,'

### ..

, , 

# ..
. ;".,.

DEPARTMENT OFENVIRONMENTAL QUALITY AIR QUALITY DIVISION Permit Application Analysis AP-3545 November 18, 2008

"" NAME OFFIRM: NAMEOFFACILITY: FACILITY LOCATION:

" TYPE'OF OPERATION:

.. RESPONSIBLEOFFICIAL: (", MAILING ADDRESS:

.¥•• ':, TELEPHONE NUMBER:

,I R,EVIEWERS:

<.;, PURPOSE OF APPLICATION: Mountain CementCompany LaramieCement Plant SE'/. Section 17, TI5N, R73W Albany County, Wyoming POItlandCementPlant Phil Lane, PlantManager 5 Sand Creek Road Laramie, WY 82070 (307) 745-4879 Andrew Keyfauver, NSR Permit Engineer Don Watzel, Air Quality Modeler

Mountain Cemcnt Company submitted an application to modify operations at the Laramie Cement Plant with the replacement ofthe two existing long-dry kilns (KI and K2) with a fivc-stage cyclone preheater rotary kiln, The kiln will be designed to producc 963,600 tons ofclinkerannually which is approximately a 20% increase in clinker production over the currently permined level of801,500 tons ofclinkcr per year. In addition, the newkiln will be fired on coal, petroleum coke, ornatural gas, Mountain Cement Company replaced an ESP with abaghouse to control particulate emissions from Kiln 

## .c:' #2 under pcI'mit waiverAP-4004, Underthe waiverthe baghouse retained the same particulate emission limit as the ESP, and a revised emission limit was to be established with the application for the new kiln at the facility, The Division is proposing to establish an emission rate of0,008 grldscf(0,I Iblton clinkcr) and 6,2 Iblhr forthe baghousecontrolling Kiln #2, Additionally, the Division is proposingthe installation 

## , ' ofa PM continuous emission monitor (CEM) onthe Kiln#2 baghouse as this baghousc will be utilized to control the new kiln, ,':

,', .;:

'.

# f Mountain Cement Company - Laramie Cement Plant AP·3S45 Application Analysis Page 8 Table VI Mountain Cement Company Hazardous AirPollutant (HAP) Emissions HAP TPY Arsenic 0,01 Beryllium 0,0003 Cadmium 0,0011 Chromium 0.004 Hydrogen Chloride 67.45 Mercury 0.06 Lead 0.04 Selenium 0.10 acenaphthylene 0.06 Benzene 7,71 benzola)anthracene 0.00002 benzo(a)pyrene 0.0001 benzo(b)fluoranthene 0.0003 benzo(g,h,I )perylene 0.00004 benzolk)fluoranthene 0.0001 chrysene 0.0001 dibenz(a,h)anthracene 0.0003 fluoranthene 0.004 fluorene 0.01 formaldehyde 0.22 naphthalene 0.82 phenanthrene 0.19 pyrene 0.0021 Total 76.62
CHAPTER6, SECTION 2 - BESTAVAILABLE CONTROLTECHNOLOGY (BACT): Per the requirements ofChapter 6, Section 2 ofthe WAQSR, all facilities must demonstrate the use of BACT. Therefore, Mountain Cement Companyconducted aBACTanalysis forthe control ofpollutants.

• NO, Emissions Control Options Mountain Cement Company identified the following technologies for the control ofNO, emissions from the proposed preheaterkiln atthe Laramie Cement Plant: LowNO, Burners (LNB) Flue Gas Recirculation Multi-Stage Combustion Good Combustion PracticesMountain Cement Company - Laramie Cement Plant AP-3545 Application Analysis Page9 SelectiveCatalytic Reduction (SCR) SelectiveNon-Catalytic Reduction (SNCR) Low-NO, burners control the formation of NO, by controlling the mixing of air and fuel, causing off-stoichiometric combustion (uses excess air). LNBs are designed to reduce peak flame temp, and residence time which is the main cause ofNO, formation. The most common fornls ofLNBs arc staged airorstaged fuel burners usually designed for boilers. Flue gas recirculation is intended to reduce the oxygen contentofthe primary combustion air used forthe main burnerpipe, thereby loweringthe peak flame temperature in the burningzone. Multi-stage combustion is designed to burn fuel in two stages. Staged air combustion suppresses the formation ofNO, by operating under fuel-rich, reducing conditions (less than stoichiometric oxygen) in the flame or primary zone where most ofthe NO, is formed. This is followed by oxygen-rich conditions in a downstream, secondary zone where CO is oxidized at a lower temperature with minimal NO., formation. SCR reduces NO, emissions by injecting ammonia into the exhaust gas stream upstream ofa catalyst. The ammonia reacts with NO, on the catalyst to fonn molecular nitrogen and water vapor. For the SCR system to operate properly, the exhaust gas must be within a temperature range of 300 to I100°F dependingon thecatalysttype used. Selective non-catalytic reduction (SNCR) reduces NO, emissions by injection ofammonia or urea into theexhaustgas stream. SNCR is similarto SCR in that both systems use ammoniato react with nitrogen; however, SNCR operates at higher temperatures than SCR and does not use catalyst. The effective temperature range for SNCR is 1

