1400 11 TH ~BISON AVENUE· HELENA, MT 59601 • 406-442-5768

ENGINEERING, FAX: 406-449-6653 • E-MAIL blson@blson-eng.com • www.bison-eng.com INC. 

January 25, 2008 k~cYsj1~:!!l1­

Subiect to Confidentiality Cialni ,~

Callie Videtich 

Air Quality Planning and Management Unit 

US EPA - Region 8 

1595 Wynkoop Street 

Denver, CO 80202-1129 

Dear Ms. Videtich: 

RE: Holcim BART Analysis - Response to EPA Comments 

Holcim has received your letter dated November 26, 2007, requesting more information. 

On behalf of Holcim US, Inc. (Holcim), Bison Engineering, Inc. (Bison) is pleased to 

submit responses to your questions. We have copied EPA's comments from your letter 

(numbered and marked by a black dot and small type), and furnished Holcim's 

responses in larger type. The responses are contained in Attachment A to this letter. 

A revised wet S02 scrubber cost analysis discussed in the comment responses is 

contained in Attachment B. A cost analysis for S02 control is contained in attachment C. 

Please note Holcim considers the data contained in Attachment Band 

Attachment C CONFIDENTIAL and requests that EPA not distribute or publish 

these attachments. 

Please let us know if you have any questions on our responses. I can be reached at 

406-442-5768, or Eric Ervin can be reached at 406-285-3985. 

ib'l Hal obbins 

U President 

cc: Eric Ervin - Holcim 

Attachments 

An Employee Ovvned Company 
Attachment A
 

EPA Comment #1 

S02 Emissions and Controls 

•	 The analysis used 10 years as the basis for the remaining useful life ofthe scrubber, however
 

the useful life of these control technologies is expected to be 15 years based on information
 

from the EPA Control Cost Manual ("EPA Air Pollution Control CostManual", Sixth ed.,
 

EPA-452-02-001, January 2002, Section 5.2, Chapter 2, page 2-51). Holcim needs to
 

reanalyze the annualized costs forthe scrubber using fifteen years as provided in the EPA'
 

Control Cost Manual. '.
 

Holcim Response 

Holcim understands that the useful life expectancy of a wet venturi scrubber is up to 15 

years; however, Holcim still believes a 10-year basis for BACT and BART analysis is 

standard and typical. This is based on financial concerns (Le., duration of financing 

rather than equipment life expectancy). To be complete, Holcim has analyzed the 

annualized cost for 15 years. These calculations include a revised cost estimate for the 

wet venturi scrubber as explained in comment #3. As you can see from the equations 

below, the annualized cost changes from $5.3 million/yr on a 10-year basis to $5.0 

million/yr on a 15-year basis. This change is not large enough to substantially affect the 

results of Holcim's BART analysis as to whether the control device is economically 

feasible on a $/ton or a $/deciview basis. 

.	 i(l +i)" -- Capital Recovery Factor (CRF) Formula:	 ---'-----'­

(1 + i)" -1 

7%(1 + 7%)10	 . -- CRF for 10 yrs @ 7%: 10 = 0.142 (Annualized cost =$5,334,982/yr) (1 + 7%) -1 . 

7%(1 + 7%)15 . -- CRF for 15 yrs @ 7%: 15 =0.110 (Annualized cost =$5,029,378/yr) (1 + 7%) -1 

$5,334,982 = $19,847,4041 deciview & $5,334,982 = $10,342Iton
 

0.269deciviewb. 516tonb.
 

$5,029,378 = $18,710,4821 deciview & $5,029,378 = $9,750Iton
 

0.269deciviewb. 516tonb.
 

EPA Comment #2 

•	 In section 4.3.2, Holcim eliminates fuel substitution as a means for reducing S<h referencing
 

a statement in the BART Guidelines which reads: "Pollution prevention: use ofinherently
 

lower-emittingprocesseslpractices, including the use of control techniques (e.g.low-NOX
 

burners) and work practices that prevent emissions and resUlt in lower "production specific" .
 

emissions (note that it is not our intent to direct States to switch fuel forms, e.g. from coal to
 

gas)" (see 70 FR39164, July 6, 2005). EPA did not intend this to mean that sources should
 

Attachment A	 Page 1 
not be looking at potentially switching to a lower sulfur content coal (or coke) if the source is 

already using coal (or coke) for fuel. The language is meant for situations where a facility 

~'ould be looking at switching from one type of fuel to another, such as coal to natural gas. 

