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 – SO2 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, ERM 
ERM ES-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

EXECUTIVE SUMMARY 

The Clean Air Act (CAA) requires the protection of visibility in 156 scenic 

areas across the United States. Under CAA Section 169 (b)(2)(A), States 

must require certain existing stationary sources to install Best Available 

Retrofit Technology (BART). New York has implemented BART 

requirements under Title 6 of the New York Code of Rules and 

Regulations (NYCRR) Part 249. A stationary source (facility) is subject to 

BART if it: 

1. is in one of 26 specific source categories identified in 6 NYCRR 231-

2.2(c) (1) through (26); 

2. was not in operation prior to August 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 (SO2), nitrogen 

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

diameter (PM10). 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 BART applicability and has obtained the 

Department’s concurrence that the West Plant 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). 

The owner or operator of a source that is determined to be BART-eligible 

must conduct an analysis to determine 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 environmental 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 either meet presumptive BART; or 

demonstrate that no additional control is technically and economically 

feasible (economic infeasibility is based on a control cost of less than 
ERM ES-2 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

$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 

SO2 NOx PM10 

Potlines Add-on SO2 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 

SO2 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 BART 
ERM 1-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

1.0 INTRODUCTION 

The Clean Air Act (CAA) requires the protection of visibility in 156 scenic 

areas across the United States. Under CAA Section 169 (b)(2)(A), States 

must require certain existing stationary sources to install Best Available 

Retrofit Technology (BART). New York has implemented BART 

requirements under Title 6 of the New York Code of Rules and 

Regulations (NYCRR) Part 249. A stationary source (facility) is subject to 

BART if it: 

1. is in one of 26 specific source categories identified in 6 NYCRR 231-

2.2(c) (1) through (26); 

2. was not in operation prior to August 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 (PM10). Alcoa operates two primary and secondary aluminum 

smelting facilities in Massena New York – the East Plant and the West 

Plant. 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 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 applicable. The West Plant has the potential 

to emit greater than or equal to 250 tons/year of SO2, NOx, and PM10. 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 based 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 1-2 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

According to 6 NYCRR Subpart 249.3, the BART analysis must consider 

the following five factors: 

1. the costs of compliance; 

2. the energy and non-air quality environmental 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 (SO2, NOx, and PM10). 

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 determination of economic infeasibility is 

based on a control cost of less than $5,500 per ton of pollutant reduced. 

This is consistent with the response 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 modification application to the NYSDEC in 

support of modernization activities in Massena. For the purpose of 

estimating cost effectiveness of various emission control options, Alcoa 

has conservatively used the projected actual emissions from the Title V 

modification application. These post 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) SO2 NOx PM10

Potlines* 2,568 44 143 

Bake Furnaces 455 203 24 

Boilers** 248 164 13 

*emissions reflect 98% through the control devices

**Assuming PM10 emissions equal total PM emissions
ERM 2-1 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

2.0 BART-ELIGIBLE SOURCE EVALUATIONS 

2.1 POTLINES 

The Hall-Heroult process1 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 maintains the cell operating temperature. 

Molten cryolite (Na3AlF6) functions as both the electrolyte and the solvent 

for the alumina. The electrolytic reduction of Al2O3 by the carbon from the 

electrode occurs as follows: 

2AL2O3 + 3C → 4Al + 3CO2

Carbon anodes are continuously depleted by the reaction. In the 

electrolytic reduction of alumina, the carbon anodes are lowered into the 

cell and are consumed at a rate of about 2.57 cm (1 in) per day. Molten 

cryolite functions as both the electrolyte and the solvent for the alumina. 

Pure cryolite has a melting temperature of 1010 OC (1850 OF). The 

electrolyte contains fluorospar (CaF2), some AlF3, and lithium in some 

instances, which along with the dissolved alumina, reduces the melt 

temperature sufficiently to permit the cells to operate between 940 and 980 

OC (1725 and 1795 OF). Aluminum is deposited at the cathode, where it 

remains as molten metal below the surface of the cryolite bath. Aluminum 

metal is tapped every 24 to 48 hours beneath the cryolite cover using a 

vacuum siphon. The aluminum is then 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 prepared for the USEPA by Pacific 

Environmental Services, Inc. 
ERM 2-2 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

consistent with the method used for most of the aluminum produced in 

the U.S. 

