optimum performance with the ROFA system in operation. The design coal sulfur content was 1.6 lb/MMBtu, although the FSI system was desig ned to be robust enough to accommodate the normal range of sulfur contents experienced at Robinson, which is approximately 1.4 to 2.6 lb/MMBtu. Objectives were to maximize SO 2 reduction while minimizing impacts upon upper furnace fouling and ESP performance. Of primaryProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-3 

## GE Energy

importance in the Process Design was to optimize mixing between the sorbent stream and the furnace gas. The FSI system was designed considering the following crit ical parameters:

• Flue gas temperature at sorbent injection locations

• Sorbent type

• Sorbent to sulfur stoichiometric ratio

• Sulfur content in coal

• Injection configurations and locations

• Sorbent air flow rates Table 1-1 summarizes the design basis for the FSI system.

TABLE 1-1. FURNACE SORBENT INJECTION DESIGN BASIS

Parameter Design Basis
Sorbent Type Ca(OH) 2 Injection Elevation Between Burners and Convective P ass Entrance Injection Type Wall Injection Injection Pressure 10 - 30" WC Ca/S Ratio 1.0 - 3.5 Burner SR Same as Baseline ROFA Flow Same as Baseline Sorbent Air 4% - 6% of Total Combustion Air To avoid the need for burner or overfire air adjustments, the basis for the trial system was for the sorbent air to add to the total boiler air. That is, as sorbe nt injection air was added, a proportionate amount of air was not reduced from other boiler input streams.

For effective SO 2 control, hydrated lime has an optimum injection temperature of approximately 2100 – 2200oF. Based on furnace temperature and flow field dat a, the process design work found that the optimum injection approach was to have two inje ctor elevations, including one optimized for full load operation and one for low load operation.
Along with the sorbent injection system, deposit management and ESP per formance were also evaluated during the Process Design phase. The deposit management studies developed recommendations that included restoring existing sootblowers to desig n operating conditions,Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-4 

## GE Energy

installing new sootblowers, and installing sonic horns to control ash-sor bent deposits in the upper furnace. These upgrades were coupled with an Intelligent Sootblowi ng system furnished to Progress Energy by Emerson. Regarding the ESP, the objec tive was to make nominal upgrades to allow the test project to be completed, with the understanding that further measures might be required if it was decided to permanently reta in the FSI system. To this end, it was recommended to install new Transformer/Rectifie r sets in the inlet fields of the ESP. A series of physical repairs was also recommended, inc luding washing the unit, repairing and adding anti-sneak baffles, repairing support insulat ors, and installing lower frame stabilizers and hopper baffles. 

### 1.3 Engineering Design The FSI system was designed to store hydrated lime sorbent, transport it to t he upper furnace, and inject it into the boiler with sufficient air to provide good mixi ng with the furnace gas. The system was designed to include the following major components: b ulk storage silos, a weigh hopper, rotary air lock feeder, sorbent transport system, boil er penetrations, sorbent injectors, and boost air fan / ductwork. The system is of a semi -permanent design, meaning that it is designed to accommodate a continuous trial several months in duration.
The system was designed for sorbent delivery to the facilit y in self-unloading bulk transport trucks, which unload into three identical, prefabricated bulk storage sil os. Each silo was designed to have a capacity of approximately 150 tons of Ca(OH) 2 . Combined, the three silos provide approximately five days capacity at full load operation. The silos were designed with a cone bottom, air activation to ensure the good flow of material, bin vent filter, and humidi ty monitors. The silos are skirted and have an enclosed base. The base s of the silos house all of the sorbent metering and transport equipment. The sorbent is dischar ged from the silos into a day hopper via a rotary feeder.
The sorbent was designed to be fed by means of a rotary airlock fe eder with a capacity of approximately 15,000 lb/hr. The feeder discharges the solids into a dilu te phase transport line. The sorbent transport blower then transports the sorbent in dilute pha se from the silo up to the furnace sorbent injectors. The sorbent transport lines from the silo to the furnace are reinforced rubber hose. Near the boiler the sorbent is conveyed through a splitter and is sent to the furnace injectors. The furnace injectors are located at tw o elevations, with one optimized for full load and one for low load. The injection nozzles have a coaxial design. The sorbent is injected through the inner nozzle, and propelled into the furnace via injection airProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-5 

## GE Energy

from the outer annulus. New waterwall penetrations were made in th e furnace to allow for the installation of the sorbent injectors.
Injection air is supplied to each sorbent injector via a new injec tion air supply system. This system consists of a injection air fan/blower, flow control instr umentation and a system of ductwork/piping to supply the air to each of the sorbent injectors. There is a flexible connection and isolation valve to each injector. Progress Energy direc tly managed FSI system installation work, with GE support on system commissioning and checkout. 

### 1.4 Field Test Program FSI performance tests began after completion of installation a nd checkout. FSI test tasks included equipment performance tests, parametric tests, and the long -term trial. The equipment performance tests were designed to ensure that FSI s ystem sorbent and air flow rates were able to meet specifications with regard to capac ity and accuracy. The system was generally found to meet flow rate objectives.
A parametric and long-term test plan was defined to meet the major technical requirements for performance of the installed FSI system. The primary objectives of the t esting were to:

• Characterize the performance of the FSI system relative to ke y parameters that influence boiler thermal performance and operability, SO 2 reduction performance, particulate emissions and ash handling.

• Define operating curves for integration into the distributed control system (DCS ).

• Optimize FSI operation over the normal boiler load range.

• Demonstrate the ability to operate the sorbent injection system over a long-term test period while maintaining SO 2 reduction and acceptable boiler operability and particulate emissions.

• Identify any problems and suggest corrective actions. Key test parameters included sorbent flow rate, Ca/S ratio, boile r load, sorbent injection air flow rate, coal sulfur content, injector elevation, and ROFA system operation. Appr oximately three weeks of parametric tests were conducted. The long-term t rial lasted approximately nine weeks.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-6 

## GE Energy
1.5 FSI System Performance The primary focus of the project was to reduce SO 2 emissions from the Robinson boiler. Other technical objectives were to maintain boiler operability, to comply with air permit requirements, to effectively manage byproducts, and to define impact s upon emissions of other species, notably NO X and mercury. Primary measurements and performance indicators included stack CEMS measurements for SO 2 , O 2 , CO 2 , NO X and mercury, stack opacity, unit temperatures and steam conditions, boiler load and heat rate, burner til ts, ROFA conditions, and sorbent feed rate.

The test work revealed that SO 2 reduction levels were generally consistent with projections made during the Process Design phase of the project. Figure 1-1 summarizes SO 2 reduction as a function of Ca/S ratio for the parametric test runs, along w ith initial performance projections. At the design Ca/S ratio of 2.5, SO 2 reduction ranged from approximately 40% to 55%. The parametric tests were more well-controlled than the l ong-term tests in terms of isolating process variables. In particular, baseline SO 2 measurements were obtained each test day during the parametric tests. For the long-term trial, base line sulfur measurements were taken from coal analyses. Generally multiple coal sources were fired during each long-term test day, leading to a higher margin of uncertainty with regar d to baseline sulfur levels. The highest SO 2 reduction achieved during the long-term trial was 71.6%, at a Ca/S r atio of 3.8 at 70 MWg.

0 10 20 30 40 50 60 70

0 1 2 3 4 Ca/SSO2Reduction, %

2007 Prediction

~159 MWg ~134 MWg ~76 MWg

Figure 1-1. SO 2 reduction as a function of Ca/S ratio for parametric tests.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-7 

## GE Energy

Regarding dependence of system performance upon operating paramet ers, SO 2 reduction increased with increasing sorbent injection air flow rate. This is attributed to improve mixing between the sorbent and furnace gas. The system was configured such that increasing sorbent air caused overall furnace gas flow rate and oxygen concentration to increase, decreasing boiler efficiency and causing opacity to increase. Therefore, for the scope of the demonstration project it was not feasible to maximize sorbent air for all test runs. However, system modifications could be made to improve mixing and penetration wit h reduced amount of sorbent air for potential permanent application.

It was found that SO 2 reduction was higher at low load than at full load. This is attri buted to better sorbent-furnace gas mixing, as the sorbent stream can more readily penetrate the furnace flow field when overall furnace flow rates and velocities are lower. FSI system sulfur reduction was slightly better with ROFA on than with ROFA off, a lthough the effect was small. This is consistent with the system design basis, which involved optimizing performance with ROFA on.
FSI provided approximately 80% mercury reduction during the trial. Poss ible mechanisms for this performance are direct capture of mercury by the lim e sorbent or improved mercury capture by fly ash carbon due to SO 3 reduction by the sorbent.
Regarding boiler performance during FSI operation, furnace deposits were found to be manageable by the unit sootblower/sonic horn system. While upper furnac e deposits were visually observed to increase during FSI operation, the deposits could be readily removed by operating the unit deposit management system, which consisted of operat ing the sonic horns continuously and the sootblowers in a cyclic manner. Boiler thermal e fficiency decreased slightly during full load FSI operation. However, most of this effec t is attributed to the increased air flow rate associated with FSI operation. For perma nent application, system operations could be made to maintain constant total air flow rate duri ng FSI by reducing burner air and ROFA air flows. A study of impacts upon parameters such as CO emissions and tube wastage would be required prior to reducing burner air.
Opacity and particulate matter emissions increased during FSI op eration. This effect was expected, since FSI increases fly ash mass loading and resistivity and decr eases mean particle size. The plant’s opacity limit is 40%, and the guideline during the project was to reduce FSI operation when opacity exceeded 35%. At certain full load conditions, opaci ty limited the amount of sorbent that could be injected into the boiler. The single most important parameterProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-8 

## GE Energy

upon opacity was found to be ESP gas temperature. Other parameters such as dust loading and coal sulfur content were found to be secondary factors. Coal sul fur content appeared to be less important to opacity during FSI operation than during baseli ne coal firing, possibly due to SO 3 capture by the sorbent. The extra air associated with FSI oper ation caused ESP temperature to increase, leading to an increase in opacity. Lowe r sorbent air flow rates led to lower ESP temperatures and lower opacity readings. Also, the tes t work began in summer and concluded in late fall. It was found that as ambient temperatur es decreased through the fall, ESP temperatures and thus opacity decreased.
Opacity was also found to increase with increasing sorbent flow rate and flue gas volumetric flow rate. From an operational standpoint, during the course of the test work several ESP operational modifications were made, including restoring the inlet field to nameplate power input and implementing an FSI-specific rapping program. These modifi cations provided moderate improvements to performance. PM mass emissions were me asured during three series of manual method sampling runs and were found to be well below permit limits but above pre-FSI historic values. Sorbent particles are relatively fine and reflective, and thus have higher impact upon opacity than upon mass emissions. 

### 1.6 Recommendations for Permanent Operation at Robi nson While the FSI system allowed the demonstration tests to be compl eted, a series of system modifications and upgrades would be required for potential permanent appli cation. First, the basis for the trial system was for the sorbent air to add to the total boiler air. That is, as sorbent injection air was added, a proportionate amount of air was not reduced from other boiler input streams. Therefore, furnace oxygen concentration and flow r ate increased during FSI operation, which caused boiler thermal efficiency to decreas e, back-end system temperatures to increase, and ESP collection efficiency to de crease. For permanent application it is recommended to reconfigure the system to allow total air flow rate to remain constant during FSI operation. This would require a study of burners and other system components to define the range of allowable operation and to evaluate a ny impacts upon other species such as NO X and CO.
As mentioned above, opacity had the potential to limit FSI operati on at full load boiler conditions. Several system upgrades could be made to facilitate potent ial a permanent FSI application. Options include:Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-9 

## GE Energy

• Reduce sorbent injector size or number of injectors to minimize inj ection air requirements.

• Humidification. A humidification system would consist of a series of atomization nozzles to spray water into the ductwork upstream of the ESP. Through evaporative cooling, the system would reduce gas temperature, reduce dust resis tivity, and reduce flue gas volume. Such a system would present operating risks as it w ould be necessary to ensure complete evaporation, since interactions between sorbent byproducts and liquid water could generate cement-like deposits.

• Field Addition. An inlet field could be added to the Robinson ESP. This a pproach would greatly upgrade ESP capture efficiency, although at significant cost

.

• Fabric Filter Baghouse. A conventional fabric filter baghouse or advanc ed system such as GE’s Max-9 electrostatic fabric filter could be insta lled to replace the existing ESP. This approach might be of interest relative to potential future PM2.5 regulations.

• Ash Dropout Box. A louver plate system could be installed upstream of the ESP, using inertial separation principles to act as a pre-collection de vice, at a significant cost due to the Robinson boiler configuration, space, and support steel structures.
While the FSI equipment itself generally performed as intended duri ng the test program, several issues were noted. Feeding from a silo proved difficult at times, possibly due to residual sorbent that may have gotten wet or otherwise agglomerat ed. A detailed checkout and cleaning of the affected silo is recommended. The reinforced rubber sorbent transport hoses experienced erosion problems just downstream of the splitter. It is believed that the splitter outlet hose barbs had smaller diameter than the hoses, ca using a region of high velocity and flow recirculation, leading to erosion. It is recommende d to change this configuration such that the diameter of the hose barbs is close to t hat of the hose via crimpon hose fittings similar to what was used on the 6" hose or replace with hard piping. Erosion areas were also noted in other constrained areas of the hoses. The distribution system design parameters need to be reviewed and potentially the hose distribution s ystem needs redesign. In addition to prevent erosion, the hose distribution system improvement should also consider an air cleanout system to clear lines as they plug.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-10 

## GE Energy

As a final recommendation, it is suggested to consider using the s orbent-ash byproduct stream as an input stream to production of construction materials. F or purposes of the demonstration the byproduct was shipped to a landfill. To improve process economics other reuse applications should be pursued. 

### 1.7 Transferability of Results to Other Boilers In general the FSI process could be applied to a wide range of boi lers. In past applications, FSI has been applied to pulverized coal-fired boilers with tangenti al, wall, and cyclone firing configurations. The primary technology requirement is to have boiler access and sufficient mixing and residence time for sorbent sulfation in the optimum furnace gas temperature window of approximately 2100–2200oF. These requirements are achievable in a wide range of boilers. The parameters that impact potential FSI performance on a specifi c boiler include:

• Coal sulfur concentration

• Boiler design and furnace flow field characteristics

• Boiler access for sorbent injectors in the optimum temperature window

• Availability of space at the plant to locate FSI equipment Other factors also define the level of plant upgrades that may be required to accommodate FSI. These factors include ESP design and specific collection ar ea, ash handling system design and capacity, ash pond capacity (if wet ash management is ut ilized), and upper furnace ash deposit management system design. These parameters requi re plant-specific evaluation to evaluate potential FSI performance for a given boiler.
Regarding potential application of FSI to other Progress Energy boil ers, boilers of potential interest are Cape Fear Unit 5 & 6. Cape Fear 6 is virtually i dentical to Robinson 1 and also has ROFA. Before the current project settled upon Robinson Unit 1 as t he FSI application site, GE performed an initial assessment of FSI application to C ape Fear Unit 5. This unit is slightly smaller than the Robinson boiler, but has many design simi larities. Cape Fear Unit 5 is a 153 MWe, four-corner tangentially fired boiler that is locate d in Moncure, NC. The unit was installed by Combustion Engineering in 1957. It is equipped with four levels of burners. A ROFA system was installed in 2000. The unit is equipped with a cold -side ESP. Cape Fear Unit 5 fires eastern bituminous coals from the Fola and Camp Cree k mines. These coals have similar analyses to the Robinson coals. Therefore, in terms of fur nace gas flow field characteristics and furnace gas sulfur levels, Cape Fear 5 is similar to the Robinson boiler.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1-11 

## GE Energy

While more detailed evaluation of sootblowers, the ESP, and the ash mana gement system would be required to accurately estimate total FSI project cost s and performance, in general FSI performance at Cape Fear Unit 5 would be expected to be simi lar to that obtained at Robinson.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 2-1 

## GE Energy

2.0 Introduction
2.1 Furnace Sorbent Injection Technology Overview The Furnace Sorbent Injection (FSI) process involves injection of dry sorbents into the upper furnace of a boiler for reduction of SO 2 emissions, forming solid products that are captured in the plant particulate control equipment. Figure 2-1 is a schematic of the FSI technology. Primary equipment includes sorbent storage silos, feeders, transport lines and inje ctors.

Along with sorbent reactivity towards SO 2 , other important FSI design considerations include impacts upon boiler deposit management, ESP performance, and byproduct ma nagement. To characterize potential operational impacts and to develop recommended corrective actions, a detailed Failure Modes and Effects (FMEA) analysis was develope d. The FMEA was compiled during a series of meetings between GE and Progress Energy . Potential failure modes were grouped into four categories. Each failure mode was ass igned a Relative Priority Number based on the likelihood, detectability, and severity of the fa ilure. As summarized in Table 2-1, a total of 341 potential failure modes were identified. The FMEA was updated throughout the course of the project. Stack

ESP Upgrades APH

Coal

Air FSI storage and transport equipment Management of upper

furnace deposits

Byproduct management: Usage/disposal Sorbent Delivery Sorbent

Storage Stack

ESP Upgrades APH

Coal

Air FSI storage and transport equipment Management of upper

furnace deposits

Byproduct management: Usage/disposal Sorbent Delivery Sorbent

Storage

Figure 2-1. FSI system schematic.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 2-2 

## GE Energy

Calcium-based sorbents are most commonly used in the FSI process because they have relatively high reactivity and generate manageable boiler deposits . Magnesium- and sodiumbased sorbents have also been applied to the FSI process. However, magnesium sor bents tend to be less reactive than calcium sorbents, and sodium sorbents can gener ate extensive fouling deposits. The FSI process typically provides 40%-60% SO 2 control. As compared to wet scrubbing and spray drying techniques, FSI has higher operating cos ts due to lower sorbent utilization (hence greater sorbent requirements for comparable leve ls of control), but has lower capital cost. FSI is best suited to smaller boilers ( i.e. less than 300 MWe), shorter life cycles, and moderate SO 2 control. FSI is also suited to requirements for emissions control on a plant-by-plant basis as opposed to a cap-and-trade approach.
FSI emission reduction performance is site-specific due to diffe rences in boiler geometry, fuel properties, time-temperature history through the boiler, sorbent characteristics, injection configuration, and other factors. Sorbent utilization is a measure of the efficiency of the process, and achieving maximum utilization reduces the quantity of so rbent required and waste produced in a given installation. To achieve maximum utiliza tion, the injection system must be designed carefully, with appropriate mixing to disperse the sorbent into the boiler flow field and to maximize sorbent residence time within the rea ction temperature window without deactivating the sorbent due to sintering. GE has experience in more than 20 FSI installations worldwide and is one of the original innovators of the p rocess. GE’s design

TABLE 2-1. FAILURE MODES AND EFFECTS ANALYSIS

Relative Priority Number Range Material

Handling Boiler Emissions Control Byproduct

Removal Total

0-100 3 71 7 1 82 101-200 17 39 5 4 65 201-300 9 69 4 1 83 301-400 9 29 9 3 50 401-500 2 28 0 1 31 501-600 0 21 6 1 28 601-700 0 1 1 0 2 701-800 0 0 0 0 0

Total 40 258 32 11 341Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 2-3 

## GE Energy

methodology includes computational and physical modeling tools to achieve ma ximum sorbent utilization.
The most reactive sorbents, such as hydrated lime, typically have the smallest particle sizes. These are challenging materials from a handling and transport perspective. They can cause storage and feed problems such as fluidization, bridging and surging. Sorbent is typically injected into the boiler furnace pneumatically. Discharge of stat ic electricity and surging in pneumatic transport systems also can occur if appropriate desi gns and materials are not used. In the current project GE designed FSI injectors providing variable i njection velocities to maximize sorbent utilization over the boiler load range.
Sorbents can alter both the quantity and the characteristics of ash deposits on boiler heat transfer surfaces. If not properly mitigated, these deposits can affect boiler thermal performance and efficiency. For example, significantly increas ed use of retractable sootblowers in the superheat and reheat sections has often been required to maintain steam temperatures, which in turn increases tube wastage rate. Sorbent materials can interact with fly ash and change ash properties, such as by decreasing fusion t emperatures and emissivity, which can change deposit patterns, shift heat transfer within the boi ler and reduce the effectiveness of sootblowers. Interactions between sorbent and ash are coal- and boilerspecific. Proper characterization and planning is required to ensure t hat acceptable boiler operability, availability and efficiency are retained. A number of techniques are available to evaluate and control particulate deposition. Detailed sorbent and as h analyses can be obtained and used in conjunction with boiler performance indices and ash chem istry predictions to characterize the potential impacts of sorbent inject ion on boiler slagging and fouling. Boiler physical and computational flow modeling techniques can b e used to evaluate particulate deposition in more detail. Pilot-scale combustion test w ork can also be performed to evaluate sorbent-ash interactions and deposit characteristics wi th specific fuels. The results of each of these analyses can be used to estimate site-spe cific potential particulate deposition effects and to define mitigating measures, such as modifications to the number, type, and operating frequency of sootblowers. These analyses can also be used to evaluate the potential impacts of changing coal type on particulate deposition. Bottom a sh and economizer hopper ash handling systems need to be evaluated for capacity to handle this increased ash volume and to avoid plugging.
The FSI process can adversely affect particulate control device efficiency, leading to increased PM10 and PM2.5 emissions, by changing fly ash properties in several ways. TheProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 2-4 

## GE Energy

most significant impacts are greatly increased dust loading fa ced by the ESP. Even if control efficiency is maintained, this results in increased particula te emissions. The other factors impacting ESP performance include:

• The alkaline sorbent materials increase fly ash resistivity, which can quickly degrade electrical power in precipitator fields. This may potentially r equire electrostatic precipitator upgrades such as installing a humidification system, upg rading controls, or increasing specific collection area.

• Fly ash size distribution can be affected. In particular hydrated lime sorbents typically have mass mean diameters of less than 5 microns, which is much s maller than typical fly ash. This can affect control device efficiency, again potentia lly requiring upgrades.

• Ash volume is increased, potentially requiring modifications to ESP rapping cycles. At the nominal full-load system design point, fly ash loading to the pr ecipitator increased by about 40%. Further, the collected material can becom e cement-like upon contacting moisture, which can lead to hard deposits on collection plat es, ducts, and hoppers.
Each of these factors must be carefully considered to ensure that plant opacity and particulate matter emissions remain within acceptable bounds.
Furnace sorbent injection increases the volume of byproducts generate d. FSI also changed waste characteristics, potentially increasing leachate pH a nd the concentration of calcium compounds. If a wet ash management system such as an ash pond is used, impermeable pond liners and/or neutralization may be required. Robinson plant installed and used a dry ash system to avoid these issues. Also, collected sorbent byproducts ar e typically found in a calcined state. In this state the materials are reactive w ith water and the hydration process generates heat and steam and must be properly managed. 

### 2.2 Project Objectives The primary focus of the project was to measure, evaluate and as sess the efficiency and costeffectiveness of FSI as a potential means of meeting current a nd pending regulatory SO 2 emissions control requirements. Specific technical objectives of the project w ere as follows:Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 2-5 

## GE Energy

• To achieve 40%-50% SO 2 reduction,

• To effectively manage furnace and convective pass deposits, allowing the FSI system to be operated for an extended period of time with manageable impact u pon boiler efficiency and without causing boiler shutdown,

• To meet air permit requirements for PM emissions and opacity,

• To effectively and safely manage byproduct materials, and

• To provide process data to allow an accurate assessment of the f easibility of the FSI technology. Programmatic objectives were to complete the test work in 2008 and t o provide Progress Energy with summary results in a timely manner to allow the F SI technology to be assessed for potential permanent application to Progress Energy boilers. Environm ental, health, and safety objectives were to manage all project materials and oper ate project equipment in a safe manner, and to meet all plant permit requirements.
To accomplish these objectives, a multi-phase project was conducted. Ini tial work focused on conceptual and process design, followed by engineering design, equipment installation (not in GE’s scope), and the FSI test program. 

### 2.3 Program Overview The FSI program was structured into a multi-phase approach. Major p hases and the schedule for the project were as follows:

• Phase 1. Conceptual Design and Failure Modes & Effects Analysis ( FMEA): April 2006 – September 2006

• Phase 2. Pilot-Scale Testing: October 2006 – December 2006

• Phase 3. Process Design and Detailed Design: September 2006 – June 2007

• Phase 4. FSI System Procurement and Installation: November 2007 – July 2008

• Phase 5. Field Trial and Performance Evaluation: July 2008 – December 2008

• Phase 6. System Recommendations and Reporting: December 2008 – February 2009 GE specifically performed all design and pilot test work in Phases 1-3. Progress Energy directly managed the Phase 4 procurement and installation work, wit h technical review byProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 2-6 

## GE Energy

GE. Phase 5 was a joint effort in which Progress Energy provided operations personne l to run the FSI system, with GE on-site engineering and technical support to define test plans, obtain and reduce data, and collect samples. GE completed the Phase 6 rec ommendations and reporting.
Project reviews and decision points were in place after Phase 1 and Phase 2 of the project. GE’s past experience with FSI indicated that along with sorbent reactivity, secondary impacts upon boiler operability with regard to managing furnace de posits, ESP performance, and byproduct management were of direct importance to the potential success of the technology. To evaluate, rank, and define how to address these impacts, a detailed Failure Modes and Effects Analysis was performed.
After the Process Design work projected that boiler impacts could be effectively mitigated and that sorbent reactivity objectively could be met, the project proce eded to the design and construction phases. From standpoint of both permitting and project scope, t he plan was to run the long-term trial for several months and then shut down system ope ration. However, the equipment was designed to allow conversion to a permanent installat ion should this be of interest. In particular, the FSI system foundation, silos, feeders, and injectors are suitable for permanent operation.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-1 

## GE Energy

3.0 Unit Description

Robinson Unit 1 is a 188 MWg, tangentially fired boiler located in Hart sville, South Carolina (Figure 3-1). It was installed by Combustion Engineering, Inc. in 1963 and is owned and operated by Progress Energy. This section of the report describes the boiler design and operating characteristics.

