# ALCOA, Inc.
Best Available Retrofit Technology (BART) Assessment Massena West Plant Massena, New York

September 2010

Environmental Resources Management 1159 Pittsford-Victor Road Suite 200 Pittsford, New York 14534

### i TABLE OF CONTENTS

EXECUTIVE SUMMARY ES-1

1.0 INTRODUCTION 1-1

1.1 PROJECTED ANNUAL ACTUAL EMISSIONS 1-2

2.0 BART-ELIGIBLE SOURCE EVALUATIONS 2-1

2.1 POTLINES 2-1

2.1.1 Sulfur Dioxide 2-2

2.1.2 Nitrogen Dioxide 2-3

2.1.3 Particulate Matter 2-3

2.2 BAKE FURNACE 2-6

2.2.1 Sulfur Dioxide 2-6

2.2.2 Nitrogen Dioxide 2-7

2.2.3 Particulate Matter 2-7

2.3 BOILERS 2-7

2.3.1 Sulfur Dioxide 2-8

2.3.2 Nitrogen Dioxide 2-8

2.3.3 Particulate Matter 2-9

3.0 CONCLUSION 3-1

TABLES

TABLE ES-1 BART SUMMARY TABLE 1-1 PROJECTED ANNUAL ACTUAL EMISSIONS

TABLE 2-7 SCALED NESCAUM MODEL RESULTS

### ii LIST OF APPENDICES

APPENDIX A: Hatch Alcoa Primary Metals – SO 2 

### Scrubber for Alcoa Massena West Prefeasibility Study, 18 February 2009 APPENDIX B: Potline and Bake Furnace Limestone Slurry Forced Oxidation (LSFO) Scrubber Cost Calculations APPENDIX C: Bake Furnace NOx RACT, December 1994, ENSR APPENDIX D: West Plant Boilers NOx RACT, September 2010, ERMERM 

### ES-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### EXECUTIVE SUMMARY

The Clean Air Act (CAA) requires the pr otection of visibility in 156 scenic areas across the United States. Unde r CAA Section 169 (b)(2)(A), States must require certain existing station ary sources to install Best Available Retrofit Technology (BART). New York has implemented BART requirements under Title 6 of th e New York Code of Rules and Regulations (NYCRR) Part 249. A stationa ry source (facility) is subject to BART if it: 1. is in one of 26 specific source ca tegories identified in 6 NYCRR 231- 2.2(c) (1) through (26); 2. was not in operation prior to Augu st 7, 1962 and was in existence on August 7, 1977, or underwent reconstruction between these dates; and 3. has a potential to emit (PTE) 250 tons per year (tpy) or more of any visibility-impairing pollutant.

Visability impairing pollutants include sulfur dioxide (SO 2 

### ), nitrogen oxides (NOx), and particulate matter less than or equal to 10 microns in diameter (PM 10 

### ). Only the Alcoa West Plant (Massena West) is considered a BART eligible source (the East Plant was constructed outside of the BART applicability timeframe in 1959). Massena West has been working with the New York State Department of Environmental Conservation (NYSDEC) to define the scope of BA RT applicability and has obtained the Department’s concurrence that the We st Plant emission sources to be included in this BART analysis are lim ited to the potlines, bake furnaces, and boilers (reference the e-mail from NYSDEC’s Scott Griffin to Alcoa’s Jordan Parent dated 10 May 2010).

The owner or operator of a source that is determined to be BART-eligible must conduct an analysis to determin e the appropriate emission limitation necessary to meet BART requirements . The analysis must consider the following five factors: 1. the costs of compliance; 2. the energy and non-air quality envi ronmental impacts of compliance; 3. any existing pollution control technology in use at the source; 4. the remaining useful life of the source; and, 5. the degree of improvement in visibility which may reasonably be anticipated to result from the use of such technology.

Units may forego the visibility analysis referenced in item No. 5 above if they can demonstrate that they ei ther meet presumptive BART; or demonstrate that no additional control is technically and economically feasible (economic infeasibility is based on a control cost of less thanERM 

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### $5,500 per ton of pollutant reduced). The Massena West Plant’s BART conclusions are summarized in the following table:

Table ES-1 BART Summary

Source/ Pollutant SO 2 NO x PM 10

Potlines Add-on SO 2 control on the potlines was determined to be economically infeasible Add-on NOx control is not technically feasible for the potlines due to the low exhaust temperature in comparison to the required exhaust temperature for effective use of the candidate add-on controls – selective catalytic and non-catalytic reduction (SCR and SNCR) Existing potline PM emission control has an estimated capture efficiency of 98% and a removal efficiency of greater than 95%. Given the high degree of PM emission reduction, and the insignificant affect of PM on the total visibility impact, Alcoa proposes that existing PM emission control satisfies BART

Bake Furnace Cost effectiveness of SO 2 control on the bake furnaces was determined to be economically infeasible Similar to the potlines, the exhaust temperature of the bake furnace is not high enough for SNCR or SCR to be effective for NOx control. Therefore additional control was determined to technically infeasible PM from the bake furnaces are controlled by a pulse jet baghouse and Alcoa proposes that existing control satisfies BART

Boilers Alcoa proposes to comply with a 1% fuel oil sulfur content limit to satisfy presumptive BART Add-on control in the form of SNCR or SCR in addition to the existing controls of low NOx burners and flue gas recirculation was determined to be economically infeasible The current boiler PM emission rate of 0.045 lbs/MMBtu meets the presumptive BART range of 0.02 - 0.07 lb/MMBtu. Given the low PM emission rate, and the insignificant affect on PM on total visibility impairment, Alcoa proposes that existing PM emissions satisfy BARTERM 

### 1-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### 1.0 INTRODUCTION

The Clean Air Act (CAA) requires the pr otection of visibility in 156 scenic areas across the United States. Unde r CAA Section 169 (b)(2)(A), States must require certain existing station ary sources to install Best Available Retrofit Technology (BART). New York has implemented BART requirements under Title 6 of th e New York Code of Rules and Regulations (NYCRR) Part 249. A stationa ry source (facility) is subject to BART if it: 1. is in one of 26 specific source ca tegories identified in 6 NYCRR 231- 2.2(c) (1) through (26); 2. was not in operation prior to Augu st 7, 1962 and was in existence on August 7, 1977, or underwent reconstruction between these dates; and 3. has a potential to emit (PTE) 250 tons per year (tpy) or more of any visibility-impairing pollutant.

Visibility impairing pollutants include sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter less than or equal to 10 microns in diameter (PM 10 

### ). Alcoa operates two primary and secondary aluminum smelting facilities in Massena New Yo rk – the East Pl ant and the West Plant. Only the Alcoa West Plant (M assena West) is considered a BART eligible source (the East Plant was constructed outside of the BART applicability timeframe in 1959). Massena West operates emission units that fall within the categories of primary aluminum ore reduction plants and secondary metal production facilities - two of the 26 identified source categories to which BART is applicab le. The West Plant has the potential to emit greater than or equal to 250 tons/year of SO2, NOx, and PM 10 

### . As a result, the Massena West Plant is defined as a BART-eligible source.

Massena West has been working with the NYSDEC to define the scope of BART applicability and has obtained the Department’s concurrence that the emission sources to be included in this BART analysis are limited to the potlines, bake furnaces, and boilers (reference the e-mail from NYSDEC’s Scott Griffin to Alcoa’s Jordan Parent dated 10 May 2010). All other BART-eligible emission sources at Massena West were insignificant (impact that was less than 0.1 deciviews of visibility impairment). This insignificance determination is base d on the modeling conducted for the report entitled, “Contributions to Regional Haze in the Northeast and Mid-Atlantic United States” prepared by Northeast States for Coordinated Air Use Management (NESCAUM) for the Mid Atlantic/Northeast Visibility Union (MANE-VU).ERM 

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### According to 6 NYCRR Subpart 249.3, th e BART analysis must consider the following five factors: 1. the costs of compliance; 2. the energy and non-air quality envi ronmental impacts of compliance; 3. any existing pollution control technology in use at the source; 4. the remaining useful life of the source; and 5. the degree of improvement in visibility which may reasonably be anticipated to result from the use of such technology.

Alcoa’s approach to this BART analysis involves assessing each BARTeligible source type and their subject pollutants (SO 2 

### , NO x 

### , and PM 10 

### ). Consistent with NYSDEC guidance and correspondence ( reference the Memorandum from NYSDEC’s Leon Sedefian to NYSDEC’s Scott Griffin dated 10 May 2010 regarding Alcoa’s 20 April 2010 BART proposal ), units may forego the visibility analysis referenced in item No. 5 above if they can demonstrate that they either:

1. Meet presumptive BART; or

2. Demonstrate that no additional control is technically and economically feasible. Please note that a determ ination of economic infeasibility is based on a control cost of less than $5,500 per ton of pollutant reduced. This is consistent with the respon se to comments associated with 6 NYCRR Part 249, and is based on the current threshold used for Reasonably Available Control Technology economic feasibility.

