### ALCOA

25 October 2010 Alcoa Pn=ry M'lills!A/coo Forglngs and Extrusions Massena 

### Opcrabonsl-\ht Planl 

## P"'***~...,""** r." Moutno,.I\'Y J3U2-<lISO

## us....

Mr. Chris lalone, PE. :'\.'YSDEC

- Region 6 Division ofAir Resources 317 Washington Street Watertown, 

# 1'\..,,,, York 13601


### RE: Alcoa MassenaWest Operations BART and NOx RAG Assessment RespollSl! to 1\'YSDECs Comments and Questions [)(>ar Mr. lalone: This correspondence is being submitted by Alcoa Massena West Operations (Alcoa) in respolt5e to comments regarding the Alcoa Best Available Retrofit Technology (BART) report dated September 

### 2010 and the associated NOx Reasonably Available Control Technology (RACT) assessment. 

### Specifi<:ally, Alcoa's responses**addr~** the comments received on 14 October 2010 in your ","mail to the undersigned Oordan Parent, Alcoa). l\'YSDEC comments are identified in 

### ,talles. and Alcoa responses follow each respective romment. BART S«tion 1.1: 1. Why

### aren't roo/monitorI"rnl55Umsfrom tiltpotline roalwl1!d

### as apossible 

### SQUm'of**~m'55lOn ~duction?**  Control of roofmonitor emissions was eliminated [rom consideration based on the dear e.::onomic infeasibility of controlling such a large volume ofexhaust gas with a relatively low pollutant concentration. Specifically, total particulate matter (PM) concentration in the roof monitor exhausts are typically in the range of0.2 mgJdscf
....ith an exhaust flow typically greater than 4 million dsdm. Control of

### this element ofthe potline PM emission would dearly exceed the BART e.::onomic feasibility threshold. Regulatory development studies corroborate 

### this rationale and have collCiuded that roof monitor controls are cost prohibitive. For example, Appendix BofCSEPA's NBasis and Purpose" document for the 

### Primary Aluminum Maximum Achievable Control (MACT} Standard concludes that the use ofwet scrubbing technology to control PM emissions ranged from about 

### $13,000 \0 o\'er 

### 542.000 per ton. 

### 2. The 

### PM-lOemisswns

### from thepotlme utilizedin tile 

### BARTanalY51Sare 143 

### tpy "'h,1e 

### thepostmo<krnizatWn PM-lOemi55ions

### from tilepallin<: 

### al? 165 tpy. 

### \'\Ihat 's tile 

### sourceo/this d'scrqancy' Page 1 ofSThe 143 TPY PM·I0 emission rate represents the emission from the potline stack emissions only (the A-398 stack emissions). The roof monitor emissions were excluded for the reaSOn stated above. Total**P~I·1O** (stack and roofmonitor) emissions reported for the post-modernization pollines are actually 168 TPY (not 165). Please 

### see the below basis:

A·393 • 1 91 1 lbs 1':\1_10 149.298 'onAI 1 'on 143 TrY ton AI 

# '"'**~,.** J.lornlor

- 0.339 lbsPM·]O 149293 IOn AI 

# ,". • 

# "'"**~"** 

# '"'**~,.** To
..l _ 

# ,.'"

3, 1k NO, emISSIOnSfrom the boilers shouldbi basedOn boIlerPTE and not titt'future actual emissions. 'The PTE should be basedan the maximum**~rmit!<'d** NO, em15SlOn rale unless thefaCility is ll·illmg to lUapt a lmn'rpownMl emISSIOn I,mlt. 'The PTEfor NO, alilltptrmltemisswn 

### l,mit rJfO.3Ib/MNfBIll is 1051 

### tpy. Alcoa is <:ommitted to maintaining annual boiler NUx emissions to the level ""presented as future actual rate in the modernization permit application and assumed that this rate would be incorporated into the permit as an enforceable tenn. BART Se<:tion 2.1.1: 4. Since a wd,um-«<sed wet scrublnng syslem is u"li",d successfully at the Alcoo Eas' Plant it would be nice to 'itt the comple'e economic analysis rJf a SImilar sys!<'m at'he Alcoa 