Robinson Unit 1 is a plain-tube tangentially fired twin-furnace boiler , which has a width of 42' 2-3/8", a depth of 24' 1-1/2", and a gross furnace volume of 102,400 cubic f eet. A side view of the unit is shown in Figure 3-2. The unit is equipped with five CE-Raymond No. 633 bowl mills and five levels of tilting tangential burners on each ei ght corners. The burner firing angles and nozzle arrangement are shown in Figure 3-3 and F igure 3-4, respectively. The superheater temperature can be controlled by spray attemperator or burner tilt. The boiler uses the burner tilts as a primary method for superheat control. The unit has a multistage superheater with platens, an inter-stage reheater, a CF-S type economizer and two Ljungstrom generative air heaters. Figure 3-1. Robinson Unit 1.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-2 

## GE Energy

Figure 3-2. Side view of Robinson Unit 1.

32 o 22 o 32 o 22 o

32 o 22 o 22 o 32 o

Front Wall Figure 3-3. Burner firing angle.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-3 

## GE Energy

Robinson Unit 1 is equipped with a rotating overfire air (ROFA) sys tem for NOx control. The system consists of 14 injection boxes located at four differe nt elevations from 77 to 92 feet as shown in Figure 3-5. The injection angle of each injector is shown in Figure 3-6. The ROFA fan capacity is 174,000 ACFM at 570 o F and 40 in. WC. All 14 injector boxes are designed to operate up to 30 in. WC. The upper boxes of ROFA system are not being used in order to reduce erosion in the secondary superheater. Some injectors w ithin a given box are partially blocked. The blocked injectors are UR1 center injector, UF R2 lower injector, UFL2 lower injector, UFL1 upper injector and UL1 center injector. The bas eline study in this project is based on a full load and a low load operating condition wit h the ROFA system in place. At full load operating condition (188 MWg), the amount of ROFA flow is estimated to be up to 25% of total combustion air. At low load operating condition (61 MWg) , the ROFA flow rate is approximately up to 38% of total combustion air. The ROF A flow rate is estimated based on the ROFA box pressure measurements that were provided by Progress Energy and GE site visit. The sorbent injection system is desig ned to operate at various ROFA flow rates. Top Air

Coal
Oil/Auxiliary Air

Coal

Coal

Coal

Coal Oil/Auxiliary Air Auxiliary Air

Auxiliary Air

Bottom Air

Figure 3-4. Burner arrangement.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-4 

## GE Energy

The sootblower system in the Robinson unit consists of twelve long ret ractable blowers (IK’s), thirty-two furnace wall blowers (IR’s), and two air preheater sootblowers. Two 300- psig sootblowing air compressors and an air receiver tank supply compre ssed air to the sootblowing system through a pressure reducing station. The design dat a for the sootblowing air compressors, wall sootblowers and retractable soot blowers a re listed in Table 3-1 to Table 3-2. The sootblower arrangement is shown in Figure 3-7.
The original electrostatic precipitator (ESP) was installed by Buell in the 1970’s and had eight (8) transformers. The precipitator was rebuilt by Environm ental Elements Corporation in 1997. Prior to the FSI demonstration program, the precipitator had six tr ansformers. All six precipitator transformers remained at 100% power to redu ce opacity as low as needed (or required). In the existing system, if opacity is below 20%, power -off rapping is utilized below 120 MW by changing the I&C. The precipitator has a collecti on area of approximately 330 ft 2 /kacfm. The precipitator information is summarized in Table 3-3 through Table 3-5.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-5 

## GE EnergyFigure 3-5. Unfolded view of Robinson Unit 1 ROFA system.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-6 

## GE Energy

SW NW

SE NE

112 ′′

A=10 o B=5 o C=0 o A=-10 o B=-5 o C=0 o A=0 o B=0 o C=0 o A=0 o B=0 o C=0 o

156 ′′ 192 ′′

48 ′′ 96 ′′ 168 ′′

UFR2 168 ′′

96 ′′

84 ′′
48 ′′

A=-6 o B=-3 o C=0 o A=-4 o B=-2 o C=0 o A=-18 o B=-12 o C=0 o A=18 o B=18 o C=18 o A=-18 o B=-18 o C=-18 o A=18 o B=12 o C=0 o A=4 o B=2 o C=0 o A=6 o B=3 o C=0 o UFR1 LFR2 LFR1 LFL1 LFL2 UFL1 UFL2 LBR2 LBR1

LBL1 LBL2

UR UL 112 ′′

84 ′′ 192 ′′ 156 ′′

Figure 3-6. ROFA system plan view.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-7 

## GE Energy

TABLE 3-1. DESIGN DATA FOR SOOTBLOWING AIR COMPRESSOR

Parameters Units Value Manufacturer Worthington Type 3 Stage Vertical Angle Discharge Pressure psig 300 Capacity cfm 690 Mechanical Power bhp 188 Compressor Speed rpm 500

Motor Data Manufacturer General Electric Motor Horsepower hp 200 Motor Speed rpm 505 Electrical Ratings volt 440 amp 282 phase 3 Power Supply Large 480 volt Load Center

TABLE 3-2. SOOTBLOWER DESIGN DATA

Parameters Units Wall Sootblower Retractable Sootblower

Manufacturer and Model Diamond Model IR Diamond Model IK Series 300 Motor Size hp 1.6 1.5 Motor Speed rpm 1800 1750 Motor Starter Limit Switches Located Remotely in a Separate Cabinet Located on Each End of the Blower AssemblyProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-8 

## GE Energy

EL. 35 ′ 3 ′′ EL. 66 ′ 0 ′′ EL. 77 ′ 11 ′′ EL. 106 ′ 6 ′′ EL. 111 ′ 0 ′′

EL. 92 ′ 11 ′′

Figure 3-7. Sootblower arrangement.

TABLE 3-3. PRECIPITATOR INFORMATION

Parameters Information

Year Built 1997 Type Cold Side Manufacturer Environmental Element Rectifier Transformer Location Top Dielectric Fluid Type Mineral OilProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 3-1 

## GE Energy

TABLE 3-4. ELECTROSTATIC PRECIPITATOR CONFIGURATION

Parameters Unit Value Number of casings

- 1 Chambers per casing

- 2 Gas passage width in 12 1⁄2 Pas passage per field

- 29 Number of mechanical fields

- 3 Field 1 ft-in 12'-11⁄2" x 36'-0" Field 2 ft-in 12'-11⁄2" x 36'-0" Field 3 ft-in 12'-11⁄2" x 36'-0" Electrical field

- Field 1A mA-kV 1,400-50 Current Density μ A/ft 2 55 Field 1B mA-kV 1,400-50 Current Density μ A/ft 2 55 Field 2A mA-kV 1,400-50 Current Density μ A/ft 2 55 Field 2B mA-kV 1,400-50 Current Density μ A/ft 2 55 Field 3A mA-kV 1,400-50 Current Density μ A/ft 2 55 Field 3B mA-kV 1,400-50 Current Density μ A/ft 2 55

TABLE 3-5. ELECTROSTATIC PRECIPITATOR OPERATING CONDITION

Parameters Unit
Total collecting plate area ft 2 151,902 Treatment length ft 2 36.38 Aspect ratio - 1.01 Specific collecting area, SCA ft 2 /1000 acfm, actual 249 ft 2 /1000 acfm @ 12" GP 260 Gas velocity ft/s 4.67 Treatment time s 7.8 Number of electrical fields - 6 current density μ A/ft 2 55 applied voltage kV/inch 8 ValueProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-1 

## GE Energy
4.0 Furnace Sorbent Injection Process Design

4.1 Overview Furnace sorbent injection (FSI) technology consists of injecting c alcium-based sorbent such as limestone (CaCO 3 ) or hydrated lime (Ca(OH) 2 ) into the upper portion of the furnace. Once injected, the sorbent is calcined and reacts with SO 2 to form calcium sulfate under fuel lean conditions. Numerous studies have shown that the capture of SO 2 depends on flue gas temperature at injection elevation, initial SO 2 concentration, sorbent type, sorbent particle size, quench rate, and the mixing rate of the injected sorbent.
The design of an FSI system for a utility boiler requires car eful examination of the boiler structural configuration, process parameters, operational character istics, and gas-side flow field characteristics. The primary design objectives are to:

• Maximize sorbent utilization, and

• Maintain acceptable boiler operation performance and emissions.
Achieving these objectives requires rapid and uniform mixing of the sorbent with t he flue gas while maintaining near-baseline boiler performance. The Robins on FSI process design study applied several design tools, including physical flow modeling, computational fluid d ynamics (CFD) modeling, thermal modeling, and sulfation modeling, to simulate the boiler and FSI system performance. The results from the study were used t o define FSI system design specifications, which served as the basis for the engineering design phases of thi s project. 4.1.1 Baseline Operating Conditions The operating parameters for Robinson Unit 1 in Table 4-1 are based on information provided by Progress Energy and GE site visit findings. The information pr ovided by Progress Energy is based on an average plant data during the period of August 2005 to March 2006. The available operating data includes the flow rates, temperatures, a nd pressures of steam and flue gas. The burner tilt positions range from –30 to +30 degrees range. At low load, the bottom Mills D and E are out of service to maintain steam temperature.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-1 

## GE Energy

TABLE 4-1. COAL FIRING OPERATING CONDITIONS

Gross MW MW 188 188 62 62 Exit O 2 * % wet 3.34 3.34 7.23 7.23
Steam/Water Flows Steam Flow Klb/hr 1382 1382 469 469 Feed Water Flow Klb/hr 1382 1382 469 469 Steam/Water Pressure Throttle Pressure psig 1802 1802 1802 1802 Feed Water Pressure psig 2451 2451 2657 2657 Cold Reheat Pressure psig 489 489 185 185 Hot Reheat Pressure psig 440 440 178 178 Drum Pressure psig 1959 1959 1824 1824 Steam/Water Temperatures Main Steam Temperature °F 1003 1003 937 937 Cold Reheat Steam Temperature °F 665 665 419 419 Hot Reheat Steam Temperature °F 966 966 731 731 Feed Water Temperature At Eco Inlet °F 461 461 379 379 Feed Water Temperature At Eco Outlet °F 499 499 435 435 Steam Drum Temperature °F 633 633 623 623
amps 61 61 40 40 amps 60 60 41 41 amps 162 162 94 94 amps 160 160 107 107 degrees -1.2 to 16.4 -1.2 to 16.4 9.9 to 25 9.9 to 25 Air Temperature Air Heater Air In °F 73 73 81 81 Air Heater Air Out °F 492 492 448 448 Mill Temperature °F 165 165 165 165 Ambient Temperature °F 58 58 59 59 Flue Gas - Temperature Gas to Air Heater °F 612 612 513 513 Gas out from Air Heater °F 264 264 240 240 Wind Box Pressure in WC 3.61 3.61 0.42 0.42 Furnace Pressure in WC -0.26 -0.26 -0.27 -0.27
* GE site visit Minimum Design Case Maximum Design Case Nominal Full

Load Boiler Parameters

FD Fan A Power Per Fan

ID Fan A Power Per Fan

Burner Tilt Position Nominal Low Load

ID Fan B Power Per Fan FD Fan B Power Per Fan

The boiler exit O 2 concentrations on a wet basis are shown to be 2.64% and 6.13% for the 188 MWg and 62 MWg load, respectively. GE’s site visit and evaluation ha ve shown that at 188 MWg and 62 MWg, the boiler exit O 2 concentrations are slightly higher than the plant report by 0.7% and 1.1% (wet). Thus, the boiler exit O 2 concentrations on a wet basis that are used in the sorbent system design are 3.34% (wet) and 7.23% (wet) for t he 188 MWg and the 62 MWg load conditions, respectively.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-2 

## GE Energy

4.1.2 Boiler Temperature Field The furnace sorbent injection (FSI) technology typically deliver s sorbent into a temperature window of approximately 2,100 to 2,400 o F, where sorbent is calcined without deadburning and reacts with SO 2 . The temperature window in this range is typically located bet ween the burners and the convective pass. The location of the window also varies wi th boiler load. The optimal temperature window at full load is located at a higher el evation than that at low load. To better understand the furnace temperature profile, a series of High Velocity Thermocouple (HVT) tests were conducted. The locations of the measure ments are shown in Figure 4-1. Figure 4-2 through Figure 4-4 show plots of the HVT measurements in Robinson Unit 1 for both full load and low load operating conditions conducted on October 10, 2006. The data plotted were obtained with the ROFA system in operation.
Since the optimal temperature window for the sorbent injection only s pans between 200- 300oF, the residence time in the window is usually short. The estima ted bulk residence time in Robinson Unit 1 from the ROFA elevations to the convective pass entra nce ranges from 1.2 to 2 seconds. Good mixing between the sorbent and flue gas within the avai lable residence time is critical to achieve high removal rates of SO 2 .Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-3 

## GE Energy

Figure 4-1. HVT measurement elevations.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-4 

## GE Energy

2000 2100 2200 2300 2400 2500

0 2 4 6 8 10 12

Distance from Wall, ftTemperature, deg.F

From East Wall

From West Wall

Figure 4-2. HVT measurements for 188 MW load at Elevation 78 ′

.

1500 1600 1700 1800 1900 2000

0 10 20 30 40

Distance from West Wall, ftTemperature, deg.F

Figure 4-3. HVT measurements for 188 MW load at Elevation 107 ′

.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-5 

## GE Energy

1500 1600 1700 1800 1900 2000 2100 2200

0 10 20 30 40

Distance from West Wall, ftTemperature, deg.F

Burner Tilts Up 30 degrees

Figure 4-4. HVT measurements for 62 MW load at Elevation 78 ′

. 

### 4.2 Sorbent Injection Process Design An integrated process design methodology, combining several model ing tools, was used to evaluate and optimize the performance of the FSI system for Robins on Unit 1. The methodology applies thermal and CFD modeling to identify the optimum i njection elevation at different operational loads. The isothermal (physical model) a nd CFD modeling tools were employed to optimize the mixing performance of the sorbent injecti on system. A sulfation model was then used to predict SO 2 capture. Figure 4-5 illustrates the process design methodology.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-6 

## GE Energy

Boiler Design/Operating Details Boiler

Isothermal Flow Modeling Isothermal Boiler Thermal Performance Modeling/CFD Boiler

Flow Field Flow Field Temperature Field Field

Sorbent Injection & Mixing Sorbent
Mixing Reaction Modeling Reaction

Thermal History Thermal History

SO 2 Removal

System Performance SO 2 Removal System Calcination

Sulfation Sulfation Experimental Sorbent Characterization Experimental Sorbent

Sorbent Reactivity Sorbent Computational Fluid Modeling Computational Fluid Sorbent Alternatives Sorbent Alternatives

Final Injection System Design Final Injection

Figure 4-5. Process design methodology.

4.2.1 Sorbent Injection Requirements and Constraint s This section describes the design basis for the Robinson Unit 1 sor bent injection system. The FSI system was designed for a load range from 62 to 188 MWg with the ROFA system in operation. The designed system has to reach a high SO 2 capture rate with a minimum impact on ESP performance and upper furnace fouling. The FSI system was designed considering the following critical parameters:

• Flue gas temperature at injection elevations,

• Sorbent type,

• Sorbent to sulfur stoichiometric ratios,

• Sulfur content in coal,

• Injection configurations and locations, andProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-7 

## GE Energy

• Sorbent air flow rates.
Table 4-2 summarizes the design basis for the FSI system.

TABLE 4-2. FURNACE SORBENT INJECTION DESIGN BASIS

Parameter Design Basis
Sorbent Type Ca(OH) 2 Injection Elevation Between Burners and Convective P ass Entrance Injection Type Wall Injection Injection Pressure 10 - 30" WC Ca/S Ratio 1.0 - 3.5 Burner SR Same as Baseline ROFA Flow Same as Baseline Sorbent Air 4% - 6% of Total Combustion Air

The baseline study in this project is based on 188 MWg and 62 MWg load operating conditions with the ROFA system in operation. The FSI system was designed to operate between the maximum and the minimum design conditions. The operating range is summarized in Table 4-3.
The maximum design case represents the maximum injection air flow rate, sorbent flow rate (Ca/S mole ratio of 3.5), and coal sulfur content (1.99 lbSO 2 /MMBtu) when operating at 188 MWg. The minimum design case represents the minimum sorbent air f low rate, minimum sorbent rate (Ca/S mole ratio 2.0), and nominal coal sulfur content (1.6 l bSO 2 /MMBtu) when operating at 61 MWg. The nominal full load (188 MWg, Ca/S = 2.5, 1.6 lbSO 2 /MMBtu) and nominal low load (61 MWg, Ca/S = 2.5, 1.6 lbSO 2 /MMBtu) design cases also are listed in Table 4-3. The sorbent air for full load operating condition was est imated to be at a maximum flow rate of 5.5% of the total combustion air.
The design approach of the system was to maintain the burner stoic hiometric ratio and the amount of ROFA flow as they are currently operated prior to the installation of the SO 2 injection system. The addition of the sorbent air would result in an i ncreased boiler exit O 2 . The material balance for nominal full load conditions with sorbent inj ection assumed that burner air and ROFA air flow rates are maintained at baseline conditions, resulting in an increase in boiler exit gas O 2 concentration due to the added sorbent air. Alternatively, inProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-8 

## GE Energy

order to avoid significant boiler derating, the ROFA air flow rat e could be reduced slightly such that the total of ROFA plus sorbent injection air equals the baseline ROFA ai r flow.

TABLE 4-3. SORBENT INJECTION SYSTEM OPERATING RANGE

Parameters

Total Boiler Heat Input MW 188 188 61 61 Sulfur Content lb SO 2 /mmBtu 1.99 1.60 1.60 1.60 Ca/S mole ratio - 3.50 2.50

2.50

2.00 ROFA Flow % Total Comb. Air 25 25 38 38 Sorbent Total Transport Air* % Total Comb. Air 5.5 5 5 4 Main Fuel

- Coal Coal Coal Coal Burner zone Stoichiometry

- 0.887 0.887 0.950 0.950 Burnout Zone Stoichiometry

- 1.254 1.247 1.623 1.607 Exit Stoichiometry

- 1.270 1.263 1.642 1.627 Windbox Pressure in WC 3.61 3.61 0.42 0.42 Furnace Pressure in WC -0.26 -0.26 -0.27 -0.27 Fuel Content Carbon wt % 68.77 68.77 68.77 68.77 Hydrogen wt % 4.50 4.50 4.50 4.50 Nitrogen wt % 1.70 1.70 1.70 1.70 Sulfur wt % 1.19 0.96 0.96 0.96 Oxygen wt % 4.98 4.98 4.98 4.98 Chlorine wt % 0.08 0.08 0.08 0.08 Ash wt % 12.34 12.34 12.34 12.34 Moisture wt % 6.44 6.67 6.67 6.67 100.00 100.00 100.00 100.00 Higher Heating Value Btu/lb (wet) 11,976 11,946 11,946 11,946 Btu/lb (dry) 12,800 12,800 12,800 12,800 Steam/Water Flow Main Steam Production klb/hr 1,382 1,382 469 469 Feed Water Flow klb/hr 1,382 1,382 469 469 Boiler Excess O 2 %, wet 4.21 4.13 7.85 7.74

* Percent in addition to the total combustion air Nominal Full Load Nominal

Low Load Minimum

Design Case Maximum Design CaseProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-9 

## GE Energy

4.2.2 Computation Fluid Dynamics Studies A full-scale three-dimensional CFD computer simulation model was developed for Robinson Unit 1. The model mesh was constructed based on the boiler drawings pr ovided by Progress Energy. The CFD geometry, shown in Figure 4-6, includes hopper, burner fr onts, nose, and convective pass, and ends at the economizer entrance.
A commercial mesh generation tool, ICEMCFD, was used to generate hi gh quality hexahedral meshes for both the baseline and the FSI retrofit models . Special attention was paid to the grid density near the burners and injectors to resolve the detailed flow structures. The mesh size was controlled to allow a reasonable run time for design optimization. The mesh size for the baseline model was 550,000 cells and the mesh size for the design model was increased to 688,000 cells.
A commercial software package, FLUENT 6.2, was used to solve the t ransport equations in each cell. The transport equations along with physical models account ing for turbulence, combustion, coal devolatilization, and char burnout were solved for coal-firi ng conditions in Robinson Unit 1. The model inputs for CFD studies were based on mater ial balances for the baseline and the design operating points. The wall temperatures and e xchanger heat duties were defined by the thermal model, which ensures that the CFD gas -phase furnace heat transfer was properly coupled to the unit steam generation and steam superheating characteristics.
Once the Robinson Unit 1 CFD model was developed and run successfull y, it was calibrated against field data taken during the period of August 2005 to March 2006. Af ter the baseline calibration, the mesh was revised slightly to accommodate the new FSI syste m. Full-scale three-dimensional CFD computer simulations were then performed to evaluate the impacts of the FSI system on the furnace gas flow field and C O emissions. The model results and analyses along with the isothermal modeling study results helped establish the sorbent injector design configuration, front-wall/side-wall flow split rat io, and injector placement leading to effective furnace mixing and minimum CO emissions. Through each step of this process, the CFD model was compared and validated against the isother mal flow model results.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-10 

## GE Energy

Burners Packs ROFA Convective Passes

Figure 4-6. CFD design model geometry.

4.2.3 Isothermal Model Studies An isothermal physical flow model of the Robinson Unit 1 furnace was built to study the furnace flow field, evaluate the mixing performance of the FSI system, and validate the CFD model prediction. The subscale (1/12) physical flow model was constr ucted using transparent acrylic to allow visualization of the boiler flow field, sorbent je t penetration, and subsequent mixing. The model was designed to be an exact geometric replica of the full-scale furnace, simulating the flow path from the burners in the furnace through the first few banks of the convective pass. A photograph of the model is shown in Figure 4-7.
To ensure similarity of the flow patterns between model and protot ype, the Robinson model was scaled geometrically, the burners and ROFA and sorbent injectors were scaled using the Thring-Newby method, and the convective pass sections were scaled to match the full-scale pressure loss coefficients. The FSI systems were also evaluat ed using Thring-Newby scaling criteria to account for thermal expansion in the boiler.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-11 

## GE Energy

Burners Convective passes

ROFA

Figure 4-7. Lab scale isothermal physical flow model of Robinson Unit 1.

Several visualization and measurement techniques were used to cha racterize the furnace flow field and evaluate the mixing performance of various FSI injection c onfigurations. Velocity profiles measured at the overfire air and nose elevations were us ed to guide sorbent injector placement and jet penetration. Smoke and bubble tracers were injecte d through one or more burners to visualize the flow patterns and characterize the flow f ield inside the furnace. Mixing performance, based on jet penetration and flow coverage, was exa mined using smoke visualization. Dispersion measurements of tracer concentration were conducted to quantify the flow distribution in the upper furnace. To take dispersion measure ments, a gas tracer was added to the air stream feeding the sorbent injectors. Point meas urements of the tracer concentration then were made across a grid at the nose and ROFA pl anes. The variation in tracer concentration over each measurement plane was evaluated using the Coefficient of Variation (COV), which is the standard deviation of the concentration m easurements divided by the mean concentration. In general, low COVs reflect good mixi ng performance: the closer the COV is to zero, the more uniformly the jet fluid is di spersed. All of theseProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-12 

## GE Energy

measurements were used in conjunction with CFD results to define t he process and hardware design specifications.

4.2.4 Thermal Model Studies Furnace heat transfer and boiler performance models were developed t o investigate the impacts of the FSI system on Robinson Unit 1 thermal performance. Th ese models, which close the heat balance between the steam and gas sides of the boiler, were calibrated using field data supplied by Progress Energy. The calibrated model was us ed to simulate boiler operation with the retrofitted FSI system and develop operating sc enarios that minimize the impact of the FSI system on boiler thermal performance. The hea t transfer analysis focused on determining the furnace gas temperature profile and exchanger hea t duties, and identifying any factors associated with FSI system that ma y prevent the boiler from operating at full-load conditions within the current operational design limit s (e.g., steam temperatures and attemperation flow rates).
The thermal analysis was performed with a two-dimensional furna ce heat transfer and combustion (2DHT) model (as shown in Figure 4-8) applied in conjunction wi th a one-dimensional steam path and boiler performance model. First, the furna ce heat transfer code was used to predict the flue gas temperature profile and heat absorption to the furnace waterwall and upper furnace radiant exchangers. A converged solution of the furnace heat transfer code yielded heat transfer parameters required to eva luate overall boiler performance, such as furnace wall and radiant exchanger heat abs orption and economizer exit gas temperature. These values were subsequently used in th e boiler performance code to predict steam-side performance parameters (e.g. attemperat ion flow rates and water/steam temperatures). The models provided an estimate of the impacts that sorbent injection has on the furnace flue gas temperature profile and boiler steam-side performan ce.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-13 

## GE Energy

23 SCR Tubes

RH

Platen SH

24 25

ROFA ROFA

11 12

Burner

Pack 

# }

Burner Pack 

# {

ROFA

Burner Pack 10

13 14 15 16 17 18 19 20 21 22 23 24 25 26 2728

9 8 7 6
5
4
3
2
1 11 12

10 13 14 15 16 17 18 19 20

9 8 7 6
5
4
3
2
1 21 22 26 27 28

23 SCR Tubes

RH

Platen SH

24 25

ROFA ROFA

11 12

Burner

Pack 

# }

Burner Pack 

# {

ROFA

Burner Pack 10

13 14 15 16 17 18 19 20 21 22 23 24 25 26 2728

9 8 7 6
5
4
3
2
1 11 12

10 13 14 15 16 17 18 19 20

9 8 7 6
5
4
3
2
1 21 22 26 27 28

Furnace Division into Layers Model Configuration

Figure 4-8. Schematic of Robinson Unit 1 thermal model.