1.1 PROJECTED ANNUAL ACTUAL EMISSIONS

Alcoa has submitted a Title V modifica tion application to the NYSDEC in support of modernization activities in Massena. For the purpose of estimating cost effectiveness of vari ous emission control options, Alcoa has conservatively used the projected actual emissions from the Title V modification application. These po st modernization projected emissions are greater than current actual emissions and are conservative since higher emissions will improve cost effectiveness. Specific projected annual emissions used in this BART analysis are presented as follows: Table 1-1 – Projected Annual Actual Emissions

Source/Pollutant Emissions (tons/yr) SO 2 

### NO x 

### PM 10 

### Potlines* 2,568 44 143
Bake Furnaces 455 203 24
Boilers** 248 164 13 *emissions reflect 98% through the control devices **Assuming PM 10 

### emissions equal total PM emissionsERM 

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### 2.0 BART-ELIGIBLE SOURCE EVALUATIONS

2.1 POTLINES

The Hall-Heroult process 1 

### is used to produce aluminum metal by electrolytic reduction of alumina that takes place in shallow rectangular cells, or "pots," which are steel shells lined with carbon. Carbon electrodes extending into the pot serve as the anodes and the carbon lining as the cathode. Electrical resistance to the current passing between the electrodes generates heat that mainta ins the cell operating temperature. Molten cryolite (Na 3 

### AlF 6 

### ) functions as both the el ectrolyte and the solvent for the alumina. The electrolytic reduction of Al 2 

### O 3 

### by the carbon from the electrode occurs as follows:

2AL 2 

### O 3 

### + 3C → 4Al + 3CO 2


### Carbon anodes are continuously de pleted by the reaction. In the electrolytic reduction of alumina, the carbon anodes are lowered into the cell and are consumed at a rate of ab out 2.57 cm (1 in) per day. Molten cryolite functions as both the electrol yte and the solvent for the alumina. Pure cryolite has a melting temperature of 1010 O 

### C (1850 O 

### F). The electrolyte contains fluorospar (CaF 2 

### ), some AlF 3 

### , and lithium in some instances, which along with the di ssolved alumina, reduces the melt temperature sufficiently to permit the cells to operate between 940 and 980

O 

### C (1725 and 1795 O 

### F). Aluminum is deposited at the cathode, where it remains as molten metal below the su rface of the cryolite bath. Aluminum metal is tapped every 24 to 48 hours beneath the cryolite cover using a vacuum siphon. The aluminum is th en transferred to a reverberatory holding furnace where it is alloyed, fluxed and degassed to remove trace impurities. From the holding furnace, the aluminum is cast or can be transported in molten state to fabricating plants up to 300 miles away.

Emissions from the Massena West potlines are controlled by a dry alumina injection system followed by a fabric filter. The facility uses a prebaked (PB) anode cell for the electrolytic reduction process which is

1 Much of the following technical description is an excerpt from the Background Report, AP-42 Section 12.1, Primary Aluminum dated November 12, 1998 prepar ed for the USEPA by Pacific Environmental Services, Inc.ERM 

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### consistent with the method used for most of the aluminum produced in the U.S.

2.1.1 SO 2



### A detailed SO 2 

### control analysis was completed for Alcoa’s Massena West Plant potlines on 18 February 2009 by Hatch (included as Appendix A). Hatch developed a design basis and specification for a flue gas desulfurization (FGD) system (limestone slurry forced oxidation (LSFO) scrubber) and sent a request for budget proposal to nine vendors. Hatch then developed its SO 2 

### control analysis report based largely on the cost proposal provided by Babcock (the only proposal that fully met specifications). The results of this anal ysis estimate that the installation of a LSFO scrubber to control SO 2 

### from the West Plant potlines would cost approximately 208.7 million dollars in capital and 7.9 million dollars in annual operating costs. Assuming that the life of the scrubber system is 15 years and the interest rate is 7%, the total annualized cost of the scrubber system would be 30.8 million dollars. Based on current estimates of the future SO 2 

### emissions from the West Plant potlines of 2,568 TPY (derived from a 2.5% sulfur in coke cont ent) and an assumed 95% control efficiency, the cost to control SO 2 

### emissions would be $12,623 per ton of SO 2 

### controlled. Cost effectiveness ca lculations are provided as follows:

2568.28 Tons 95% Control Efficienc y = 2439.87 Tons Controlled Year

$30,798,608 = $12,623

Year 2439.87 Tons Controlle d Ton Controlled



### This cost effectiveness value is well above the $5,500 per ton of SO 2 

### controlled economic feasibility threshol d used for case-by-case RACT and BART. The full cost effect iveness calculations are in cluded in Appendix B. Please note that the above referenced Hatch control cost calculation is premised on ensuring 100% control equipment availability consistent BART control objectives.

According to the Hatch report, two other possible scrubber options are limestone slurry scrubbing with natural oxidation (LSNO) and conventional lime wet scrubbing. Mo st of the equipment required for LSFO is required for LSNO with the exception of the oxidation air blowers. Therefore, the use of LSNO only produces a minor cost savings. For conventional lime wet scrubbing, the raw material (pebble or quick lime) is more expensive at $125/ton compared to $25/ton for limestone used for LSFO. The quantity of lime required for conventional scrubbing is less that that required for LSFO, which reduces but does not eliminate the cost advantage of LSFO. Additi onally, Alcoa considered the use ofERM 

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### sodium based scrubbing technology and found that limestone had some significant advantages including: a solid waste stream that is more environmentally friendly; a bleed stream that is 5 to 10 times smaller; a wastewater treatment advantage with asso ciated cost savings; a more cost effective reagent; and a reduced need for fresh water rinsing. Therefore the economic infeasibility determination for LSFO is representative of all scrubbing options.

A BART analysis dated March 2007 conducted for the Alcoa Tennessee Plant determined that a pollution preven tion limit of 3% sulfur in the coke used to manufacture anodes sati sfies BART. A November 2007 BART analysis for the Alcoa Washington Plant also determined that a pollution prevention limit of 3% sulfur in th e coke used to manufacture anodes satisfies BART. Control cost analys is completed for these Plants was comparable to the Massena assessment and likewise concluded – in both cases - that add-on control was econom ically infeasible. BART submittals for both Plants have been accepted by their respective agencies. The Massena West Plant is already committed to using coke with a sulfur content of less than 3%.

2.1.2 NO x



### Available NO x 

### emission control has been foun d to be technically infeasible through a prior RACT analysis. Based on the NYSDEC approved Massena East NO x 

### RACT Plan dated 24 March 2009, there are no NO x 

### control technologies deemed to be tec hnically feasible for potline emission control. This same conclusion is applicable to the Massena West Plant. All combustion modification techni ques were eliminated because there are no conventional burners or combustion points to affect in an aluminum reduction cell. The plan went on to evaluate add-on NO x 

### control technologies of Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR). Both technologies were deemed technically infeasible because exhaust gas temperature is well below the range required for each technology (SCR requires 650-750°F; and SNCR requires 1600 – 2200°F). The exhaust gas temperature from West Plant potlines is approximately 170°F.

This conclusion is consistent with the approved BART determinations for the Alcoa Tennessee and Washington Plan ts which determined that BART for potline NOx emissions is no controls.

2.1.3 PM 10


### Alcoa is proposing existing PM control as BART.ERM 

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### According to the modeling conducted for the report entitled, “Contributions to Regional Haze in the Northeast and Mid-Atlantic United States” prepared by Northeast States for Coordinated Air Use Management (NESCAUM) for the Mid Atlantic/Northeast Visibility Union (MANE-VU); modeling specific to the Alcoa Massena West Plant shows that of the total visibility impact s from the Plant, PM contribution is insignificant (accounting for about 0.8% of the total deciviews).

Alcoa reported higher PM emission levels than those used in the NESCAUM model in a 20 April 2010 correspondence to NYSDEC. The PM emission contribution remains in significant even with the increased rate reported in the correspondence. The below Table 2-1 scales the NESCAUM modeled impacts to assess the impact of the higher emission rates reported in the correspondence. The scaled-up PM emission impacts are estimated to account for less than 1.55% of the total deciviews.

The current potline control device is a shaker baghouse. The system has a capture efficiency of 98% and a PM removal efficiency of greater than 95%. Given the high degree of PM redu ction, and the insignificant affect on PM on the total visibility impact, Alcoa proposes that existing PM emission control satisfies BART.ERM 

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### Table 2-1 Scaled NESCAUM Model Results

Alcoa West NESCAUM Modeled Impacts (ddv)
Source Total SO4 NO3 PM10
Potlines 0.3788 0.3756 0.0016 0.0017 Bake Furnaces 0.0464 0.0424 0.0034 0.0005 Other 0.0094 0.0001 0.0091 0.0003 Boilers 0.0046 0.0000 0.0043 0.0002

Other 0.0042 0.0024 0.0018 0.0000 Other 0.0039 0.0005 0.0023 0.0011
Total 0.4473 0.0037 PM10 percent of Total Impact: 0.83%

NESCAUM Model Input (g/s)
Source SO2_ g ps NOx_ g ps PM10_ g ps Potlines 58.0 0.3 0.8 Bake Furnaces 5.9 0.6 0.2 Other 0.0 1.5 0.1 Boilers 0.01 0.6 0.1

Other 0.4 0.3 0.0 Other 0.1 0.4 0.5

Alcoa Emissions (g/s) from Table 1-1, 4/20/2010 Correspondence
Source SO2_ g ps NOx_ g ps PM10_ g ps Potlines 72.909 0.282 1.935 Bake Furnaces 13.661 2.568 1.617 Boilers 28.99 4.924 1.517

Ratio Increase Above NESCAUM inputs
Source SO2_ g ps NOx_ g ps PM10_ g ps Potlines 1.26 1.05 2.53 Bake Furnaces 2.31 4.66 7.25 Boilers 4195.25 7.65 18.75

Alcoa Reported Emissions from 4/20/2010 Relative Affect on Impact (ddv)
Source Total SO4 NO3 PM10
Potlines 0.4780 0.4720 0.0016 0.0043 Bake Furnaces 0.1179 0.0981 0.0161 0.0037 Other 0.0094 0.0001 0.0091 0.0003 Boilers 0.2205 0.1838 0.0331 0.0036

Other 0.0042 0.0024 0.0018 0.0000 Other 0.0039 0.0005 0.0023 0.0011 Total 0.8339 0.0129 PM10 percent of Total Impact: 1.55%ERM 

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### 2.2 BAKE FURNACE

Anodes are manufactured in an on-sit e paste production plant. Anodes are made from a "paste" (petroleum co ke mixed with a pitch binder). Paste preparation includes the crushing, grinding, and screening of coke and cleaned spent anodes (butts) and blendi ng the coke with a pitch binder. The paste mixture is molded into self supporting green anode blocks that are baked in a direct-fired ring furnace.