2.1.1 SO2 

A detailed SO2 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 SO2 control analysis report based largely on the cost 

proposal provided by Babcock (the only proposal that fully met 

specifications). The results of this analysis estimate that the installation of 

a LSFO scrubber to control SO2 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 SO2 emissions from the West Plant potlines of 2,568 TPY (derived 

from a 2.5% sulfur in coke content) and an assumed 95% control 

efficiency, the cost to control SO2 emissions would be $12,623 per ton of 

SO2 controlled. Cost effectiveness calculations are provided as follows: 

2568.28 Tons 95% Control Efficiency = 2439.87 Tons Controlled

Year

$30,798,608 = $12,623

Year 2439.87 Tons Controlled Ton Controlled

This cost effectiveness value is well above the $5,500 per ton of SO2

controlled economic feasibility threshold used for case-by-case RACT and 

BART. The full cost effectiveness calculations are included 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. Most 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. Additionally, Alcoa considered the use of 
ERM 2-3 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

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 associated 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 prevention limit of 3% sulfur in the coke 

used to manufacture anodes satisfies BART. A November 2007 BART 

analysis for the Alcoa Washington Plant also determined that a pollution 

prevention limit of 3% sulfur in the coke used to manufacture anodes 

satisfies BART. Control cost analysis completed for these Plants was 

comparable to the Massena assessment and likewise concluded – in both 

cases - that add-on control was economically 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 NOx 

Available NOx emission control has been found to be technically infeasible 

through a prior RACT analysis. Based on the NYSDEC approved 

Massena East NOx RACT Plan dated 24 March 2009, there are no NOx

control technologies deemed to be technically feasible for potline emission 

control. This same conclusion is applicable to the Massena West Plant. 

All combustion modification techniques 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 NOx

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 Plants which determined that BART 

for potline NOx emissions is no controls. 

2.1.3 PM10 

Alcoa is proposing existing PM control as BART. 
ERM 2-4 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

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 impacts 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 insignificant 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 reduction, and the insignificant affect 

on PM on the total visibility impact, Alcoa proposes that existing PM 

emission control satisfies BART. 
ERM 2-5 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

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_gps NOx_gps PM10_gps

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_gps NOx_gps PM10_gps

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_gps NOx_gps PM10_gps

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 2-6 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

2.2 BAKE FURNACE 

Anodes are manufactured in an on-site paste production plant. Anodes 

are made from a "paste" (petroleum coke mixed with a pitch binder). Paste 

preparation includes the crushing, grinding, and screening of coke and 

cleaned spent anodes (butts) and blending 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 and a pulse jet baghouse. The baking 

furnace structure is a series of interconnected 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 control equipment through a series of 

ducts. The furnaces are fueled with natural gas. 

2.2.1 SO2 

SO2 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 SO2 control cost, the 

estimate for the installation of a LSFO scrubber on the potline was scaled 

for installation on the bake 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 SO2

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 SO2 controlled and, therefore, the 

installation of SO2 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 pollution prevention limit of 3% sulfur 

in the anode coke. Massena West already meets this limit. 
ERM 2-7 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

SO2 control cost analysis completed for Alcoa’s Tennessee and 

Washington Plants likewise concluded that bake furnace control was 

economically unreasonable. 

2.2.2 NOx 

Similar to the above referenced potline discussion, available NOx 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 temperature 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 determined 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 PM10 

Alcoa is proposing existing PM control 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 insignificant 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 consists 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 pairs with each pair served 

by a common breech to one exhaust stack. 
ERM 2-8 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

2.3.1 SO2

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 presumptive 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 NOx

Alcoa is proposing its existing NOx control (low NOx burners and flue 

gas recirculation) as BART. This approach is also being proposed as caseby-case RACT under 6 NYCRR Part 227-2 (please reference Appendix D). 

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 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 boilers 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 emission rates 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 operator 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. Economic 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 implementation 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 appropriately to be used to control all four 

boilers. Individual boiler add-on control was considered, but was 
ERM 2-9 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

determined to be even less cost effective. Other conservative factors used 

in the costing analysis included the use of 1998 dollars; a control efficiency 

of 70% for SNCR and 80% for SCR (these 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 be 

considered 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 the current RACT limit of 0.3 lbs/MMBtu. 