### \tWs, pumt. As stated in Section 2.1.1 of the BART report, Alcoa considered the use ofsodium based scrubbing technology and found that limestone scrubbing options had some significant advantages including, a solid waste stream that is mO"" environmentally friendly; a bleed stream that is 0; to 10 times smaller; a wastewater treatment advantage with associated co:st savings; a more cost effective reagent; and a reduced nero. for fresh water rinsing. In addition, Alcoa·s experience at the East Plant has also revealed a significanl water treatment issue associated with the sulfate levels in the scrubber blowdown. The result is the inability to effectively treat fluoride in high sulfate concentration wastewaters prior to discharge, thus jeopardizing compliance with federal Effluent Limit Guideline (ELG) 40 CFR421.l3n, for wet air pollution 

### OO11trol. For these reasons, a direct cost analysis of the sodium based technology was determined to be unnecessary. The cost is recognized to be approximately the same as the co:st estimate developed for the limestone slurry forced oxidation system. and sodiwn based technology is recogniZed to have the above referenced technical disadvantages. BART Section 2.2.1: Page20fS

### 5. Alcoa should prol'ldt

### an aS5eSsmentofa sodlum-ba5ed wetscrubbing systemjJr the anodt baklng furMas.

Please see the above referenced response to comment No
... abo'·e. BART Se<:non 2.3.3: 

### 6. iJ\1ult PM-l0emlSSlan lilt.> 

### IS Alcoo

### pr0p05lngjJ. BARP 15 It 

### the r:nstmg ptmllt 

### limit. the Histing emIsSIOn lilt.>, 

### orSOme mllU' ll'ith 

### thepTt'SllmptH'e limit**ran~** 

### conlmned In 

### MANE-VU's 

### FIl'f'-fa£tor analysis' As 

### stated in 

### Section No. 2.3.3 

### ofthe BART report. given the low PM emission rate, and the insignificant aff"<:t ofP:>Ol 

### on the Iotal visibility impairment. Alcoa proposes that the existing P:>01 

### emission rate satisfies BART (i.e.; the current permit limit ofO.llbs per MMBtu). NOx RAcr Sedion 3.5, 

### 7. Huwold all' lhe cumnt low NO, 

### bu"",rs In 

### the ""'lers! Alcoo 

### shouldIm'f'shgale thepossilnilty of inswJling IIe'W loTI' NO, 

### burners tlml could prmndt

### amllnufaclureTs guarantudemISSIon mit thatIs lowe. than the cu.....ntRACThmlt0f0.3lb/MMBlu lindpossibly mtl't 

### Ihe 1U'lI'

### RACTlimit of 0,15 Ib/MMbtu. The cuTTentlow KOx 

### burnel'$ were installed in 1998. 

### The boilers have established emission rates through recent testing of0.08 Ib/MMBtu and 0.27 lbIMMBtu when firing gas 

### and oil respectively. This actual rate is lower than the current RACT 

### limit of 0.3 

### Ib/MMBtu On an 

### annual average basis, given the ratio offuel oil to gas combustion.. boiler acrual emissions do meet the new RACT 

### limit ofO.13lb/MMBtu. Since the boilers already have low NO" burners (1998 

### vintage), use flue gas recirculation firing technology. and meetlhe new NO" limit on an annual average basis: Alcoa did not develop a cost analysis for bumcr replacement that would be focused exclusively on reducing oil fired emission to below the new NOx limit of0.15 IbsIMMBtu. BART 

### Appendix A -**H~tch** SO,**Prefe~sibilily** 

### Study: 2 - 

### Summary: 

### 8. Halch sw.ted lhat thepna of lhe 

# usa system inrllultdabsorbers 1l11hfive spmy l.n'tls 

### lindfive pumpslind thatHatch belia'f'da 95% 

### rernOl-'01 of 

## so, couldbe oclria'td 

### u1thfewer sprrry kt'tls 

### Huw much Ion",. 

### would the rost be 

### n'Ithfe""" spray let",ls? Based 

### on information provided by Hatch. the inclusion offive full spray levels in the absorber tower design is 

### found to be conservative and comes from the application in power plants where this is a common practice. Hakh has indicated that the total can be reduced by at least one full 

### spray le"el (possibly h\-'o) including a pump for each absorber tower. If one spray level could be reduced, it would eliminate the following equipment and associated 

### capital costin an absorber tower:



### • one set of 

### piping
• one set 

### ofspray nozzles ?age30f5• a recycle pump ('<Jmplete with motor and controls

• one large '-alve in the suction ofthe pump
• five ffft ofabsorber tower ht>ight; and

• one set supporting beams inside the absorber tower. Hatch has estimated that the associated cost reduction is in the order of 1.5 percent ofthe total installed costs (approximately $3.1 in uSD). This reduction has only a marginal affed when applied to the cost effectiveness evaluation, and still leaves the total c05t effectiveness above 512,000 per ton of