Alcoa has two anode bake furnaces that are commonly controlled by a single dry alumina injection system an d a pulse jet baghouse. The baking furnace structure is a series of interc onnected refractory flues connected to side main exhaust manifolds. Products of combustion and other emissions created in the baking furnaces are drawn into the refractory flues and exhausted to the emission co ntrol equipment through a series of ducts. The furnaces are fueled with natural gas.

2.2.1 SO 2



### SO 2 

### emission controls have been found to be economically infeasible, and the Massena Plant currently operates consistent with accepted BART conclusions from other Alcoa facilities. To assess SO 2 

### control cost, the estimate for the installation of a LS FO scrubber on the potline was scaled for installation on the ba ke furnace. Scaling was performed using ratios of exhaust flows, emission rates and economies of scale. The scaled cost effectiveness for the bake furnace was estimated at $13,795 per ton of SO 2 

### controlled for the installation of an LSFO. The full cost effectiveness calculation is included in Appendix B, and is summarized as follows:

455 Tons 95% Control Efficiency = 432.25 Tons Controlled Year

$5,962,688 = $13,795 Year 432.25 Tons Controlled Ton Controlled



### The cost effectiveness estimate was greater than the economic feasibility threshold of $5,500 per ton of SO 2 

### controlled and, therefore, the installation of SO 2 

### control on the bake furnace is economically infeasible.

Like the above referenced potline discussion, BART submittals for both the Tennessee and Washington Plants have been accepted by their respective agencies and rely on a pollu tion prevention limit of 3% sulfur in the anode coke. Massena West already meets this limit.ERM 

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### SO 2 

### control cost analysis completed for Alcoa’s Tennessee and Washington Plants likewise conclude d that bake furnace control was economically unreasonable.

2.2.2 NO x 

### Similar to the above referenced potline discussion, available NO x 

### emission control has been found to be technically infeasible through a prior RACT analysis. Specifically, a December 1994 NOx RACT analysis (Appendix C) for the bake furnaces determined that SCR and SNCR are not technically feasible due to an exhaust gas temp erature that is below the required technology temperature ranges. Bake furnace exhaust gas temperature is approximately 190°F, compared with a range 650-750°F; and 1600 – 2200°F for SCR and SNCR, respectively. Additionally, cost calculations were completed for reference and determin ed that cost-effectiveness was well above the $5,500 per ton threshold at $30,110 and $22,860 per ton of NOx removed for SCR and SNCR, respectively.

This conclusion is consistent with the approved BART determinations for the Alcoa Tennessee and Washington Plants.

2.2.3 PM 10


### Alcoa is proposing existing PM co ntrol as BART. The current bake furnace control device is a dry alumina injection system with a pulse jet baghouse. It has a control efficiency of greater than 95%. Similar to the above referenced potline discussion , given the high degree of PM reduction, and the relatively insignific ant affect that PM has on the total visibility impairment, Alcoa contends that existing PM emission control satisfies BART.

2.3 BOILERS

The Massena West Plant Boiler house co nsists of four virtually identical oil/gas fired Babcock & Wilcox boilers. Boiler Nos. 1 and 2 are model FM2150 and Boiler Nos. 3 and 4 are model FM2310. Each boiler has one natural gas/No. 6 fuel oil wall fired burner (single gun with 12 gas spuds) which has a maximum rated heat ca pacity of 200 MMBtu/hr for natural gas, and approximately 160 MMBtu/h r for No. 6 oil using atomized steam. The four boilers are divided into two pairs with each pair served by a common breech to one exhaust stack.ERM 

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### 2.3.1 SO 2


### As indicated in NYSDEC’s e-mail to Alcoa dated 10 May 2010 (Scott Griffin to Jordan Parent), EPA’s BART rule contains a presumptive limit for large oil fired boilers of 1% sulfur content or less (reference Federal Register/ Vol. 70, No. 128/ Wednesday, July 6, 2005/page 39133). Alcoa proposes to comply with this pres umptive BART limit, and will use oil with less than 1% sulfur content. Alcoa will ensure compliance with this limit no later than the BART compliance date of 1 January 1 2014.

2.3.2 NO x 

### Alcoa is proposing its existing NOx control (low NOx burners and flue gas recirculation) as BART. This appr oach is also being proposed as caseby-case RACT under 6 NYCRR Part 227- 2 (please reference Appendix D).

The NYSDEC regulatory impact statem ent pertaining to the revised Part 227-2 states: “ ... the Department determined the presumptive RACT limits for large boilers. The limits for large boilers are based on the application of low NOx burners regardless of the type of fuel used. ” Additionally, the revised Part 227 establishes a NOx emission limit for large oil/gas fired boilers of 0.15 lbs/MMBtu. The West Plant boil ers meet the presumptive RACT presented in the Part 227 regulatory impact statement through the use of low NOx burner and flue gas recirculation firing technology. However, the boilers have established emissionrates through recent testing of 0.08 lb/MMBtu and 0.27 lb/MMBtu when firing gas and oil respectively. Because the oil fired NOx emission rate exceeds the revised NOx RACT limit of 0.15 lb/MMBtu, Alcoa has developed an analysis of other possible RACT compliance options (Appendix D), and is requesting a case-by-case NOx RACT limit consistent with the requirements of Part 227-2.5 (c), which states: For those sources for which the owner or op erator demonstrates that the applicable presumptive RACT emission limit in section 227- 2.4 of this Subpart is not economically or technically feasible, the owner or operator can request the department to set a higher emission source specific emission limit. Ec onomic or technical feasibility must be demonstrated through an analysis that includes, at a minimum, an evaluation of the use of fuel switching the use of a system averaging plan, and implementati on of any available control technologies (including, for example, selective catalytic reduction).


### A review of possible add-on NOx emission control (Selective Catalytic Reduction [SCR], and Selective Non-catalytic Reduction [SNCR]), indicates that their annualized cost exceeds NYSDEC’s economic feasibility threshold of $5,500 per ton. The cost of retrofitting the four West Plant boilers with NOx control is $9,950 per ton and $12,226 per ton for SNCR and SCR, respectively. This cost assumes that a single add-on control system would be sized appropriat ely to be used to control all four boilers. Individual boiler add-on control was considered, but wasERM 

### 2-9 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### determined to be even less cost effect ive. Other conservative factors used in the costing analysis included the us e of 1998 dollars; a control efficiency of 70% for SNCR and 80% for SCR (the se control efficiencies are on the high end of the ranges provided for these technologies); a 15 year equipment lifetime; and projected actual NOx emission estimates that are representative of those expected after the completion of the Massena modernization project. Additionally, the SCR costing conservatively does not factor in costs for reactor height, ammonia flow rate, retrofit, SCR bypass, or initial charge of catalyst.

Given that the Alcoa West Boilers utilize presumptive RACT firing technology (low NOx burners and flue gas recirculation), and that the use of additional emissions control (SCR and SNCR) is economically infeasible – Alcoa proposes that the boilers’ existing emission performance beconsidered RACT and BART. Specifically, Alcoa proposes that a case-bycase RACT and BART limit be incorporated into the West Plant operating permit that is consistent with th e current RACT limit of 0.3 lbs/MMBtu.

2.3.3 PM 10


### PM from the boilers has negligible impact on visibility and Alcoa is proposing no additional control. A PM compliance test conducted on 28 March 2006 resulted in a total particulate emission rate of 0.045 lb/MMBtu burning No. 6 fuel oil, which is well below the boilers’ Part 227-1 PM limit of 0.1 lb/MMBTU.

The June 1 , 2007 document entitled Five -Factor Analysis of BART Eligible Sources, Survey of Options for Conducting BART Determinations prepared by NESCAUM for MANE-VU indicates that presumptive PM control levels for industrial boilers is a range of 0.02 - 0.07 lb/MMBtu. The Alcoa Massena emission rate of 0.045 lbs/MMBTU meets this presumptive limit.

Similar to the above referenced di scussions for the potline and bake furnace, given the low PM emission rate, and the insignificant affect of PM on the total visibility impairment, Alcoa proposes that existing PM emissions satisfy BART.ERM 

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### 3.0 CONCLUSION

For the potline, the calculated cost effectiveness value of $12,623 for LSFO SO 2 

### control is well above the $5,500 per ton economic feasibility threshold used for case-by-case RACT and BART . Therefore, this BART analysis determined that add-on SO 2 

### control on the potline is not economically feasible. It is not technically feasible to control NO x 

### emissions from the potline due to the low exhaust te mperature as compared with the temperature required for effective us e of SNCR or SCR controls. With regard to PM 10 

### , the potline has a capture efficiency of 98% and a PM removal efficiency of greater than 95%. Given the high degree of PM reduction, and the insignificant affect on PM on total visibility impairment, this analysis determined that existing PM emission control satisfies BART.