2.3.3 PM10

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

3.0 CONCLUSION 

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

SO2 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 SO2 control on the potline is not economically 

feasible. It is not technically feasible to control NOx emissions from the 

potline due to the low exhaust temperature as compared with the 

temperature required for effective use of SNCR or SCR controls. With 

regard to PM10, 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, SO2 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 furnaces was estimated at $13,795 per ton of 

SO2 controlled for the installation of an LSFO. Similar to the potline, this 

BART analysis determined that add-on SO2 control on the bake furnaces is 

economically infeasible. Also similar to the potlines, NOx control is 

considered technically infeasible since 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. Additional 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-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 range. 
Appendix A 

Hatch Alcoa Primary Metals – 

SO2 Scrubber for Alcoa Massena 

West Prefeasibility Study 

18 February 2009 
 Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West

Pre-feasibility Study - February 19, 2009

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page i

 © 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 File 
 Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West

Pre-feasibility Study - February 19, 2009

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page ii

 © 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 Correspondence
 Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West

Pre-feasibility Study - February 19, 2009

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 1

 © 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 (SO2) from the potroom off-gas from the Massena West smelter. A 

reduction in SO2 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 SO2 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% SO2 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 2

 © 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 

SO2 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/Nm3

 at the 

scrubber outlet. This is not a guaranteed value however. In previous studies the increase was 

even greater, up to 20 mg/Nm3

 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 3

 © 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 

SO2 mg/Nm3 300 (105 ppmv) 

SO3 negligible 

Oxygen % by volume 19 

Moisture % by volume 3 

HFgaseous mg/Nm3 1 

Total particulates mg/Nm3 5 

Static pressure required at inlet to collector duct 

(to be developed by vendor booster fans) 

in wg 3.0 

 

Limestone Wt. % CaCO3 95 

SO2 Removal Efficiency - Required % 95 

4. Raw Materials and Gypsum Product 

4.1 Raw Materials 

Limestone, mainly calcium carbonate (CaCO3), 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 (CaCO3). 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 4

 © 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 smelter

Omya StArmand, 

Quebec 

112 Limestone (-3/8 in) 

Typ. 95% CaCO3

5.20 19.60 25* 

Limestone (-3 mm) 

Typ. 97% CaCO3

Graymont Inc, 60* 

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 

SO2 from the off-gas. The overall chemical reaction is: 

SO2 (g) + CaCO3 (s) + 1⁄2 n O2 (g) + 2 H2O (l)  nCaSO4x (1-n) CaSO3x2H2O(s) + CO2 (g) 

where n>0.97 
 Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West

Pre-feasibility Study - February 19, 2009

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 5

 © 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 SO2 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 SO2 removal. With the low SO2

levels in the raw potroom gas, the use of organic buffers to enhance SO2 removal is not required. 

The bleed from the scrubber is controlled to allow a large retention time of the gypsum solids for 

both 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 SO2 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 6

 © Hatch 2006/03 a

Table 5-1: Process Data 

Performance Unit Predicted Values 

Babcock Power 

SO2 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 CaSO4 x 2H2O wt% 92.9 

 CaCO3 wt% 1.6 

 CaF2 wt% 0.22 

 Insolubles wt% 4.9 

Blowdown (purge) Quantity & Composition Assume no blowdown 

Particulate (stack) Emissions mg/Nm3 7.5 

Absorber superficial gas velocity ft/sec 12 

L/G (liquid/gas ratio) gal/1000 ft3 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/Nm3

 to 7.5 mg/Nm3. 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 7

 © 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 1 
 Alcoa Primary Metals - SO2 Scrubber for Alcoa Massena West

Pre-feasibility Study - February 19, 2009

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 8

 © 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 9

 © 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 SO2 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 10

 © 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% CaCO3, 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

ISO 9001 H329821-0000-xx-124-000x, Rev. 0, Page 11

 © 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 

Calculations 
Potline and Bake Furnace Limestone Slurry Forced Oxidation (LSFO) Scrubber Costing Calculations

Based on the HATCH 18 February 2009 SO2 Scrubber Report

Flowrate (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 efficiency

Capital Cost Potline Cost Million $

Anode Bake Scaling 

Factor*

Anode Bake 

Cost Million $

Equipment 71 0.20 14Installation 71 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 costs 158 31Indirect costs including Owners cost & EPCM (assume 10% of direct costs) 16 0.20 3Total direct & indirect cost 174 34

Contingency 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 in Perry's Chemical Engineer's Handbook , Sixth Edition, McGraw-Hill.

Annual Operating Cost Unit Cost Potline Quantity

Potline Total 

Cost $/yr

Anode Bake Scaling 

Factor Note

T

Limestone $25/ton 6,300 tons/yr 157,000 0.18 1 Electricity $0.08/kW hr* 5,275 kW 3,696,000 0.13 2 

Water $1.5/1000 gal** 570 gpm 449,000 0.13 2 

Compressed air $0.01/scfm/hr** 120 scfm 11,000 0.13 2 

Labor $41.5/hr*

1 operator, 3 shifts/day

+15% supervision 417,000 None 

Gypsum disposal $83/ton 11,800 tons/yr* 979,000 0.18 1 Maintenance 2,172,000 0.13 2 

