# ALDEN Solving Flow Problems Since 1894 

# The Wet vs. Dry Question for Scrubbers Alden Webinar Series 

# December 8, 2011

For audio, please dial 1 (866) 809 - 5996, participant code 6504656

We will begin shortly

# ALDEN Solving Flow Problems Since 1894 

# Housekeeping
• Questions and Audio • Availability of slide pdf file • Q&A period
For audio,

please dial 1 (866) 809- 5996, participant code 6504656

# ALDEN Solving Flow Problems Since 1894 

# • Introduction - Martin Kozlak, Alden • The Regulatory Environment and Short Overview of Scrubbing Technologies - Chris Wedig, Shaw 

# • Wet versus Dry FGD Case Study - Ned West, Southern Co. • On the Choice of a Dry Scrubber for Dominion’s 

# Brayton Point Power Plant - Thomas Penna, Dominion 

# Agenda

# ALDEN Solving Flow Problems Since 1894 

# Introduction

Martin Kozlak 

# Director, Gas Flow Systems Engineering 

# Alden

# ALDEN Solving Flow Problems Since 1894 

# • Engineering services:

– Hydraulic Modeling & Consulting



# – Fish protection consulting and laboratory work

– Field measurement services

– Flow meter calibration 

# About Alden

# ALDEN Solving Flow Problems Since 1894 

## – Dry and wet scrubbers

– Other air pollution control equipment



## – Process equipment

– Gas turbine peripherals

– Ventilation (pollutant, smoke, fire) 

# About Alden

• Physical and computational modeling to ensure the proper performance of gas flow systems:

# ALDEN Solving Flow Problems Since 1894 

# Regulatory Environment and Short Overview of Scrubbing 

# Technologies Chris Wedig Senior AQCS Technology Specialist

Shaw

# ALDEN Solving Flow Problems Since 1894 

# Regulatory Environment
• Utility MACT

- Particulate Matter

- Hydrogen Chloride



# - Mercury 

# • Cross State Air Pollution Rule (CSAPR)

- Nitrogen Oxides

- Sulfur Dioxide

# ALDEN Solving Flow Problems Since 1894 

# Regulatory Environment • Regional Haze (where applicable)

- Particulate Matter

- Sulfur Dioxide



# - Nitrogen Oxides 

# • Consent Decree (if applicable)

- Particulate Matter

- Sulfur Dioxide

- Nitrogen Oxides



# - Other

# ALDEN Solving Flow Problems Since 1894 

# Related Potential Future Regulatory Environment
• Coal Combustion Residuals (CCRs) • GHG NSPS (potential) • Thermal Power Plant Cooling Water Intake (316 b) 

# • Waste Water Discharge Issues • Permit Renewal Process

# ALDEN Solving Flow Problems Since 1894 

# Options to Consider
• Utilities may consider a range of options in addressing the regulatory environment. 

# • One of several options is to evaluate different retrofit technologies for flue gas cleaning. 

# • There are a variety of processes available for consideration, including “scrubbers”.

# ALDEN Solving Flow Problems Since 1894 

# Factors Considered in Scrubber Technology Selection
• Stack emission requirements. • Fuel type and flue gas properties. • Site - specific technical and economic (capital and annual O&M costs)

# ALDEN Solving Flow Problems Since 1894 

# Factors Considered in Scrubber Technology Selection (con’t)

- Site-specific technical and economic (capital and annual O&M costs) • Financial factors and costs (e.g. economic life, interest rate, unit costs, etc.) • Size of plant, • Capacity factor, • Reagent type and usage rate, • Byproduct type and production rate, • Electrical power usage, • Water type and usage rate, • Waste water production rate and permit issues, • Steam requirement (if required), • Cooling water usage (if required), • Impacts on the existing draft system, stack, plant electrical distribution and other systems,

# ALDEN Solving Flow Problems Since 1894 

# Factors Considered in Scrubber Technology Selection (con’t)

- Site-specific technical and economic (capital and annual O&M costs) (continue) • Impact of the retrofit scrubber on the existing air quality control (AQC) equipment at the power plant (e.g. PAC or Trona impact on flyash), • Methods to dispose or reuse scrubber waste byproducts and/or conversion of scrubber by- products to useful materials, • Real estate required for the scrubber system equipment, • O&M personnel (staffing), • Maintenance required, including parts replacement (e.g. bag/cage), • Spare part requirements, • System reliability required, • Compatibility of retrofit scrubber with any future potential systems such as cooling water systems, waste water systems, solid byproduct waste landfill projects, and carbon dioxide (CO 2 ) capture systems, • Permit issues, including issues related to retrofit scrubber and byproducts.

# ALDEN Solving Flow Problems Since 1894 

# Types of Scrubbing Technologies

• Dry Sorbent Injection (DSI with Trona, SBC, HL) 

# • Spray Dryer Absorber (SDA with lime, HL) 

# • Circulating Dry Scrubbers (CDS/NID with lime, HL) 

# • Wet Scrubbers (e.g. limestone, lime, etc.) 

# • Multi - Pollutant (e.g. ReACT, etc.) 

# • Other

# ALDEN Solving Flow Problems Since 1894 

# Summary
• In addressing the Regulatory Environment, Utilities may evaluate a range of options. 

# • One of several options is to evaluate retrofit “scrubbers”. • Selection of scrubber technology type is based on plant specific economic and technical considerations.

