Document ID: EPA-R08-OAR-2012-0026-0084
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2013-02-11T05:00Z

February 7, 2013
To:  Doug Grano
Fm:  Jim Staudt
Re:  Review of estimated BART compliance Costs for Wyoming Electricity Generating Units (EGUs)
Attachment: Microsoft Excel Workbook WY EGU BART_RP Costs_20130201.xlsx
On June 4, 2012 (77 FR 33022), EPA proposed the Wyoming Regional Haze Federal implementation plan. Andover Technology Partners (ATP) has evaluated the cost of NOx controls for a number of power plants in Wyoming that are subject to EPA's proposed rulemaking.  This memo documents a similar analysis for Jim Bridger Units 1-4.

For each unit, estimates were made for the following technologies, where applicable:
   * Combustion Controls, including Low NOx Burners (LNBs) with Separated Overfire Air (SOFA)
   * Selective Non-Catalytic Reduction (SNCR)
   * Selective Catalytic Reduction (SCR)

Estimates were based upon an initial average annual NOx level equal to 2001-2003 historical rates (average of annual average for each of the three years) when advanced combustion controls were not in use at these units.  Emission rates with combustion controls were estimated from more recent data: the lower of 2011 or 2012 annual emission rates.   2001-2003 historical data were also used to estimate annual heat input and the associated capacity factor for each unit; these estimates are used in all calculations.

In estimating the cost of controls, the following were considered:
   * IPM Cost models
   * US EPA Air Pollution Control Cost Manual
   * Data provided by the facilities
   * Other data that have been published and are described in more detail
      
The BART guidelines recommend use of the EPA Air Pollution Control Cost Manual, and the methodology used for estimating cost is consistent with the recommendations in the manual, such as inclusion of taxes, insurance and administrative costs, and the use of overnight cost for capital cost.

Combustion Controls
For combustion controls, the capital and operating cost estimates by the owners were used.  These are in the Wyoming Department of Environmental Quality May 28, 2009 BART Analysis.  These were adjusted to "overnight" costs by removal of AFUDC and owner's costs using factors developed from the December 2007 BART Analysis by CH2MHill which included details of the capital cost components in its appendices.  Note that the combustion controls have already been installed on the Jim Bridger units, with installation dates between 2005 and 2010.

SNCR
Consistent with previous work,1 for SNCR, capital cost is assumed to be $20/kW.  According to the 2008 Institute of Clean Air Companies' SNCR White Paper, "Typical SNCR capital costs for utility applications are $5-$15/kW, vendor scope, which corresponds to a maximum of $20/kW if balance-of-plant capital requirements are included."    This is also consistent with my personal experience, having worked with the following electric utilities and power plants on their SNCR installations as a consultant or as a past employee of Research-Cottrell and Fuel Tech  -  suppliers of SNCR systems.
   * Constellation Energy  -  C P Crane units 1&2 and Wagner Unit 2 
   * Conectiv  -  Edge Moor unit 3 and Indian River 
   * New England Power  -  Salem Harbor Station 
   * Montaup Electric  -  Somerset Unit 8 

And, I have also published reports that describe the cost and application of technologies used for control of NOx, including SNCR.,  
Therefore, $20/kW provides a reasonable estimate for the capital cost of SNCR.  Furthermore, due to the low capital cost of SNCR, the operating cost  -  especially reagent cost  -  is the much more important component of cost.
SNCR reagent consumption and the level of NOx reduction vary based upon a number of factors  -  such as initial NOx level and furnace temperatures.  It was not possible to evaluate all of the relevant factors because detailed furnace characteristics were not available.  Figure 1 is an example of test data from an SNCR optimization program on a pulverized coal fired boiler that shows NOx reduction and chemical utilization versus Normalized Stoichiometric Ratio (NSR  -  a measure of chemical treatment rate).  Chemical utilization equals per cent reduction divided by NSR and is a measure of the efficiency of reagent use.  The data include data from optimized as well as unoptimized configurations, which is why some of the data points fall below the curves.  The curves that would be developed for any given unit will vary from one unit to another and, while having similar shapes as those in Figure 1, may have somewhat different values.  For the purpose of making an estimate of reagent consumption for the Wyoming pulverized coal  units it was assumed that the chemical utilization was 25% and that NOx reduction diminished with lower NOx concentrations  -  30% for NOx greater than 0.25 lb/MMBtu, 25% for NOx between 0.20 and 0.25 lb/MMBtu, and 20% for NOx under 0.20 lb/MMBtu.  This is expected to provide a reasonable estimate of NOx reduction and reagent consumption.
Other elements of SNCR variable operating cost and fixed operating cost are estimated using IPM algorithms.