For the bake furnaces, SO 2 

### control cost were estimated by scaling the control costing developed for the potlines. Scaling was performed using ratios of exhaust flows, emission rates and economies of scale. The scaled cost effectiveness for the bake furna ces was estimated at $13,795 per ton of SO 2 

### controlled for the installation of an LSFO. Similar to the potline, this BART analysis determined that add-on SO 2 

### control on the bake furnaces is economically infeasible. Also similar to the potlines, NOx control is considered technically infeasible sinc e the exhaust gas temperature of the bake furnace is not high enough for SNCR or SCR technology. PM from the bake furnaces are controlled by a pulse jet baghouse and it was determined that existing control satisfies BART.

For the West Plant boilers, BART was determined to be 1% sulfur content to satisfy presumptive BART. Addition al add-on control in the form of SNCR or SCR in addition to the current control (low NOx burners and flue gas recirculation) was determined to be economically infeasible. The June 1 , 2007 document entitled Five-F actor Analysis of BART Eligible Sources, Survey of Options for Conducting BART Determinations prepared by NESCAUM for MANE-VU indicates that presumptive PM control levels for industrial boilers is a range of 0.02 - 0.07 lb/MMBtu. The Alcoa Massena emission rate of 0.045 lbs/MMBTU meets this presumptive range.

# Appendix A Hatch Alcoa Primary Metals – SO 2 

# Scrubber for Alcoa Massena West Prefeasibility Study 18 February 2009Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a 

## Alcoa Primary Metals SO2 Scrubber for Alcoa Massena West
Pre-feasibility Study

Prepared by: February 18, 2009
Don Wilson Date

Approvals

Hatch

Approved by: Stephan Broek Date

Alcoa Primary Metals

Approved by: Jim Engstrom Date



### Distribution List

Hatch: M. Desmeules H329821 FileAlcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a 

### Table of Contents

1. Introduction ................................................................................................................... ......................... 1

2. Summary ........................................................................................................................ ......................... 1

3. Design Basis ................................................................................................................... ......................... 2

4. Raw Materials and Gypsum Product ............................................................................................... ........ 3

4.1 Raw Materials .................................................................................................................. .............. 3
4.2 Gypsum Product ................................................................................................................. ........... 4

5. Technical Information.......................................................................................................... ................... 4

5.1 Process Description............................................................................................................ ............ 4 5.2 Process Data ................................................................................................................... ............... 5
5.3 Equipment ...................................................................................................................... ............... 6

6. Costs .......................................................................................................................... ............................. 8

6.1 Capital Cost ................................................................................................................... ................ 8
6.2 Operating Costs ................................................................................................................ ............. 9
6.3 Comparison with Other FGD Processes ....................................................................................... 10

7. Schedule....................................................................................................................... ......................... 11



### Appendices:
Appendix A
Babcock Power Environmental Proposal
Appendix B
Siemens Energy Proposal
Appendix C

Cost of Ductwork
Appendix D
Miscellaneous CorrespondenceAlcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a 

## 1. Introduction

Alcoa Primary Metals is evaluating the feasibility of installing a flue gas desulphurization (FGD) system to remove sulfur dioxide (SO 2 ) from the potroom off-gas from the Massena West smelter. A reduction in SO 2 emissions may be required in order to meet EPA legislation aimed at improving air quality by reducing haze and visibility impairment.

Major objectives of this pre-feasibility study are the development of capital and operating costs. In order to obtain these costs, Hatch developed a design basis and included this in a specification and sent it to nine vendors requesting budget proposals. A turnkey price for supply and erection was requested. This report is largely based on a proposal from a major FGD vendor, Babcock Power. A second proposal was received from Siemens Environmental Systems & Services who offered an alternate system to the one specified. Seven vendors declined to bid because of a heavy workload and lack of resources to prepare a bid.



## 2. Summary

The following are the main conclusions from the study.

• 95% removal efficiency of SO 2 with Limestone Slurry Forced Oxidation scrubber (LSFO) scrubber is achievable.

• Babcock Power has proposed an LSFO system, as per the specification, and their proposal is used as the basis for this report. Some data is also used from a similar study for the Alcoa Tennessee smelter carried out in 2006.

• The total installed capital cost is $209 million, which is higher than might be anticipated. The cost is summarized in Table 6-1. Key factors contributing to the high costs are:



###  High level of activity in the FGD industry. There are many FGD systems under construction resulting in high costs for manufactured items such as pumps, spray nozzles etc. In addition, there have been large increases in the cost of alloy steels that are required for the absorbers. Also, the major FGD vendors have full order books and are struggling to implement projects. It is probable, however, that the very recent fall in commodity prices are not reflected in the vendor pricing.



###  The requirement for 100% availability, which resulted in the need to install two 100% absorbers, one operating and one stand by.



###  Babcock has included five spray levels and five pumps for each of the two absorbers. The extra spray levels add additional height to the scrubber, as well as the cost of the pumps and nozzles. Hatch believes that 95% SO 2 removal efficiency may be achievable with fewer spray levels.



###  The cost of ductwork from the existing dry scrubber stacks is high and estimated at $14 million. Cost for the ductwork was not included in the scrubber vendor’s scope and was estimated separately by Hatch.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a 

###  A 20% contingency has been added.

• There is a considerable potential for a capital cost saving if only one rather than two absorbers are installed. Babcock estimated that the equipment cost would be reduced from $71 to $51 million for a saving of $20 million. With construction equal to the equipment cost, the total saving would increase to $40 million. The disadvantage, of course, is that there will not be any
SO 2 removal during periods of scrubber downtime which would be expected to be of the order of 1.5% or 51⁄2 days per year.

• Direct operating costs are estimated to be $7.9 million/yr. A major contributor is the electrical power cost at $3.7 million. Compared with other similar studies, this is a high value. The higher cost may be attributed to the power drawn from the main ID fan and the need to develop a relatively higher pressure drop, and the operation of four slurry pumps that supply to four operating spray levels. A third reason is Alcoa’s relatively high economic electrical power cost, of $80/MW.

• It is assumed that the new FGD system will be located to the west of building 402. The location is shown on a sketch in Appendix C. Another location to south of courtyard between buildings 401 and 402 was considered but the ductwork would have been more expensive.

• Babcock expects that particulate emissions will increase from 5 at the inlet to 7.5 mg/Nm 3 at the scrubber outlet. This is not a guaranteed value however. In previous studies the increase was even greater, up to 20 mg/Nm 3 by another vendor.

• As with previous studies, Babcock confirmed that the cost saving using either Limestone Slurry Scrubbing with Natural Oxidation (LSNO) or Conventional Lime Wet Scrubbing would be small. Notwithstanding, if the project moves forward to the next stage, it is recommended that Conventional Lime Wet Scrubbing should be considered as an option.



## 3. Design Basis

The potrooms of the Massena West smelter are already equipped with three (3) Gas Treatment Centers (GTCs). The GTCs use the Alcoa 398 dry scrubbing system in which alumina is injected into the off-gas in reactors to react with hydrogen fluoride followed by capture on the bags of a fabric filter baghouse. There is a total of thirty six reactor stacks. Table 3-1, summarizes the key design parameters.
Based on previous studies, it was decided to focus on Limestone Slurry Scrubbing with Forced Oxidation (LSFO). LSFO is the most widely used process in the utility industry.
Vendors were requested to compare LSFO with other technologies such as Conventional Lime Wet Scrubbing and LSNO (Limestone Slurry Scrubbing with Natural Oxidation.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Table 3-1: Design Basis

Units Each of Three Dry Scrubbing Centers Total gas flow – design (normal) operation acfm (oF) 300,000 (at 160) Total gas flow – minimum acfm (oF) 250,000 (at 160)

Total Flow for New Central SO2 Scrubbing Centre Total gas flow – design (normal) operation acfm (oF) 900,000 (at 160) Total gas flow – minimum acfm (oF) 750,000 (at 160)

Gas Conditions Gas temperature °F 160 to 300 SO 2 mg/Nm 3 300 (105 ppmv) SO 3 negligible Oxygen % by volume 19 Moisture % by volume 3 HF gaseous mg/Nm 3 1 Total particulates mg/Nm 3 5 Static pressure required at inlet to collector duct (to be developed by vendor booster fans) in wg 3.0

Limestone Wt. % CaCO 3 95

SO 2 Removal Efficiency - Required % 95



## 4. Raw Materials and Gypsum Product

4.1 Raw Materials

Limestone, mainly calcium carbonate (CaCO 3 ), is the raw material used for both LSFO and LSNO, while quicklime (or pebble lime), mainly calcium oxide (CaO), is used for conventional lime scrubbing. Two suppliers were contacted and a summary is included in

Table 4-1. The delivered costs to the Alcoa Massena West smelter for limestone are $25 and $60 per short ton, respectively from Omya and Graymont. The quicklime cost is approximately $125 per short ton. In the case of Omya, a major component in the cost is transportation, which is $19.60 per ton. The higher cost for the Graymont limestone is in part due to of the high quality product which is typically 97% calcium carbonate (CaCO 3 ). Assuming that the gypsum product is not used in a cement kiln and instead is sent to landfill, high quality limestone is not required. The $25 per ton price provided by Omya is used in the calculation of operating costs.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Table 4-1: Raw Materials
Company Distance From Alcoa Smelter miles Product Material Cost $/short ton Transportati on Cost $/short ton Total Cost $/short ton delivered to smelterOmya StArmand, Quebec 112 Limestone (-3/8 in) Typ. 95% CaCO 3 5.20 19.60 25*

Limestone (-3 mm) Typ. 97% CaCO 3 60* Graymont Inc, Bedford, Quebec 135

Quicklime 125*

*Costs are rounded off Pricing converted from Canadian dollars using exchange rate of CAD=0.80 USD



### 4.2 Gypsum Product

Two options exist for its use. One potential destination is a cement kiln for use as an additive and another is use in wallboard production. There is little chance that gypsum would be useable for wallboard production because the Alcoa smelter would produce a relatively small amount, 11,800 tons/yr of product containing 15% moisture. For a cement plant, there is a risk that the gypsum product properties could degrade the cement quality leading to inferior properties of their product. Either potential reuse option would require sampling and analysis prior to acceptance of the product. This means that an FGD system must be put into operation before the product can be accepted. Finally, given that the quantity of gypsum is relatively small compared with FGD systems installed at large utility coal fired boilers that produce of the order of 1 million tons/yr or more, it would be difficult to generate interest from end users.