4.2.5 Sulfation Model Studies Sulfation of alkaline sorbents, such as limestone (calcium carbonate, CaCO 3 ), and lime (calcium hydroxide, Ca(OH) 2 ), is the end result of a series of physical and chemical processes. When a sorbent is injected into a hot environment, it calc ines to form calcium oxide (CaO) by either of the reactions:

CaCO 3 = CaO + CO 2, Ca(OH) 2 = CaO + H 2 O.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-14 

## GE Energy

Before SO 2 can react with CaO it must first diffuse from the surroundin g gas to the particle surface, diffuse through the porous CaO structure, and diffuse through a product layer of CaSO 4 . Then, the SO 2 reacts according to the first order reaction:

CaO + SO 2 + 1⁄2 O 2 = CaSO 4 . Calcium sulfate, CaSO 4 , has greater molar volume than CaO, results in a product layer t hat fills the calcine pore structure as the reaction proceeds. As a consequence, the pore structure can become plugged and sorbent utilization rate can be reduced.
GE developed a sulfation model that takes into account of sorbent mixing characteristic and local flue gas quench rates. The sorbent mixing characteristics were obtained from the isothermal modeling of tracer concentration measurements. The quench rates and the injection temperature were predicted from thermal analysis. The sulfation model was applied to predict the sulfur capture for the proposed system.


### 4.3 Sorbent Characterization Sorbent utilization varies among different sorbent types, as illust rated in Figure 4-9 for three different pressure hydrated limes and limestone considered for the Robinson project. The experimental results were obtained from GE’s Boiler Simulator Facility (BSF). SO 2 captured by the hydrated limes is markedly higher than by the limes tone. Performance varies for products from different commercial sources. The Chemical Lime product demonstrated the highest sorbent utilization in these tests.
The hydrated lime used in this study is estimated to have a pu rity of 95%. The sorbent particle size distribution is listed in Table 4-4. Figure 4-9 show s that as Ca/S increases, the SO 2 capture also increases. The pilot-scale results show that the S O 2 capture objective (40% to 50% SO 2 capture) can be achieved with a Ca/S between approximately 2.0 to 3.5.
Flue gas SO 2 concentration will also affect the sulfation process by influenc ing the rates of external mass transfer, pore diffusion, product layer diffusion and che mical reaction. The SO 2 concentrations evaluated for this design are 1.99 lb/MMBtu and 1.6 lb/MMBt u for the maximum and nominal cases, respectively.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-15 

## GE Energy

0 10 20 30 40 50 60 70 80

0 1 2 3 4 Ca/SSO2Capture, %

Chem Lime, CaCO3 Carmeuse, Ca(OH)2 Chem Lime, Ca(OH)2 Mississippi, Ca(OH)2

Figure 4-9. Comparison of SO 2 capture for four different sorbents in the BSF.

Optimum sorbent reaction with SO 2 occurs in a limited temperature window (2,100 to 2,400 o F), thus it is important for sorbent to be injected to the furnace at the elevation where the sulfation temperature window lies. The furnace temperature profi le is predicted from thermal and CFD analysis, which were validated against the HVT data provided by Progress Energy. TABLE 4-4. SORBENT PARTICLE SIZE DISTRIBUTION
Particle Size Weight Fraction (micron)

0.800 0.050 1.500 0.100 2.100 0.125 2.800 0.150 3.700 0.200 4.600 0.150 5.500 0.100 6.500 0.075 7.700 0.040 9.500 0.010Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-16 

## GE Energy

4.4 Process Design of FSI Injection System 4.4.1 Baseline Study This section describes the study findings of the baseline operati on conditions. The furnace flow field was established with the aid of CFD and isothermal mode ling. Figure 4-10 shows the isothermal (top) and CFD (bottom) results of the vertical compone nt velocity profiles at the nose plane elevation at 188 MWg. Both profiles show a high velocity gr adient around the front wall region and low velocity gradient around the left corner of the boiler rear wall region. Such an unevenly distributed flow pattern would have a major effe ct on sorbent injector performance.

Figure 4-11 shows an upper furnace flow field of the 188 MWg by trac ing path lines released from the top burner row colored by temperature. The flow field i s typical of the T-fired boilers with a rotating flow moving upward. The flow field shows a n acceleration of the flow leaving the furnace due to the area contraction at nose elevation. T he flow field within the ROFA elevation region is highly complex. The flow from the ROFA j ets dominates the upper furnace flow field to create high velocity vortex, angular fl ow near the wall and slow 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 2.10 2.20 2.30 2.40 2.50

Isothermal model

CFD

Figure 4-10. Vertical velocity profiles at the nose plane elevation of 188 MWg l oad.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-17 

## GE Energy

vertical flow in the center. The CFD result also shows strong tangential flow concentration at rear and division wall corners.

At low load (62 MWg), the ROFA flow distribution is different from the full load condition (188 MWg). Figure 4-12 shows an upward velocity profile of 62 MWg load at 87'-2" elevation plane. Figure 4-11. Robinson Unit 1 upper furnace flow field at 188 MWg load.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-18 

## GE Energy

At Elevation 87'-2", the vertical velocity profile indicates strong vortex in the counterclockwise direction. Strong tangential flows concentrate along the front wall and the rear wall, and around the center of the boiler half. The high velocity gradient resul ts from the high ROFA velocity head. Similar to the full load condition, the flow field within the ROFA elevation region for low load is highly complex. The flow from ROFA jets dominates the upper furnace flow field to create a high velocity vortex. 4.4.2 Injection Elevation Selection Once the flow field is mapped, the injection elevation can be identif ied. The flue gas temperature profile through the boiler furnace is one of the most impor tant considerations for identifying the optimum sorbent injection elevation.
The computer simulations provide the average gas temperature profil es for the full load and low load operation conditions (See Figure 4-13 and Figure 4-14). Considering accessibility of locations for injectors on the boiler (Figure 4-15), the optimal injection elevations are 87'- 2" and 77'-0" for full load and low load operating conditions, respectively.

Figure 4-12. Upward velocity profile of 62 MWg load at 87'-2".Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-19 

## GE Energy

2000 2100 2200 2300 2400 2500 2600 2700 2800

50 60 70 80 90 100 110 Elevation, ftAverage Gas Temperature, oF Optimum

Injection Temperature ROFA

Injection Temperature Window

Figure 4-13. Average gas temperature profile at a nominal full load injecti on elevation.

1600 1700 1800 1900 2000 2100 2200 2300 2400 2500

50 60 70 80 90 100 110 Elevation, ftAverage Gas Temperature, oF

Optimum Injection Temperature ROFA

Injection Temperature Window

Figure 4-14. Average gas temperature profile at a nominal low load injection e levation.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-20 

## GE EnergyFigure 4-15. Robinson front wall injection accessibility.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-21 

## GE Energy

4.4.3 Injection Configuration Selection Preliminary jet calculations were performed to estimate an a ppropriate injector diameter. Then, CFD and isothermal model results were employed to evaluate m ixing performance of the injection system. Finally, sulfation analysis was applied to predict the SO 2 removal with the optimal configuration.
Using empirical jet entrainment and jet trajectory models, the initial number of injectors, injector diameters, and injection velocity head can be identified. Pr evious experience shows that 200-300 ms of mixing time is typically required to achieve good mixing. Figure 4-16 shows mixing time as a function of sorbent air for various jet diam eter sizes using 12 jets at a full load operation condition. For the sorbent air of 3-7% of total combus tion air, the jet diameter is required to be in a range of 4 to 6 inches in diamet er in order to provide a good mixing at reasonable pressure requirement (less than 40" WC).

The jet injection studies in the isothermal model were designed to evaluate the mixing and dispersion characteristics of jets in a simulated boiler flow field. First, screening studies were carried out by introducing smoke into the jet fluid. This allowed visua l observations of how the jets mixed and dispersed within the furnace flow. Selected t est cases, which showed good visual dispersion of the jets, were studied in detail by making gas tracer measurements at a 10 100 1000 10000

2 3 4 5 6 7 8

Sorbent Air, % Total Combustion AirMixing Time, ms 7 inch 6 inch 5 inch 4 inch 3 inch

Good Mixing Region

Figure 4-16. Mixing time as a function of sorbent air for various jet diameter si zes.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-22 

## GE Energy

downstream location from the injection point in the model. This involved int roducing a small amount of CO 2 into the jet fluid and taking measurements of the tracer conce ntrations over a grid plane downstream of injection locations. This facilitated com parisons of the dispersion patterns from the smoke traces and concentration measurements. The distributions of the normalized tracer concentrations were also used later to predic t the sulfur capture potential for any specific injection configurations.
Preliminary Location: Smoke Screening
A sample of smoke screening is shown in Figure 4-17. This is a smoke sketch of 12-double simple jets with LFW-RFW-SW configuration. With evenly distributed air t hrough each port, the left-front-wall ports penetrate toward center along the front wall of the furnace. The rightfront-wall ports and the sidewall ports combine to over-penetrate the left corner along the rear wall of the boiler. This configuration results in excessive amount of sorbent at the left rear corner and a lack of coverage on the right front corner of the furnace. Figure 4-18, however, shows that the 12-double simple jet with LFW-RFW-SW configur ation provides better mixing. With evenly distributed air though each port, the lef t-front-wall ports penetrate toward center along the front wall of the furnace. The right-front- wall ports provide the coverage to the front right corner. The sidewall ports effectivel y penetrate the left corner along the rear wall of the boiler. This configuration results in bett er mixing at nose plane elevation.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-23 

## GE Energy

Figure 4-17. Smoke sketch of 12-double simple jet with LFW-RFW-SW configuration.

Figure 4-18. Smoke sketch of 12-double simple jet with LFW-CFW-SW configuration.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-24 

## GE Energy

Quantitative Analysis: Trace Injection Mixing Performance
Dispersion measurements made for the test conditions are presente d as isopleths of tracer concentration normalized against the well-mixed tracer concentrat ion. The smaller the deviation of this ratio from 1.0, the more uniformly the tracer is dis persed. A measurement of the non-uniformity of the tracer concentration over the measurement plane is the coefficient of variation (COV), which is the standard deviation of the concentr ation measurements divided by the mean concentration. This has been calculated for t he dispersion profile and is a measure of the degree of well-mixedness produced by the injecti on system. In general, good mixing is indicated by low COV’s. The closer the COV is t o zero, the more uniformly the jet fluid is dispersed.
Comparison of Single Simple Jet and Double Simple Jet Configurations:
Figure 4-19 shows dispersion profiles at a nose plane of single simpl e jet (top) and double simple jet (bottom) configuration. The single simple jet configura tion consists of 6 simple jets at Elevation 87'-2", three jets on each side of the boile r. Figure 4-19 shows study of a half furnace. The double simple jet configuration consists of 12 simple jets at the same elevation, six jets on each side of the boiler. At each injection loca tion, 2 injectors are located staggered on top of the other. The COV for the single simple jet and the double simple jet configurations are 36% and 30%, respectively, as shown in Figure 4-19. The refore, it is concluded that the double simple jet configuration provides better mi xing than the simple single jet configuration.
Comparison of Jet Locations:
Figure 4-20 shows dispersion profiles of various injection locations at the full load operating condition. All of the profiles were tested at 5% sorbent air, 25% RO FA with 12-double simple jets. Figure 4-20c shows a configuration with the best mixi ng performance (COV = 27%) while Figure 4-20d shows a configuration with the worst mixing performance (COV = 45%). The only difference between the two profiles is that the confi guration in Figure 4-20c has left and center front wall injectors while the configuration i n Figure 4-20d has center and right front wall injectors. The previous velocity profile study reve als that the high velocity flue gas flow around the right front wall greatly impacts the sorbent dispersion characteristics. Because of the high flue gas flow rate around t he left front wall, the jets have difficulty penetrating into the boiler and because of the strong counter -clockwise vortex, the injected sorbent was swept to the right rear wall of the boiler (Figure 4-20d).Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-25 

## GE Energy

Single Simple Jets

Double Simple Jets COV = 36%

COV = 30%

Figure 4-19. Dispersion profiles at nose plane.

COV = 30% COV = 35% COV = 27%

COV = 45% COV = 32% (a) LFW-RFW-SW (b) LFW-CFW-RFW (c) LFW-CFW-SW

(d) CFW-RFW-SW (e) 2LFW-SW

Figure 4-20. Dispersion profiles at nose plane of various location injection syst ems.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-26 

## GE Energy

Other injection configurations such as shown in Figure 4-20a b, and d provide acceptable mixing performance but not as good as that shown in Figure 4-20c. There fore, the configuration in Figure 4-20c was selected for the FSI system.

Sorbent Air Flow:
The amount of sorbent air required to achieve good mixing in previous FSI applications was typically 3% to 7% of total combustion air. The quantitative analy sis shows that the amount of sorbent air at 7%, 5%, and 3% of total combustion air will provide COV of 20%, 24%, and 46%, respectively, at a nose plane measurement (Figure 4-21) for full load conditions. While the 7% sorbent air has a COV of 4% better than the 5% sorbent a ir case, sulfation analysis shows that both conditions provide similar predicted SO 2 capture. Since smaller amount of sorbent air requires less injection fan power and has smaller impact on ID fan limitation, 5% sorbent air flow was selected for design specification.

7% Transport Air

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00
5% Transport Air

3% Transport Air COV = 20%

COV = 24%

COV = 46%

Figure 4-21. Dispersion profiles at nose plane of various sorbent air flow rate s.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-27 

## GE Energy

ROFA Flow Effect:
Because of the uncertainty in the amount of ROFA flow, mixing w as evaluated over a range of ROFA flow rates. Figure 4-22 shows study results for ROFA flow of 15% to 25% of total combustion air at full load operation. While the COVs for each case (24% , 42%, and 33% for the 25%, 20% and 15% ROFA, respectively) are different, sulfation resul ts show that the predicted SO 2 capture is similar for all three cases.

25% ROFA

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00

20% ROFA

15% ROFA COV = 24%

COV = 42%

COV = 33% 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00

Figure 4-22. Dispersion profiles at nose plane of various ROFA flow rates.

Front Wall/Side Wall Flow Split:
Additional studies to evaluate unequal flow distribution to the injectors were also performed. Figure 4-23 shows dispersion profiles at evenly distributed flow and 60/40 front wall/sidewall (FW/SW) split distribution for the 5%-sorbent air, 25%-ROFA, and RFWCFW-SW configuration. Although the 60/40 FW/SW split may provide slight ly better SO 2 capture, the added complexity of the sorbent injection system (i.e ., multiple feeders and transport systems) probably would not be justified. Sulfation analysis for these cases predicts only small differences in SO 2 capture. Therefore, evenly distributed flow is preferredProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-28 

## GE Energy

considered optimum for SO 2 capture commensurate with ease of operation and low capital and maintenance cost.

Evenly Distributed Flow

60/40 FW/SW Split

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00
COV = 24% 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 0.00 2.00 4.00 6.00 8.00 10.00 12.00

COV = 27%

Figure 4-23. Dispersion profiles.


### 4.5 FSI Impact on Boiler Thermal Performance The boiler thermal models were calibrated against the HVT te st data to ensure they properly simulated boiler performance. Field data that were matched in the model during calibration include the exit flue gas temperature and O 2 , the steam generation rate and temperature, and heat duties for each of the major heat transfer components. The param eters adjusted during the model calibration were waterwall and heat exchanger fouling characteristics, the convective heat transfer coefficients, char reactivity, and the fuel flow r ate. 4.5.1 Coal Firing at 188 MWg HVT sequence 8 data were used to calibrate the models at the f ull load (188 MWg) condition. Table 4-5 summarizes the predicted overall boiler performan ce with 20% ROFA and 1.96% flue gas O 2 (wet). The table compares the results obtained for the calibrati on case with available field data. In general, the predicted steam- and ga s-side performance parameters agree well with field data, confirming the model ca libration at the full load baseline.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-29 

## GE Energy

The calibrated full load baseline was then scaled to the 2.64% flue gas O 2 (wet), which is specified as the full load operating condition in the project Design Basis Memorandum [1]. The scaled baseline was used as the basis when evaluating the impacts of the sorbent air injection. The sorbent air was injected at the elevation of 87 ′ -2 ′′ . The percentage of the sorbent air was fixed at 5%. For the sorbent injection case, the f uel flow rate was slightly adjusted (1% increase) to match the baseline main steam flow rate and/or temperature. Table 4-6 lists the scaled baseline performance and the simulation resul ts for the sorbent injection case. Figure 4-24 plots the mean gas temperature profile predic ted by the furnace heat transfer code (2DHT) for the furnace zones.
It can be found that the injection of sorbent air slightly changes t he furnace temperature profile. The gas temperature at the injection elevation becomes low er. The flue gas temperature at the economizer exit increases from 612 o F (scaled baseline) to 621 o F. Generally, the waterwall heat absorption decreases, while the convective backpass heat absorption increases. The change of the heat duties in the boiler im pacts the steam side performance. In order to maintain the main steam flow rate, the f uel consumption needs to be increased by 1%. On the other hand, the main steam temperature becom es 10 o F higher than that of the scaled baseline case.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-30 

## GE Energy

TABLE 4-5. BASELINE PERFORMANCE PREDICTIONS AT FULL LOAD

188 MW 188 MW Sequence 8 Baseline Model 20% ROFA 20% ROFA 9-Oct-06 Data 1.96% O 2 wet

Flue Gas O 2 (% wet) 2.0 2.0 Fuel Flow Rate (klb/hr) 154.1 Sorbent Carrier Air Flow Rate (klb/hr) n/a n/a Flue gas Temperature ( o F) Leaving 77 ft Mean Temperature 2,392 2,405 Backpass Inlet 1,470 Economizer 605 606 Air Heater 285 285 Flow Rates (klb/hr) Feedwater 1407 1407 Main Steam 1407 1407 Reheat Steam* 1266 1266 Attemperation flow (klb/hr) SH Att. 0.0 0.0 RH Att. 0.0 0.0 Water/Steam Temperatures ( o F) Economizer In 458 458 Economizer Out 498 498 Waterwall Out 634 634 Primary SH Out 833 Platen SH Out 972 973 RH In 665 665 RH Out 969 971 Heat Absorption (kW) Economizer 18,673 18,654 Waterwall 270,011 269,968 PSH + Platen SH 132,685 132,897 RH 62,224 62,670 Total Heat Absorption (kW) 483,593 484,189

* Assumed to be 90% of the steam flow rateProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-31 

## GE Energy

TABLE 4-6. SORBENT INJECTION PERFORMANCE PREDICTIONS AT FULL LOAD

188 MW 188 MW Scaled Baseline ROFA Sorbent Injection 20% ROFA 20% ROFA + 5% FSI Air 2.64% O 2 wet 3.46% O 2 wet

Flue Gas O 2 (% wet) 2.6 3.5 Fuel Flow Rate (klb/hr) 154.1 155.6 Sorbent Carrier Air Flow Rate (klb/hr) n/a 86.6 Flue gas Temperature ( o F) Leaving 77 ft Mean Temperature 2,419 2,393 Backpass Inlet 1,473 1,475 Economizer 612 621 Air Heater 288 293 Flow Rates (klb/hr) Feedwater 1408 1407 Main Steam 1408 1407 Reheat Steam* 1267 1266 Attemperation flow (klb/hr) SH Att. 0.0 0.0 RH Att. 0.0 0.0 Water/Steam Temperatures ( o F) Economizer In 458 458 Economizer Out 500 504 Waterwall Out 634 634 Primary SH Out 842 856 Platen SH Out 987 997 RH In 665 665 RH Out 975 975 Heat Absorption (kW) Economizer 19,656 21,207 Waterwall 269,274 267,494 PSH + Platen SH 136,649 139,209 RH 63,373 63,404 Total Heat Absorption (kW) 488,953 491,314

* Assumed to be 90% of the steam flow rateProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-32 

## GE Energy

1,200 1,400 1,600 1,800 2,000 2,200 2,400 2,600 2,800

0 25 50 75 100 125 150 Furnace Elevation, ftMean Gas Temperature,oF

Scaled Full Load Baseline, 2.64% O 2 , 20% ROFA Sorbent Injection, 3.46% O 2 , 20% ROFA + 5% Transport AirBurner RowsROFAROFAROFAROFA+Sorbent

Figure 4-24. Predicted bulk furnace gas temperature at full load.

4.5.2 Coal Firing at 61 MWg The models were calibrated for the low load (61 MWg) condition using HVT sequence 5 data. Table 4-7 summarizes the overall boiler performance predicted at low load with 29% ROFA and 5.9% flue gas O 2 (wet). The table compares the results obtained for the calibration case with the sequence 5 data. In general, the predicted s team- and gas-side performance parameters agree well with field data, confirmin g the baseline calibration at the low load baseline.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-33 

## GE Energy

The calibrated low load model was then used to simulate the sorbe nt air injection at the elevation of 77 ′ . The percentage of the sorbent air was 5%. In this case, the fuel flow rate wa s slightly increased by 0.6% to avoid boiler derate. Table 4-7 lis ts the modeling results for the sorbent injection at low load. Figure 4-25 plots the predicted mean gas temperature profile in the furnace zones.
The injection of the sorbent air at low load generally impacts t he boiler performance in the similar trend as it does at full load. The gas temperature at t he injection elevation becomes lower than the baseline value (86 o F lower at 77 ′ elevation). The flue gas temperature at the economizer exit increases to 520 o F, which is 7 o F higher than the baseline value. The waterwall heat absorption decreases, while the convective backpass heat absorption generally increases. The change of the boiler heat duties requires a slight adjustment of the fuel flow rate to match the baseline main steam flow at low load. However , the predicted main steam temperature change is very slight (1 o F). The overall boiler performance at low load is not significantly impacted by the injection of the sorbent air.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-34 

## GE Energy

TABLE 4-7. BASELINE AND SORBENT INJECTION PERFORMANCE

PREDICTIONS AT LOW LOAD

61 MW 61 MW 61 MW Sequence 5 Baseline Model Sorbent Injection 29% ROFA 29% ROFA 29% ROFA + 5% FSI Air 9-Oct-06 Data 5.9% O 2 wet 6.9% O 2 wet

Flue Gas O 2 (% wet) 5.9 5.9 6.9 Fuel Flow Rate (klb/hr) 52.5 52.9 Sorbent Carrier Air Flow Rate (klb/hr) n/a n/a 37.2 Flue gas Temperature ( o F) Leaving 77 ft Mean Temperature 1,891 1,928 1,842 Backpass Inlet 981 974 Economizer 511 513 520 Air Heater 253 254 258 Flow Rates (klb/hr) Feedwater 492 494 494 Main Steam 492 494 494 Reheat Steam* 443 444 445 Attemperation flow (klb/hr) SH Att. 0.0 0.0 0.0 RH Att. 0.0 0.0 0.0 Water/Steam Temperatures ( o F) Economizer In 370 370 370 Economizer Out 431 430 434 Waterwall Out 624 624 624 Primary SH Out 693 695 Platen SH Out 826 826 827 RH In 427 427 427 RH Out 768 766 765 Heat Absorption (kW) Economizer 9,061 9,075 9,765 Waterwall 106,665 107,086 106,431 PSH + Platen SH 31,097 31,150 31,273 RH 23,465 23,447 23,379 Total Heat Absorption (kW) 170,288 170,758 170,848

* Assumed to be 90% of the steam flow rateProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-35 

## GE Energy

800 1,000 1,200 1,400 1,600 1,800 2,000 2,200 2,400 2,600

0 25 50 75 100 125 150 Furnace Elevation, ftMean Gas Temperature,oF

Low Load Baseline, 5.9% O 2 , 29% ROFA Sorbent Injection, 6.9% O 2 , 29% ROFA + 5% Transport AirBurner RowsLower Two OOSROFAROFAROFAROFA+Sorbent

Figure 4-25. Predicted bulk furnace gas temperature at low load.


### 4.6 Sulfur Capture Results of extensive studies, including measurements on the boiler at Robinson Unit 1, isothermal modeling, CFD modeling, and heat transfer computational mod eling, were presented in previous sections. This information provides a basis for t he prediction of SO 2 capture expected in the Robinson Unit 1 furnace. The prediction of SO 2 removal potential requires a combination of all of the engineering tools used to specify the injection system design.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-36 

## GE Energy

In the evaluation of the impact of dispersion upon SO 2 capture, a simple methodology is employed which is based upon dispersion profiles obtained in the isotherma l flow model. In this approach, the boiler cross-section is divided into a grid system, a nd sorbent dispersion profiles are used to identify local variation in Ca/S ratio. Thes e may then be translated into local SO 2 capture, normalized by the local velocity, and then integrated acros s the flow to yield total SO 2 capture. The empirical method was used to predict amount of SO 2 capture. The prediction of SO 2 capture at full load as a function of Ca/S ratio is shown in Fig ure 4-26. About 40 to 50 percent of SO 2 reduction at Ca/S of 2.5 is predicted.

0 10 20 30 40 50 60

1 1.5 2 2.5 3 3.5 4
Ca/SSO2Capture, %

Figure 4-26. SO 2 Capture as a function of Ca/S at full load operation.


### 4.7 Design Specification The process design specifications for nominal full load conditions ( 188 MWg) and nominal low load conditions (61 MWg) derived from the studies are described in this section.
The maximum design case represents the maximum sorbent injecti on air flow rate, maximum sorbent injection rate (Ca/S mole ratio of 3.5), and maximum coal sul fur content (1.99 lbSO 2 /mmBtu) when operating at 188 MW (Gross). The minimum design case r epresents the minimum sorbent injection air flow rate, minimum sorbent rate (Ca/ S mole ratio 2.0), minimum coal sulfur content (1.6 lbSO 2 /mmBtu) when operating at 61 MW (Gross). The nominal full load (188 MW gross, Ca/S = 2.5, 1.6 lbSO 2 /mmBtu) and nominal low load (61Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-37 

## GE Energy

MW gross, Ca/S = 2.5, 1.6 lbSO 2 /mmBtu) design cases also are listed in Table 1. Additional information used in developing this process design specification can be fo und in the Progress Energy Robinson Unit 1 Furnace Sorbent Injection Project Design Basis Memorandum Rev 1.0 [1].
The FSI injection system consists of 12 injection boxes. Six injec tion boxes are located at Elevation 87 ′ -2 ′′ (±6 ′′ ) and the other six are located at Elevation 77 ′ -0 ′′ (±6 ′′ ), as shown in Figure 4-27 and Figure 4-28. At each injection elevation, two inject ion boxes are located on the sidewalls and four boxes on the front wall. The plan views of the injection locations at the Elevation 87 ′ -2 ′′ (±6 ′′ ) and 77 ′ -0 ′′ (±6 ′′ ) are shown in Figure 4-29 and Figure 4-30, respectively. Each injection box contains two round coaxial injector s, as conceptually shown in Figure 4-31. The nozzle diameter for all injectors is 4.026 ′′ (4-inch Sch 40 pipe). At full load, all of the jets at the upper elevation are fully in use and t he flow rate of the lower elevation injectors will be reduced to cooling air flow rate. At low load, the air flow rate through the lower injectors of each injection box at the lower eleva tion will be in full use and the air flow rate through the rest of the injectors will be re duced to cooling air flow rate. The lower injectors on each injection box at the lower elevation will be sized to provide an alternative flow injection for full load.
The sorbent will be transported in a dense phase and injection air wil l be added at the injector to enhance mixing. The sorbent injectors are designed to allow 5±0.5% of total air for injection (sum of transport and injection air) at full load. Additional cooling air is required and should be taken into consideration when sizing equipment. Both nominal full l oad and nominal low load operating points are at 5% of total air. The minimum design condition requires 4% of total air. The design specifications of the sorbent injectors are summarized in Table 4-8. This injector design specification is for the overall t ransport sorbent injection, i.e. including sorbent, transport air, and injection air. The process flow dia gram (PFD) for this system is shown in Figure 4-32. The material balances for various de sign conditions are shown in Table 4-9 to Table 4-12.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-38 

## GE Energy

ROFA El. 87'-2"

El. 77'-0"

Front Wall Sorbent Injector Buckstay 4' 4' 4' 4'

8'-9" 8'-9" 10'-6 5/8" 10'-6 5/8"

Figure 4-27. Front view of the sorbent injector locations.