### SOO to 2J00 OF. ]OliminateTechnically Infeasible**Option~** Based on an initial evaluation of the identified control technologies, Mountain Ccment Company eliminated flue gas recirculation, multi-stage combustion, and SCR. rlue gas recirculation was eliminated as reducing conditions caused by oxygen deficiency are detrimental to maintaining cement clinker quality. Multi-staged combustion was eliminated as this technology is applied to preheater/precalciner kiln systems and not stand-alone preheater kiln systems. SCR was eliminated as these systems have been proven to be unsuitable as the fine alkaline dust from the cement process inhibits catalystactivity. Rank RemainingTechnologies The following NO, control technologies are ranked according to the level ofemission rates achievable (control effectiveness);"aufltllin Cement Compllny - Laramie Cement Plant AP-J545Application Analysis I'age 10 Table VII Mountain Cement Company Ranking ofNO, ControlTechnolo!!ies Control Technology Emission Rate Tons peryear (Ib/ton clinker) SNCR/Low NO, Burners 2.0 963.6 Low NOx Burners 4.0 1927.2 Good Combustion Practices 5.9 2842.6 Evaluate Remaining Technologies Mountain Cement Company proposed Low NO, burners as their base case for NO, control for the

. ,... proposed kiln. Therefore, Mountain Cement Company further examined the environmental, energy, and ,- economic impacts of installing SNCR in addition to Low NO, burners. Economic impacts for SNCR were evaluatcd overa range ofcontrol efficiencies (20-50%). The following table shows the average cost effectiveness forcontrollingNO, emissions with the use ofSNCR in addition to Low NO, burners. Table VIII Mountain Cement Company Avera!!e Cost Effectiveness NO, Additional Emission (%) Control Emission Rate Annual Cost Cost Effectiveness Reduction (tpy)

Reduction Case I 20 

### 3.2 Iblton clinker $1,748,518 

### $4,540/ton 385.4 Case 2 30 

### 2.8 Ib/ton clinker $1,796,698 $3,II

### Olton 578.2 Case 3 40 2.4 Ib/ton clinker $1,844,878 

### $2,390/ton 770.9 Case4 50 

### 2.0 Iblton clinker $1,893,058 

### $1,960/ton 963.6 The average cost effectiveness is the total annualized cost for the option, including capital cost and annual operating and maintenance costs, divided by the emission reduction. The Division considers the average cost effectiveness to be reasonable for all four options. In addition to average cost effectiveness, the draft 1990 New Source Review Workshop Manual provides a method to evaluate incremental cost effectiveness between dominant options known as the least cost envelope. For this method, a plot of annual emission reduction vs. total annualized cost is produced and the dominant control options are indicated by fitting acurve or line through the lowerand right most points. Points above and to the leftof the line are considered inferior controls because points on the line provide more emissions reduction for less money. The lease cost envelope for NO, control is shown below:NO. Least Cost Evelope
$1,920,000 