The most realistic option for gypsum is landfill. The actual cost of freight, and whether or not Alcoa could sell the gypsum, is really an issue for future discussion between end users and Alcoa. The firm Waste Management, that has a contract with Alcoa to handle all plant wastes, provided a budget disposal cost of $83/ton for transportation and landfill.



## 5. Technical Information

5.1 Process Description

The following is process description of Limestone Slurry Forced Oxidation (LSFO) scrubbing. The system proposed by Babcock is used.

An aqueous solution/slurry of gypsum and dissolved & undissolved limestone is used to absorb the
SO 2 from the off-gas. The overall chemical reaction is:

SO 2 (g) + CaCO 3 (s) + 1⁄2 n O 2 (g) + 2 H2O (l)  nCaSO 4 x (1-n) CaSO3x2H2O(s) + CO 2 (g)

where n>0.97Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Spray nozzles are used to inject slurry into the gas stream to create droplets with large surface area to affect the gas/liquid transfer. The scrubbing device is the open, multi-level, counter current spray tower where the gas enters the bottom of the tower and passes upward through four levels of spray banks. Liquor is collected in the reaction tank, which is the bottom of the tower, and sparged with air to oxidize the calcium sulfite to calcium sulfate. Additional fresh slurry is added to the reaction tank. Four recirculation pumps, one for each level, deliver slurry to the spray levels.

Limestone is delivered to site in small lumps and stored in silos. For use in the process the limestone must be a fine powder to enhance the rate of dissolution in the slurry. Typically limestone dissolves very slowly into the solution. Wet grinding of the limestone takes place using in a ball mill.

Using pH control, the correct amount of limestone slurry is added to the scrubber. The LSFO process operates at pH levels of 5.4 to 6 depending on the reactivity of the limestone, the SO 2 removal efficiency required, and excess limestone allowed in the gypsum by-product. The operating pH is also affected by the use of additives sometimes used to enhance SO 2 removal. With the low SO 2 levels in the raw potroom gas, the use of organic buffers to enhance SO 2 removal is not required.

The bleed from the scrubber is controlled to allow a large retention time of the gypsum solids forboth crystal growth and reaction completion. The control over the bleed causes a slight supersaturation of calcium sulfate. This results in controlled precipitation of gypsum crystals on existing gypsum crystals. This principle has been found to mitigate scaling problems that used to exist in these types of scrubbers. The absorber tower typically operates with slurry containing 12 wt% suspended solids. Because oxidation is rarely 100%, the solution contains a small amount of residual sulfite. Oxidation blowers have been included in the scope of supply to promote oxidation of the sulfite, but given the low level of SO 2 in the incoming gas, they may not be required.

The bleed flow from the scrubber is fed to a battery of hydroclones in which the first step of dewatering takes place. The hydroclones are set to produce an optimal underflow for solids particle size and slurry concentration. Fine materials are forced to the overflow that is returned to the scrubber. This allows recovery of fine, reactive limestone as well as return of undersized gypsum crystals for further growth. The underflow from the hydroclones contains approximately 50 wt% suspended solids. A rotary vacuum filter is used to reduce the moisture content even further to 15%.

As it is assumed that the gypsum will be land filled, a gypsum wash system is not provided so that impurities that otherwise must be purged separately, are kept within the gypsum product.



### 5.2 Process Data
Key process data from Babcock’s proposal are included in Table 5-1. Limestone consumption is 6,300 tons/yr and the gypsum product, including 15% moisture, is 11,800 tons/yr. It is also important to note that the electrical power consumption of 5,275 kW is relatively high. The high consumption is due to the higher pressure drop required by the Babcock, the need to operate four recycle pumps.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Table 5-1: Process Data

Performance Unit Predicted Values Babcock Power SO 2 Removal Efficiency % 95 Electric Power Consumption kWh/h 5,275 Make-up Water Consumption gpm 570 Limestone Consumption lb/hr (short tons/yr) 1,440 (6,300) Total Pressure Drop For Fan Selection in. wg 7 Compressed Air (instrument air) scfm 120 Gypsum Quantity including 15% moisture lb/hr (short tons/yr) 2,695 (11,800) Gypsum Quality Gypsum CaSO 4 x 2H2O wt% 92.9 CaCO 3 wt% 1.6 CaF 2 wt% 0.22 Insolubles wt% 4.9 Blowdown (purge) Quantity & Composition Assume no blowdown Particulate (stack) Emissions mg/Nm 3 7.5 Absorber superficial gas velocity ft/sec 12 L/G (liquid/gas ratio) gal/1000 ft 3 105 pH 5.5 Solids concentration in recirculation slurry wt% 12

Stack height ft above grade 75 Stack gas exit velocity ft/min 3,300 Stack gas temperature oF 97

It is also important to note that the particulate emission has actually increased from the scrubber inlet of 5 mg/Nm 3 to 7.5 mg/Nm 3 . An increase has also been found in other studies. The increase represents the solid carryover in droplets that pass through the mist eliminators.



### 5.3 Equipment

The following list of equipment (Table 5-2) was included in the Babcock proposal. 100% backup is provided for all major equipment, with the exception of the ball mill, to ensure 100% availability.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Table 5-2: Equipment for Limestone Slurry Forced Oxidation (LSFO)
Quantity Absorber Island Number of absorbers 2 (1 operating + 1 spare) Absorber material of construction 316 stainless steel Absorber diameter 38 ft Reaction tank diameter 48 ft Recycle pumps/absorber 5 levels (4 operating + 1 spare) Recirculation piping Included Spray headers and nozzles 5 levels (4 operating + 1 spare) Mist eliminators and wash system 2 levels/absorber Reaction tank agitators 1/absorber Oxidation air blowers & lances 1/absorber

Flue Gas System Ductwork from existing GTC stacks to booster fans 3 ducts (one from each GTC) Ductwork from booster fans to absorber inlet Included Absorber inlet isolation damper Included Booster fans 2 (1 operating + 1 spare) Booster fan inlet and outlet isolation dampers Included Duct expansion joints As required Stack integrated on top of absorbers 1 per absorber (fabricated from FRP)

Reagent Unloading and Storage Reagent unloading hopper 1 system Limestone conveying to limestone silos 1 system

Reagent Preparation System Limestone silo 1 Grinding ball mill 1 Mill product tanks 1 Mill product pumps 1 Hydrocyclones 1

Limestone Slurry Storage & Feed System Reagent feed tank 2 (1 operating + 1 spare) Reagent feed tank agitator/tank 1 Reagent feed pumps 2 (1 operating + 1 spare)

Dewatering Equipment & Gypsum Storage Hydrocyclones, tank & agitators Included with 100% redundancy Rotary vacuum filters 2 (1 operating + 1 spare) Gypsum transfer conveyor 1 Filtrate tanks, agitator, and pumps 1 set Gypsum storage bunker 1Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Quantity Balance of Equipment/Services Electrical substation and transformers Included Electrical distribution from transformers Included Electrical switchgear and motor control centers Included Miscellaneous sump pumps, agitators, linings Included



## 6. Costs

6.1 Capital Cost

In response to the specification, Babcock provided an equipment price of $71 million for the specified scope of supply. They also stated that the installation cost usually equals or is slightly higher than the material price.

The cost includes:

• Engineering.

• Absorber vessels, stacks, reagent preparation, and product dewatering.

• Booster fans.

• Electrical systems including transformers and rectifiers.

• Instrumentation.

• Installation and commissioning.
The cost of the ductwork from the existing dry scrubber stacks to the new FGD system was estimated by Hatch. Duct lengths were scaled off plant drawings, wall thicknesses were selected from similar projects and weights were calculated. Factors were applied for stiffeners and supports. Alstom Power, a major supplier of such systems was contacted and provided a unit installed price of $5/pound. Details are included in Appendix A.

Foundation cost was assumed to be 1.5% of the equipment cost.

Indirect costs including both Owner’s cost and EPCM were estimated at 10% of the direct costs. This 10% assumption is on the low side of what is normally used but is felt justified as the project will be turn-key and there is only one major vendor.

A contingency of 20% was also added.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a The capital cost is summarized in Table 6-1. Comments on the capital costs:

• The total capital cost including contingency is $209 million.

• The relatively high cost is, in part, explained by the need for 100% availability, which resulted in two 100% absorbers, one operating and one stand by.

• Another factor driving higher costs is the high degree of activity in the FGD industry. There are many FGD systems under construction that has resulted in high costs for manufactured items such as pumps, spray nozzles, mist eliminators etc. In addition, there have been larger increases in the cost of alloy steels that are required for the absorbers. Major FGD vendors are also very busy and profit margins have increased.