R e a r W a l l

F r o n t W a l l

El. 87'-2"

El. 77'-0"

Left Wall F r o n t W a l l

R e a r W a l l

Right Wall ROFA Sorbent Injector 6' 9'-4 1⁄2"
6' 9'-4 1⁄2"

9'-4" 9'-4"

Buckstay Figure 4-28. Side view of the sorbent injector locations.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-39 

## GE Energy

Front Wall 10'-6 5/8 "±6" 4'±6" 4'±6" 6 ' - 0 " ± 6 "

Division Wall

10'-6 5/8 "±6" 10'-6 5/8 "±6" 6 ' - 0 " ± 6 "

10'-6 5/8 "±6"

Figure 4-29. Plan view of sorbent injector locations at the Elevation 87 ′ -2 ′′ (± 6 ′′ ).

Front Wall 12'-4 7/8 "±6" 4'±6" 4'±6" 9 ' - 4 " ± 6 "

Division Wall

8'-9 "±6" 8'-9 "±6" 9 ' - 4 " ± 6 "

12'-4 7/8 "±6"

Figure 4-30. Plan view of sorbent injector locations at the Elevation 77 ′ -0 ′′ (± 6 ′′ ).Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-40 

## GE Energy10.026 in



### Sorbent and Transport Air Boost Air

4.026 in

Figure 4-31. Conceptual design of an injection box.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-41 

## GE Energy

TABLE 4-8. SORBENT INJECTION SYSTEM DESIGN SPECIFICATION

Parameters

Sorbent Air Design Capacity % 5.5 5 5 4 Sulfur Content lb SO 2 /mmBtu 1.99 1.60 1.60 1.60 molar ratio 3.5 2.5 2.5 2.0 Boiler Excess O 2 %, wet 4.21 4.13 7.85 7.74 Front Wall Injector Sorbent Mass Flow Split % 66.67 66.67 66.67 66.67 Air Mass Flow Split % 66.67 66.67 66.67 66.67 Sorbent Flow Rate lb/hr 10,417 6,012 2,048 1,638 Sorbent Air Flow Rate lb/hr, wet 63,286 57,584 25,507 20 ,405 Number of Jets - 8 8 4 4 Injection Elevation 1 - 87'-2" 87'-2" 77'-0" 77'-0" Jet Inside Diameter 2 inch 4.026 4.026 4.026 4.026 Injection Temperature oF 58 ± 30 58 ± 30 58 ± 30 58 ± 30 Velocity Head in WC 28.0 ± 1.6 22 ± 1.4 16.9 ± 1.0 10.8 ± 0.7 Injection Velocity ft/s 330 ± 18 295 ± 18 261 ± 16 209 ± 13 Side Wall Injector Sorbent Flow Split % 33.33 33.33 33.33 33.33 Air Mass Flow Split % 33.33 33.33 33.33 33.33 Sorbent Flow Rate lb/hr 5,209 3,006 1,024 819 Sorbent Air Flow Rate lb/hr, wet 31,643 28,792 12,753 10 ,203 Number of Jets - 4 4 2 2 Injection Elevation 1 - 87'-2" 87'-2" 77'-0" 77'-0" Jet Inside Diameter 2 inch 4.026 4.026 4.026 4.026 Injection Temperature oF 58 ± 30 58 ± 30 58 ± 30 58 ± 30 Velocity Head in WC 28.0 ± 1.6 22 ± 1.4 16.9 ± 1.0 10.8 ± 0.7 Injection Velocity ft/s 330 ± 18 295 ± 18 261 ± 16 209 ± 13 Minimum Design Case Nominal Full Load Maximum Design Case

Ca/S Nominal Low LoadProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-42 

## GE EnergyFigure 4-32. Process flow diagram for Robinson Unit 1.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-43 

## GE Energy

TABLE 4-9. MATERIAL BALANCE FOR MAXIMUM OPERATION AT 5.5% SORBENT AIR

1 Coal 154,217 2 Inlet Air 1,873,757 58 3 APH Leakage 170,342 58 4 Combustion Air 1,392,952 492 3.61 5 Primary Combustion Air 310,463 492 6 ROFA 431,493 492 7 Secondary Burner Air 961,459 492 8 PA/Coal 464,680 165 9 Casing Leakage 22,558 58 10 Sorbent 15,626 11 Transport Air 3,146 58 12 Sorbent/Air 15,626 3,146 58 13 Boost Air 91,783 58 28.01 14 Flue Gas at Economizer Outlet 28,581 1,957,406 612 15 Bottom Ash 3,806 16 Economizer Ash 952 17 Duct Humidication Inlet Gas 28,581 2,127,748 18 Duct Humidication Outlet Gas 28,581 2,131,924 41,760 19 Humidication Inlet Water 41,760 20 Compressed Air 4,176 21 Fly Ash 28,581 22 Stack Gas 2,131,924 41,760 23 Feed Water 1,382,000 461 24 Superheat Steam Out 1,382,000 1003 25 Reheat In 1,243,800 665 26 Reheat Out 1,243,800 966 Assumptions: Wet Basis: Humidity = 0.00658 lb H 2 O/lb Dry Air Load: 188 MW, Gross; HHV = 12,800 lb/hr (dry) 95% Sorbent Purity Ca/S = 3.5; 1.99 lbSO 2 /mmBtu SR 1 = 0.89, SR T

= 1.27 Exit O 2 %, wet = 4.21%

Stream Description Stream No. Temperature °F Pressure

in WC Solid Gas Water Flow Rate (lb/hr)Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-44 

## GE Energy

TABLE 4-10. MATERIAL BALANCE FOR NOMINAL FULL LOAD OPERATION AT 5% SORBENT AIR

1 Coal 154,603 2 Inlet Air 1,875,295 58 3 APH Leakage 170,481 58 4 Combustion Air 1,393,574 492 3.61 5 Primary Combustion Air 311,240 492 6 ROFA 431,877 492 7 Secondary Burner Air 961,697 492 8 PA/Coal 465,842 165 9 Casing Leakage 22,693 58 10 Sorbent 9,017 11 Transport Air 1,815 58 12 Sorbent/Air 9,017 1,815 58 13 Boost Air 84,560 58 21.99 14 Flue Gas at Economizer Outlet 23,094 1,949,638 612 15 Bottom Ash 3,816 16 Economizer Ash 954 17 Duct Humidication Inlet Gas 23,094 2,120,119 18 Duct Humidication Outlet Gas 23,094 2,124,295 41,760 19 Humidication Inlet Water 41,760 20 Compressed Air 4,176 21 Fly Ash 23,094 22 Stack Gas 2,124,295 41,760 23 Feed Water 1,382,000 461 24 Superheat Steam Out 1,382,000 1003 25 Reheat In 1,243,800 665 26 Reheat Out 1,243,800 966 Assumptions: Wet Basis: Humidity = 0.00658 lb H 2 O/lb Dry Air Load: 188 MW, Gross; HHV = 12,800 lb/hr (dry) 95% Sorbent Purity Ca/S = 2.5; 1.60 lbSO 2 /mmBtu SR 1 = 0.89, SR T = 1.26 Exit O 2 %, wet = 4.13% Pressure in WC Solid Gas Water Stream No. Stream Description Flow Rate (lb/hr) Temperature °FProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-45 

## GE Energy

TABLE 4-11. MATERIAL BALANCE FOR NOMINAL LOW LOAD OPERATION AT 5% SORBENT AIR

1 Coal 52,671 2 Inlet Air 831,105 58 3 APH Leakage 75,555 58 4 Combustion Air 649,514 448 0.42 5 Primary Combustion Air 106,036 448 6 ROFA 290,777 448 7 Secondary Burner Air 358,737 448 8 PA/Coal 158,708 165 9 Casing Leakage 9,653 58 10 Sorbent 3,072 11 Transport Air 618 58 12 Sorbent/Air 3,072 618 58 13 Boost Air 37,642 58 16.88 14 Flue Gas at Economizer Outlet 7,868 849,714 513 15 Bottom Ash 1,300 16 Economizer Ash 325 17 Duct Humidication Inlet Gas 7,868 925,269 18 Duct Humidication Outlet Gas 7,868 927,096 18,270 19 Humidication Inlet Water 18,270 20 Compressed Air 1,827 21 Fly Ash 7,868 22 Stack Gas 927,096 18,270 23 Feed Water 469,000 379 24 Superheat Steam Out 469,000 937 25 Reheat In 422,100 419 26 Reheat Out 422,100 731 Assumptions: Wet Basis: Humidity = 0.00658 lb H 2 O/lb Dry Air Load: 61 MW, Gross; HHV = 12,800 lb/hr (dry) 95% Sorbent Purity Ca/S =2.5; 1.6 lbSO 2 /mmBtu SR 1 = 0.95, SR T = 1.64 Exit O 2 %, wet = 7.85% Stream No. Stream Description Flow Rate (lb/hr) Temperature °F Pressure in WC Solid Gas WaterProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 4-46 

## GE Energy

TABLE 4-12. MATERIAL BALANCE FOR MINIMUM OPERATION AT 4% SORBE NT AIR

1 Coal 52,671 2 Inlet Air 831,105 58 3 APH Leakage 75,555 58 4 Combustion Air 649,514 448 0.42 5 Primary Combustion Air 106,036 448 6 ROFA 290,777 448 7 Secondary Burner Air 358,737 448 8 PA/Coal 158,708 165 9 Casing Leakage 9,653 58 10 Sorbent 2,458 11 Transport Air 495 58 12 Sorbent/Air 2,458 495 58 13 Boost Air 30,113 58 10.81 14 Flue Gas at Economizer Outlet 7,395 841,920 513 15 Bottom Ash 1,300 16 Economizer Ash 325 17 Duct Humidication Inlet Gas 7,395 917,475 18 Duct Humidication Outlet Gas 7,395 919,302 18,270 19 Humidication Inlet Water 18,270 20 Compressed Air 1,827 21 Fly Ash 7,395 22 Stack Gas 919,302 18,270 23 Feed Water 469,000 379 24 Superheat Steam Out 469,000 937 25 Reheat In 422,100 419 26 Reheat Out 422,100 731 Assumptions: Wet Basis: Humidity = 0.00658 lb H 2 O/lb Dry Air Load: 61 MW, Gross; HHV = 12,800 lb/hr (dry) 95% Sorbent Purity Ca/S =2.0; 1.6 lbSO 2 /mmBtu SR 1 = 0.95, SR T = 1.63 Exit O 2 %, wet = 7.74% Pressure in WC Solid Gas Water Stream No. Stream Description Flow Rate (lb/hr) Temperature °FProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 5-1 

## GE Energy

5.0 Furnace Sorbent Injection Engineering Design

GE designed the sorbent injection system for Progress Energy Robi nson Station Unit No. 1. The detailed engineering design of the sorbent injection system is based on the design specifications described in Section 4.7. Progress Energy issued a co ntract to Nol-Tec Systems for the supply of the sorbent injection system major equipment and materia ls. 

### 5.1 General Description Figure 5-1 shows a system overview of the sorbent injection syst em. The sorbent injection system can be divided into the following subsystems:
1. Silo fill system - Unloading the sorbent (hydrated lime) from trucks into si los.
2. Silo discharge and metering feeder system – Transferring the sorbent from silos to the day bin and feeding the sorbent from day bin into the convey line.
3. Injection system – Injecting the sorbent into the upper or lower injectors.

Figure 5-1. System overview.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 5-2 

## GE Energy

5.2 Silo Fill System The sorbent (hydrated lime) is delivered to the Robinson site via pne umatically-unloaded truck trailers. The trailers are totally enclosed tankers w ith a capacity of 20-25 tons. The trailers are unloaded at the sorbent silo truck unloading station. Truc k unloading is accomplished using a truck mounted blower to convey the sorbent pneumatic ally via a pipeline to one of the three sorbent storage silos, each silo having a separate unloading connection - station. Conveying air is vented from the top of each stor age silo through a silo vent cartridge type of filter equipped with replaceable element s. Each silo vent filter operates continuously during truck unloading – silo filling with the silo’s vent fil ter’s electrical power and compressed air is to be automatically turned on by the truck unloading station cont rols.
During sorbent transfer operations, sorbent flow from one of the three conical bottom storage silos is enhanced by fluidizing bin bottoms. Each storage silo has an automatic slide gate isolation valve (butterfly valve approved substitution) located in the si lo discharge pipe between the storage silo and a silo sorbent positive flow rotary feed valve which feeds sorbent into the pneumatic conveyor transfer system. Only one silo di scharges sorbent at a time.
The dilute phase pneumatic transfer system conveys sorbent from t he storage silos to a day silo. The weigh hopper is mounted on four load cells, which is to continuously monitor the sorbent quantity (weight) in the silo. Pneumatic conveying transfer air is vented from the top of the weigh hopper silo through a cartridge type of vent filter equipped with replaceable elements. In order for the vent type of filter to operate properl y during filling of the weigh hopper silo, electrical power and compressed air to the vent filter are automatically turned on by the pneumatic conveying loading station controls. 

### 5.3 Silo Discharge and Metering Feeder System Sorbent flows by gravity out of the weigh hopper’s conical bottom an d is enhanced by fluidizing air slides. Sorbent out of the weigh hopper flows through a knif e gate or butterfly isolation valve and into a sorbent positive flow rotary feed valve which is used to control the amount of sorbent feed to the boiler via a variable frequency drive s orbent out of the speed controlled rotary feed valve is gravity fed into a second rotary feed valve to provide an air lock from the boiler delivery pneumatic conveying – transport system. This second rotary feed valve operates at a constant speed with a higher throughput cap acity than the first variable speed controlled rotary feed valve to prevent any buildup of sorbent bet ween the twoProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 5-3 

## GE Energy

rotary valves. Any air leakage from the transport line back through the airlock rotary valve is vented through a vent pipe back into the top of the weigh hopper.
The boiler sorbent delivery utilizes pneumatic conveying. Transpor t air is provided by a rotary positive displacement blower (Transport Blower), which operate s at a constant volume output. Transport air is monitored by an arrangement of flow meters, pr essure and temperature sensors.
Pressurized transport air from the Transport Blower is delivered to the discharge of the second rotary valve airlock beneath the weigh hopper where sorbent is fed i nto the pneumatic conveying transport line. The sorbent is pneumatically conveyed via a heavy wall rubber hose to a Diverter Valve. The Diverter Valve controls sorbent flow to either the lower furnace sorbent injectors or the upper furnace sorbent injectors, depe nding on boiler steam flow. After the diverter valve, sorbent flows into flow splitter(s ) which divide the sorbent flow into twelve (12) equal outlet streams which are connected to the twelve (12) furnace – boiler injectors.
At the sorbent injectors, the pneumatically transported sorbent is m ixed with a high volume of sorbent injection air supplied from a centrifugal fan located near the boiler. The sorbent injection air fan is used to provide a high mass flow of air to mi x with the sorbent upon entering the boiler furnace to aid in the penetration and mixing with the furnace combustion gas for efficient control of SO 2 from the coal combustion process. 

### 5.4 Injection System The intent of the sorbent injection system is to capture sulfur di oxide (SO 2 ) and produce calcium sulfate and calcium oxide, which are captured by the electrostatic precipitator.
The Sorbent Injection System is designed with the following parameters:
1) Sorbent transfer rate from silo to weigh hopper 32,000 lbs/hr minimum. 2) Sorbent transport rate from weigh hopper to boiler a) 9,017 lbs/hr nominal full load; b) 3072 lbs/hr nominal low load; c) 15,626 lbs/hr maximum; d) 2458 lbs/hr minimum.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 5-4 

## GE Energy

3) Sorbent transport rate minimum system turndown capacity 6.4:1. 4) Sorbent to air mass ratio for dilute phase transport 4:1 ratio. 5) Minimum transfer and transport line velocity 3500 feet / minute. The sorbent feed system delivers the selected sorbent and total sorbent air (transport air plus injection air) from the weigh hopper to the boiler at specified deli very rates corresponding to four system operating conditions: nominal full load, nominal low load, maxi mum and minimum (see Table 5-1).

TABLE 5-1. OPERATION SPECIFICATIONS

Parameter Units Nominal Full Load Nominal

Low Load Maximum Minimum

Sorbent Feed Rate to Boiler (hydrated lime) lb/hr 9,017 3,072 15,626 2,458
Total Injection Air to Boiler (transport air plus boost air) lb/hr 86,375 38,260 94,929 30,608

In this regard, the following specific performance guarantees were established using the measurement systems identified (or equivalent.).

• The feed rate of sorbent from each of the storage silos shall conf orm to the set point feed rates (for each of the four operating conditions noted above) with an accuracy of
± 10%. This shall be measured using the time required to fill the we igh bin feeder silo. The system shall demonstrate an ability to maintain the set point feed rates for a minimum of a 2-hour test period.

• The total sorbent flow delivered to the injectors shall conform to the four set points with an hourly average accuracy not to exceed ± 5%. This average hourly feed rate shall be determined based on weigh bin measurements. Three separate runs shall be made at each load condition with each run having a duration of 2 hours. (Total of 12 test runs) During these tests feed rate data shall be gather ed on a 2 minute rolling average basis to determine the 1-hour block average feed rate. To ass ure temporal stability of sorbent feed, the 2-minute rolling average shall not deviate from the set point by more than 7%. To determine the precision of the feed sys tem, eachProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 5-5 

## GE Energy

subsequent 2-hour test shall be performed at a different load condition. The system precision shall not exceed 5% as determined by the standard deviati on of the 1-hour average feed rate for each load condition.

• There shall be no significant pressure pulsing or flow surges in the sorbent transport lines during continuous steady-state operation. The instantaneous static pressure in the transport line immediately downstream of the feeder shall not deviate from the 2- minute rolling average pressure by more than ± 20%. This shall be verified using an appropriately scaled pressure gage or transmitter installed in the transport line within 10 diameters downstream of the point where solids are introduced into t he transport line. The test shall be conducted at all four operating conditions for a period of 2 hours each.

• The total clean transport airflow rate must remain stable. The flow rate shall be continuously measured for a test period of at least one hour at condition s equivalent to nominal full load and nominal low load. From each data set, 2-minute rol ling average flow rates shall be determined. The standard deviation in the flow rate shall not exceed 3%.

• The splitters shall be designed to distribute solids and transport ai r uniformly to each injector at each injection elevation.

• The uniformity of transport air shall be determined by installing a calibration section immediately upstream of each injector. The calibration section i s a piece of straight pipe that is at least 10 diameters long and with a port located 2/3 of the way down the test piece. The injector air velocity shall be measured using a terminal velocity probe or a pitot probe inserted through the port in the test section. The maxi mum variation in clean air transport velocity shall not exceed ± 5% from the mean.

• The splitter must also uniformly distribute the flow of sorbent sol ids. The maximum variation in solids flow among the different injectors shall not exc eed 10% relative standard deviation. The solids flow shall be determined by placing fi lter socks over each of the 12 injectors and then weighing the amount of material coll ected in each filter sock following the test. This test shall be performed a t the nominal full load condition only. Transport air flow rate shall be established at t he test condition priorProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 5-6 

## GE Energy

to commencing sorbent feed. The sorbent feed test duration shall be 5 to 10 minutes, or other duration as determined by mutual agreement between Supplier and Buyer.

• There is concern that moisture in the airflow used to transport t he solids will cause the sorbent to agglomerate and potentially to cause bridging or plugging of the feed system. The vendor shall demonstrate that such a potential problem will not occur by examining the particle size distribution of sorbent in the weigh bin hopper immediately following a rain or following a simulated rain show er. Rain may be simulated using hose to spray water in the immediate vicinity of the fan inlets. Sorbent in the day bin shall be evacuated and examined for presenc e of agglomerated pellets and a sample collected for determination of the particl e size distribution as compared to material delivered to the main storage silo. If agglom eration is present, the situation must be remedied by an appropriate corrective action up to and including addition of either a heater or desiccant dryer at the appropriate fan or blower air inlet.

• Static electricity discharge is a key safety concern. No e lectrical shocks or visible sparking shall be permitted in any portion of the sorbent delivery system.

• No visible solids leaks shall be permitted in any portion of the s orbent delivery system, especially in the region between the weigh hoppers and the injectors.

• Different types of valves may be acceptable for isolation purposes on the main storage silos and the weigh hopper. The vendor shall be responsible for se lecting and installing isolation systems that provide zero discharge of solids from the storage device(s). Since isolation of storage containers is intended for p eriod when the storage silo is not in use, the zero discharge condition shall be de monstrated when the hopper feed enhancer (aeration system of vibrating bottom) is not in operation.

• In the event the system cannot be designed to economically achieve these performance specifications at all four operating conditions without e quipment changes: performance at the nominal full load operating condition shal l take precedence over the other conditions, followed by the nominal low load, m aximum and minimum operating conditions (in descending order of precedence).Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 5-7 

## GE Energy

5.5 Controls and Instrumentation A control system is designed for the proposed material handling system. The control system includes the features requested below as well as the features that would add to the reliability or functionality of the controls and operation of this system.
The following control documents were provided for the project:
1. P&ID – Detailed P&ID of sorbent storage, transport and injection system. 2. I/O List – List of all I/Os that are added, and modified was identified, docu mented, and submitted. 3. Equipment List – List of all field equipment including instrument and valves was supplied. 4. Instrument Datasheets – Data sheets for all supplied equipment was submitted. Equipment list contains the identification numbers of relevant datasheet index number , which corresponds to the supplied instrument datasheet. 5. Instruction Manual – Instruction manuals of the supplied equipment and instrument was supplied. 6. System Functional Description – Detailed functional description of the sorbent inj ection system was supplied. The document is the basis of detailed logic configurati on development. It describes the sequence of operation, operator controls, alarm and fault conditions and alarm and fault actions. 7. SAMA and Ladder Logic Drawing – Actual logic configuration completed f or complete operation of the system with interfaces to existing plant Delta V DCS cont rol system via Ethernet. 8. Wire Termination Drawings – complete wire termination drawings for any interconnections required or interfaces to existing plant systems.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 6-1 

## GE Energy

6.0 ESP Upgrades

Based on the number of changes that have occurred in the course of the fur nace sorbent injection demonstration program design, the electrostatic precipita tor performance estimate has been reviewed. The analysis has been done with assumptions discusse d in the following section. 

### 6.1 Analysis Assumptions The design coal utilized for the emission estimate is shown in the Table 6-1. Based on the design coal, 25% excess air, 9% in-leakage and an ESP inlet tempe rature of 270°F, a combustion calculation defines the gas volume as 609,372 ACFM or 402,688 DSCFM.
Stack test data was provided for the years 2004, 2005, and 2006. The data showe d mass emission levels and the corresponding opacity measurements. For the purpose of calibrating a performance-estimating model, the 2006 test results shown in Table 6-2 were used.

TABLE 6-1. ESP COAL DESIGN SPECIFICATIONS
Parameter Unit Value
Carbon % 68.77 Hydrogen % 4.5 Sulfur % 1.19 Oxygen % 4.98 Nitrogen % 1.70 Moisture % 6.44 Ash % 12.34 Heating Value (AR) BTU/lb 11,976

TABLE 6-2. ROBINSON UNIT #1 STACK TEST RESULTS FOR 2006 Run # Opacity (%) PET (lb/MMBtu) MMBtu/hr SO 2 (%) Ash (%) BTU

Test 1 6.3 0.068 1,633 2.46 11.34 11,619 Test 2 6.4 0.069 1,632 2.86 12.42 11,624 Test 3 5.7 0.078 1,625 2.50 11.62 12,024 Average 6.1 0.072 1,630 2.61 11.79 11,756Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 6-2 

## GE Energy

6.2 Estimated Electrostatic Precipitator Performanc e For the purpose of estimating the outlet dust loading during furnace s orbent injection, a hydrated lime injection rate of 11,700 lb/hr was utilized. When the desi gn coal is applied to the calibrated electrostatic precipitator model, the estimated emissions with sorbent injection are indicated in Table 6-3.

TABLE 6-3. ROBINSON UNIT #1 ESTIMATED STACK EMISSIONS W/FSI

Opacity (%) PET (lb/MMBtu) MMBtu/hr
16.0 0.17 1,800 Therefore, relative to the 2006 stack test results, the performanc e projection was for opacity to increase by approximately a factor of 2.6 and PM emissions by a factor of 2.4.
This estimated performance level incorporates basic maintenance upgrades such as:

• Internal alignment

• Internal water wash

• Removal of accumulated dust on inlet distribution devices

• Removal of accumulated dust on discharge electrodes

• Repair of high voltage rapper trains

• Optimize rapping program

• Cleaning insulators. 