Total 7,881,000 

*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 Redundant Single

Cost Effectiveness Absorption Towers Absorption Tower

Potline Bake Furnace Potline

A. Total Annualized Costs (incl. Capital and O&M)Expected Lifetime of Equipment Costs (yrs) 15 15 15Interest Rate 0.07 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 $24,914,494

B. 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 2440

Cost 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 ESTIMATES 

 
ERM 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 been 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 Subpart 227 requires the submittal 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 statement 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 boilers 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 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 compelled to present an analysis of other 

possible RACT compliance options. A review of possible add-on NOx 

emission control (Selective Catalytic 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 gas 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 be 

considered 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 the 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 been 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 large boilers are based on the application of low NOx 

burners regardless of the type of fuel used.” The West Plant boilers 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, because the 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 analysis 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 consist 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 pairs with each pair served by a common 

breech to one exhaust stack. 

2.1 PROJECTED ACTUAL NOX 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 factor to account for an anticipated 

increase in heat input demand resulting 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 options 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 statement 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 compelled to present an analysis of other 

compliance options in the 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 maintain the flexibility to fire both fuels 
ERM 3-2 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

as a means of assuring business continuity. Therefore, fuel switching is 

not a viable option. 

3.4 SYSTEM AVERAGING PLAN 

The system averaging plan employs a weighted average permissible 

emission rate. A weighted average permissible emission rate is the 

average emission rate of all operating 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 with the permissible emission rate 

applicable to that emission source. 

The system averaging plan is not applicable 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 (N2) 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% rangei

NOx is removed by the following chemical reactions: 

4NO + 4NH3 + O2  4N2 + 6H2O 

4NO2 + 4NH3 + O2  3N2 + 6H2O 

These reactions require significant activation 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, 6th Edition, 2002. 
ERM 3-3 ALCOA MASSENA WEST PLANT-0118199-9/23/2010

oxides), the recommended operating 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 controls 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). Additionally, 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). Please note that cost estimates were 

developed assuming that all four boilers were vented to a single emission 

control device. Separate control devices were reviewed (one per boiler) 

and determined to be even less cost effective (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 operator 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. Economic 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 implementation 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 Statement 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 technology 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 retrofitting 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 limit of 0.3 lbs/MMBtu be incorporated 

into the West Plant operating permit. 
Attachment A – Projected Actual 

Emissions 
Emission Unit B-00001 Pollutant NOx SO2 

West Plant Boilerhouse Emissions lb/yr 327,158 495,811 

18.03% increase in MMBTU annual demand due to carbon plant production doubling

Percentage 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 MMBTU

MMCF or 1000 gal P-225 Plan

Natural Gas 681.7 106 ft3 695,300 125,384 125.4 Average West Plant Aluminum 

No. 6 Fuel Oil 1782.2 1000 gallons 267,334 48,208 321.4 Sca

Natural Gas assumes - 1,020 Btu/cfNo.6 Fuel Oil assumes - 150,000 Btu/gal

Natural Gas Natural Gas No. 6 Fuel Oil No. 6 Fuel Oil

Pollutant (lb/MMbtu) (lb/MMcf) (lb/MMBtu) (lb/ 1000 gal)Carbon Monoxide 0.007 7.14 0.013 2.0

Nitrogen Oxides 0.08 81.6 0.27 41Particulate Matter 0.064 10NOx 0.3 306 0.3 45

PM 0.1 15Natural Gas assumes - 1,020 Btu/cfNo.6 Fuel Oil assumes - 150,000 Btu/gal

Natural Gas No. 6 Fuel Oil

Pollutant (lb/106 ft3) (lb/ 1000 gal)

Carbon Monoxide 7.14 2.0Sulfur Dioxide 0.6 236Particulate Matter 7.6 9.6Nitrogen Oxides 306 45.0Emission Factors in red are based on 2006 boiler test data and the rest are 1998 AP-42 emission factors

Emission Factors in blue are based on Permit emission limitsYearly Emissions

Yearly

Natural Gas No. 6 Fuel Oil Natural Gas No. 6 Fuel Oil Worst Case Total

Pollutant (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 38,367 327,158

Additional Emissions

2006 Boiler Tested Emission Factors

Emissions by Fuel Type

Fuel Emission Factors

Permit Emission Limits
Attachment B – Cost Estimates 
Selective Noncatalytic Reduction

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/hr

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) $2,455,099

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) $1,139,313 TAC = IDAC + Maint + Reagent + Electrical

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

Cost Efficiency $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 Reduction

Cost Analysis for (4) Massena West Plant Boilers

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 Mr 16.59 lb/hr

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 catalyst) 

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 Efficiency $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.