• There is a considerable capital cost saving potential if only one rather than two absorbers is installed. Babcock estimated that on the supply only, the equipment cost would be reduced from $71 to $51 million for a saving of $20 million. This saving would increase to $40 million when adding in construction. The disadvantage, of course, is that there will not be any SO 2 removal during periods of scrubber downtime which would be expected to be of the order of 1.5% or 51⁄2 days per year.

Table 6-1: Capital Cost
Cost Million $ Equipment supplied by Babcock 71 Installation of Babcock Equipment 71 Ducts, supports and dampers from existing dry scrubber stacks to absorbers 14 Foundations (assume 1.5% of equipment cost) 2 Total direct costs 158 Indirect costs including Owners cost & EPCM (assume 10% of direct costs) 16 Total direct & indirect cost 174 Contingency at 20% 35 Total project cost 209



### 6.2 Operating Costs

Table 6-2 is a compilation of operating costs based on Babcocks’s technical data. A major cost of $3,696,000/yr is the consumed electrical power of 5,275 kW. Two large consumers account for the majority of the consumed power i.e. one operating induced draft fan consuming 2,775 kW, and four operating absorber pumps consuming 2,500 kW. The induced draft fans are very large and must handle the high gas flow of 900,000 acfm and a pressure drop of 7 in wg. In addition, Alcoa’s economic cost for electrical power is relatively high. Maintenance is also a major cost item.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Table 6-2: Yearly Operating Cost Unit Cost Quantity Total Cost $/yr Limestone $25/ton 6,300 tons/yr 157,000 Electricity $0.08/kW hr* 5,275 kW 3,696,000 Water $1.5/1000 gal** 570 gpm 449,000 Compressed air $0.01/scfm/hr** 120 scfm 11,000 Labour $41.5/hr* 1 operator, 3 shifts/day +15% supervision 417,000

Gypsum disposal $83/ton 11,800 tons/yr* 979,000 Maintenance*** 2,172,000 Total 7,881,000
*Values provided by Alcoa ** From previous study *** Based on a similar installation described in a National Lime Association FGD report, January 2003.



### 6.3 Comparison with Other FGD Processes

As noted earlier, Limestone Slurry scrubbing with Forced Oxidation (LSFO) is widely used and is the workhorse of the utility industry. Although limestone slurry scrubbing with natural oxidation (LSNO) is an option, most of the equipment is identical to LSFO including the most expensive item, the two absorbers. The only item that will not be required is the oxidation air blowers which also may not be required for LSFO as noted above. LSNO and LSFO producing disposal grade gypsum can use a lower quality and less expensive limestone analyzing less than 95% CaCO 3 , which would potentially reduce costs. LSFO does, however, have an advantage in producing a product that retains less moisture thus reducing overall transportation cost. In addition, it is more readily consolidated at a landfill site.

Conventional lime wet scrubbing is also a candidate. The raw material, pebble or quick lime, delivered to the Alcoa smelter at $125/ton, is significantly more expensive than the $25/ton for limestone. Due to stoichiometry, however, the quantity of lime required is significantly less, only 56% of the tonnage of limestone thus reducing but not eliminating, the operating cost advantage of
LSFO.

Babcock has stated that the there will only be a small cost saving with either LSNO or conventional lime scrubbing compared with LSFO.

Siemens Environmental Systems proposal, however, was based on conventional lime scrubbing rather than the requested LSFO. In addition, they only offered one scrubber (absorber), with no back up, instead of two as per the specification. Finally the pricing for installation seems at 70% of the equipment cost seems unrealistically low. There is, however, potential to reduce capital cost but with and increase in operating cost. Notwithstanding, if the project moves forward, it is recommended that a closer look at lime scrubbing should be carried out.Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West Pre-feasibility Study - February 19, 2009

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© Hatch 2006/03 a Dual alkali sodium/lime scrubbing (dilute mode) is not marketed by major FGD vendors who claim the system is too complicated and expensive. Given the very active market for FGD systems, it is unlikely that a vendor could be found who would be willing to supply a system.



## 7. Schedule

A typical time line from notice to proceed to initial operation is 30 to 36 months.

# Appendix B Potline and Bake Furnace Limestone Slurry Forced Oxidation (LSFO) Scrubber Cost CalculationsPotline and Bake Furnace Limestone Slurry Forced Oxidation (LSFO) Scrubber Costing CalculationsBased on the HATCH 18 February 2009 SO2 Scrubber ReportFlowrate (modeled) 923,646 acfm 121,200 acfmUncontrolled SO2*2,568 tons/yr 455 tons/yr*Potline has a 98% capture efficiency and bake furnace has 100% capture efficiencyCapital CostPotline Cost Million $Anode Bake ScalingFactor*Anode BakeCost Million $Equipment71 0.20 14Installation71 0.20 14Ducts, supports and dampers from existing dry scrubber stacks to absorbers 14 0.20 3Foundations (assume 1.5% of equipment cost) 2 0.20 0Total direct costs158 31Indirect costs including Owners cost & EPCM (assume 10% of direct costs) 16 0.20 3Total direct & indirect cost174 34Contingency at 20%35 7Total Capital Investment Costs (TCIC) 209 41*Estimate anode bake scrubber cost from average potline scrubber cost and ratio of gas flowrates (121,200 acfm/923,646 acfm) scaled by 0.8 power for economy of scale;exponential capacity-ratio method inPerry's Chemical Engineer's Handbook, Sixth Edition, McGraw-Hill.Annual Operating CostUnit Cost Potline QuantityPotline TotalCost $/yrAnode Bake ScalingFactor NoteAnode BakeTotal Cost $/yrLimestone$25/ton 6,300 tons/yr 157,000 0.18 127,817Electricity$0.08/kW hr* 5,275 kW 3,696,000 0.13 2484,986Water$1.5/1000 gal** 570 gpm 449,000 0.13 258,917Compressed air$0.01/scfm/hr** 120 scfm 11,000 0.13 21,443Labor$41.5/hr*1 operator, 3 shifts/day+15% supervision 417,000 None417,000Gypsum disposal$83/ton 11,800 tons/yr* 979,000 0.18 1173,460Maintenance2,172,000 0.13 2285,008Total7,881,0001,448,632*Values provided by Alcoa** From previous studyBased on a similar installation described in a National Lime Association FGD report, January 2003.1-Estimate from the ratio of uncontrolled SO2 (455 tons/yr / 2,568 tons/yr)2-Estimate from ratio of gas flowrates (121,200 acfm / 923,646 acfm)Two RedundantSingleCost EffectivenessAbsorption Towers Absorption TowerPotline Bake Furnace PotlineA. Total Annualized Costs (incl. Capital and O&M)Expected Lifetime of Equipment Costs (yrs) 15 15 15Interest Rate0.07 0.07 0.07Capital Recovery Factor (CRF)* 0.1098 0.1098 0.1098Total Capital Investment Costs (TCIC) $208,731,600 $41,113,633 $155,139,600Annualized Capital Investment Costs (TCIC x CRF) $22,917,608 $4,514,056 $17,033,494Annual O&M Costs (O&M) $7,881,000 $1,448,632 $7,881,000Total Annualized Costs (ACIC + O&M)$30,798,608 $5,962,688 $24,914,494B. SO2 Removal per YearBaseline SO2 level (tons/yr) 2,568 455 2,568Controlled SO2 level @ 95% Removal (tons/yr) 128 23 128SO2 Removed per year (tons/yr)2440 432 2440Cost Effectiveness ($/ton SO2 removed)$12,624 $13,795 $10,213*The Capital Recovery Factor is derived from EPA Air pollution Control Cost Manual, Sixth Ed., EPA/452/B-02-001,January 2002, Chapter 2, p. 2-21, based on the lifetime and interest rate shown.Potline Anode Bake Furnace

# Appendix C Bake Furnace NOx RACT December 1994 prepared by ENSR

# Appendix D West Plant Boilers NOx RACT September 2010 prepared by ERM

# ALCOA, Inc. Boiler NOx Reasonably Available Control Technology (RACT) Analysis Massena West Plant Massena, New York

23 September 2010

Environmental Resources Management 1159 Pittsford-Victor Road Suite 200 Pittsford, New York 14534

### i TABLE OF CONTENTS

EXECUTIVE SUMMARY ES-1

1.0 INTRODUCTION 1-1

2.0 DESCRIPTION OF FACILITY OPERATION 2-1

2.1 PROJECTED ACTUAL NOX EMISSIONS 2-1

3.0 RACT COMPLIANCE STRATEGIES 3-1

3.1 INTRODUCTION 3-1

3.2 PRESUMPTIVE RACT 3-1

3.3 FUEL SWITCHING 3-1

3.4 SYSTEM AVERAGING PLAN 3-2

3.5 ALTERNATIVE RACT EMISSION LIMIT 3-2

4.0 CONCLUSION 4-1

ATTACHMENT A: PROJECTED ACTUAL EMISSIONS

ATTACHMENT B: COST ESTIMATESERM 

### ES-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### EXECUTIVE SUMMARY

The requirements of Title 6 of the New York Code of Rules and Regulations (NYCRR) Part 227 have b een revised effective July 2010. The Alcoa Massena West Plant operates four dual fuel boilers that are classified as “large boilers” (each ha ve a maximum heat input capacity of greater than 100 MMBtu/hr and equal to or less than 250 MMBtu/hr). The revised Subpart 227 requires the su bmittal of a Reasonably Available Control Technology (RACT) analysis that explains why the control technology the facility currently employs should still be considered RACT for that source by 1 January 2012. This document addresses the Part 227 submittal obligation.