Figure 1.  NOx Reduction and Reagent Utilization versus reagent treatment rate in NSR for a Pulverized Coal Fired Boiler during an SNCR optimization program 
      (Data points plotted below the curves are at unoptimized conditions)  
                                       

SCR
Selective Catalytic NOx Reduction (SCR) capital cost is estimated using the IPM algorithms with retrofit factors adjusted on a unit by unit basis.  The retrofit factor is a subjective factor used to account for the estimated difficulty of the retrofit that is unique to the facility.  Because site visits were not possible, the retrofit factor was estimated from satellite images that provide some insight to the configuration of the units and degree of congestion around the site and in the vicinity of where the SCR would be installed.  These factors impact the ability to locate large cranes on the site  -  that impact how the SCR is assembled (are large sections lifted into place or is the SCR "stick built"), how much ductwork is needed, if the SCR must be built onto a large, elevated steel structure or can be built near the ground, and if other equipment must be relocated to accommodate the space of the SCR.    When using the IPM capital cost model, retrofit difficulties associated with an SCR may result in capital cost increases of 30 to 50% over the base model. 

In addition, historical industry cost data were considered to determine if the costs were reasonable in the context of what has been reported at other facilities.7, ,   The owners estimated capital cost of SCR to be $166,500,000 per unit, including AFUDC.  On an overnight basis, that is $154,760,000 ($292/kW), or about 15% greater than estimated by the IPM algorithm using a retrofit factor of 1.5 (roughly $134 million, or $253/kW).  These are both in the same range and within the range of costs found in industry.

Assumptions

In estimating cost of control, it is assumed that a full complement of combustion controls are implemented prior to installation of post-combustion controls (SNCR and SCR).  Emissions rates for the 2001-2003 period were used to estimate the emission rate prior to installation of combustion controls.
The average reported emission rates for 2001-2003, 2011, and 2012 as well as the Wyoming recommended BART limit are shown in Table 2.   For all Jim Bridger units there has been some significant NOx reduction since 2003 at these facilities through implementation of additional combustion controls.
Table 2.  Reported emission rates and Wyoming proposed BART limits for affected EGUs
                                 Facility Name
                             Facility ID (ORISPL)
                                    Unit ID
                           Annual Heat Input, MMBtu
                                 2001-03 avg.
                           Avg. NOx Rate (lb/MMBtu)
                                       
                                       
                                       
                                       
                                   2001-2003
                                     2011
                                   2012 YTD
                         Wyoming BART recommendation*
Jim Bridger
                                                                           8066
BW71
                                                                      4.298E+07
                                                                         0.3921
                                                                         0.1929
                                                                         0.1800
                                     0.26
Jim Bridger
                                                                           8066
BW72
                                                                      4.090E+07
                                                                         0.3705
                                                                         0.1853
                                                                         0.1868
                                     0.26
Jim Bridger
                                                                           8066
BW73
                                                                      4.217E+07
                                                                         0.3725
                                                                         0.1977
                                                                         0.1965
                                     0.26
Jim Bridger
                                                                           8066
BW74
                                                                      4.103E+07
                                                                         0.3964
                                                                         0.1981
                                                                         0.1936
                                     0.26
All historical emissions and heat input data developed from Air Markets Program Data
* 30 day rolling average

Cost Estimating
The cost estimates summarized in the following sections of this memo are detailed in a Microsoft Excel workbook WY_EGU_BART_RP_Costs_20130201.xlsx that is an attachment to this memo.  The details of the estimating methods are described in the workbook.  Consistent with the EPA Control Cost Manual, capital cost estimates do not include AFUDC or Owner's Costs.  For combustion controls, capital and operating costs were based upon what was in the Wyoming proposed SIP supporting attachments, when available. 
For SNCR, the capital cost was assumed to be $20/kW.  Reagent consumption was determined using a chemical utilization factor of 0.25.  After combustion controls, SNCR can typically achieve NOx reductions of 20% to 30%.   NOx reduction with SNCR is known to be greater at higher NOx emission rates than lower rates. NOx reduction was estimated as 30% for initial NOx greater than 0.25 lb/MMBtu, 25% for NOx from 0.20 to 0.25 lb/MMBtu and 20% for NOx less than 0.20 lb/MMBtu. 
For consumables, notably urea, there has been significant variability in cost, and current cost estimates were used (delivered price of about $450/ton of 50% by weight urea solution).  