### 6.3 Short Term Electrostatic Precipitator Upgrades There are specific activities that can be implemented to impr ove the existing electrostatic precipitator capabilities. These are activities that do not modif y collecting plate area, but improve collection efficiency by restoring control of exhaust tha t is currently bypassing the treatment zone. The value of many of these activities was de monstrated during electrical testing performed in January 2007. These activities include the followings. 6.3.1 Vertical and Hopper Anti-Sneak Baffles Vertical baffles will be designed for the leading and traili ng edge of each field between the casing and the first panel assembly, to prevent gas bypassing the treatment zone along the walls.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 6-3 

## GE Energy

Horizontal hopper baffles will be designed for the bottom of the leadi ng and trailing edge of each field to prevent gas from bypassing the treatment zone into the hopper region. All baffles will be designed using nominal 10 Ga. sheet steel. They are typically shop fabricated.

6.3.2 Lower Frame Stabilizers Lower frame stabilizers help maintain the electrical clear ances between the voltage electrodes and the collecting plates during the operation of the ESP. Each anti -sway assembly is composed of a single alumina rod and brackets to attach to the bot tom of the lower highvoltage frame and the bottom of the collecting plates. The anti-sw ays are typically installed in opposite corners of the lower high voltage stabilizer frames, t wo (2) per frame. Without proper alignment, clearances will be compromised, and the fields will not be charged to their full potential without prematurely sparking. GE typically stocks the alumina insulator rods, reducing the lead time when compared to purchasing directly from the vendor.

If the electrical clearance can be restored to like new c ondition, then it would be possible to energize each field to 55 Kvavg. The current T/R sets are only ca pable of delivering 50 Kvavg. Simply adding 5 Kvavg can dramatically improve the collect ion efficiency of the ESP.
6.3.3 Addition of Four (4) T/R Sets to the Inlet Fiel ds It is recommended to replace the two (2) existing T/R sets on the inlet fields and add two (2) additional T/R sets, which will provide a total of four (4) T/R se ts on the inlet field. These T/R sets will have a higher secondary voltage, which will impart a greater charge on the plates, thus increasing the collection performance of the inlet f ield. The T/R set addition would also require the following associated equipment: bus and guard, key i nterlock modifications, control cabinets, SQ-300 AVC's and VI-CLR's (Variable Inductance Current Limiting Reactors). The new T/R sets will have the specifications shown in Table 6-4.

TABLE 6-4. NEW T/R SETS SPECIFICATIONS QTY Description Volts Amps KV (avg.) kV (p) mA kVA kW FF
4 T/R set 1A/1B w/single gnd. switch 400 104 65 102 450 41.8 37.6 1.2Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-1 

### GE Energy



## 7.0 Field Test Program

GE performed an evaluation of Furnace Sorbent Injection (FSI) on t he Robinson Unit 1 boiler. The evaluation included equipment performance tests, parametric tests, and a longterm trial. This section of the report describes the test objectives, plan, procedure , and results. 

### 7.1 Test Objectives The overall goal of the FSI demonstration program was to provide a c omprehensive evaluation of FSI technology performance on the Robinson Unit 1 boiler. T he primary objectives of the field test program were to:

• Characterize the performance of the FSI system relative to ke y parameters that influence SO 2 reduction performance, boiler thermal performance and operability , particulate emissions, and ash handling;

• Optimize FSI operation over the normal range of boiler operating conditions;

• Demonstrate the ability to operate the sorbent injection system over a long-term test period while maintaining SO 2 reduction and acceptable boiler operability and particulate emissions; and

• Define operating curves for integration into the distributed control system (DCS ).


### 7.2 Test Plan In order to meet the test objectives, a test plan and a test m atrix were prepared to guide the equipment performance checkout, FSI system parametric optimization, and long-term trial. The equipment performance checkout was designed to ensure proper operat ion of the FSI system. Following system checkout, a comprehensive parametric test progr am was conducted to optimize the FSI operation by varying the sorbent flow rate, i njection airflow rate, and injection elevation and configuration. The key metric was SO 2 reduction, however, boiler thermal performance, boiler slagging, loss on ignition (LOI), CO e missions, opacity, ash handling and particulate matter (PM) emissions were evaluated t o determine the overall impacts on boiler operation. Once the FSI system was characteriz ed, a long-term test was conducted to demonstrate the performance of the boiler and FSI syste m over long-term operation. Table 6-1 lists the project test matrix.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-2 

### GE Energy

TABLE 7-1. PROGRESS ENERGY FSI TEST MATRIX

Test Description Date

CompletedTest No.# ofInjectionsLoad,MWgROFAFlowTotalInjectionAir, lb/hrExit O2, %wetInjectionElevationSorbentFlow Rate,lb/hrCa/S,mol/mol

1. FSI Start Up 1.1

9/15/2008 2.0 N/A 154 On N/A 3.0 N/A 0 0 2.1 12 153 On 77,928 4.2 Upper 7200 2.4 9/16/2008 2.2 N/A 137 On N/A 3.4 N/A 0 N/A 2.3 12 137 On 77,928 4.2 Upper 5000 1.8 2.4 12 138 On 77,928 4.2 Upper 5000 1.8 2.5 12 138 On 77,928 3.9 Upper 5000 1.8 9/17/2008 2.6 N/A 165 On N/A 2.9 N/A 0 N/A 2.7 12 162 On 77,928 4.2 Upper 3100 0.9 9/18/2008 2.8 N/A 171 On N/A 2.9 N/A 0 N/A 2.9 12 171 On 77,432 4.2 Upper 3109 0.9 2.10 12 171 On 75,847 4.2 Upper 3109 0.9 9/19/2008 2.11 N/A 139 On N/A 3.2 N/A 0 N/A 2.12 12 139 On 74,113 4.2 Upper 7010 2.6 2. Preliminary Test

2.13 12 139 On 74,418 4.2 Upper 6912 2.5

9/22/2008 B N/A 154 On N/A 3.0 N/A 0 N/A 11R1 12 154 On 74,568 4.2 Upper 3118 0.9 9/23/2008 B N/A 123 On N/A 3.5 N/A 0 N/A 12R1 12 144 On 70,856 4.1 Upper 8951 2.6 10R1 12 164 On 79,362 4.2 Upper 2513 0.7 9/24/2008 B N/A 134 On N/A 3.1 N/A 0 N/A 12R1 12 134 On 71,797 4.0 Upper 9003 2.7 11R1 12 134 On 72,041 4.1 Upper 3100 0.9 10R1 12 134 On 72,225 4.2 Upper 2579 0.8 12 134 On 73,974 4.3 Lower 3050 0.9 B N/A 132 On N/A 3.3 N/A 0 N/A 9/25/2008 B N/A 98 On N/A 4.4 N/A 0 N/A 10R3 12 99 On 58,987 5.0 Upper 2564 0.9 3. Equipment Performance Tests

11R3 12 126 On 72,932 4.0 Upper 3077 0.9Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-3 

### GE Energy

TABLE 7-1. PROGRESS ENERGY FSI TEST MATRIX (CONTD)

Test Description Date

CompletedTest No.# ofInjectionsLoad,MWgROFAFlowTotalInjectionAir, lb/hrExit O2, %wetInjectionElevationSorbentFlow Rate,lb/hrCa/S,mol/mol

9/29/2008 4.0 N/A 159 On N/A 3.0 N/A 0 0 4.1 12 159 On 77,746 4.16 Upper 2498 0.8 4.2 12 158 On 76,713 4.18 Upper 6904 2.2 4.3 12 158 On 76,088 4.14 Upper 8218 2.6 9/30/2008 4.4 N/A 159 On N/A 2.94 N/A 0 N/A 4.5 12 161 On 69,455 4.13 Upper 7204 2.6 4.6 12 161 On 77,414 4.19 Upper 6677 2.5 4.7 12 158 On 81,993 4.15 Upper 6566 2.4 4.7.1 12 158 On 87,076 4.15 Upper 6011 2.2 10/01/2008 4.8 N/A 159 On N/A 2.9 N/A 0 N/A 4.9 12 159 On 76,272 4.31 Lower 6950 2.6 4.10 12 159 On 78,379 4.26 Lower 5031 1.9 4.11 12 159 On 79,836 4.26 Lower 2565 1.0 10/02/2008 4.16 N/A 76 On N/A 5.66 N/A 0 N/A 4.18 12 77 On 39,510 5.8 Lower 1519 1.0 4.17 6 76 On 45,961 5.91 Lower 1428 0.8 4.18.1 8 77 On 47,781 5.89 Lower 3050 1.9 4.19 10 76 On 49,558 5.9 Lower 3140 2.0 4.19.1 12 76 On 50,654 5.93 Lower 3099 2.0 10/03/2008 4.12 N/A 158 Off N/A 2.85 N/A 0 N/A 4.13 12 159 Off 82,166 3.67 Upper 2590 0.9 4.14 12 159 Off 77,044 3.68 Upper 4987 1.7 4.15 12 159 Off 68,623 3.68 Upper 7043 2.4 10/06/2008 4.20 N/A 157 Off N/A 2.97 N/A 0 N/A 4.21 12 159 Off 82,166 3.63 Upper 7009 2.37 4.22 12 159 Off 77,044 3.65 Upper 7044 2.38 10/07/2008 4.24 12 178 Off N/A 2.75 N/A 0 N/A 4.25 12 176 Off 69,781 3.67 Upper 0 N/A 4.26 12 178 Off 69,833 3.24 Upper 0 0.03 4.27 12 178 Off 73,223 3,23 Upper 2535 0.5 4.28 12 181 Off 73,610 3.28 Upper 2530 0.5 4.29 12 182 Off 78,673 3.28 Upper 3873 0.8 4. Parametric Tests

4.30 12 181 Off 78,413 3.26 Upper 4985 1.0 5.0 Long Term Test 12/12/2008Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-4 

### GE Energy

7.2.1 Equipment Performance Tests The equipment performance guarantees cover various aspects of the FSI system: sorbent storage, transport and injection system as well as the transport a nd boost air system. The detail equipment performance guarantee can be found in Progress Energy Robinson Unit 1 Technical Specification, Rev. E [7] and Progress Energy Furnace Sorbent Injection FSI Equipment Performance Test Plan, Revision 0.0 [3].
The objectives of the equipment performance tests were to ensure that the following components worked properly at the designed operating conditions.

• Sorbent injection system,

• Sorbent feed system,

• Transport air supply,

• Splitters,

• Moisture in air, and

• Miscellaneous aspects such as electricity discharge and valve operation. The equipment performance tests were conducted in two phases. During the first phase of the tests, visual inspections and splitter uniformity tests were conduct ed. The splitter uniformity tests were conducted in two steps; first with just clean transport air and sec ond with a mixture of sorbent and transport air. Prior to the splitter clean air unifor mity tests, preliminary visual inspections were performed to check for air leaks especially a t the joints such as at camlok fittings, flange connections, diverter, and splitter connections. Splitt er clean air uniformity tests were conducted on both upper and lower furnace injectors. The uniform ity of transport air was determined by installing a calibration section imme diately downstream of the splitters.
Immediately following the sorbent injection system shakedown, the sec ond phase of the equipment performance test program was performed. During these t ests, sorbent was injected into the boiler and careful attention was taken to define and mitiga te any detrimental effects on the boiler performance.

7.2.2 Parametric Tests The parametric tests facilitated the evaluation of the most pr omising injection test conditions and identified the conditions for the subsequent long-term testing. As s hown in the test plan,Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-5 

### GE Energy

the impacts of sorbent injection rate, injection air flow rate , injection elevation, and ROFA operation were evaluated systematically during the parametric testing. While not specifically listed as a test parameter, coal sulfur content also varied duri ng the parametric tests, allowing this variable to be characterized as well. The purpose of parametr ic testing was to determine optimum FSI operating conditions without impacting the boiler operation at all loads. However, due to additional air addition to the furnace and considering saf ety aspects of the boiler especially at high loads, GE and Progress Energy jointly a greed to conduct the desired Ca/S of 2.5 tests up to 159 MWg, which is 86% of the maximum boiler ca pacity. Loads above 159 MWg were tested at Ca/S of 1.0. Each parametric test condi tion was conducted for 2 to 3 hours. The typical test day was 0900 hrs to 1600 hrs. During t his period, a total of three test conditions were typically tested.
After the parametric tests were completed, analysis of the results identified additional test conditions of interest and gaps in the data set. The initial paramet ric tests focused on the impacts of sorbent injection on the boiler and ESP. At the completion of the parametric tests, all test results were reviewed and summarized. During the tes ting, increase in stack opacity became a concern and was a limiting factor in increasing sorb ent rates at higher loads. From the analyses it was understood that additional tests were required to characterize opacity. For this purpose, a recommended operating strategy for the long-term te st was jointly developed with Progress Energy’s plant and engineering staff based on the parametric test results. The basis of this strategy was to maximize sorbent injection to the extent possible while maintaining boiler operability and opacity. A specific guideline w as to reduce sorbent system operation whenever opacity reached 35%. In the early part of the lo ng-term trial this guideline limited FSI system operation at high load boiler operation. By the end of the trial, the combination of ESP operational changes, control of injection air fl ow rate, cooler ambient weather, and firing of higher sulfur coal allowed the F SI system to be operated for longer periods of time at higher sorbent flow rates.
7.2.3 Long-Term Tests In general a long-term trial is desirable to allow the FSI s ystem and boiler response to reach steady state and to allow performance to be defined over the rang e of operating conditions that would normally be encountered at the Robinson boiler, such as changes i n boiler load and coal composition. After the parametric tests, the long-term tri al was conducted. The objective of the long-term trial was to assess performance a nd long-term impacts of the sorbent injection process. At the beginning of the long-term testing, t he FSI system was optimized to operate continuously and to maximize injection rates to the extent possible atProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-6 

### GE Energy

high loads. The extended optimization test analyses revealed that se veral factors such as dust loading, flue gas flow rate, boiler excess oxygen, air heater gas out let temperature, sulfur content in coal and ESP conditions showed influence on opacity. GE also applied Six-Sigma tools and performed regression analysis to identify the direct im pact of these parameters on opacity. The regression analysis identified that air heater gas outlet temperature has a dramatic impact on opacity, especially when the gas outlet temp erature is above 275 o F. The typical air heater gas outlet temperature at Robinson varies betw een 250 and 270 o F at full load conditions, but with FSI in operation these temperatures increas ed to a maximum of 290

o F. Since air heater gas outlet temperature is not a directly c ontrollable parameter, it was determined that adding additional ambient sorbent injection air to the furnace caused back end temperatures to increase. Since the sorbent injection air is not pre-heated, the flue gas leaving the air heater increases during FSI. If the same ai r were to be pre-heated in the air heaters, the increase in flue gas temperature would be very low. To maintain the air heater gas outlet temperature within the limits, the optimum injection ai r condition was determined for the loads above 120 MWg. The remaining parameters were also optim ized to the extent possible. Various ESP rapping programs were also developed and tested. These rapping programs showed minimal to moderate effect on opacity. Further ESP field tuning might help to further mitigate the opacity.
After the long-term optimization testing, the opacity levels wer e brought under control and allowed continuous sorbent injection at Ca/S of 2.5 up to 160 MWg load and Ca/ S of 1.5 from 160 MWg to 188 MWg.
Boiler thermal performance was documented over the range of boiler and FSI operation. The impact of FSI and sootblowing on sectional heat absorptions and fouling factors were established. Projected SO 2 capture trends were validated.


### 7.3 Measurement Plan The detailed measurement test plan was described in Progress Energy Robinson Unit 1 Furnace Sorbent Injection Project Sorbent Injection Test Plan, Revision 5.0 [4]. Table 6-2 summarizes the emissions measurement procedures. The data that w ere collected during the sorbent injection tests included:

• Operating conditions from the boiler data acquisition and control system,

• Sorbent and injection air flow rate and temperature,

• Plant O 2 at the economizer outlet,Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-7 

### GE Energy

• NO X , CO 2 , SO 2 , and mercury from the plant CEMS at the stack,

• Furnace gas temperature (SpectraTemp) near the nose elevation,

• Observations of furnace slagging patterns,

• Fuel samples,

• Sorbent samples, and

• Fly ash samples. 7.3.1 Boiler Operating Data Boiler control room data were recorded by GE personnel several t imes during each test. In addition, boiler operating data were collected and logged automaticall y by the plant PI system. These electronic data included all boiler, mill, air flow, air heater, and plant CEMS data available on the network. During the parametric tests, the data were retrieved at oneminute intervals. During the long-term tests, the data were retri eved at six-minute intervals from the beginning of the test day to the end of the final tests.

7.3.2 Emissions Data Emissions data were collected from the existing CEMS system . Data were retrieved every minute during the parametric tests and every six minutes during to the long-term trial. The collected data at stack include NO X , CO 2 , SO 2 , mercury, flue gas flow rate and temperature. Table 7-2 summarizes the emission measurement procedures.

TABLE 7-2. EMISSION MEASUREMENTS PROCEDURES Parameter Method Sampling Location
SO 2 , NO X , O 2 , CO 2 , Hg Continuous Monitoring System Stack Total Particulate EPA Method 201A and 202 Stack SO 2 EPA Method 6 Stack
7.3.3 Coal & Ash Sampling Coal samples were taken from the coal feeder outlet daily by GE personnel. Approximately one cup of coal was collected every few hours, then blended into a composit e sample and sent out to be analyzed as a representative coal sample of the da y. Fly ash samples were collected at the economizer outlet duct. Selected fly ash sample s were shipped to an independent laboratory by PGN for analysis of LOI, calcium, and sulfur content.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-8 

### GE Energy

7.4 Test Results This section reports the test results obtained from start up, param etric and long term testing. The equipment performance is evaluated. The impacts of the boiler ope rating conditions as well as the sorbent injection system operating parameters on SO 2 capture rate and calcium utilization are discussed. The long-term sorbent injection performanc e and its impact on boiler performance are reviewed. The test data is also used to validate the process model predictions derived from earlier process design studies. 7.4.1 Start-Up Performance and Demonstrations During the first phase of the test program, visual inspection and spli tter uniformity tests were conducted. The splitter performance guarantee tests were divided int o two sections: clean air and sorbent injection. During the first part, the test apparatus was installed to measure flow from each line. Then, the sorbent flow was determined by placin g sorbent filter device over each injector and the sorbent is collected and weighed from each fi lter following the test. Both tests were performed at the nominal full load. The test re sults are summarized in GE’s Sorbent Distribution Test Results, dated 10 July 2008 [8].

Clean Air Test Results During the initial test, orifice plates were installed based on system design. After taking the flow readings, the velocities from each line were compared. A modi fied set of orifices was installed to balance the flows. This process was repeated until the lines were all balanced. Figure 7-1 and Table 7-3 show flow label and corresponding pressure drop, f low rates and velocities for each line of the upper elevation injectors. The operati ng air temperature was 140 oF. The total flow rate was 5,417 lb/hr. The variation in clean air t ransport velocity was 6.1% from the mean.

Solid Flow Distribution Results After the clean air test was concluded, the appropriate orifice plates were left in the flow line. Sorbent solids flow distribution was measured using drum/filter asse mblies. Each apparatus was first installed according to the test plan. Each empty sorbent drum and air filter was weighed. Then the transport blower air was turned on to allow flow t o stabilize for 15 minutes. The total sorbent feed rate was set at 9,018 lb/hr. From the PLC, the weigh hopper indicated total sorbent feed was approximately 700 lbs. The test was conducted over 6 minutes and 15 seconds. Then the transport air blower was run for 10 mi nutes to purge the sorbent in the lines.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-9 

### GE Energy

Table 7-4 shows test results. On average, each drum weighed 53 lbs. The variation in sorbent transport velocity was 20% from the mean.

9 10 11 12 3 1 H

L

Figure 7-1. Injection labels for upper elevation injectors.

TABLE 7-3. CLEAN AIR TEST RESULTS FOR UPPER ELEVATION INJECT IONS

Line Orifice

Diameter Venturi

∆ P Static P Flow Density Flow Velocity
in in H2O in H2O scfm lb/ft3 lb/hr ft/s

1H 1.478 7.424 46 82 0.0753 378 412 107.61 1L 1.478 7.146 47 81 0.0753 371 405 105.55 3H none 8.453 46 88 0.0752 403 439 114.76 3L none 8.456 45 88 0.0751 403 439 114.85 9H 1.149 9.634 38 94 0.0739 429 468 124.40 9L 1.149 9.565 38 93 0.0739 427 466 123.94 10H 1.117 9.456 36 93 0.0735 425 464 123.84 10L 1.086 9.489 34 93 0.0733 426 464 124.48 11H 1.117 9.915 36 95 0.0735 435 474 126.83 11L 1.117 9.593 35 93 0.0734 728 467 124.89 12H 1.086 9.127 34 91 0.0732 418 456 122.37 12L 1.055 9.474 31 93 0.0727 425 464 125.44
Total 1083 5268 5417 Average 8.978 39 90 0.074 439 451 119.91 Standard Deviation 0.910 6 5 0.001 93 23 7.33 COV, % 6.12 Corrected Flow lb/hrProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-10 

### GE Energy

TABLE 7-4. SOLID FLOW DISTRIBUTION RESULTS FOR UPPER ELEVATI ON INJECTIONS

Line Orifice

Diameter Tare

Weight Flange

Weight Initital

Weight Final

Weight Sorbent

Weight in lbs lbs lbs lbs lbs

1H 1.478 53.5 2.5 56.0 95.0 39.0 1L 1.478 49.0 2.5 51.5 91.0 39.5 3H none 43.0 2.5 45.5 90.0 44.5 3L none 52.0 2.5 54.5 99.5 45.0 9H 1.149 50.5 2.5 53.0 107.5 54.5 9L 1.149 49.5 2.5 52.0 99.5 47.5 10H 1.117 43.5 2.5 46.0 108.5 62.5 10L 1.086 48.0 2.5 50.5 117.0 66.5 11H 1.117 48.0 2.5 50.5 119.0 68.5 11L 1.117 52.0 2.5 54.5 120.0 65.5 12H 1.086 49.0 2.5 51.5 105.5 54.0 12L 1.055 44.5 2.5 47.0 95.5 48.5

Total 635.50 Average 104.00 52.96 Standard Deviation 10.63 10.61 COV, % 20.03

Injection Equipment Tests
During the second phase of the equipment performance test program, s orbent was injected into the boiler. The test program began with a transport airflow s tability test as shown in Table 7-5. Transport airflow stability test was conducted at just transport air of 1,000 ACFM. The test was performed as prescribed in the guarantee secti on for one-hour. During this onehour test period, the transport airflow was recorded online from th e flow transmitter installed downstream of the transport air blower (BL4). The results were c ollected and reduced for standard deviation. Prior to sorbent feed rate tests, visual inspecti on was performed along the system transport line for any sorbent leaks. Any identified sorbent leaks were rectified before commencing the feed rate tests.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-11 

### GE Energy

The sorbent feed rates were conducted at four different flow conditions . The four different flow conditions are shown in Table 5-1. According to the guarantees, the re were three different equipment performance tests to be conducted to evaluate the sorbent feed rate. The three different performance tests were 1) when the sorbent from the storage silo is transferred to daily silo, 2) when the sorbent from the daily silo is injected into the furnace from injectors and 3) static pressure stability in the transport line. For the pur pose of minimizing the total test time, these tests were carried out simultaneously.
The test sequence included test runs for the sorbent feed rates is summarized in Table 7-5. The test sequence started with filling the daily silo bin by tr ansferring sorbent from storage silo 1, which has the capacity of 630,000 lbs. The rotary airlocks under the storage silos were driven by constant feed motor to deliver the constant sorbent feed rat e of 32,000 lb/hr. The rotary airlocks were designed in such a way that the daily s ilo bin, which has a capacity of 20,000 lbs filled in 1⁄2 hour. After filling the daily silo bin, the contr ol valve under the storage silo was open to fill the weigh hopper, which has a capacity of 7,000 lbs. The sorbent weight of the weigh hopper from the load cell indicator after closing the c ontrol valve was recorded. This operation was followed each time the control valve under the da y bin silo is closed and open. A total of 12 test runs were conducted, including 3 test runs at ea ch sorbent flow condition. To determine the precision of the feed system, each subsequent 2-hour test was performed at a different sorbent feed condition.
Table 7-6 shows the equipment performance results. Overall most t ests met the guarantee criteria. A few tests marginally passed the test. For exa mple, during test 10R2, the total sorbent flow to injector stability exceeded 7% of the set point ove r a few minutes during the test period. The deviation values eventually decreased over the course of the test, which could indicate that the system was still stabilizing.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-12 

### GE Energy

TABLE 7-5. SORBENT FEED RATE TEST SEQUENCE

Sequence Sorbent Flow Condition (4) Test Date Test & Run Duration Designed Flow Transferre d Total Sorbent Available Discharged Remained in Weigh hopper # # hrs:mins lb/hr lb/hr lb/hr lb/hr lb/hr 1 Transfer - Silo 1 to Day Silo Fill - 1 0:30 32,000 1 6,000 16,000 2 Injection - Minimum 10 R1 2:00 2,458 4,916 3 Injection - Nominal Low 11 R1 2:00 3,072 6,144 4,940 4 Transfer - Silo 2 to Day Silo Fill - 2 0:30 32,000 16 ,000 20,940 5 Injection - Nominal Full 12 R1 2:00 9,017 18,034 2,906
Total Number of Hours 7:00 6 Transfer - Silo 3 to Day Silo Fill - 3 0:30 32,000 16 ,000 18,906 7 Injection - Maximum 13 R1 1:00 15,626 15,626 3,280 8 Transfer - Silo 1 to Day Silo Fill - 4 0:20 32,000 10 ,667 13,947 9 Injection - Minimum 10 R2 2:00 2,458 4,916 10 Injection - Nominal Low 11 R2 2:00 3,072 6,144 2,887
Total Number of Hours 5:50 11 Transfer - Silo 2 to Day Silo Fill - 5 0:30 32,000 1 6,000 18,887 12 Injection - Nominal Full 12 R2 2:00 9,017 18,034 853 13 Transfer - Silo 3 to Day Silo Fill - 6 0:30 32,000 1 6,000 16,853 14 Injection - Maximum 13 R2 1:00 15,626 15,626 1,227 15 Transfer - Silo 1 to Day Silo Fill - 7 0:20 32,000 1 0,667 11,893 16 Injection - Minimum 10 R3 2:00 2,458 4,916
Total Number of Hours 6:20 17 Injection - Nominal Low 11 R3 2:00 3,072 6,144 833 18 Transfer - Silo 2 to Day Silo Fill - 8 0:40 32,000 2 1,333 22,167 19 Injection - Nominal Full 12 R3 2:00 9,017 18,034 4,133 20 Transfer - Silo 3 to Day Silo Fill - 9 0:30 32,000 1 6,000 20,133 21 Injection - Maximum 13 R3 1:00 15,626 15,626 4,507
Total Number of Hours 6:10 Total Sorbent Consumption (lb/hr) 159,725
(4) Sorbent should be transferred to daily silo onl y after the daily silo is completely empty. 3-Jul-08