### ,------r---------,..----_,_--- Mountain Cement Company- Laramie Cement Plant AP-3545 Application Analysis Page II



## _. , $1,900,000 . $1,880,000 $1,860,000

) $1,840,000 

## " 

# " , c $1,820,000 

### i 

# ------1 -,I 

### i i 

# ·r·---·------._--,---

I ' Cast3
i
_._-

__••-1.

__ .. '-"--'-i"-
$1,800,000 Case2

1000 900 700 800 500 800 400

I i 

### ·_--t'--_· CaSt I ! $1,780,000 $1,760,000 

# r-·-----r ---I 51,7040,000**+-----r--------;----_-----4-----4------;----~** 300 .f

NOx Emission Reduction (tpvl All of the options are on the curve and are, therefore, dominant options. The incremental cost effectiveness for all the options is calculated in the following tablc_ Thc incremental emission reduction and incremental increase in total annualized cost is the difference in these values for each option from the previous table_ The incremental cost effectivcness is the incremental increase in total annualized cost divided by the incremental emissionreduction. Table IX Mountain CementCompany NO, Incremental Cost Incremental Emissions Incremental Increase in Incrcmental Cost Options Compared Effectiveness Reduction (tpy) Total Annualized Cost ($) ($/ton) Case I and Case 2 192.8 48,180 250 Case 2and Case 3 192.7 48,180 250 Case 3 and Case4 192_6 48,180 250 [n this case, the average cost effectiveness for all options is clearly within thc range the Division has considered acceptable. The Division considers the incremental cost effectiveness of $250 Iblton reasonablc for an additional 193 tpy emission reduction. Therefore, the incremental cost effectiveness is considered reasonable for an emission level of2 Ib/ton clinker (Case 4)_Mountain Cement Company- Laramie Cement Plant AP-}545 Application Analysis Page 12 As part oftheir analysis for SNCR, Mountain Cement Company presented information that additional loadingofammonia inthe flue gas could lead to the formation ofadetached plume, and thatthis detached plumc could potentially exceed opacity standards. Sub-micron aerosols consisting primarily ofN/-l.C1 and (NH.),SO. are considered to be the major constituents ofdetached plumes. These compounds are formed by the reaction ofammonia with chlorides and sulfates in the exhaustgases. The Division reviewed the EPA's RACT/BACT/LEAR Clearinghouse (RBLC) for permits with NO, limits associated with portland cement plants. The five (5) most recent permits entered into the clearinghouse (2004-2006) indicate that recent determinations have required the use of SNCR for the control of NO, with pennined levels of 1.95 Ib NO/ton clinker on a 30-day rolling average. Additionally, the technical analyses for these permits also indicated the possibility ofthe formation ofa detached plume with the use ofSNCR. The Division contacted the Florida Department of Environmental Protection (FDEP) regarding the CEMEX

- Brooksville Cement Plant which has preheater kilns controlled with SNCR. FDEP indicated thatthese kilns are limitedto 2.0 Ib/ton clinkerNO, based on a30-dayrolling average and thatthese kilns have actual NO, emission rates in the range of 1.5-1.7 Iblton clinker. FDEP also indicated that detached plumes are a possibility with SNCR, but that any issues associated with a detached plume can be remedied. Onesuch remedyconsists ofadding lime to the top ofthe preheatertower. During reviewofthis application, EPA proposed revisions to Subpart Fof40 CFR part 60 which is anew sourceperformance standard for portland cement plants. In the proposed revisions to Subpart F, EPA has proposed a NO, emission limit of 1.5 Ib/ton of clinker on a 30-day rolling avcrage for sources constructed, reconstructed or modified after June 16, 2008. The proposed NO, limit in Subpart F will apply to all kiln types, but the proposed NO, limit is based on the operation ofpreheater/precalcinerkilns and not preheater kilns. However, for preheater/precalciner kilns to achieve this NO, emission rate it would require the installation ofSNCR. It should also be noted that EPA considered the possibility of SNCR systems creating a detached plume when they established the NO, I imit under the proposed revisions to Subpart F. SelectNO, BACT(Conclusion) Based on the cost effectiveness and incremental cost ofinstalling SNCR, the Division considers SNCR with Low NO, burners with emission limits of2.0 lb/ton clinker (30-day rolling average) and 220 Ib/hr (30-day rolling average) as representing BACT for NO, for the preheater kiln. The Division evaluated Mountain Cement Company's concem regarding the presence of a detached plume; however, after discussions with FDEP and reviewing EPA's proposed revisions to Subpart F the issues regarding a detached plume can be remedied. The Division will propose thatNO, emissions from the kiln be limited to 2.0 Ib/ton clinker. However, as the EPA revisions to Subpart F(includes NO, limits) are not final, the Division will require Mountain CementCompany to provide areport on the impactofthe final Subpart F revision as discussed in the new source performance standards section ofthis analysis. Ifthe report identifies that the preheater kiln is subject to a lower NO, limit, then the Division will administratively amend thc permitto reflectthe lowcr limit.