Fuel substitution to lower the fuel sulfur content can be a very cost effective means for 

reducing S02 emissions and should be analyzed. 

Holcim Response 

To start, Holcim believes that the design of the current kiln, a long, wet kiln with a strong 

alkali and lime atmosphere is, by itself, an ideal wet S02 scrubber. Holcim calculates 

that the kiln is approximately 95 to 99+% effective in removing S02 from the kiln 

exhaust gas. This results in little to no sulfur left in the exhaust gas stream. Historical 

data confirms this. For example, the last reference method stack test for S02, performed 

in September of 2007, showed an S02 emission rate of 0.06 Ibs/hour. In addition, the 

average S02 emission rate for calendar year 2007 was 13.1 Ibs/hr (based on CEM 

data). This information confirms that the current plant configuration lends itself as an 

effective S02 scrubbing system. 

The data indicates that switching to a lower-sulfur fuel will, in reality, have little 

measurable effect on S02 emissions. In addition, these lower sulfur emissions lead to a 

negligible improvement in visibility at nearby Class I areas since modeled improvements 

are based on extreme situations rather than the norm. 

Nonetheless, to answer the comment, a fuel switching analysis has been performed to 

determine the visibility improvement and associated costs with several different fuel 

blend scenarios. Keep in mind, this whole analysis is based on the emission limit of 124 

Ibs/hr on a 30-day rolling basis, and actual emissions are closer to zero. Thus, the 

visibility improvements and cost calculations are grossly inflated. 

Currently, Holcim's goal is to operate the kiln using a 40% petroleum coke / 60% coal 

blend on a Btu basis. Holcim's current coke supply has an average sulfur content of 

approximately 5.3%, with a heat value of approximately 14,000 Btu/lb on an as-received 

basis. Holcim's current coal supply has an average sulfur content of approximately 

0.8%, with a heat value of approximately 9,350 Btu/lb on an as-received basis. 

The coal Holcim uses is a low sulfur, high Btu content western coal. Holcim is not aware 

of a coal supply with a significantly lower sulfur content. For purposes of a fuel switching 

analysis, it is assumed that this coal will be used exclusively. The petroleum coke 

Holcim uses has a relatively high sulfur content, but is considered typical for a coke 

used as a fuel. There are other grades of coke that have similar Btu values, but have 

lower sulfur contents. Holcim has identified two other grades of coke that are available, 

at higher costs. 

For the purposes of this fuel switching analysis, Holcim has briefly followed the same 

BART five-step process as outlined in the Holcim BART report. 

Attachment A Page 2 
Step 1 - Identify S02 Reducing Fuel Blends 

For purposes of this analysis, Holcim has identified the current desired operating 

coal/coke blend as the baseline case. Four other coal/coke blends, as identified below, 

were analyzed for costs and visibility impacts. The scenarios are as follows (all blends 

are on a Btu basis): 

• Baseline: 40% coke (5.3% S) / 60% coal (0.8% S) 

• Option 1: 25% coke (5.3% S) / 75% coal (0.8% S) 

• Option 2: 25% coke (3.5% S) / 75% coal (0.8% S) 

• Option 3: 25% coke (2.9% S) / 75% coal (0.8% S) 

• Option 4: 0% coke /100% coal (0.8% S) 

Step 2 - Eliminate Technically Infeasible Fuel Blend Options 

All of the above listed fuel blends can be easily implemented; therefore none is 

eliminated on the basis of being technically infeasible. 

Step 3 - Evaluate Control Effectiveness of Remaining Control Options 

Table 1 below lists the estimated S02 control efficiencies of the fuel blend options. 

Step 4 - Evaluate Impacts and Document Results 

Fuel Blending Economic Impacts 

Holcim has calculated the cost-effectiveness for employing each of the fuel blend 

options for S02 control, with the results presented in Table 1 below. Holcim has utilized 

vendor information on coke availability and cost on a dollar per ton basis in these 

calculations. To calculate the cost-effectiveness of a fuel blend in dollars per ton ($/ton), 

the following equation is used: 

Cost-effectiveness ($/ton) = [(total capital investment x capital recovery factor 

{CRF}) + Direct Annual Cost + Indirect Annual Cost]/(tons S02 controlled) 

In this case, since Holcim already blends fuels, there is no capital investment or indirect 

annual cost, the only cost is the direct added cost of lower sulfur fuels. 