### SO, controlled. 

### 9. Hatch slated thai asmall cost5/lv;ng "':rnld

### be realiud uSlllg aconl'fnlronal II"", wf'l 

### scrubblllg**~tem** 

### andsuggesled thai sud, asystem shouldbe 

### cDr,sidt>red as all 

### optlOIl. Did

### Ale,., perform an eCOllom;canalysisfor a <lJn"rnt!ollallllnl" "'rt 

### saubbmg system? Hatch has completed an economical analysis ofwet lime scrubbing although this was not speocifically done for Alcoa's Massena operations. In Hatch's experience the wet lime scrubber has a 7 percent lower capital cost to install and a 5.5 pera-nt lower capitali7.ed. cost per ton of metal relative to the L5FO process. 

## nus would mean that for the Massena operations, the total installed costs for conventional lime wet scrubbing are in order of5194 million 

## usn (,-ersus 5208 million for LSFO). While this is lo
.....er than the LSFO process, the difference is such that the required overall investment and cost effectiveness is still in the same order of magnitude and well above the threshold ofS5500 per ton. BART Appendix B - Siemens Energy**Propos~l:** 10. 

### \'VI,"!! wasn't tilt' S
...

### ""'ns quote, fd"ch "'as 569 

### mill,ollforequ,pmelltand ;nsta!lnlwn of a

### one hm",r u",1

### Jlue gas

### desuljunzalwn (FGD) 

### absororr, u5l'd ,n calmlahng tilt' cost

### eJfectifoeness ofrelllCl'mg so, 

### from lilt'poW""erhaust' The 

### Siemens estimate,s 533 

### ml1l;OIl less 

### than the 

### Babcockquotefor a s'milar 

### system. Based on information provided by Hatch, the Siemens proposal had a different scope than that provided by Balx:ock. Specifically, the Siemens proposal contains only one absorber tower, one gypsum de
.....atering unit and one centrifugal fan which are insufficient to assure BART compliana-, To provide 100% up-time, almost tv.·ice the amount ofequipment offered by Siemens is required. Further, Hatch has indicated that the installationcosts provided by Siemens are too low. Hatch's experience is that costs to install FGD systems are more in the range of50 percent ofthe total direct costs (the installation ofFGD at an aluminum smelter is much more uncommon than at a power plant). Given these reasons, Hatch found that the Balx:ock Power scope was more complete, provided more reliable cost information, and was more appropriate as a primary source for the report. 11. 5
..."
...

### "s stated tilat

### Iht'y «11et",dadry FGD 

### typr: 

### spray dryerab50rorr

### may 

# « SUIted

### forcontrol of 

# so, ffl/isswns

## from**t~** 

### potli"", \'VI,"!! was I"is 

### option notfi'<lluated? Siemens based its comment regarding the use ofa dry FGD scrubber on the application ofthis technology in coal fired power plants combusting low suUur coal. The Akoa application is a much different scenario. 

### Dry scrubbing control for a smelter was reviewed by HATCH and determined to be technically infeasible due to: insufficient exhaust gas temperature from 

### a Page -I ofSsmelter (in power PWlt applia.tions 

### the reagent is 

### injected into theboiler 

### dischuge when,> the temperature is**aoo..~** 

### the re;oction temperature required for 

### a.bsorption on 

### the lIbsorberrt), the technology 

### has not

# mn demonstrated on a large-scale itS no smelter emplo)'5 this 

### technology, 

### and the la.rge phY'5ical volume required

- 

### the requirement for a dl')' 

### filter S}'5tem is mudt 

### larger tha.n the**~'olume** in a wet pr0ce55. 

### For**~lassena** thi!; wOl.lld 

### rne..n that a separate...t of filters would 

### be requlrtd, 

### lind there is simpl}' not enough space for this applia.tion. Additionally, if the technology was applicable, 

### the dl')' process has a mIlCh

### higher operating enst due to lower utilization ofthe reagent and higher power COItSI.lmption. B«ause all of the gasesrould be addressed 

### by a wet scrubber with a much smaller volume, the dry process was excluded from further study. Thank you for your assistance with this maUer. [f you have any questions or comments. please do not hesitate to contact me at 

### (315) i64-4737.

# ~;;~/v--- kdanJ. Parmi 

### Sr. SllIffEnvironmenllll Enitnft'r



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