4-Jul-08 Expected

1-Jul-08

2-Jul-08Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-13 

### GE Energy

TABLE 7-6. EQUIPMENT PERFORMANCE TEST RESULTS

Test Comment Date Duration Load Sorbent Feed Rate Injection

AirTotal Sorbent FlowTestSorbent FlowStability TestSorbent FlowPrecisionPressure inTransport LineStability

mm/dd/yy hour MW net lb/hr CFM

11R1 9/22/2008 2.0 145 3100 16000 PASS PASS PASS PASS 12R1 9/23/2008 2.0 145 9000 16000 PASS PASS PASS PASS 10R1 9/23/2008 2.0 158 2500 18000 PASS PASS PASS PASS 12R2 9/24/2008 1.0 125 2500 16000 PASS PASS PASS PASS 11R2 9/24/2008 1.0 125 3100 16000 PASS PASS PASS PASS 10R2 9/24/2008 1.0 125 9000 16000 PASS Marginal Marginal PAS S 10R3 9/25/2008 1.0 145 2500 16000 PASS PASS Marginal PASS 11R3 9/25/2008 0.5 145 3100 16000 PASS PASS PASS PASS 12R3 9/25/2008 1.0 145 9000 16000 Data Mision Due to PI-D CS Problem

7.4.2 Coal Sample Analysis Coal samples were taken daily during the tests. Ultimate and proximate analyses are summarized in Table 7-7. Average coal moisture content was 5.5% and ave rage ash content was about 12%. Coal heating value was around 12,233 Btu/lb. Coal sulfur content was specifically measured and used to calculate the theoretical SO 2 emissions, as discussed in next section.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-14 

### GE Energy

TABLE 7-7. COAL ULTIMATE AND PROXIMATE ANALYSIS Proximate Analysis As Received, % Ultimate Analysis As Received, % Date Sampled Moisture Ash Volatile Fixed Carbon Sulfur BTU Carbon Hydrogen Nitrogen Oxygen

07/11/08 6.73 12.5 33.40 47.37 0.99 11,884 67.50 4. 36 1.34 6.58 07/26/08 6.83 9.96 35.65 47.56 0.85 12,333 68.21 4. 78 1.42 7.95 09/17/08 7.54 12.51 33.69 46.26 1.09 11,774 65.73 4 .50 1.28 09/18/08 5.48 12.53 33.99 48.00 1.11 12,050 67.57 4 .60 1.36 7.35 09/18/08 5.27 12.49 35.57 46.67 1.76 12,089 67.60 4 .55 1.32 7.01 09/19/08 5.02 13.34 33.86 47.78 1.03 11,993 67.07 4 .64 1.33 7.57 09/19/08 5.88 10.85 34.29 48.98 1.35 12,276 68.59 4 .74 1.33 7.26 09/24/08 5.93 12.28 34.48 47.31 1.18 12,042 67.14 4 .60 1.19 7.68 09/24/08 4.97 11.59 35.09 48.53 1.31 12,267 67.98 4 .61 1.25 8.29 09/24/08 4.94 12.22 35.31 47.53 1.25 12,207 67.15 4 .91 1.38 8.15 09/25/08 4.03 11.34 36.47 48.16 1.28 12,505 68.75 5 .14 1.46 8.00 09/25/08 3.71 12.30 35.42 48.57 1.30 12,363 67.87 4 .93 1.37 8.52 09/29/08 4.83 12.16 34.75 48.26 1.17 12,266 68.08 4 .54 1.62 7.60 09/29/08 5.02 12.01 33.48 49.29 1.2 12,121 67.98 4. 56 1.61 7.62 09/29/08 4.91 11.82 33.98 49.29 1.39 12,074 67.38 4 .49 1.57 8.44 09/29/08 5.62 12.34 33.89 48.15 1.23 12,055 67.51 4 .50 1.60 7.20 10/01/08 5.41 11.59 33.52 49.48 1.02 12,028 68.35 4 .36 1.30 7.97 09/30/08 5.58 13.10 33.79 47.53 1.10 11,861 66.78 4 .52 1.27 7.65 09/30/08 6.22 12.76 34.29 46.73 0.95 11,949 66.66 4 .56 1.29 7.56 09/30/08 5.56 13.58 34.01 46.85 1.06 11,718 65.86 4 .46 1.25 8.23 10/02/08 5.03 10.27 34.25 50.45 0.98 12,493 70.48 4 .29 1.76 7.19 10/02/08 4.49 13.25 33.86 48.40 0.99 12,144 68.74 4 .28 1.69 6.56 10/03/08 4.83 13.28 33.39 48.50 1.21 12,128 68.53 4 .38 1.70 6.06 10/03/08 4.50 9.43 35.52 50.55 0.92 12,661 71.74 4. 55 1.81 7.05 10/06/08 5.25 11.75 34.09 48.91 1.00 12,336 68.57 4 .64 1.53 7.26 10/07/08 4.16 12.05 35.59 48.20 1.27 12,437 69.19 4 .68 1.32 7.33 10/08/08 3.88 11.24 35.44 49.44 1.33 12,531 70.01 4 .58 1.33 7.63 10/17/08 5.01 11.64 33.72 49.63 1.28 12,304 68.35 4 .48 1.43 7.81 10/16/08 4.44 11.05 35.37 49.14 1.37 12,525 69.75 4 .61 1.41 7.37 10/20/08 3.81 12.25 35.41 48.53 1.16 12,352 69.03 4 .57 1.37 7.81 10/21/08 4.06 11.39 35.42 49.13 1.38 12,541 68.92 4 .68 1.35 8.22 10/22/08 3.74 12.22 34.73 49.31 1.19 12,390 68.71 4 .71 1.39 8.04 10/23/08 5.69 11.16 34.75 48.40 1.42 12,289 68.20 4 .58 1.33 7.62 10/23/08 5.80 10.54 35.54 48.12 1.63 12,391 68.39 4 .66 1.35 7.63 10/28/08 5.17 10.48 35.70 48.65 1.70 12,537 69.65 4 .81 1.27 6.92 10/29/08 5.15 11.88 34.68 48.29 1.59 12,230 67.45 4 .63 1.29 8.01 10/31/08 5.95 11.93 34.19 47.93 1.52 12,177 67.44 4 .66 1.33 7.17 10/30/08 5.71 13.17 34.30 46.82 1.54 11,932 66.48 4 .64 1.32 7.14 11/03/08 5.71 11.86 33.85 48.58 1.48 12,198 68.00 4 .59 1.32 7.04Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-15 

### GE Energy

TABLE 7-7. COAL ULTIMATE AND PROXIMATE ANALYSIS (CONTD)

Proximate Analysis As Received, % Ultimate Analysis As Received, % Date Sampled Moisture Ash Volatile Fixed Carbon Sulfur BTU Carbon Hydrogen Nitrogen Oxygen

11/04/08 4.60 13.97 33.08 48.35 1.38 11,964 66.68 4 .59 0.94 7.84 11/04/08 5.31 12.93 32.80 48.96 1.36 12,077 67.03 4 .57 0.95 7.85 11/04/08 4.95 12.43 33.08 49.54 1.40 12,189 67.72 4 .58 0.92 8.00 11/04/08 4.59 11.09 34.28 50.04 1.62 12,444 69.03 4 .75 1.00 7.92 11/04/08 4.97 12.62 33.34 49.07 1.38 12,141 67.95 4 .64 0.92 7.52 11/05/08 6.09 12.00 33.93 47.98 1.33 12,092 66.85 4 .49 1.37 7.87 11/05/08 4.70 12.37 33.76 49.17 1.54 12,199 67.93 4 .60 1.36 7.50 11/05/08 6.69 11.54 33.54 48.23 1.25 12,200 66.76 4 .63 1.23 7.90 11/05/08 7.45 10.92 33.89 47.74 1.17 12,198 67.71 4 .58 1.37 6.80 11/06/08 6.61 11.63 34.24 47.52 1.10 12,085 67.46 4 .63 1.35 7.22 11/07/08 5.61 11.14 34.99 48.26 1.26 12,356 68.45 4 .77 1.33 7.44 11/10/08 5.55 11.88 35.10 47.47 1.20 12,220 67.49 4 .75 1.46 7.67 11/11/08 3.80 11.04 35.96 49.20 1.30 12,606 70.46 4 .85 1.44 7.11 11/12/08 4.52 10.89 34.86 49.73 1.31 12,508 69.71 4 .67 1.37 7.53 11/13/08 5.24 9.75 35.20 49.81 1.35 12,607 69.25 4. 79 1.56 8.06 11/14/08 4.15 10.91 35.23 49.71 1.58 12,563 69.99 4 .54 1.51 7.32 11/17/08 6.17 10.92 34.08 48.83 1.51 12,307 67.74 4 .64 1.11 7.91 11/20/08 5.22 11.97 34.59 48.22 1.14 12,339 68.52 4 .57 1.44 7.14 11/21/08 5.05 11.27 35.72 47.96 1.51 12,366 67.88 4 .62 1.45 8.22 11/25/08 5.59 11.99 34.48 47.94 1.25 12,194 67.47 4 .81 1.25 7.64 11/26/08 5.85 11.69 33.75 48.71 1.21 12,143 67.96 4 .60 1.38 7.30 12/02/08 6.13 10.07 35.32 48.48 1.25 12,410 68.50 4 .70 1.31 8.04 12/03/08 6.06 11.97 34.39 47.58 1.22 12,166 67.80 4 .71 1.29 6.95 12/04/08 5.58 11.75 33.86 48.81 1.22 12,236 68.12 4 .53 1.39 7.41 12/08/08 6.33 10.95 34.13 48.59 1.27 12,257 68.21 4 .53 1.48 7.23 12/08/08 7.25 10.60 34.32 47.83 1.20 12,204 68.09 4 .54 1.47 6.85 12/09/08 6.94 11.29 34.06 47.71 1.33 12,098 64.87 5 .32 1.49 8.76 12/09/08 5.73 11.75 34.25 48.27 1.39 12,257 12/09/08 5.63 12.74 34.10 47.53 1.47 12,154 12/10/08 6.80 11.94 34.20 47.05 1.13 12,011 66.94 4 .41 1.32 7.46 12/10/08 5.91 11.05 34.59 48.45 1.33 12,355 68.48 4 .85 1.38 7.00 12/10/08 6.14 11.82 34.43 47.61 1.26 12,127 66.66 5 .02 1.43 7.67

7.4.3 Baseline SO 2

Emissions During the parametric tests, flue gas SO 2 concentration at the stack was measured daily prior to sorbent injection. The measured SO 2 concentration was used for establishing the baseline SO 2 emission and calculating SO 2 reduction. Coal samples were also taken daily for theProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-16 

### GE Energy

analysis of the coal sulfur content as shown in Table 6-3. Coal sulf ur was then used to calculate the theoretical SO 2 emission, which was compared to the measured baseline SO 2 emission.
For the long-term tests, sorbent was injected around-the-clock to the extent possible, and therefore baseline SO 2 emissions were not measured each day. However, periodically sorbent injection was suspended due to issues associated with the injection system. The SO 2 measured during no-sorbent injection time was then used as baseline data to compare with the theoretical SO 2 emission.
Figure 7-2 shows a comparison between the theoretical SO 2 emission calculated from the coal sulfur content and the measured baseline SO 2 emission. Results from both parametric and long-term tests are shown. The coal sulfur content ranged from a pproximately 1.0% to 1.7% and the SO 2 emissions ranged from 1.5 to 2.8 lb/MMBtu during the testing. Due to plant coal sourcing plans, the coal sulfur content in the long-term tests was higher t han that in the parametric tests. In general, the measured SO 2 emission is consistent with the theoretical calculations. Since there were no daily baseline SO 2 measurements during the long-term tests, the theoretically calculated SO 2 emission was used to estimate the SO 2 removal rate for the assessment of the FSI performance in the long-term tests.

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00

0.5 1 1.5 2

Coal Sulfur Content, %SO2Emission, lb/ MMBtu

Measured SO2, Parametric Test Measured SO2, Long Term Theoretical SO2

Figure 7-2. Comparison of theoretical SO 2 and measured baseline SO 2 emissions.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-17 

### GE Energy

7.4.4 SO 2

Removal Results
SO 2 removal rates measured from the preliminary and parametric t ests are shown in Figure 7-3 as a function of Ca/S ratio. The SO 2 capture values are derived from SO 2 concentrations measured with and without sorbent injection. The capture values are the refore not based on a theoretical SO 2 yield, and take no credit for inherent SO 2 capture. Typically coal mineral matter captures a few percent of the SO 2 generated during combustion.
The preliminary and parametric tests were conducted for a load range of 76 MWg to 156 MWg. The calcium-to-sulfur ratio was varied from 1 to 3. Figure 7- 3 shows that the SO 2 removal rate increased with Ca/S as expected for the load range tested. The trend is consistent with GE’s model predictions made in 2007. About 45% to 50% SO 2 removal was achieved with Ca/S ratio of 2.5. The scattering of the data is due to the variations in boiler and FSI injection system operations, which will be discussed in the next section.
The results from the long-term tests further confirm the achie ved SO 2 removal performance from the preliminary and parametric tests as shown in Figure 7- 4. Since there were no daily baseline SO 2 measurements as discussed in the previous section, the removal rat e is derived using the theoretical SO 2 emissions. The removal rate calculated might therefore include t he inherent SO 2 capture. The long-term test data are presented in two groups. One group was obtained before October 19 when the FSI system was shut down for repai ring the tube leaks. The second group was obtained after the FSI system was resumed for testing. The scatter in the data set may largely be due to the fact that SO 2 reduction values are calculated based on a single composite coal sample that was taken each day, while coa l composition (and the ratio of coals taken from different source piles) was known to have varied t hroughout each test day. In general, the SO 2 removal rates through out the months long tests were consistent w ith the model predictions made in 2007. High reduction rate (> 60%) was achie ved at Ca/S ratio of 3 with manageable impacts on boiler operation and performance.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-18 

### GE Energy

0 10 20 30 40 50 60 70

0 1 2 3 4 Ca/SSO2Reduction, %

2007 Prediction

~159 MWg ~134 MWg ~76 MWg

Figure 7-3. SO 2 removal as a function of Ca/S during the parametric tests.

0 10 20 30 40 50 60 70 80

0 1 2 3 4 Ca/SSO2Reduction, %

2007 Prediction ~159 MWg ~134 MWg ~76 MWg Long Term Before 10/19 Long Term After 10/19

Figure 7-4. SO 2 removal as a function of Ca/S for all tests.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-19 

### GE Energy

7.4.5 Impacts of Boiler Operation on Sulfur Capture One project objective was to minimize boiler impacts during FSI operation. The burner zone stoichiometric ratio, ROFA flow rate and the ROFA operating mode during FSI operation were maintained at baseline settings. Therefore, the boiler loa d and the ROFA operating mode (on/off) were two of the primary boiler operation changes evaluate d in the test program. The FSI system was designed to inject sorbent through the upper elev ation injectors for medium and high boiler loads. The lower elevation injectors were desig ned for low load operation. Figure 7-5 shows three groups of test data: (1) lower elev ation sorbent injection at 76 MWg load; (2) upper elevation sorbent injection at 158 MWg; and (3) l ower elevation sorbent injection at 158 MWg load. The data indicate that at lower Ca/S ratios, i.e., Ca/S ~1, the SO 2 reduction rate is comparable for both loads. However, when Ca/S rat io is increased to a higher value, SO 2 removal is more efficient for low load conditions than for higher loa d conditions. The difference can be explained by the mixing and penetrat ion effectiveness of the sorbent injection. At low load, the furnace velocity is relativel y low and the sorbent stream can more readily penetrate the furnace flow field to provide good mixing. The flue gas flow rate and velocity increase with increasing load, making it more difficult for the sorbent stream to penetrate and mix with the furnace gas. Therefore, as expe cted based on the Process Engineering work, the SO 2 removal rate increases at decreasing boiler load.

The sorbent utilization rate is also calculated for these test s, as shown in Figure 7-6. The sorbent or calcium utilization rate is calculated by taking t he ratio of SO 2 removal rate to the Ca/S ratio. As shown in the plot, the calcium utilization rate sta ys relatively constant at 24% in the low load tests and drops from 27% to 17% for the high load tests. Improving the sorbent injection penetration and mixing for high load operation could impr ove the sorbent utilization rate, although this would require higher sorbent air flow rate and velocity, potentially magnifying impacts upon boiler operation.
A test was also performed to investigate the performance of l ower elevation injections at 158 MWg (Figure 7-5). The data show that at this load, the lower elev ation injection is not as effective as the upper elevation injection. This is consistent with the system design basis. At high load, the furnace temperature at lower elevation is above of t he optimal SO 2 reaction window.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-20 

### GE Energy

0 10 20 30 40 50 60

0 1 2 3 4 Ca/SSO2Reduction, %

158 MW Upper Elevation 158 MW Lower Elevation 76 MW Lower Elevation

Figure 7-5. Sorbent removal rate at two different loads during parametric te sting.

0 5 10 15 20 25 30

0 1 2 3 Ca/SCa Utilization, %

158 MWg 78 MWg

Figure 7-6. Sorbent utilization for 158 MWg and 78 MWg loads.
Robinson Unit 1 is equipped with a ROFA system for NO X control. The FSI system was designed to operate with the ROFA system on. However, to examine t he impact of ROFA operation on FSI performance, one of the parametric test series w as conducted with theProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-21 

### GE Energy

ROFA system off. Figure 7-7 compares the SO 2 reduction rate and the calcium utilization for the ROFA on and off conditions. ROFA appears to have a small impact on the FSI performance. The ROFA off condition has slightly lower SO 2 reduction and calcium utilization rates, consistent with the design basis.

0 10 20 30 40 50 60

0 1 2 3 Ca/SSO2Reduction, %

ROFA On ROFA Off

(a) SO 2 reduction as a function of Ca/S.

0 10 20 30

0 1 2 3 Ca/SCalcium Utilization, %

ROFA On ROFA Off

(b) Calcium utilization as a function Ca/S. Figure 7-7. Impact of ROFA on SO 2 removal and calcium utilization.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-22 

### GE Energy

7.4.6 Impacts of Sorbent Injection on SO 2 Removal The key design parameters of the FSI system, such as injector s ize and injection angle were optimized during the earlier process design phase. Along with inje ction elevation, parameters that can be adjusted during the FSI tests include sorbent flow rate and transport air flow rate, both of which have a upper limits due to system specifications. Withi n system constraints, tests were conducted to evaluate the impact of the injection air f low rate and Ca/S ratio on the SO 2 removal rate during the parametric testing.
The Ca/S ratio has a first order impact on SO 2 removal as shown in previous plots. The measured SO 2 reduction vs. Ca/S ratio throughout the testing program generally follows the model predictions derived by considering chemical kinetics, boiler que nch rate and sorbent mixing. Typically 45% to 50% SO 2 reduction at a Ca/S ratio of 2.5 was achieved in the tests.
Sorbent injection air flow rate was designed to be around 5% of the total combustion air. A set of parametric tests was conducted to vary the sorbent air fl ow rate and to observe the response of the FSI performance. As shown in Table 7-8, the sorbe nt air flow rate was varied from 5% to about 6.2% of total combustion air, while the boiler load was maintained at 158 MWg. The fuel flow rates shown in the table are calculated base d on the steam generation. The total air flow rates are calculated from a material ba lance by using the measured exit oxygen. The test results are illustrated in Figure 7-8. Both SO 2 removal rate and the calcium utilization are found to increase with the sorbent air flow rate. H igher sorbent air flow rate corresponds to higher the injection velocity and better mixing and pene tration. However, a side impact of increasing the sorbent air is the increase in boi ler excess air if the burner air and ROFA air remain unchanged. Another adverse impact of increasi ng sorbent air flow rate is increasing the air heater outlet gas temperature, which is one of the factors leading to opacity increase. Therefore, an objective of FSI system desig n is to minimize the sorbent air flow while maintaining good mixing and penetration.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-23 

### GE Energy

TABLE 7-8. TEST CONDITIONS FOR VARYING INJECTION AIR RATE

Parameter Note Unit Test 1 Test 2 Test 3 Test 4 Load CEMS MWg 160.73 160.57 158.32 158.39 Exit O 2 CEMS % wet 4.13 4.19 4.15 4.15 Fuel Flow Rate Calculated lb/hr 134,630 134,810 132 ,130 133,026 Total Air Flow Rate Calculated lb/hr 1,499,521 1,50 1,523 1,473,500 1,483,475 Sorbent air Flow Rate Flow Rate Measured Lb/hr 74,344 82,287 86,860 9 1,962 % of Total Combustion Air Calculated % 4.96 5.4 8 5.89 6.2 Ca/S Calculated % 2.63 2.45 2.42 2.23

0 10 20 30 40 50 60 70

4 5 6 7 Total Injection Air, % of Combustion AirCalcium Utilization, %

0 10 20 30 40 50 60 70SO2Reduction, % Ca Utilization
SO2 Reduction

Figure 7-8. Impact of sorbent air flow rate on the FSI performance.

7.4.7 Ash Analyses Daily ash samples were taken for analysis. The ash mineral cont ent and other ash indices are summarized in Appendix A. Loss on ignition (LOI) from the ash analyses is plotted in Figure 7-9. LOI ranged from 0.5% to 13% for medium to high load with an averag e of 6.5%. Low load tests (76 MWg) conducted on October 2nd (not shown in the plot) yielded an average LOI of 16%.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-24 

### GE Energy

7.4.8 Mercury Emissions This section of the report describes the effect of furnace sorbent injection on mercury (Hg) emissions. Figure 7-10 shows the total Hg emission levels with and w ithout FSI as a function of unit gross load. Figure 7-10 also shows the total Hg reduction wi th the load. As shown in figure, baseline total Hg emissions ranged widely, from 3.0 to 7.5 μ g/m 3 at all unit loads. During sorbent injection the Hg emission levels decreased to betwe en 0.3 and 1.5 μ g/m 3 . The high variation in baseline Hg emissions could be due to changes of sever al parameters such as fuel composition, unburned carbon levels and air heater outlet temperat ure. The total Hg removal with sorbent injection was approximately 80% at all unit loads.
Figure 7-11 represents Hg emissions as a function of calcium to mercury molar ratio for all loads. Mercury reduction increased with increasing sorbent feed ra te. One possible mechanism for mercury control is direct capture of mercury by t he lime sorbent. It is also known that SO 3 can poison mercury absorption by carbon, so another possible mechanism is that by capturing flue gas SO 3 , the sorbent allowed the fly ash carbon to more effectively control mercury. 0 2 4 6 8 10 12 14 16

6/21 7/21 8/20 9/19 10/19 11/18 12/18 DateLOI, %

Before FSI Test Preliminary Test Parametric Test Long Term Test Average 6.51%

Figure 7-9. Loss on ignition during the tests.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-25 

### GE Energy

7.5 Operating Curves After optimizing the FSI system, operating curves were esta blished to integrate into the plant DCS to allow operators to run the system 24/7 in automatic mode. Th e purpose of the 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0

0 50 100 150 200 Load, MWgHg-T,μg/m3

0 10 20 30 40 50 60 70 80 90 100Total Hg Reduction, % Baseline Hg-T Hg-T w ith FSI Hg Reduction

Figure 7-10. Mercury emissions as a function of unit gross load.

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0

0 20 40 60 80 100 120

Ca/Hg-T, 10 3

lbmol/lbmolHg-T,μg/m3

0 10 20 30 40 50 60 70 80 90 100Total Hg Reduction, %

Baseline Hg-T Hg-T w ith FSI Hg Reduction

Figure 7-11. Mercury emissions as a function of Ca/Hg.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-26 

### GE Energy

operating curves was to specify the optimized sorbent flow and inj ection air rate, diverter valve position and excess oxygen set point when FSI is in service as a function of boiler steam generation. In order to achieve these parameters, a total of four operating curves were developed. The four operating curves developed as function of steam flow were as foll ows:

• Sorbent flow rate,

• Injection air,

• Diverter valve position, and

• Excess oxygen set point. 7.5.1 Sorbent Flow Rate Figure 7-12 shows sorbent flow rate as a function of steam flow rate at diff erent baseline-SO 2 emission levels. The figure is plotted using the data shown in Tabl e 7-9. The Table contains calculated sorbent flow rate at Ca/S of 2.5 up to 1200 KPPH of stea m, which is 150 MWg and above 150 MWg the limit of maximum injection was established fr om the optimized conditions such that opacity levels do not exceed the plant allowable l imit. The plant allowable opacity limit was 33%, which is 7% lower than the state limit of 40%.
The plant control system is designed to incorporate either a direct equation or set of data for the logic output. Here in this case, Progress Energy opted to use one single set of data at baseline-SO 2 of 2.2 lb/mmBtu instead of a wide range of baseline SO 2 sorbent injection data shown in Table 7-9. The sorbent flow rate can also be calculated using Equation 6.1. 