Jim Bridger, Units 1-4

An overhead view of Jim Bridger plant is shown in Figure 2. All four units are tangentially fired and are currently equipped with combustion controls to reduce NOx emissions.  Annual emission rates with combustion controls are assumed to be the lesser of the 2011 or 2012 annual average emission rate.
Retrofit costs
Retrofit costs for combustion controls are based upon company estimates.  Retrofit costs for SNCR are expected to be consistent with other similar units and a presumed capital cost of $20/kW is assumed.
It was previously determined that post-combustion NOx controls, including SCR, are feasible, but they were not selected in Wyoming's proposal as BART due to cost.  The estimates of SCR capital cost made here are adjusted for retrofit difficulty using subjective factors that are integrated into the IPM cost estimating algorithms.  Based upon the satellite photo, the SCR reactors would likely be installed above the ESPs and ductwork routed to the boiler.  The boilers do not appear to be unusually constrained, except possibly the middle two which will be somewhat more difficult to achieve access for equipment.  For this reason a retrofit difficulty factor of 1.5 is assumed for the middle units and 1.25 for the units on either end.
Table 3 shows the estimated costs of control for each of the Jim Bridger units.  Costs are shown for:
   * Combustion Controls alone
   * SNCR alone but after installation of combustion controls
   * SCR alone but after installation of combustion controls
   * Combustion controls in combination with SNCR
   * Combustion controls in combination with SCR

                       Figure 2. Jim Bridger Power Plant

                 Table 3. Jim Bridger Estimated Control Costs
JB 1
                        Cost from 2003 emission levels
 
                              Combustion Control
                                     (CC)
                                     SNCR
                                      SCR
                                  CC and SNCR
                                  CC and SCR
Capital Cost, $/kW
                                                                            $19
                                                                            $20
                                                                           $211
                                                                            $39
                                                                           $231
Control Efficiency
                                                                            54%
                                                                            20%
                                                                            72%
                                                                            63%
                                                                            87%
Uncontrolled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                           2175
                                                                            998
                                                                            998
                                                                           2175
                                                                           2175
NOx Rate (lb/MMBtu) 
                                                                           0.39
                                                                           0.18
                                                                           0.18
                                                                           0.39
                                                                           0.39
NOx (TPY)  
                                                                           8426
                                                                           3868
                                                                           3868
                                                                           8426
                                                                           8426
Controlled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                            998
                                                                            799
                                                                            277
                                                                         798.61
                                                                         277.29
NOx Rate (lb/MMBtu) 
                                                                           0.18
                                                                           0.14
                                                                           0.05
                                                                           0.14
                                                                           0.05
NOx (TPY)  
                                                                           3868
                                                                           3094
                                                                           1074
                                                                        3094.39
                                                                        1074.44
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Tons/Year Removed  
                                                                           4558
                                                                            774
                                                                           2794
                                                                        5332.02
                                                                        7351.97
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Total Cost/year
                                                                     $1,167,297
                                                                     $3,235,461
                                                                    $16,425,339
                                                                     $4,402,757
                                                                    $17,592,636
$/Ton  
                                                                           $256
                                                                         $4,182
                                                                         $5,880
                                                                           $826
                                                                         $2,393
$/ton Incremental
                                                                              
                                                                              
                                                                         $6,530
                                                                         $4,182
                                                                         $6,530
 JB 2
                        Cost from 2003 emission levels
 
                              Combustion Control
                                     (CC)
                                     SNCR
                                      SCR
                                  CC and SNCR
                                  CC and SCR
Capital Cost, $/kW  
                                                                            $19
                                                                            $20
                                                                           $251
                                                                            $39
                                                                           $270
Control Efficiency
                                                                            50%
                                                                            20%
                                                                            73%
                                                                            60%
                                                                            87%
Uncontrolled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                           2035
                                                                           1018
                                                                           1018
                                                                           2035
                                                                           2035
NOx Rate (lb/MMBtu) 
                                                                           0.37
                                                                           0.19
                                                                           0.19
                                                                           0.37
                                                                           0.37
NOx (TPY)  
                                                                           7577
                                                                           3789
                                                                           3789
                                                                          7,577
                                                                          7,577
Controlled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                           1018
                                                                            814
                                                                            275
                                                                            814
                                                                            275
NOx Rate (lb/MMBtu) 
                                                                           0.19
                                                                           0.15
                                                                           0.05
                                                                           0.15
                                                                           0.05
NOx (TPY)  
                                                                           3789
                                                                           3031
                                                                           1022
                                                                          3,031
                                                                          1,022
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Tons/Year Removed  
                                                                           3787
                                                                            758
                                                                           2767
                                                                          4,545
                                                                          6,554
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Total Cost/year
                                                                     $1,167,297
                                                                     $3,193,662
                                                                    $18,590,683
                                                                     $4,360,958
                                                                    $19,757,979
$/Ton  
                                                                           $308
                                                                         $4,214
                                                                         $6,719
                                                                           $959
                                                                         $3,015
$/ton Incremental
                                                                              