Fuel Blending Environmental Impacts 

Holcim is not aware of any adverse environmental impacts of using any of the fuel blend 

options. 

Attachment A Page 3 
Fuel Blending Energy Impacts 

Holcim is not aware of any adverse energy impacts of using any of the fuel blend 

options. 

Step 5 - Evaluate Visibility Impacts 

Holcim used the CALPUFF model to predict visibility impacts of the identified fuel 

blending 802control options, using the 98th percentile visibility result as recommended 

by EPA. The results of the analysis are shown in Table 1 on the following page. The 

results are only presented for the Gates of the Mountains Wilderness Area, as it is the 

closer, and more impacted Class I Area. Details of the modeling are found in Appendix 

B of the original Holcim BART report. 

Holcim notes that this data seems to show option #1 is the most cost-effective method 

of reducing visibility impacts on both a dollar per ton and dollar per deciview 

improvement. Holcim believes, however, that this table does not represent actual 

emission rates or visibility impacts at the Trident plant. Table 1 does not take the 

effectiveness of the kiln as an 802 scrubber into account, which shows up in the tons 

emitted of 802 from the different options. 

Holcim analyzed the data in Table 1 using the same baseline as in the original Holcim 

BART report. However, as explained above, Holcim believes the baseline 802 emission 

rate of 124 Ibs/hr over-represents the actual emissions from the kiln. Using the average 

2007 802 emissions rate from the 802 CEM8 changes the baseline emission rate to 

approximately 13 Ibs/hr, Table 2 gives a realistic estimate of tons removed, costs and 

visibility impacts from implementing fuel switching at the Trident plant. 

Attachment A Page 4 
» 

3 

Table 1: Fuels Switching 502 Analysis (Baseline of 124 Ibs/hr 502)

fir 

C'l 

::r 

CI> 

;l 

» 

Control Option 

Annualized 

Cost 

S02 

Removal 

Efficiency 

(%) 

S02 

Emission 

Rate 

(tpy) 

Tons 

Removed 

Cost 

($/ton) 

Incremental 

($/ton) 

Gates of the Mou

S02 

Impact 

(deciview) 

Deciviews 

(24 hr -~)

Co

($/d

Option 4:100% 

Coal $659,651 62% 205 338 $1,954 -$37,447 1.324 0.24 $2,795

Option 3: Using 

25% Coke with a 

2.9% Sulfur $3,215,480 50% 274 269 $11,941 $65,672 1.337 0.22 $14,39

Content 

Option 2: Using 

25% Coke with a 

3.5% Sulfur $1,620,480 45% 298 245 $6,614 $18,940 1.341 0.22 $7,402

Content 

Option 1:Using 

25% Coke with a 

5.3% Sulfur $240,515 32% 371 172 $1,397 -­ 1.354 0.21 $1,170

Content 

Baseline: Using 

40% Coke with a 

5.3% Sulfur $0 0% 543 0 -­ -­ 1.56 -­ -­ 

Content 

"'U 

OJ 

<C 

CI> 

U1 
3 

Table 2: Fuels Switching 502 Analysis (Baseline of 13 Ibs/hr 502) 

» 

fir 

n 

::J 

CD 

;l 

» Control Option 

Annualized 

Cost 

Efficiency 

(%) 

S02 

(tpy) 

Tons 

Removed 

Cost 

($/ton) 

Incremental 

($/ton) 

Gates of the Mountains 

S02 

Impact 

(deciview) 

Deciviews 

(24 hr - M 

Cost 

($/dc) 

Using 100% Coal $659,651 62% 22 35 $18,637 -$357,090 1.290 0.0065 $101,065,953 

Option 3: Using 

25% Coke with a 

2.9% Sulfur $3,215,480 50% 29 28 $113,874 $626,276 1.291 0.0052 $617,520,202 

Content 

Option 2: Using 

25% Coke with a 

3.5% Sulfur $1,620,480 45% 31 26 $63,077 $180,614 1.292 0.0047 $342,057,924 

Content 

Option 1:Using 

25% Coke with a 

5.3% Sulfur $240,515 32% 39 18 $13,325 -­ 1.293 0.0033 $72,258,844 

Content 

Baseline: Using 

40% Coke with a 

5.3% Sulfur $0 0% 57 0 -­ -­ 1.297 -­ -­ 

Content 

Note: Baseline emissions of 57 tons/yr were based on the average CEM data at the Trident plant 2007 under normal o

The average 802 emissions during those years was 13.1 Ibs/hr. This is 89.5% lower than the permitted limit. 