## ( ) ( )( )       + = S Ca et t SO baseline SteamFlow hr lb Rate Flow Sorbent arg 455

. 192 364 .1 ) / ( 2 6.1

Where:

• Steam Flow is in KPPH

• Baseline SO 2 is in lb/mmBtu

• Target Ca/S ratio ranges from 0 to 3.0Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-27 

### GE Energy

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

0 400 800 1200 1600 2000 Steam Flow, KPPhSorbent Rate, lb/hr

SO2 = 1.6 lb/mmBtu SO2 = 2.0 lb/mmBtu SO2 = 2.2 lb/mmBtu SO2 = 2.4 lb/mmBtu SO2 = 2.6 lb/mmBtu Max. limit of injectionLoad Limit : 1200 KPPH

Figure 7-12. Sorbent flow rate as function of steam flow.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-28 

### GE Energy

7.5.2 Injection Air Figure 6-14 shows the injection air control curve as a function of ste am flow. As shown in Figure 6-14, the injection airflow is linear up to a steam fl ow of 700 KPPH (94 MWg). Above 700 KPPH the injection airflow remains constant at 13,000 CFM. The limit of maximum injection air of 13,000 CFM was established because any furt her increase in injection air leads to increase air heater gas outlet temper atures due to air heater energy balance, which in turn has a detrimental effect on opacity. However, l imiting injection airflow, especially at full load, reduces SO 2 reduction, which is believed to be due to poor TABLE 7-9. SORBENT FLOW RATE AS A FUNCTION OF STEAM FLOW

Steam Flow Load KPPH MW g SO 2 :1.6 SO 2 : 2.0 SO 2 : 2.2 SO 2 : 2.4 SO 2 : 2.6

400 54 2956 3695 4065 4434 4804 450 60 3229 4037 4440 4844 5248 500 67 3503 4378 4816 5254 5692 550 74 3776 4720 5192 5664 6136 600 80 4049 5061 5568 6074 6580 650 87 4322 5403 5943 6484 7024 700 94 4596 5745 6319 6894 7468 750 101 4869 6086 6695 7303 7912 800 107 5142 6428 7071 7713 8356 850 114 5416 6769 7446 8123 8800 900 121 5689 7111 7822 8533 9000 950 127 5962 7453 8198 8943 9000 1000 134 6235 7794 8574 9000 9000 1050 141 6509 8136 8949 9000 9000 1100 147 6782 8477 9000 9000 9000 1150 154 6000 6000 6000 6000 6000 1200 161 6000 6000 6000 6000 6000 1250 168 6000 6000 6000 6000 6000 1300 174 6000 6000 6000 6000 6000 1350 181 6000 6000 6000 6000 6000 1400 188 6000 6000 6000 6000 6000 1450 194 6000 6000 6000 6000 6000 1500 201 6000 6000 6000 6000 6000 Sorbent Injection @ Ca/S of 2.5 up to 150 MWg, lb/h rProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-29 

### GE Energy

mixing of sorbent stream with the flue gas. The design injection a ir at 100% load condition was initially supposed to be 19,000 CFM.

7.5.3 Diverter Valve Position The purpose of the diverter valve is to switch sorbent injection from lower to upper injectors or vice versa when required. In order to make the control system to shift the location automatically, logic was written as a function boiler steam generation. As shown in Figure 7-13, the diverter valve position remains to lower injectors up to 670 KPPH (90 MWg) and above 670 KPPH the logic outputs to switch to upper injectors. The point of s hift was determined from both parametric and long term testing. The both tes t data revealed that below 90 MWg load, the SO 2 reduction was reduced when sorbent was injected from upper injectors. Consequently, when sorbent was injected from lower injector s above 90 MWg, SO 2 reduction dropped about 4% to 5%. 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000

0 50 100 150 200 250 Load, MWgInjection Air, CFM

Injection Air Curve Max. Limit : 13,000

Figure 7-14. Injection air flow rate as a function of steam flow.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-30 

### GE Energy

7.5.4 Excess Oxygen Curve The other important operating curve when the FSI system is in oper ation is the excess oxygen set point curve. Here as well, Progress Energy opted to use set of data instead of curve equation in the control logic scheme. Two excess oxygen set point data sets were developed: 1) when FSI in service with coal only and 2) with FSI in se rvice when ROFA is in function. The two FSI excess oxygen data set points are based on the injection air curved described in the section 6.5.2. These two sets of oxygen set point data a re shown in Table 7-10 along with the baseline excess oxygen levels.
Since the injection air is added to the total boiler air rather t han taking air from burners or ROFA, the total excess oxygen set point was needed to increase b y about 0.6% at full load condition. The increase in excess oxygen leads to reduced boiler therm al efficiency and causes increased back-end flue gas temperatures, especially wh en the injection air is not preheated in the air heaters. Increase in back-end temperature h as adverse effect on ESP efficiency. For permanent application it is recommended to use e ither pre-heated ROFA or burner air for sorbent injection air so that total combustion air remains constant, however, biasing burner or ROFA airflow to the injection air required to eva luate the impacts on boiler performance and boiler exit gas emissions such as NO X and CO. 0 250 500 750 1000 1250 1500

Steam Flow, KPPHDiverter valve Position

Low er Injection Upper Injection670 KPPH upper injectors

Figure 7-13. Diverter valve position as a function of steam flow.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-31 

### GE Energy

7.6 Impact of FSI on Boiler 7.6.1 Ash Deposition During FSI injection, a daily walk-down of the boiler was performed t o inspect ash deposition that resulted from sorbent injection. The inspections were ma de on the front wall, superheater pendants, bottom of the reheat pendants and nose arch from the rectangular observation ports that are located on the 6 th level at El. 106’-6”. The eight front wall observation ports located at equidistance on the front wall were use d to see the secondary superheater pendants & division wall tubes. The two sidewall ports on either side of the sidewall were used to see the front wall, division wall, nose arc h and bottom of the reheat pendants. Similar to the 6 th level ports, there are also 12-observation ports available at the 7 th level at El. 120’, 8 on the front wall and 2 on either side of the side wall, but these ports are prone to furnace puffing, hence were not used often.
No significant evidence of ash deposition was observed on these heat t ransfer sections during the entire program of sorbent injection. There were slight ash deposits observed on the TABLE 7-10. FSI EXCESS OXYGEN CURVE AS A FUNCTION OF STEAM FLOW

Load Steam Flow COAL O 2 St. Pt. COAL/ROFA O 2 St. Pt. COAL/ROFA/FSI

O 2 St. Pt. COAL/FSI O 2

St. Pt. MWg KPPH 0-10% 0-10% 0-10% 0-10% 0.0 0 7.73 8.00 9.00 8.50 13.4 100 7.40 7.50 8.20 7.70 26.8 200 7.02 7.10 7.80 7.30 40.2 300 6.61 6.70 7.35 6.85 53.6 400 6.00 6.12 7.00 6.50 67.0 500 5.35 5.62 6.50 6.00 80.4 600 4.80 5.09 5.80 5.30 93.8 700 4.35 4.57 5.20 4.70 107.2 800 4.00 4.10 4.60 4.10 120.6 900 3.60 3.63 4.10 3.60 134.0 1000 3.25 3.27 4.00 3.50 147.5 1100 2.90 2.99 3.77 3.50 160.9 1200 2.60 2.80 3.54 3.36 174.3 1300 2.60 2.80 3.49 3.30 187.7 1400 2.60 2.80 3.45 3.26 201.1 1500 2.60 2.80 3.41 3.22Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-32 

### GE Energy

secondary superheater pendants and on the backside of the division wall as shown in Figure 7-14 when sorbent injection rates at high loads were above Ca/S of 1.5. The ash deposits were solid flaky particles and not a molten ash. The particles were accumulated over the duration of the sorbent injection and formed approximately 10” thick and 24” high in an 8- hour injection period. These ash deposits were easily manageable wit h the retractable sootblowers located at the nose arch elevation. The sootblowers that we re used to remove these deposits were IK9, 10, 11, 12, 15 & 16. These sootblowers were used three times in 24 hours of FSI operation. There were some locations, especially on the ba ckside of the division wall, where sootblowers were not able to reach and had signs of ash accumulation during high loads but were removed when the loads dropped to minimum due to low furnac e temperatures. The front wall always appeared to be clean and has no significant ash deposition at any time.

Routine furnace observations were also made from 5 th level ports for ash accumulation. Some slag buildup was noted on the sidewalls & eyebrows on ROFA ports . It appeared that these deposits were typical of normal operation, and were not believe d to be caused by sorbent because the sorbent was injected at higher elevation.
Air-heater observations were also made during FSI operation and sorb ent accumulations were noted in the corners where soot blowers were not able to reach. During the course of sorbent injection, air heater sootblowers were continuously in operation to blow off the sorbent to avoid plugging.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-33 

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Two boiler inspections were conducted to assess the effect of sorbent injection on boiler components. The first inspection was performed with a team of four en gineers on 10/25/2008 after one month of sorbent injection. Two team members inspected t he boiler backpass and airheaters and the other two inspected the ESP. The detailed inve stigation report of the ESP is described in the Section 6.6.4 of this document. The secondary superheate r, reheat pendants and radiant heat surfaces were inspected from the observation doors.
The airheater inspection photographs are shown in Figure 7-15. The inspec tion crew reported the airheater appeared normal except few locations especially the corners and outer ring of the baskets were found ash deposits. It seems the findings are consi stent with the airheater differential pressure. Zero to marginal increase in airheater differ ential pressure was observed during sorbent injection. Ash Deposition Width = 10 ′′ Height = 24 ′′ Observation

Ports (8)

Figure 7-14. Sketch of ash deposition on secondary superheater and reheat pendants.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-34 

### GE Energy

The second inspection was performed on 12/16/2008, approximately two months aft er the first inspection. During this period of two months, sorbent was injecte d continuously for 24 hours for most of the days. During this outage only radiant pendants, co nvective pendants and airheaters were inspected. An ESP inspection was not performed.
The inspection team reported that the radiant and convective pass app eared to be in relatively good condition. However, alpha and bravo airheaters were an area of conce rn. As shown in Figure 7-16, the cold air side of the alpha air heater had two to three inches in width of the outer baskets plugged and three to four inches deep of cold end corrosion near the center baskets. The cold air side of the bravo air heater had a six to ei ght inches deep of cold end corrosion on the center baskets. The reason for the corrosion of the basket s was not fully known. Figure 7-15. Photographs of airheater inspection.

Figure 7-16. Inspection photographs of A & B airheaters.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-35 

### GE Energy

Primary superheater and primary reheater pendants appeared normal . The inspection photographs of these pendants are shown in Figure 7-17. As shown in the pic tures, both the primary superheater and reheat pendants have slight ash accumulat ion, which is typical of coal-fired boilers.

An ash deposit sample was also collected from primary superhea ter pendants for analyses. About 3 feet of ash deposit was found on the top of the horizontal run of tube s between the up-leg supports and the front convection wall. This was a small area of ash deposits on the total convection surface. Deposits were crusty and formed a pyram id shape on top of the tube. The analyses of ash deposits were performed at the Progress Energy metallurgical laboratory. Representative samples of the lumps of deposit were p repared and analyzed using two analytical techniques. An energy dispersive x-ray spectromete r (EDS) attached to a scanning electron microscope (SEM) was used for an elemental che mical composition characterization. An X-ray diffraction technique was used to determi ne what types of compounds were present in the analyzed deposit samples. The obtained EDS/ SEM results revealed that the analyzed deposit sample consisted primarily of ox ygen, calcium, and sulfur (most likely calcium sulfate) with lesser and varying amounts of sodium, magnesium, aluminum, silicon, phosphorous, potassium, calcium, titanium, and iron. The iron concentration was greater in the pinkish-red layers than those of the pinkish-white layers as shown in Figure 7-18. Some of the layers contained more silicon and alumi num. The X-ray diffraction analysis results revealed that the analyzed sample consisted of calcium sulfate with minor amount of non-crystalline material. Figure 7-17. Primary superheater and primary reheat pendants inspection photogra phs.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-36 

### GE Energy

7.6.2 Boiler Performance Boiler performance was monitored during each test. Due to the injec tion of additional air into the boiler, the exit O 2 increased, which resulted in a boiler efficiency reduction. Figur e 7-19 plots the calculated boiler efficiency as a function of exit O 2 for the parametric tests. The unfilled symbols are for baseline boiler conditions; the filled sym bols are for sorbent injection conditions. Results for each test day are plotted in the sa me color. The results show that the boiler efficiency linearly decreases with increase of exit O 2 over the load range. For the same load tests, the boiler efficiency dropped about 0.1% to 0.8% during sorbent injection. The loss in boiler efficiency is mainly from dry ga s losses, which is due to increase in exit gas temperature and boiler excess oxygen. However, the de crease of the boiler efficiency can be minimized by maintaining exit O 2 via reducing either burner air or ROFA flow. A study of the impacts upon parameters such as CO emissions and tube wastage would be required to evaluate potential impacts of reducing burner air upon boiler performan ce. During sorbent injection, small changes in heat absorption were see n, as evidenced by steam temperature, attemperation flow rates, or sootblowing requirements . Figure 7-20 shows that the main steam temperature increases slightly (about 20 o F) with sorbent injections. The sorbent injection also did not necessitate any changes in procedures i n remove ash from the boiler or ESP.

Boiler NO X emissions also remained unchanged during FSI tests. Even though exit O 2 increased with sorbent injection, NO X emissions did not increase as evidenced in Figure 7-21, since boiler stoichiometric ratio was not disturbed.

Figure 7-18. Photograph of the ash deposit analysis.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-37 

### GE Energy

85 86 87 88 89 90

2 3 4 5 6 7

Exit O 2 , % wetBoiler Efficiency, %

180MW Baseline 180MW W ith Sorbent Injection 158MW Baseline 158MW W ith Sorbent Injection 77MW Baseline 77MW With Sorbent Injection

Figure 7-19. Boiler efficiency as a function of exit O 2 .

800 900 1000 1100

60 80 100 120 140 160 180

Boiler Load, MWgMain Steam Temperature, deg. F Baseline Sorbent Injection

Figure 7-20. Impact of FSI on main steam temperature as a function of the boile r load.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-38 

### GE Energy

7.6.3 Opacity The test results from the parametric and long-term tests dem onstrated that the FSI system is capable of achieving expected SO 2 reduction while maintaining minimal impact on boiler performance. However, opacity was observed to increase during the sorbent injection and was at times a limiting factor during the FSI tests. Figu re 7-23 shows a representative group of test data obtained on September 29, 2008. With the increase of sorbent feed rate, opacity continuously increased throughout the test and reached 25% at the end of the test.
To better understand and control the opacity increase, dedicated tests and data analyses were conducted during the long-term trial. GE applied a Six-Sigma methodol ogy to understand and mitigate opacity issues. The potential factors that might c ause an increase of opacity are related to boiler conditions, ESP performance, sorbent injection and fuel properties. A fishbone analysis (Figure 7-24) was used to list all the potential factors. Four groups of causes are listed in the chart: Boiler conditions including load, flue gas flow rate, exit O 2 , air heater outlet temperature, dust loading, and ROFA operation; ESP condi tions including outlet field voltage, inlet field voltage, form factor and rapping scheme; fuel properties; and sorbent impact. The study and improvement on ESP performance will be discussed in next section. Fuel property impact includes the variation of coal sulfur c ontent. Sorbent impact includes sorbent feed rate, sorbent injection location, injection airflow rate and par ticle size. 0 0.1 0.2 0.3 0.4 0.5 0.6

0 20 40 60 80 10 0 12 0 14 0 16 0 18 0 20 0 Boiler Load, MWgNOx, lb/MMBtu Baseline Sorbent Injection

Figure 7-21. Impact of FSI on NO X emission.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-39 

### GE Energy

During baseline operation, i.e., no sorbent injection, field observation indica ted coal sulfur content has an impact on opacity. To understand the effect, opacity as a function of baseline SO 2 emission is plotted as shown in Figure 7-22. The data are grouped acc ording to the boiler gross load. The plot shows a trend of opacity decrease as the baseline SO 2 emission increases. This observation may somewhat contribute to the lower opaci ty obtained during the latter stages of the long-term trial, when higher sulf ur coal was fired. However, according to results of the regression analysis, coal sulfur content is not a first order parameter impacting opacity.

To better understand the impacts of boiler and sorbent injection parame ters on opacity, Figure 7-25 to Figure 7-28 plot the opacity as a function of boiler load, flue gas flow rate, dust loading, air heater outlet temperature, sorbent feed rate, and sor bent air flow rate. The plots indicate that the above parameters have somewhat of an im pact on opacity. However, these parameters are not independent. For example, the flue gas flow rate increases with load and exit O 2 . To sort out the key parameters that have the most impact on opac ity, GE performed a regression analysis by using both the average data over a test period and the transient one-minute data throughout the test day. The parameters eva luated in the regression analysis included boiler load, sorbent feed rate, sorbent air flow ra te, air heater outlet temperature, ambient temperature, exit O 2 , flue gas flow rate, baseline SO 2 emission and dust loading. Both regression analyses identify the air heater (AH) outlet temperature as a 0 5 10 15 20 25 30 35 40

1 1.5 2 2.5 3 3.5

Baseline SO 2 , lb/MMBtuOpacity, % 180 - 185 MWg 160 - 170 MWg 150 - 160 MWg 130 - 150 MWg 100 - 130 MWg < 100 MWg

Figure 7-22. Opacity as a function of SO 2 emission at baseline conditions.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-40 

### GE Energy

dominant factor for opacity increase. Figure 7-29 plots the opacity a s a function of the air heater outlet temperature for all parametric tests. The data follow a consistent trend, which indicates a strong relationship between the opacity and the AH outle t temperature. When the AH outlet temperature is greater than 270 o F, the opacity increases exponentially.
A second regression analysis was conducted to find out the causes for AH outlet temperature increase during the course of sorbent injection. The parameters incl uded in the analysis were sorbent feed rate, flue gas flow rate, exit O 2 , sorbent airflow rate and ambient temperature. The analysis identified two parameters other than load are the l eading factors for the increase of AH outlet temperature. One is the ambient temperature. During a typical testing day, the ambient temperature starts rising in the morning and increases about 20 o F in the afternoon. As the ambient temperature increases, the AH outlet temperatur e increases accordingly, even at steady boiler operating condition. It was also observed that a s the test program moved to the fall and winter, the ambient temperature was lower than that in the beginning of the test phase. The air heater outlet temperature and opacity were lower i n the cooler fall weather than in the summer. The second important factor is the sorbent injecti on air. The addition of 5% total air to the furnace increases the flue gas flow rate t hrough air heater and therefore increases the gas temperature at the outlet of the air heater.
Based on the analysis, at the later stage of the long term te sting, the sorbent injection air flow rate was maintained at 13,000 ACFM or lower. Meanwhile with a coole r ambient temperature, the opacity issue was eased.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-41 

### GE Energy

Figure 7-23. Sample data on September 29, 2008 showing opacity increase.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-42 

### GE Energy

ESP Performance

Sorbent Impact Sorbent Feed Rate Boiler Condition

Exit O 2 Change

Flue Gas Flow Rate Increase

Fuel Properties Ash Content

Sulfur Content
Mineral Content AH Outlet Temperature Increase



### Opacity Increase Boiler Load

Moisture Content Sorbent Feed Location Injection Air Flow Rate ROFA Impact Inlet Field Voltage Outlet Field Voltage

Form Factor Rapping Scheme

Particle size Dust Loading

Figure 7-24. Fish bone analysis for causes of opacity increase.

0 5 10 15 20 25 30

0:00 4:48 9:36 14:24 19:12

TimeOpacity, % Ca/S=0, 155 MW Ca/S=0.8, 155 MW Ca/S=2.2, 155 MW Ca/S=2.6, 155 MW Ca/S =0, 77 MW Ca/S = 0.97, 77 MW Ca/S=1.94, 77 MW Ca/S=2.02, 77 MW Ca/S=2.0, 77 MW

Figure 7-25. Impact of load on opacity.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-43 

### GE Energy

0 5 10 15 20 25 30 35

1550 1600 1650 1700 1750 1800

Flue Gas Flow Rate, lb/hrOpacity, %

09/15 Clean Air Test

Figure 7-26. Impact of flue gas flow rate on opacity.

0 5 10 15 20 25 30 35

0 5000 10000 15000 20000 25000 30000

Dust Loading, lb/hrOpacity, %

Figure 7-27. Impact of dust loading on opacity.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-44 

### GE Energy

0 5 10 15 20 25 30 35 40

0 1 2 3 4 5 6

Exit O 2 , %wetOpacity, % 09/29, Baseline 10/01, Baseline 09/29 Vary Sorbent Flow 10/01 Lower Injection

Figure 7-28. Impact of exit oxygen on opacity.

0 5 10 15 20 25 30 35 40

200 220 240 260 280 300 Air Heater Outlet Temperature, deg. FOpacity, % Baseline 09/29 Vary Sorbent Flow 09/30 Vary Injection Air 10/01 Lower Injection 10/02 Low Load 10/03 ROFA OFF

77 MW g 158 MWg

Figure 7-29. Impact of air heater outlet temperature on opacity.

7.6.4 ESP Performance As reviewed in Section 6.2, the predicted ESP performance during FSI operation would result an opacity increase from an average of 6.1% to 16% at a sorbent injection rate ofProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-45 

### GE Energy

11,700 lb/hr, a factor of 2.6 increase. The ESP performance tests during September show that after initiating sorbent injection, opacity increased steadily f rom about 19% to over 30%, a factor of 1.6 increase (although opacity was still increasing). A ctual opacity readings during FSI operation were found to be highly dependent upon baseline opacity and f lue gas temperature in the ESP.
The opacity increase occurred when the load was experiencing a sm all increase. Unit load increased from about 159 MW to about 173 MW over the four-hour period. This 10% change would account for an increase in the gas volume treated by the ele ctrostatic precipitator. Stack gas temperature also increased gradually over the test per iod. The initial stack temperature was about 259oF at the beginning of the test and increased to about 277oF at the end. This represents an increase of about 18oF. Based on the predicted dust resistivity, the temperature change represents one half order of magnitude increase in dust resistivity. The dust resistivity does not appear to increase to unacceptable leve ls, but an increase in resistivity is associated with a decrease in collection effi ciency. The ESP outlet temperature showed an increase on the “A” side from 258oF to 270oF and the “B” side fr om 249oF to 256oF. Neither side showed the magnitude of temperature increase exhi bited by the stack temperature.
If gas flow, temperature, dust loading, and internal conditions are equival ent between the east and west chambers, their electrical characteristics would be e xpected to be the same. It would also be expected for the spark rate to decrease and the secondary c urrent to increase when progressing through the electrical fields. From the data it can be seen that the secondary current does not increase appreciably from the A to B fields. In addi tion, the spark rate is relatively constant from the A to B fields. This indicates that the dust loading is not decreasing significantly from the first to second electrical field.
Current densities start out at strong values then degrade to mini mum values for the duration of the test. Generally when the secondary current degrades over tim e, it is an indication of increasing dust layer thickness or possibly increased resistivity of the dust l ayer. Based on the electrical trends gathered during sorbent injecti on, several recommendations were made:

• Perform air load and gas load VI curves to define the corona onset volt age and the relationship between secondary voltage and secondary current. The data doe s not show indications of back corona, but the VI curve can be used to confirm the data.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 7-46 

### GE Energy

• Revise the collecting plate rapping program on the A, B, and C fie lds to decrease the cycle time and increase force. The gradual decline in secondary current indi cates that dust is building up at a rapid rate. Rapping more aggressively can reduce the build up rate and maintain acceptable conditions for a longer period of time.

• Consider reduced power rapping for the A and possibly B collecting fi elds. The power reduction will make rapping more effective, but possibly increase r e-entrainment of dust during the cycle. Initially, the power can be reduced to about 50% of name plate when the A field raps and 70% of nameplate when the B field cleans. Instantan eous and average opacity should be monitored to define the impact of reduced power rapping. The impact of reduced power rapping should also be reviewed on the C and D fields.

• The spark rate exhibited in the West chamber is higher than th e East chamber. It should be verified that comparable gas volumes are reaching each chamber.

• The fact that the C field does not show a significant change in se condary current and that the spark rate increases dramatically indicates that rapping may be too aggressive. Review the C field program and consider decreasing lift height or increasing cycle time.

• Similarly, the D and E fields show an increase in secondary current during sorbent injection. This may indicate that the rapping program is too aggre ssive. Decreasing the rapping may reduce dust re-entrainment.

• The F field does exhibit a decrease in secondary current during s orbent injection. This indicates that the rapping program can be modified to increase l ift height and decrease cycle time.

• Fields C, D, E. and F are all secondary voltage limited. The current density associated with the applied secondary voltage is very low. Increasing the s econdary voltage nameplate rating would increase current density. Increased cur rent density reduces dust re-entrainment and improves particle removal efficiency.

• During the next opportunity for an internal review, inspect the C and D fields for a close clearance. The high spark rate observed in these fields may be re lated to an internal clearance in addition to the increased dust burden.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 8-1 

### GE Energy



## 8.0 Recommendations for System Improvements
8.1 Sorbent Injection System While the FSI demonstration system generally met performance e xpectations, a series of system modifications and upgrades can be suggested to improve system performance and boiler operability for a permanent application. The basis for the tri al system was for the sorbent air to add to the total boiler air. That is, as sorbent injec tion air was added, a proportionate amount of air was not reduced from other boiler input stream s. Therefore, furnace oxygen concentration and flow rate increased during FSI oper ation. This caused boiler thermal efficiency to decrease, back-end system temper atures to increase, and ESP collection efficiency to decrease. For permanent application it is recom mended to reconfigure the system such that total air flow rate remains constant duri ng FSI operation. The sorbent air could potentially be taken either from the burner air or from the R OFA air. Such an action would require a study of burners and other system components to define t he range of allowable operation and to evaluate any impacts upon other species such as NO X and CO. Furthermore, SO 2 reduction was observed to increase with increasing sorbent air, whi ch is believed to be due to better mixing between the sorbent stream and t he furnace gas. This result suggests that increasing either the total sorbent air or the momentum of the sorbent air stream (by increasing stream velocity) could lead to higher l evels of SO 2 reduction. For permanent application, the injection system design can be reviewed i n the context of the test results to quantify costs and benefits of either adding more sorbent air or increasing the sorbent stream velocity.
From an operational standpoint, several relatively minor issues were noted with the FSI system. Feeding from a silo proved difficult throughout the test proj ect. This may be due to the fact that sorbent was stored for a long period of time in the silo, and may have gotten wet or otherwise agglomerated. A detailed cleaning of the silo is re commended. Also, the reinforced rubber sorbent transport hoses experienced erosion problems just downstream of the splitter. The splitter outlet hose barbs had smaller diameter than the hoses, which is believed to have caused a region of high velocity and flow recirculation, leading to erosion. It is recommended to change this configuration such that the diamete r of the hose barbs is close to that of the hose. This would alleviate the issue with high velocity and erosion. Hard pipe could also be considered for high-erosion areas.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 8-2 

### GE Energy

Additional recommendations from the testing team if the FSI were to be operated on a long term or continuous basis include:
1. Sorbent Injection Hoses – the current hoses would not be suitable for l ong term operation. They erode and leak. The majority of the problem occurs clos e to the distribution header but has been observed in other areas as well. The feed hoses could be redesigned to allow service air to be blown through plugged lines.
2. FSI Controls – This area gave the most difficulty during the te sting and continuous operation of the system.
a. The PLC has communication issues and crashed repeatedly during t esting. It would lock up with no remote alarm and require rebooting.
b. There are several routine functions which could only be done at the HMI station. Examples of this are putting the system in Maintenance M ode to manually fluidize silos when the sorbent is not feeding properly. All of the remote functions should be accessible to the control operator.
c. The Loss In Weight and Volumetric modes of Sorbent Feeder control need revamping. The system uses LIW as the normal control method and then defaults to volumetric when the weigh hopper is filling. The variati on in flow caused by the change in density and the consistency of the materi al often caused the system to transfer to the volumetric mode at an exc essively high or excessively low feed rate. This feed rate was locked in until the weigh hopper was full. This caused large variations in the sorbent flow and cause d the operator to be conservative in the maximum feed rate, especially dur ing high loads with high opacities. The system needs to have a characteriz ed curve for the volumetric flow that would allow it to set feeder speed during the fill cycl e on the characterized feed rate vs. the current set point. This w ould reduce the variation in sorbent feed.
3. Sorbent Silos- Need to add fluidizing air rings or vibrators at s everal levels of the cone. Flow of the sorbent from these silos was a continuous issue espe cially when trying to run the silo empty. The possibility should be considered of ins talling a grinder on the discharge of the day bin discharge valve to eliminate a ny clumping before it enters the airlock valve.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 8-3 

### GE Energy

4. DFA Controls – Need the same functions available to the operat or as is available at the remote HMI. Several logic changes need to be made concerning the flushing and shutdown cycles. The operator should be able to interrupt the shutdown cycle. 