                                                                              
                                                                         $7,664
                                                                         $4,214
                                                                         $7,664
                 Table 3. Jim Bridger Estimated Control Costs
JB 3
                        Cost from 2003 emission levels
 
                              Combustion Control
                                     (CC)
                                     SNCR
                                      SCR
                                  CC and SNCR
                                  CC and SCR
Capital Cost, $/kW  
                                                                            $19
                                                                            $20
                                                                           $253
                                                                            $39
                                                                           $273
Control Efficiency
                                                                            47%
                                                                            20%
                                                                            75%
                                                                            58%
                                                                            87%
Uncontrolled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                           2056
                                                                           1085
                                                                           1085
                                                                           2056
                                                                           2056
NOx Rate (lb/MMBtu) 
                                                                           0.37
                                                                           0.20
                                                                           0.20
                                                                           0.37
                                                                           0.37
NOx (TPY)  
                                                                           7853
                                                                           4143
                                                                           4143
                                                                          7,853
                                                                          7,853
Controlled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                           1085
                                                                            868
                                                                            276
                                                                            868
                                                                            276
NOx Rate (lb/MMBtu) 
                                                                           0.20
                                                                           0.16
                                                                           0.05
                                                                           0.16
                                                                           0.05
NOx (TPY)  
                                                                           4143
                                                                           3314
                                                                           1054
                                                                          3,314
                                                                          1,054
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Tons/Year Removed  
                                                                           3710
                                                                            829
                                                                           3089
                                                                          4,539
                                                                          6,799
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Total Cost/year
                                                                     $1,167,297
                                                                     $3,362,773
                                                                    $18,968,124
                                                                     $4,530,069
                                                                    $20,135,420
$/Ton  
                                                                           $315
                                                                         $4,058
                                                                         $6,141
                                                                           $998
                                                                         $2,961
$/ton Incremental
                                                                              
                                                                              
                                                                         $6,905
                                                                         $4,058
                                                                         $6,905
JB 4
                        Cost from 2003 emission levels
 
                              Combustion Control
                                     (CC)
                                     SNCR
                                      SCR
                                  CC and SNCR
                                  CC and SCR
Capital Cost, $/kW  
                                                                            $19
                                                                            $20
                                                                          $213 
                                                                            $39
                                                                           $232
Control Efficiency
                                                                            51%
                                                                            20%
                                                                            74%
                                                                            61%
                                                                            87%
Uncontrolled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                           2200
                                                                           1074
                                                                           1074
                                                                           2200
                                                                           2200
NOx Rate (lb/MMBtu) 
                                                                           0.40
                                                                           0.19
                                                                           0.19
                                                                           0.40
                                                                           0.40
NOx (TPY)  
                                                                           8133
                                                                           3972
                                                                           3972
                                                                          8,133
                                                                          8,133
Controlled Rate
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
NOx Rate (lb/hr)  
                                                                           1074
                                                                            859
                                                                            277
                                                                            859
                                                                            277
NOx Rate (lb/MMBtu) 
                                                                           0.19
                                                                           0.15
                                                                           0.05
                                                                           0.15
                                                                           0.05
NOx (TPY)  
                                                                           3972
                                                                           3178
                                                                           1026
                                                                          3,178
                                                                          1,026
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Tons/Year Removed  
                                                                           4161
                                                                            794
                                                                           2946
                                                                          4,956
                                                                          7,108
 
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
Total Cost/year
                                                                     $1,167,297
                                                                     $3,278,694
                                                                    $16,545,040
                                                                     $4,445,990
                                                                    $17,712,336
$/Ton  
                                                                           $281
                                                                         $4,127
                                                                         $5,616
                                                                           $897
                                                                         $2,492
$/ton Incremental
                                                                              
                                                                              
                                                                         $6,165
                                                                         $4,127
                                                                         $6,165