The NYSDEC regulatory impact statem ent pertaining to the revised Part 227-2 states: “ ... the Department determined the presumptive RACT limits for large boilers. The limits for large boilers are based on the application of low NOx burners regardless of the type of fuel used. ” Additionally, the revised Part 227 establishes a NOx emission limit for large oil/gas fired boilers of 0.15 lbs/MMBtu. The West Plant boil ers meet the presumptive RACT presented in the Part 227 regulatory impact statement through the use of low NOx burner and flue gas recircul ation firing technology. However, the boilers have established through recent testing emission rates of 0.08 lb/MMBtu and 0.27 lb/MMBtu when firing gas and oil respectively. Because the oil fired NOx emission rate exceeds the revised NOx RACT limit of 0.15 lb/MMBtu, Alcoa is compelle d to present an analysis of other possible RACT compliance options. A review of possible add-on NOx emission control (Selective Catalyti c Reduction [SCR], and Selective Noncatalytic Reduction [SNCR]), indicates that their annualized cost exceeds NYSDEC’s economic feasibility threshold of $5,500/ton.

Given that the Alcoa West Boilers utilize presumptive RACT firing technology (low NOx burners and flue ga s recirculation), that its current fuel switching approach yields an annualized NOx emission limit that meets the revised Part 227 limit of 0.15 lbs/MMBtu, and that the use of additional emissions control (SCR and SNCR) is economically infeasible - Alcoa proposes that the boilers ‘ existing emission performance beconsidered RACT per 227. Specifically, Alcoa proposes that a case-bycase RACT limit that is consistent with the current RACT limit of 0.3 lbs/MMBtu be incorporated into th e West Plant operating permit.ERM 

### 1-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### 1.0 INTRODUCTION

The requirements of Title 6 of the New York Code of Rules and Regulations (NYCRR) Part 227 have b een revised effective July 2010. The Alcoa Massena West Plant operates four dual fuel boilers that are classified as “large boilers” (each have a maximum heat input capacity of greater than 100 MMBtu/hr and equal to or less than 250 MMBtu/hr). The revised Part 227 establishes a NOx emission limit of 0.15 pounds per MMBtu for large gas/oil fired boilers which must be complied with by 1 July 2012. The current NOx emission limit is 0.30 lb/MMBtu. Alcoa’s boilers have established tested emission rates of 0.08 lb/MMBtu and 0.27 lb/MMBtu for gas and oil firing respectively.

The revised Subpart 227-2 requires the submittal of a RACT analysis by 1 January 2012 that explains why the control technology the facility currently employs should still be considered RACT for that source. The NYSDEC regulatory impact statement pertaining to the revised Part 227-2 states: “ ... the Department determined the presumptive RACT limits for large boilers. The limits for la rge boilers are based on th e application of low NOx burners regardless of the type of fuel used. ” The West Plant boilers meet the presumptive RACT presented in the P art 227 regulatory impact statement through the use of low NOx burner an d flue gas recirculation firing technology. However, because th e oil fired NOx emission rate (0.27 lb/MMBtu) exceeds the revised NOx RACT limit of 0.15 lb/MMBtu, Alcoa is compelled to present an an alysis of other possible compliance options in the RACT analysis.ERM 

### 2-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### 2.0 DESCRIPTION OF FACILITY OPERATION

The Massena West Plant boilers consis t of four virtually identical oil/gas fired Babcock & Wilcox boilers; Boiler Nos. 1 and 2 are model FM2150 and Boiler Nos. 3 and 4 are model FM2310. Each boiler has one natural gas/No. 6 fuel oil wall fired burner (single gun with 12 gas spuds) which has a maximum rated heat capacity of 200 MMBtu/hr for natural gas, and approximately 160 MMBtu/hr for No. 6 oil using atomized steam. The four boilers are divided into two pair s with each pair served by a common breech to one exhaust stack.

2.1 PROJECTED ACTUAL NO X 

### EMISSIONS

Projected actual emissions (presented in Attachment A), are estimated to be 164 tons. This emission estimate calculation is based on the maximum fuel usage of natural gas and No. 6 fuel oil between 2003 and 2007, permit emission limits for NOx (conservative compared to the 2006 tested emission rates), and an 18% scaling fa ctor to account for an anticipated increase in heat input demand re sulting from the planned Massena modernization project.ERM 

### 3-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### 3.0 RACT COMPLIANCE STRATEGIES

3.1 INTRODUCTION

There are four possible compliance op tions associated with the Part 227 RACT requirements. They include:

 compliance with presumptive RACT requirements (a NOx emission limit of 0.15 pounds per MMBtu for large gas/oil fired boilers);

 implementation of a fuel switching approach;

 use of a system averaging plan; or

 requesting that the Department set a higher source specific emission limit by demonstrating that all other compliance options are technically or economically infeasible.

The following subsections present a discussion of each option.

3.2 PRESUMPTIVE RACT

The NYSDEC regulatory impact statem ent pertaining to the revised Part 227-2 states: “ ... the Department determined the presumptive RACT limits for large boilers. The limits for large boilers are based on the application of low NOx burners regardless of the type of fuel used. ”

The Massena West Plant boilers meet the presumptive RACT described in the Part 227 regulatory impact statement by utilizing low NOx burner and flue gas recirculation technology. However, the revised Part 227 established a NOx emission limit of 0.15 lbs/MMBtu for gas/oil fired boilers. The Massena West boilers have established emission rates of 0.08 lb/MMBtu and 0.27 lb/MMBtu when firing gas and oil respectively. Because the oil fired NOx emission rate exceeds the revised NOx RACT limit of 0.15 lb/MMBtu, Alcoa is compelle d to present an analysis of other compliance options in th e following sections.

3.3 FUEL SWITCHING

The West Plant Boilers are currently permitted to burn both natural gas and No. 6 fuel oil. Alcoa needs to main tain the flexibility to fire both fuelsERM 

### 3-2 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### as a means of assuring business contin uity. Therefore, fuel switching is not a viable option.

3.4 SYSTEM AVERAGING PLAN

The system averaging plan employ s a weighted average permissible emission rate. A weighted average permissible emission rate is the average emission rate of all operat ing emission sources in a system averaging plan. In this approach the emission rate of the emission sources in operation is equivalent to the emission rate achieved if each emission source operated in compliance wi th the permissible emission rate applicable to that emission source.

The system averaging plan is not a pplicable to the Alcoa West Plant boilers since all four boilers are physically identical and operated consistently.

3.5 ALTERNATIVE RACT EMISSION LIMIT

The two demonstrated NOx removal technologies for combustion sources are Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR). Both of these two control options involve the introduction of ammonia (or urea) into the exhaust gas stream to reduce the NOx emissions to atmospheric nitrogen (N 2 

### ) and water vapor. In the case of SCR, the exhaust gas passes through a reaction bed containing a chemical catalyst that promotes the reduction of NOx and allows the process to occur at lower temperatures. SCR can achieve NOx reductions of 70% to 90% whereas SNCR alone typically achieves reductions in the 30% to 50% range i



### NOx is removed by the following chemical reactions:

4NO + 4NH 3 

### + O 2 

###  4N 2 

### + 6H 2 

### O

4NO 2 

### + 4NH 3 

### + O 2 

###  3N 2 

### + 6H 2 

### O

These reactions require significant ac tivation energy (temperature) before the reaction will occur at a level sufficient to remove NOx from the exhaust gas stream. For the majority of commercial catalysts (metal

i 

### EPA Air Pollution Control Cost Manual, 6 th 

### Edition, 2002.ERM 

### 3-3 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### oxides), the recommended operatin g temperature for the SCR process range from 480 °F to 800 °F (250 °C to 427 °C) and SNCR requires an even higher temperature range of 1600 – 2000°F (870 °C to 1100 °C) i



### . Temperatures below these levels reduce the NOx removal efficiency significantly and increase the amount of ammonia slip (the direct release of unreacted ammonia).

The EPA Air Pollution Cost Manual, Sixth Edition was used to estimate costing for installing SNCR or SCR cont rols on the West Plant boilers. A conservative costing and emission estimation approach were used to develop annualized control cost for comparison to a cost effectiveness threshold of $5,500 per ton of NOx controlled. This threshold is used by NYSDEC to determine economical feasibility. Conservative factors included the use a control efficiency of 70% for SNCR and 80% for SCR, a 15 year equipment lifetime, and projected maximum actual NOx emission estimates (Attachment A). Additiona lly, the SCR costing does not factor in costs for reactor height, ammonia flow rate, retrofit, SCR bypass, or initial charge of catalyst. The cost of retrofitting the four West Plant boilers with NOx control is $9,950/ ton and $12,226/ton for SNCR and SCR, respectively (Attachment B). Pl ease note that cost estimates were developed assuming that all four boilers were vented to a single emission control device. Separate control de vices were reviewed (one per boiler) and determined to be even less cost e ffective (i.e.; they produced an even greater cost per ton of NOx removed).