### 8.2 Boiler Deposit Management System In previous FSI projects, significant problems were encountered wi th particulate matter deposition in the upper furnace. In the most severe instances, fouling deposi ts actually bridged the spacing between tubes and caused a boiler shutdown. In the curr ent project, deposit management studies were performed that developed a series of recommendations, including restoring existing sootblowers to design operating conditions , installing new sootblowers, and installing sonic horns to control ash-sorbent deposits in the upper furnace. These upgrades were coupled with an Intelligent Sootblowing system furnished to Progress Energy by Emerson. This system effectively managed furnace de posits during the FSI trial. For Robinson Unit 1, no further upgrades are suggested. For application t o other units, a case-by-case review would be required to develop recommendations for de posit management. Based on the experience at Robinson, it is anticipated t hat a combination of sootblowers and sonic horns would be recommended, potentially with the addition of pulse detonation technology such as the GE Powerwave process to provide more aggressive cleaning. In future applications it is also recommended to place m ore emphasis on air preheater cleaning, both to optimize thermal efficiency and to re duce flue gas temperature, which would have benefits on ESP performance. 

### 8.3 Electrostatic Precipitator The methodology for the trial was to make sufficient ESP upgrade s to allow the tests to be completed. Opacity proved to be a limiting factor in allowable sorbent flow ra te under certain conditions, and therefore more extensive PM control upgrades might be neede d for permanent application of the FSI technology. As shown in Figure 7-22, ba seline opacity values during the trial ranged widely, from 2% to 27%, and generally increased with increasing boiler load. As described in Section 6.2, the performance projection was for opacity to increase by approximately a factor of 2.6. Actual opaci ty readings during FSI operation were found to be highly dependent upon baseline opacity and flue gas temperature in the ESP.
GE personnel accompanied Progress Energy personnel on an ESP inspecti on during a weekend outage on October 25, 2008. Detailed findings and recommendations were presented in a memo issued by GE Technical Advisor Doug Wamble. In summary, a seriesProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 8-4 

### GE Energy

of mechanical repairs are recommended such as centering rapper anvils, replacing bowed discharge electrodes, and installing anti-sway insulators. These recommendations would improve ESP performance and reduce maintenance requirements, but would li kely have only nominal impact upon opacity and PM emissions.
Based on a review of ESP electrical conditions during FSI, an ana lysis and series of operating recommendations was also developed by Bob Taylor of GE an d summarized in a memo dated October 13, 2008. Some of the recommendations made, such as chan ging secondary voltage limits on the four new inlet field transformer rectifier sets to nameplate rating, were performed during the test work. An additional measure tha t is recommended for permanent application is to implement an FSI-specific rapping prog ram. Specifically, it is recommended to revise the collecting plate rapping program on the A, B, and C fields to decrease the cycle time and increase force. The gradual decline in secondar y current indicates that dust is building up at a rapid rate. Rapping more aggressively will reduce the build up rate and maintain acceptable conditions for a longer period of ti me. An assessment would be required as to the impacts of increasing rapping force upon ESP maintenance a nd life cycle.
The upgrades listed above would be expected to provide nominal improvement s to ESP performance, and more extensive measures would likely be needed for permanent FSI application. A listing of options, approximately ranked from least to m ost expensive, is as follows:

• Humidification. A humidification system would consist of a series of atomization nozzles to spray water into the ductwork upstream of the ESP. Through evaporative cooling the system would reduce gas temperature, reduce dust resistivity, and r educe flue gas volume. Each of these effects would have a beneficial impact upon ESP operation. With such a system it would be necessary to ensure complete evaporation, s ince interactions between sorbent byproducts and liquid water could generate cement -like deposits. Evaluation of duct gas flow and temperature patterns is recommended to define the optimum design of humidification lances.

• ESP Field Addition. An inlet field could be added to the Robinson ESP. Whil e further validation would be needed, GE’s preliminary technical assessment indi cated that inlet field addition would roughly cut PM emissions and opacity in half. Significant cost would be involved with field addition.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 8-5 

### GE Energy

• Fabric Filter: A conventional fabric filter or advanced system such as GE’s Max-9 electrostatic fabric filter could be installed to replace the existing ESP. Along with facilitating FSI operation, this approach might also be of interest relative to potential future PM2.5 regulations.

• Ash Dropout Box. A louver plate system could be installed upstream of the ESP, using inertial separation principles to act as a pre-collection device. One potential issue to be considered is the spatial requirement for such a system. An initia l assessment of a dropout system at Robinson revealed difficulty in installing the syst em in the available space. Another issue is that as an inertial separation system , the dropout box would preferentially remove larger flyash particles rather than fi ner sorbent particles, and thus the burden of fine, high-resistivity particles to the ESP might remain high. Nevertheless, for sites that have adequate installation space the dropout box would p otentially merit consideration. 

### 8.4 Byproduct Management System A dry ash management system was installed at Robinson prior to the FSI trial. This system generally worked as intended for the duration of the project. For purpos es of the trial, the flyash-spent sorbent byproduct material was disposed in a landfi ll. For permanent FSI application, it is recommended to consider using the byproduct materi al as an input stream to the manufacture of construction materials. While potentially providing economic benefits, the viability of a beneficial reuse application is highly dependent upon the existence of an available market near the plant. One reuse approach would be to use the byproduct to make a low-strength aggregate material. This would be a simple approach involving grinding, hydration, addition of stabilizers, and compaction into bricks or briquette s. The treatment process could be performed either on-site or at a remote location. The resulting product would be a low-strength aggregate that would be suitable for appli cations such as roadbed fill.
Another alternative for byproduct management would be to use the mat erial as an input to concrete manufacture. Two of the main input materials to cement ma nufacture are flyash and CaO. Table 8-1 summarizes the composition of the Robinson coal flyash, flyash-spent sorbent byproduct, a byproduct-CaO blend, and Portland cement. It can be s een that the byproduct CaO blend bears strong similarities to Portland cement. Therefor e, for a permanent FSI application it is recommended to evaluate the potential to ship the flyash-sorbent byproduct to a cement plant to be reused. Such an approach could have a sig nificant effectProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 8-6 

### GE Energy

upon overall FSI process economics by converting a cost stream into a neutral or value stream. While the above options could prove to be an economic benefit it m ust be recognized that such benefit is highly dependent on the presence of a viable marke t. Assessment of the market potential in the area of the Robinson plant is outside the scope of the current stud y.

TABLE 8-1. COMPOSITIONS OF FLYASH, SORBENT BYPRODUCT, AND PORTLAND CEMENT Component (wt%) Typical

Bituminous Fly Ash * Robinson Coal

Fly Ash Nominal FlyashSorbent By Product Ash-Sorbent

+CaO Blend ** Portland

Cement ***

SiO 2 20 – 60 53.5 35.5 17.7 20.3 Al 2 O 3 5 – 35 23.9 15.8 7.9 4.3 Fe 2 O 3 10 – 40 7.0 4.6 2.3 2.6 CaO 1 – 12 1.2 26.9 63.6 63.6 MgO 0 – 5 1.0 0.9 0.5 2.2 K 2 O 0 – 3 2.3 1.5 0.7 Not specified Na 2 O 0 – 4 0.3 0.2 0.1 0.2 SO 3 0 – 4 0.2 0.1 0.1 Not specified CaSO 4 Not specified 0.0 6.5 3.3 Not specified Unburned C 0 – 15 8.0 5.3 2.6 < 3.0 Other Not specified 2.6 2.6 1.3 Not specified * From US Department of Transportation specificatio ns. ** Blend of 50% flyash-sorbent byproduct with 50% C aO. ** *Type 1 Portland Cement from DOE Coal Utilizatio n By-Product Report, August 2006.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 9-1 

### GE Energy



## 9.0 Future FSI Application
9.1 FSI Technology Viability The FSI trial program at Robinson generally met technical and p rogrammatic objectives. Reduction of SO 2 was approximately 45% - 50% at a Ca/S ratio of 2.5. Notably, no technology show-stoppers were encountered. Boiler deposits were effec tively managed during FSI operation. While opacity was high under certain conditions, ES P performance was adequate for the purposes of the trial, and further PM control upg rades can be made to facilitate a permanent FSI application. The byproduct material was effectively handled by the dry ash system. No safety or environmental problems were encountered during the trial. In summary, all process subsystems worked as intended during the FSI test program. Since no technical flaws were revealed for the FSI technology, the via bility of the technology for a given boiler is largely a function of the following factors:

• Cost effectiveness. The dominant factor in assessing overall net cost of the FSI process is sorbent cost, as described in more detail in section 9.3.

• SO 2 control requirements. FSI is capable of providing approximately 50 % SO 2 control, and thus is best suited to a regulatory framework that requires mode rate control and/or plant-level control.

• Boiler size. Other SO 2 control technologies such as wet or dry FGD systems have grea tly higher capital cost than that of FSI. Furthermore, on a $/kW basis, F GD system cost increases with decreasing boiler size. A 2007 scrubber benchmarking study by the EUCG estimated wet FGD capital costs of $444/kW for units less than 300 M W, as compared to $315/kW for units in the 300-600 MW range (reference). FSI is potenti ally a lower capital cost technology depending on upgrades required for PM control (dic tated by air permit modification) and might be favored for smaller boilers (i.e., less than 300 MW) for which an FGD system might be cost prohibitive.

• Project life cycle. FSI is a lower capital cost technology and therefore is favored for shorter project life cycles, where the high capital cost of a t echnology such as FGD might not be justified.

• Multipollutant control requirements. FSI can control SO 3 , HCl, and mercury along with SO 2 . Specifically, approximately 80% mercury control was achieved dur ing the RobinsonProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 9-2 

### GE Energy

trial. Regulatory requirements and technology capabilities to cont rol these species, along with PM, arsenic, selenium and other species of concern, need to be cons idered in defining an overall emissions control strategy. It is noted that we t and dry scrubbing technologies can also provide some level of multipollutant control.
Regulatory requirements for emissions control also directly impac t the potential viability of the FSI process. The previous CAIR provisions allowed for a cap-a nd-trade approach to emissions control on a National level. Future regulations may or may not include cap-andtrade provisions. Any regulations that require plant-level control impr ove the viability of low capital cost, moderate control technologies such as FSI, particular ly for small to medium size boilers where wet or dry FGD systems may be cost prohibitive. 

### 9.2 FSI Performance Projections To accurately project SO 2 control for a given boiler it is necessary to study boiler temperature profile, gas flow field, coal composition, and injector acc essibility, as well as to define constraints with regard to allowable sorbent and air flow ra tes. Such a study was performed during the initial stages of the Robinson project, and should be repeated for other boilers of interest. Nevertheless, results from the Robinson trial can be used to make general performance assessments and projections. Robinson Unit 1 is a 188 MWg t angentially fired boiler that fires low sulfur bituminous coals. SO 2 control at Robinson was approximately 45% - 50% at a Ca/S ratio of 2.5. While site-specific assessment is needed, performance would generally be expected to be in this range for similar boil ers, such as Cape Fear Unit 5 or 6.
Coal sulfur content is one of the primary factors defining FSI perf ormance. For a given Ca/S ratio, SO 2 reduction generally increases with increasing coal sulfur conte nt (i.e., sorbent utilization increases with increasing coal sulfur content). At t he same time, higher sulfur coals also require more sorbent on a mass flow basis, which can impa ct boiler deposition and PM control device performance. Figure 9-1 provides a curve of SO 2 reduction as a function of coal sulfur content at a Ca/S ratio of 2.5. This curve is based on GE’s database of FSI performance results. The range of data obtained at Robinson is shown for comparison. Figure 9-1 can be used to roughly estimate FSI performance for differ ent coal sulfur contents, although it is noted that boiler-specific process engineering st udies are require for accurate projections.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 9-3 

### GE Energy

0 10 20 30 40 50 60 70 80

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Coal S, %drySO2Reduction, %

Approximate Range of Performance at Robinson Ca/S = 2.5

Figure 9-1. Projected FSI performance as a function of coal sulfur content.



### 9.3 FSI Cost Effectiveness As described above, compared to other SO 2 control technologies such as wet FGD, the FSI process has much lower capital cost, but also higher operating cos t due to less effective utilization of the sorbent material. FSI is generally most advantageous for:

• Smaller boilers

• Shorter life cycles

• Moderate SO 2 control levels (up to 60%)

• Multi-pollutant control (SO 2 , SO 3 , HCl, and mercury)

• Plant-level emissions control requirements as opposed to regional r equirements that have cap-and-trade provisions In developing the overall net cost of SO 2 reduction, factors that need to be considered include:

• Project capital cost

• Project amortization life

• Sorbent unit cost, including sorbent utilization and required feed rateProgress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 9-4 

### GE Energy

• FSI operating labor cost

• FSI utilities cost

• Impacts upon boiler thermal efficiency and cost of power generation

• Maintenance cost

• Byproduct disposal cost (or income if recycled)

• Value of any emission reduction credits generated A detailed review of these parameters is needed to determine the cost ef fectiveness of the FSI process on a site-specific basis. To place a lower boundary on the FS I cost of SO 2 reduction, the sorbent cost alone can be evaluated based on results of the Robinson tr ial. For the range of conditions tested, typical SO 2 control at a Ca/S ratio of 2.5 was approximately 47%, corresponding to a sorbent utilization of 18.8%. Assuming a delivered sor bent cost of $110/ton and 95% sorbent purity, sorbent cost to remove one ton of SO 2 is as follows:



## ( )

2 2 2 2

1 47.6 % 95 1 % 8. 18 1 64 74 1

SO ton remove to required Sorbent ton Purity lization SorbentUti SO lbmol lbm OH Ca lbmol lbm SO ton

= ⋅ ⋅ ⋅

2 cos 712 $ 110 $ 47. 16 SO ton one remove tot sorbent sorbent ton sorbent ton =

⋅

This value provides an estimate of FSI cost for the sorbent component onl y. Estimation of overall process cost requires evaluation of the set of factors listed above.


### 9.4 FSI Schedule The FSI development work performed by GE and Progress Energy was not conducted in a directly linear fashion, for example the project basis shifted fr om Cape Fear Unit 5 to Robinson Unit 1. Nevertheless, the FSI experience at Robinson can be use d to estimate schedule requirements for a permanent FSI installation. For purpose s of schedule estimation, it is assumed that the task structure will be similar to that of the Robinson project, that nominal ESP upgrades will be made rather than field addition or ba ghouse installation, and that the existing ash management system will be retained. Gi ven these assumptions, estimated project phases and durations are as follows:Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 9-5 

### GE Energy

• Phase 1. Failure Modes & Effects Analysis, Pilot-Scale Tes ting, and Process Design: 3 months

• Phase 2. Detailed Engineering Design and Specification Development: 6 months

• Phase 3. FSI System Procurement and Installation: 12 months

• Phase 4. Commissioning and Equipment Performance Tests: 3 months

• Phase 5. System Documentation and As-Built Drawings: 3 months Therefore it is estimated that approximately 27 months would be r equired for a complete project. Duration would be extended significantly if a baghouse instal lation or major ESP modifications were required. It is also noted that the installat ion work would need to be integrated with a boiler outage. 

### 9.5 Application of FSI to Other Boilers While well suited to tangentially fired boilers due to good furnac e mixing, the FSI process can be applied to a wide range of boilers. In past applications, GE has applied FSI to pulverized coal-fired boilers with tangential, wall, and cyclone fi ring configurations. The primary technology requirement is to have boiler access for inj ectors, spatial availability for equipment, and sufficient residence time for sorbent sulfation in the optimum furnace gas temperature window of approximately 2100 – 2200 o F. Parameters impacting the viability of applying FSI to a specific boiler include:

• Coal sulfur concentration: Higher sulfur coals have higher SO 2 reduction for a given Ca/S ratio, but also require a higher sorbent mass flow rate.

• Boiler design and furnace flow field characteristics: Strat ifications in furnace gas temperature and composition can impact mixing between the sorbent s tream and the furnace gas.

• Boiler access for sorbent injectors in the optimum temperature window: Optimum FSI performance is typically obtained at an injection temperature of 2100 – 2200 o F. If the boiler does not have access for injectors in the temperature range , FSI performance may be degraded. Multiple injector elevations may also be required to acc ommodate different boiler loads.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 9-6 

### GE Energy

• Availability of space at the plant to locate FSI equipment: Maj or equipment includes sorbent silos, a day hopper, feeder equipment, and blowers. Truck or rail access is also required for sorbent delivery.
Other plant factors also impact the cost effectiveness of FSI at a given plant. These factors include ESP design and specific collection area, ash handling syst em design and capacity, ash pond capacity (if wet ash management is utilized), and upper fur nace ash deposit management system design. The parameters require plant-specif ic evaluation to evaluate FSI performance and cost for a given boiler.
Regarding specific application of FSI to other Progress Energy boi lers, boilers of potential interest are Cape Fear Units 5 and 6. Before the current project settled upon Robinson Unit 1 as the FSI application site, GE performed an initial assessment of FSI application to Cape Fear Unit 5. This unit is slightly smaller than the Robinson boiler, but has many design similarities. Cape Fear Unit 5 is a 165 MWg, four-corner tangent ially fired boiler that is located in Moncure, NC. The unit was installed by Combustion Engineeri ng in 1957. It is equipped with four levels of burners. Similar to Robinson Unit 1, Cape Fe ar Unit 5 is equipped with a ROFA system, a cold-side ESP, and fires eastern bi tuminous coals from the Fola and Camp Creek mines. As summarized in Table 9-1, these coals have similar analyses to the Robinson coals. Therefore, in terms of furnace gas flow fiel d characteristics and furnace gas sulfur levels, Cape Fear 5 is similar to the Robins on boiler. While more detailed evaluation of sootblowers, the ESP, and the ash management system woul d be required to accurately estimate total FSI project costs and performan ce, in general FSI performance at Cape Fear Units 5 and 6 would be expected to be similar to that obtained at Robinson.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 9-1 

### GE Energy

TABLE 9-1. COMPARISON OF CAPE FEAR AND ROBINSON COAL PROPERTI ES

Boiler Coal ID SO 2 (lb/MMBtu) Ash (% dry)

Cape Fear Unit 5 Fola 1.5 13.50% Cape Fear Unit 5 Camp Creek 1.29 10.30% Robinson Unit 1 Minimum from trial* 1.36 9.90% Robinson Unit 1 Maximum from trial* 2.67 14.60% * Minimum and maximum values from daily coal analyses performed during FSI trial, October-December 2008Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 10-1 

### GE Energy



## 10.0 Conclusions

The FSI project was designed to provide a basis for technology ev aluation as a potential means of meeting upcoming regulations. Specific technical object ives of the project were as follows:

• To achieve 40%-50% SO 2 reduction,

• To effectively manage furnace and convective pass deposits, allowing the FSI system to be operated for an extended period of time with manageable impact u pon boiler efficiency and without causing boiler shutdown,

• To meet air permit requirements for PM emissions and opacity,

• To effectively and safely manage byproduct materials, and

• To provide process data to allow an accurate assessment of the f easibility of the FSI technology. The primary focus of the project was to reduce SO 2 emissions from the Robinson boiler. Other technical objectives were to maintain boiler operability, to comply with air permit requirements, to effectively manage byproducts, and to define impact s upon emissions of other species, notably NO X and mercury. Primary measurements and performance indicators included stack CEMS measurements for SO 2 , O 2 , CO 2 , NO X and mercury, stack opacity, unit temperatures and steam conditions, boiler load and heat rate, burner til ts, ROFA conditions, and sorbent feed rate.

The test work revealed that SO 2 reduction levels were generally consistent with projections made during the Process Design phase of the project. At the design C a/S ratio of 2.5, SO 2 reduction ranged from approximately 40% to 55%. The highest SO 2 reduction achieved during the long-term trial was 71.6%, at a Ca/S ratio of 3.8.
Regarding dependence of system performance upon operating paramet ers, SO 2 reduction increased with increasing sorbent injection air flow rate. This is attributed to improved mixing between the sorbent and furnace gas. The system was config ured such that increasing sorbent air caused overall furnace gas flow rate and oxygen concentr ation to increase, decreasing boiler efficiency and causing opacity to increase. T herefore, for the scope of the demonstration project it was not feasible to maximize sorbent air for all test runs. However,Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 10-2 

### GE Energy

system modifications could be made to allow sorbent air to be maxim ized for potential permanent application.

It was found that SO 2 reduction was higher at low load than at full load. This is attri buted to better sorbent-furnace gas mixing, as the sorbent stream can more readily penetrate the furnace flow field when overall furnace flow rates and velocities are lower. FSI system sulfur reduction was slightly better with ROFA on than with ROFA off, a lthough the effect was small. This is consistent with the system design basis, which involved optimizing performance with ROFA on.
Regarding boiler performance during FSI operation, furnace deposits were found to be manageable by the unit sootblower/sonic horn system. While upper furnac e deposits were visually observed to increase during FSI operation, the deposits could be readily removed by operating the sootblowers and sonic horns. Boiler thermal efficie ncy decreased slightly during full load FSI operation. However, most of this effect is at tributed to the increased air flow rate associated with FSI operation. For permanent applicati on, system modifications could be made to maintain constant total air flow rate during FSI.
Opacity and particulate matter emissions increased during FSI op eration. This effect was expected, since FSI increases fly ash mass loading and resistivity and decr eases mean particle size. The plant’s opacity limit is 40%, and the guideline during the project was to reduce FSI operation when opacity exceeded 35%. At certain full load conditions, opaci ty limited the amount of sorbent that could be injected into the boiler. The single most important parameter upon opacity was found to be ESP gas temperature. The extra air a ssociated with FSI operation caused ESP temperature to increase, leading to an increas e in opacity. Lower boiler loads and sorbent air flow rates led to low ESP temperatures and l ower opacity readings. Also, the test work began in summer and concluded in late fall. It was found that as ambient temperatures decreased through the fall, ESP temperatures and thus opacity dec reased.
In general, results of the test project indicated that FSI was able to achieve the target level of SO 2 reduction while allowing boiler operability to be maintained. Fouling deposits were effectively mitigated using the upgraded sootblower-sonic horn sys tem that was installed for the project. The FSI technology has the potential to be successfully applied to a range of boiler types and fuel specifications. Ultimate decision as to the best SO 2 control technology for a specific boiler is dependent upon regulatory requirements, boiler size, project duration, and plant financial considerations.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 11-1 

### GE Energy



## 11.0 References

[1] GE Energy and Environmental Research Corporation; Progress Energy Robinson Unit 1 Furnace Sorbent Injection Project: Design Basis Memorandum, Rev. 1; 1 March 2007; Santa Ana, CA.
[2] GE Energy and Environmental Research Corporation; Progress Energy Robinson Unit 1 Furnace Sorbent Injection Project: Process Design Report, Rev. 0 ; 6 April 2007; Santa Ana, CA.
[3] GE Energy and Environmental Research Corporation; Progress Energy Furnace Sorbent Injection FSI Equipment Performance Test Plan, Rev. 0 ; 7 March 2008; Santa Ana, CA.
[4] GE Energy and Environmental Research Corporation; Progress Energy Robinson Unit 1 Furnace Sorbent Injection Project: Sorbent Injection Test Plan, Rev. 5.0 ; 27 August 2008; Santa Ana, CA.
[5] GE Energy and Environmental Research Corporation; Progress Energy Furnace Sorbent Injection Splitter Test Report , Rev. 0; 06 August 2008; Santa Ana, CA.
[6] GE Energy and Environmental Research Corporation; Robinson Sorbent Injection System Equipment Performance Guarantee Results Memorandum; 26 September 2008; Santa Ana, CA.
[7] GE Energy and Environmental Research Corporation; Progress Energy Robinson Unit 1 Technical Specification, Rev E; Santa Ana, CA.
[8] GE Energy and Environmental Research Corporation; Sorbent Distribution Test Result , 10 July 2008; Santa Ana, CA.Progress Energy Robinson Unit 1 Furnace Sorbent Inj ection Demonstration Project Final Report, Rev. 02 Contract No. XM10023-WA169, GE JN 6900 25 February 2009 GE Proprietary Information Page 1 

### GE Energy



## Appendices

A. Ash Mineral Analysis B. Test Data Summary C. Project Environmental, Health, and Safety Plan