"1J 

OJ 

<0 

CD 

0> 
Based upon the modeling results, the use of fuel switching, in practice, will result in 

negligible visibility improvement. Even when using the best figure for control at 62%, 

this option has a projected 0.0065 deciview impact on visibility. This change in visibility 

at the nearest Class I Area is imperceptible. The costs of any of the fuel blend options, 

on a dollars per deciview improvement are astronomical. 

Select BART 

Of the alternative fuel blending options identified above, none achieve a perceptible 

visibility improvement, and none are economically feasible at the Trident facility. 

Therefore, no new fuel blending requirements for S02 control are proposed under the 

BART program. Holcim proposes to continue to employ the baseline of proper kiln 

design and operation and comply with the existing S02 emission limitation (124 Ibs/hour 

on a rolling 30-day basis). 

EPA Comment #3 

•	 The BART analysis estimates the purchase cost for a venturi scrubber at $14,500,500. We
 

have cost estimate information for venturi scrubbers that is significantly less than the cost
 

estimate you provided. Please provide documentation for this purchase cost.
 

Holcirn Response 

In responding to this comment, we have discovered an error in our cost analysis for the 

venturi scrubber. The value of $14,500,000 was mistakenly put into our cost analysis as 

the purchase cost. Holcim had estimated this value to be the approximate Capital Cost 

Investment (purchase and installation costs combined). 

Holcim has performed a revised and more detailed site-specific cost analysis for the 

venturi scrubber. The new purchased cost is estimated to be $2,703,683. Holcim has 

provided the spreadsheet showing the new cost analysis as Attachment B to this letter. 

Because other tables of the original BART report rely on this cost information, Holcim 

has revised the tables in the report addressing purchased and installed costs for the 

venturi scrubber, cost analyses for performance on a dollar per ton removed and dollar 

per deciview improvement basis. 

The tables that have been revised are Table 4-2: Summary of S02 Cost Analysis on 

page 4-11 and Table 4-3: Summary of S02 Visibility Impacts on page 4-12 of the 

original BART report. The revised tables are presented below. 

In addition, we have discovered a mathematical error in the original Table 4-3: 

Summary of S02 Visibility Impacts. The two cells containing the Cost in dollars per 

deciview ($/dc) for the Wet S02 Scrubber and the Spray Dry Absorber were calculated 

incorrectly. The revised table below corrects that error as well 

Attachment A	 Page 7 
U fSO etAnalysls. 'PiddT ate able 42- . Summary 0 2	 os I
 

502
 

Control 

Option 

Estimated 

Annualized 

Cost 

Efficiency 

(%) 

Wet S02 

Scrubber $5,334,982 95% 

Spray Dry 

Absorber 

(includes 

baahouse) $6,070,650 90% 

Baseline $0 0% 

Emissions 

(Ibs/hr) 

6.20 

12.40 

124 

502 

Emissions 

(tpy) 

Tons 

Removed 

Cost 

($/ton) 

Incremental 

($/ton) 

27 516 $10,342 -$27,090 

54 489 $12,422 -­

543 0 -­ -­

Updated Table 4-3: Summary of S02 Visibili~ Impacts 

Gates of the MountainslYellowstone National Park Estimated 502 

Control 

Option 

Annualized 

Cost 

Efficiency 

(%) 

Emissions 

(Ibs/hr) S021mpact 

(deciview)b 

Deciviews 

(24 hr - M 

Cost 

($/dc) 

Incremental 

($/dc) 

Wet S02 

Scrubber $5,334,982 95% 6.20 1.291 0.269 $19,847,404 -$147,133,624 

Spray Dry 

Absorber 

(includes 

baQhouse) $6,070,650 90% 12.40 1.296 0.264 $23,012,321 -­

Baseline $0 0% 124 1.56 0.000 -­ -­

EPA Comment #4 

•	 The conclusions presented in Table 4-2 and other parts of this docwnent are driven by the
 

high capital equipment costs f~r the wet scrubber. If the information requested above differs
 

from the original estimated cost of $14,500,500, we ask that Holcimreanalyze the part~ of
 

the BART analysis that are affected by this figure.
 