# ALDEN Solving Flow Problems Since 1894 

# Wet vs. Dry FGD Case Study

Ned West, P.E. Southern Company Generation

# ALDEN Solving Flow Problems Since 1894 

# Southern Company

• 43,000 MW of generation capacity • 73 fossil and hydro plants • 4.3 million retail customers

# ALDEN Solving Flow Problems Since 1894 

# Case Study - Plants A and B
• Plant A – 2 x 250MW units, no other coal -fired generation on plant site • Plant B – 375MW + 250MW units, one larger unit on the same site has a wet scrubber

# ALDEN Solving Flow Problems Since 1894 

# Traditional Factors – Wet vs. Dry
• Unit size • Fuel Sulfur • Capacity Factor • Byproduct disposal • Req’d SO 2 

# removal • Draft system loss • Power consumption 

# • Cost of lime versus limestone • Visible steam plume • New vs. retrofit • Existing stack mat’l 

# • Flyash disposal or sales

# ALDEN Solving Flow Problems Since 1894 

# New Factors – Wet vs. Dry FGD
• HAPS MACT Compliance • Mercury compliance • Particulate emission 

# • Wastewater treatment • Circulating Dry Scrubber performance 

# • Modularity of new designs • Pre -ground limestone 

# • Dry byproduct disposal under new CCR regs

# ALDEN Solving Flow Problems Since 1894 

# Reagent Cost Evaluation • Depends on fuel sulfur content and reagent stoichiometric ratio • Depends on unit capacity factor 

# • Relative cost of lime vs. limestone • Ratio of lime/ LS cost per ton has 

# changed from 6:1 to 2:1 in recent years due to our use of pre -ground limestone in some wet scrubbers

# ALDEN Solving Flow Problems Since 1894 

## Derived from proposal data

# ALDEN Solving Flow Problems Since 1894

# ALDEN Solving Flow Problems Since 1894 

# Has the Tipping Point Shifted?

• Should we now include the cost of wastewater treatment in the wet scrubber economics? 

# • How will anticipated regulations on disposal of Coal Combustion Residuals affect our plans? 

# • Must we now assume that a baghouse will be required 

# for MACT on wet FGD?

# ALDEN Solving Flow Problems Since 1894

# ALDEN Solving Flow Problems Since 1894 

# Case Study - Plants A and B
• Plant A – 2 x 250MW units, no other coal -fired generation on plant site • Plant A would get a dry FGD system • Better overall economics when a baghouse and wastewater treatment are included in the 

# analysis

# ALDEN Solving Flow Problems Since 1894 

# Case Study - Plants A and B
• Plant B – 375MW + 250MW units, one larger unit on the same site has a wet scrubber • Plant B would get a wet FGD system • Would replicate the existing wet scrubber to treat combined flue gas from both units. 

# • Shared reagent prep and gypsum disposal • Shared O&M staff, parts inventory, etc.

# ALDEN Solving Flow Problems Since 1894 

# On the Choice of a Dry Scrubber for Dominion’s

Brayton Point Power Plant

Presented by Thomas Penna, PE - Dominion Brayton Point Unit 3 Scrubber Project Manager 12/8/11

# ALDEN Solving Flow Problems Since 1894 • Brayton Point Station is located on Mount Hope Bay, near Fall River, MA. • Station comprised of three coal fired units, Units 1 and 2 – 250 MW each and Unit 3 – 630 MW, Unit 4 - 450 MW gas/oil fired unit, and five diesel generators. • Existing air quality control systems include Babcock Power Environmental (BPEI) selective catalytic reduction systems on Units 1 and 3, Chemco mercury reduction systems on Units 1, 2, and 3, and Wheelabrator/Siemens spray dryer absorber (SDA) semi -wet scrubbers on Units 1 and 2. • Unit 3 is a Babcock and Wilcox, opposed -fired, supercritical, double reheat boiler, with air heaters, two (2) sets of cold side electrostatic precipitators in series, ID fans, and a concrete stack with an acid brick liner.

# ALDEN Solving Flow Problems Since 1894 SDA vs. CDS Review • Unit 1 and 2 SDAs operational by December 2008. • Planning for Unit 3 scrubber started in early 2009 and initially considered rotary atomizer SDAs and circulating dry scrubbers (CDS). • Wet scrubber technology could achieve high SO 2 removal rates, but was not considered cost effective based on the Unit 3 fuel sulfur content (0.5 to 2.5 lb SO 2/MMBTU ) and treating purge stream. • Contracted consultant to conduct a study comparing the SDA and CDS technologies. • Dominion developed pro forma comparing CAPEX, annual variable O&M, annual fixed O&M, and fuel costs, and considered required duration for tie - in outage. • Dominion held meetings with the SDA and CDS original equipment manufacturers (OEM) and visited U.S. installations. • Dominion developed a ranking matrix based on CAPEX, O&M, constructability, performance, schedule, experience, and commercial risk.