Given that the Alcoa West Boilers utilize presumptive RACT firing technology (low NOx burners and flue gas recirculation), and that the use of additional emissions control (SCR and SNCR) is economically infeasible - Alcoa proposes that the existing boilers and emission performance be considered RACT per Part 227. More specifically, Alcoa is requesting a case-by-case NOx RACT limit consistent with the requirements of Part 227-2.5 (c), which states: For those sources for which the owner or op erator demonstrates that the applicable presumptive RACT emission limit in section 227- 2.4 of this Subpart is not economically or technically feasible, the owner or operator can request the department to set a higher emission source specific emission limit. Ec onomic or technical feasibility must be demonstrated through an analysis that includes, at a minimum, an evaluation of the use of fuel switching the use of a system averaging plan, and implementati on of any available control technologies (including, for example, selective catalytic reduction).


### Alcoa proposes that a case-by-case RACT limit that is consistent with the current RACT limit of 0.3 lbs/MMBtu be incorporated into the West Plant operating permit.ERM 

### 4-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010 

### 4.0 CONCLUSION

The NYSDEC Regulatory Impact Statem ent pertaining to the revised Part 227-2 states: “ ... the Department determined the presumptive RACT limits for large boilers. The limits for large boilers are based on the application of low NOx burners regardless of the type of fuel used. ” The West Plant boilers meet this presumptive RACT firing technolo gy by utilizing low NOx burners and flue gas recirculation.

Based on the use of a conservative annualized emissions control cost estimate approach, the cost of retrofi tting the four West Plant boilers with NOx control is $9,950/ton and $12,226/ton for SNCR and SCR, respectively (Attachment B). These conservative estimates exceed the Department economic feasibility threshold of $5,500/ton.

Therefore, Alcoa proposes that a case-by-case RACT limit that is consistent with the current RACT lim it of 0.3 lbs/MMBtu be incorporated into the West Plant operating permit.

# Attachment A – Projected Actual EmissionsEmission Unit B-00001Pollutant NOx SO2 PM PM10/2.5 COWest Plant Boilerhouse Emissionslb/yr 327,158 495,811 25,375 25,375 9,23818.03% increase in MMBTU annual demand due to carbon plant production doublingPercentage increase calculated by scaling double the 2007 total carbon plant steam usage (16%) by the potline scaling factor (1.13)Max Fuel Usage (03-07)Yearly Units MMBTU MMBTUMMCF or1000 galP-225 Plant Production160,040 tonsNatural Gas 681.7106ft3695,300 125,384 125.4Average West Plant Aluminum Production141,998 tonsNo. 6 Fuel Oil 1782.2 1000 gallons 267,334 48,208 321.4Scaling Factor =1.13Natural Gas assumes - 1,020 Btu/cfNo.6 Fuel Oil assumes - 150,000 Btu/galNatural Gas Natural Gas No. 6 Fuel Oil No. 6 Fuel OilPollutant (lb/MMbtu) (lb/MMcf) (lb/MMBtu) (lb/ 1000 gal)Carbon Monoxide 0.0077.140.0132.0Nitrogen Oxides 0.0881.60.2741Particulate Matter 0.06410NOx 0.33060.345PM 0.115Natural Gas assumes - 1,020 Btu/cfNo.6 Fuel Oil assumes - 150,000 Btu/galNatural Gas No. 6 Fuel OilPollutant(lb/106ft3)(lb/ 1000 gal)Carbon Monoxide7.14 2.0Sulfur Dioxide 0.6 236Particulate Matter 7.69.6Nitrogen Oxides306 45.0Emission Factors inredare based on 2006 boiler test data and the rest are 1998 AP-42 emission factorsEmission Factors inblueare based on Permit emission limitsYearly EmissionsYearlyNatural Gas No. 6 Fuel Oil Natural Gas No. 6 Fuel Oil Worst Case TotalPollutant (lbs) (lbs) (lbs) (lbs) (lbs) (lbs)Carbon Monoxide 4,867 3,475 895 627 895 9,238Sulfur Dioxide 409 419,715 75 75,687 75,687 495,811Particulate Matter 5,181 17,109 953 3,085 3,085 25,375Nitrogen Oxides 208,590 80,200 38,367 14,463 38,367 327,158Additional Emissions2006 Boiler Tested Emission FactorsEmissions by Fuel TypeFuel Emission FactorsPermit Emission Limits

# Attachment B – Cost EstimatesSelective Noncatalytic Reductio n Cost Analysis for (4) Massena West Plant Boilers Units Maximum firing rate (Qb) 755.2 MMBTU/HR -72% nat. gas 28% oil Nox Reduction (Nnox) 70% 30-50% typical for field applications MWno2 46.01 Gr/lb-mole Reagent NH3 MWr 17.03 Gr/lb-mole Reagent Flow Rate Mr 14.51 lb/h r Retention time 0.5 sec Normalized Stoichiometric Ratio 1.5 fig. 1.6 Ammonia Slip ~5 PPM fig.1.7 Estimated Nox Emission Rate 37.3468037 lb/hr -based on modernization emission calcs Electrical Cost $0.045 per kWh

A Direct Cost - DC (1998 $) $1,743,996 $950/MMBTU x Qb x {[ 2375MMBTUH / Qb MMBTUH ]^0.577} x (0.66 + 0.85 Nnox) B Indirect Cost - IC $348,799 20% of "A" C Project Contingency $313,919 15% of A + B D Total Plant Cost $2,406,714 D = A + B + C E Allowance for funds during Const. $0 Zero Assumed for SNCR F Royalty Allowance $0 Zero Assumed for SNCR G Preproduction Cost $48,134 2% D + E H Inventory Capital $250 55 gal drum (412 lb @ $0.23/lb + $50 deposit) I Initial Catalyst & Chemicals $0 Zero Assumed for SNCR Total Capital Investment (TCI) $2,455,09 9

Direct Annual Costs (DAC ) Operations and Supervisory 0 Zero Assumed for SNCR Maintenance $36,826 1.5% of TCI Annual Reagent $7,848 Assumes 43 lb./day@$0.50/lb 365 days/yr Utilities 2093.06 kW P = 0.47 * Nox-in * NSR * Qb / 9.5 Annual Electrical Cost $825,083 Assumes 8760 hrs/yr

Indirect Annual Costs (IDAC ) $269,557 IDAC = CRF x TCI Interest Rate - (I) 7.00% Equipment Life - (n) 15 years Capital Recovery Factor (CRF) 0.10979462 CRF = I (1+I)^n / (1+I)^n - 1

Total Annual Cost (TAC ) $1,139,31 3 TAC = IDAC + Maint + Reagent + Electrical

Nox Removed 114.51 Tons Nox emission rate * Nnox / 2000 lb/ton

Cost Efficienc y $9,950 per ton TAC / Nox Removed

Costing based on EPA Cost Manual, Sixth Edition, January 2002.

NOTE: This analysis does not account for many direct and indirect annual costs, is based on 1998 costs and dollar values and is based on a model that is designed for a coal fired boiler with a much higher heat input. Therefore the cost is assumed to be conservative, ie: lower than actual costs.Selective Catalytic Reductio n Cost Analysis for (4) Massena West Plant Boiler s Units Maximum firing rate (Qb) 755.2 MMBTU/HR 72% nat. gas(200 MMBtu/hr) 28% oil(160 MMBtu/hr) Nox Reduction (Nnox) 80% 30-50% typical for field applications MWno2 46.01 Gr/lb-mole Reagent NH3 MWr 17.03 Gr/lb-mole Reagent Flow Rate M r 16.59 lb/h r Retention time 0.5 sec Normalized Stoichiometric Ratio 1.5 fig. 1.6 Ammonia Slip ~5 PPM fig.1.7 Estimated Nox Emission Rate 37.3468037 lb/hr -based on modernization emission calcs Electrical Cost $0.045 per kWh

A Direct Cost - DC (1998 $) $4,365,971 $3380/MMBTU x Qb x {[ 3500MMBTUH / Qb MMBTUH ]^0.35} (conservatively does not factor costs for reactor height, ammonia flow rate, retrofit, SCR bypass, or initial charge of catalys t) B Indirect Cost - IC $873,194 20% of "A" C Project Contingency $785,875 15% of A + B D Total Plant Cost $6,025,039 D = A + B + C E Allowance for funds during Const. $0 Zero Assumed for SCR F Royalty Allowance $0 Zero Assumed for SCR G Preproduction Cost $120,501 2% D + E H Inventory Capital $250 55 gal drum (412 lb @ $0.23/lb + $50 deposit) I Initial Catalyst & Chemicals $0 Zero Assumed for SCR Total Capital Investment (TCI ) $6,145,790

Direct Annual Costs (DAC ) Operations and Supervisory 0 Zero Assumed for SCR Maintenance $92,187 1.5% of TCI Annual Reagent $7,848 Assumes 43 lb./day@$0.50/lb 365 days/yr Utilities 2093.06 kW P = 0.47 * Nox-in * NSR * Qb / 9.5 Annual Electrical Cost $825,083 Assumes 8760 hrs/yr

Indirect Annual Costs (IDAC ) $674,775 IDAC = CRF x TCI Interest Rate - (I) 7.00% Equipment Life - (n) 15 years Capital Recovery Factor (CRF) 0.10979462 CRF = I (1+I)^n / (1+I)^n - 1

Total Annual Cost (TAC ) $1,599,892 TAC = IDAC + Maint + Reagent + Electrical

Nox Removed 130.86 Tons Nox emission rate * Nnox / 2000 lb/ton

Cost Efficienc y $12,226 per ton TAC / Nox Removed

Costing based on EPA Cost Manual, Sixth Edition, January 2002.

NOTE: This analysis does not account for many direct and indirect annual costs, is based on 1998 costs and dollar values and is based on a model that is designed for a coal fired boiler with a much higher heat input. Therefore the cost is assumed to be conservative, ie: lower than actual costs.