# ALDEN Solving Flow Problems Since 1894 Technology Decision • SDA appeared to be the better technology for Unit 3 based on lower capital and annual O&M costs, performance based on fuel with a maximum of 2.5 lbs SO 2/MMBTU, domestic and international operating experience, operating facilities that are equal to or larger than required for Unit 3, contractor familiarity with SDA technology (less risk with design, construction, and contract guarantees), qualified and reputable OEMs, Station experience with operating and maintaining SDA type scrubbers. SDAs could achieve 90% SO 2 removal based on Station operating experience. • Air permit negotiations with MADEP during 3Q 2009 indicated that future SO 2 emission rate could be based on Best Available Retrofit Technology (BART) level - 0.15 lb SO 2/MMBTU at stack or 95% removal, on a 30 day rolling average. • Based on the high probability that a more stringent SO 2 emission rate would be enacted in the future, Dominion determined it would be prudent to pursue the dry scrubber technology with the highest SO 2 removal efficiency. • The SDA scrubber technology was eliminated from consideration due to the removal efficiency (approximately 94% maximum based on OEM guarantees) which would limit the fuel sulfur content to 1.5 lb SO 2/MMBTU maximum.

# ALDEN Solving Flow Problems Since 1894 CDS Performance • Pre- bid discussions with the CDS OEMS indicated the following emission guarantees could be achieved: • SO 2 Emissions : Continuously reduce SO 2 emissions to meet the least stringent of the following: maintain an emission rate of less than or equal to 0.05 lb/MMBTU SO 2 or 98% removal (rolling 30 day average) based on minimum, normal, and MCR operating conditions. • SO 3/Sulfuric Acid Removal: Continuously reduce SO 3/sulfuric acid emissions to less than or equal to 0.75 ppmdv @ 3% O 2 (0.00166 lb SO 3/MMBTU), based on minimum, normal, and MCR operating conditions. • Mercury Emissions (Unit 3 Air Permit Requirement) : Continuously reduce mercury emissions to less than or equal to 0.0025 pound/gigawatt- hour net (1 hour average basis), based on an inlet concentration less than or equal to 0.0150 lb Hg/GW- hr net and on minimum, normal, and MCR operating conditions. • Particulate Emissions (Unit 3 Air Permit Requirement) : The maximum Filterable PM/PM 10/PM 2.5 rate shall not exceed 0.010 lb/MMBTU (1 hour block average) and the maximum Total PM/PM 10/PM 2.5 rate shall not exceed 0.025 lb/MMBTU (1 hour block average), based on minimum, normal, and MCR operating conditions.

# ALDEN Solving Flow Problems Since 1894 CDS Technology OEMs as of 2009

– BPEI – Licensee for Turbosorp technology (Austrian Energy & Environment) • Four (4) operating units in US and thirty eight (38) internationally. • Largest operating installation: 570,000 ACFM (China) – single train * .

– Allied Environmental – Licensee for Lurgi Lentjes Bischoff technology • Five (5) operating units in US and forty-two (42) internationally. • Largest operating installation: 1,120,000 ACFM – single train * .

– Nooter/ Eriksen – Licensee for Graf-Wulff GmbH technology • Thirty five (35) operating units internationally – largest capacity is 2,400,000 ACFM (China) – two trains * .

– Alstom – novel integrated desulfurization (NID) technology (“J” duct design with mixer/hydrator) • Four (4) operating units in US and forty-one (41) internationally. • Largest operating installation: 840,000 ACFM – four reactors * . * BPS U3 would be the largest domestic CDS installation – 2,400,000 ACFM.

# ALDEN Solving Flow Problems Since 1894 Typical CDS Process

# ALDEN Solving Flow Problems Since 1894 Alstom NID Process

# ALDEN Solving Flow Problems Since 1894 • Considering the SDA and CDS technology project costs to be comparable, the CDS technology offered fuel flexibility, allowed recovery from upset conditions as it pertains to the 30 day SO 2 emission rolling average (could operate at a higher removal rate), and minimized maintenance issues (no “atomizer change -out” or slurry issues). • Dominion toured installations in the U.S. and Europe to verify advertised operation, identify potential maintenance or design issues, and confirm reliability. • Dominion further reviewed equipment space requirements, and lime usage and byproduct production based on operating data provided by OEMs. • Dominion determined that the four CDS OEMS would meet project specification requirements and equipment could be located within site footprint. Dominion issued the Engineering, Procurement, and Construction (EPC) RFP in September 2009. • The EPC RFP allowed bidders to receive pricing from all four technology suppliers – no exclusive teaming. The EPC bidders performed due diligence and detailed cost analysis to determine the most cost effective technology. • EPC contract was awarded in April 2010. • The successful EPC Contractor selected the Alstom NID technology for the Unit 3 scrubber project.

# ALDEN Solving Flow Problems Since 1894 

# Questions

Please use the Q&A tab in LiveMeeting Martin Kozlak: mkozlak@aldenlab.com Chris Wedig: christopher.wedig@shawgrp.com Ned West: NWest@southernco.com Thomas Penna: thomas.g.penna@dom.com