Holcirn Response 

A purchase cost of $2,703,683 was updated in the cost analysis tables and is provided 

as Attachment B. Although the purchased cost of the Wet S02 Scrubber has dropped 

dramatically, the error in Table 4-3 has artificially lowered the costs on a dollar per 

deciview change for both the Wet S02 Scrubber and the Spray Dry Absorber. The 

corrected Table 4-3 now shows lowered annualized costs, but increased the costs for 

both technologies on a dollars per deciview improvement basis. 

The data presented in the revised tables does not change Holcim's conclusions about 

the use of either S02 control technology. Both technologies listed in Table 4-3 above 

have similar performance and similar costs. Holcim believes that the cost in dollars per 

deciview for either technology is excessive. Holcim also believes that the annualized 

Attachment A	 Page 8 
costs of 5 to 6 million dollars per year are unwarranted when the visibility improvement 

is 0.264 to 0.269 deciviews, which is not detectable by the human eye. 

In addition, Holcim also wants to re-emphasize that the above analysis was based on 

the current emission limit of 124 Ibs/hr. Holcim believes this greatly exaggerates actual 

802 emissions, and overstates any 802 reduction and visibility improvements made by 

the addition of 802controls to the kiln. 

Of the two alternative 802 control technologies identified above, neither is economically 

justified or produces a perceptible result. Therefore, Holcim proposes to continue to 

employ the baseline of proper kiln design and operation and comply with the existing 

802 emission limitation (124 Ibs/hour on a rolling 30-day basis). No new requirements 

for 802 are proposed under the BART program. 

EPA Comment #5 

NOx Emissions and Controls 

•	 Section 4.4 ofyour analysis lists proper kiln design and operation as one ofthe possible
 

control options and as the baseline in the analysis for other control options but does not
 

provide information on the current design and operation ofthe kiln~ Please provide
 

information on the current kiln design and operation and an analysis on whether additional
 

reductions can be achieved through proper kiln design and operation.
 

Holcim Response 

The current kiln, which was constructed in 1973, is a long, wet kiln design. Holcim 

believes the kiln is well designed for its intended purpose, a relatively low production 

facility. (More typical cement plants constructed in the past 30 years have been much 

larger). Holcim operates the kiln to minimize NOx emissions while still meeting product 

quality requirements. Holcim is always searching for ways to improve product quality, 

production efficiency and emissions performance. 

To that end, Holcim has worked with the kiln and control system for many years to 

minimize NOx emissions. Holcim employs extensively trained kiln operators, uses a 

state-of-the-art computer control system and operates a NOx CEM8 in an effort to 

monitor and minimize NOx formation. Through years of experience and optimization, 

Holcim believes the kiln is operated properlyI and no further NOx reductions can be

made without design changes or add-on controls. 

Holcim has performed an analysis on theoretical and practical ways to reduce NOx 

emissions, as listed in pages 4-12 through 4-14 of the BART report. Holcim identified 

several changes to the system, including increased thermal efficiency through improved 

clinker cooler sealing, and decreased combustion temperatures through the switch to a 

low NOx burner and other combustion system changes. These are changes to the 

existing design and methods of operation that were not envisioned when the kiln was 

Attachment A	 Page 9 
constructed. The low NOx burner and combustion system modifications achieve all five 

of the theoretical ways to reduce NOx formation as spelled out on page 4-13. 

Holcim believes changing the kiln to another design, such as pre-heater dry kiln, may 

lower NOx emission rates, and it would be theoretically possible to implement a 

fundamental change to the kiln and plant design. Holcim also believes that the practical 

and economic realities of such a change preclude this from actually being done (See 

response to EPA comment #11). In addition, a complete rebuilding of the kiln and plant 

layout to accommodate such a change goes far beyond the scope of BART. The BART 

program is meant to apply a retrofit technology to an existing source, not to replace the 

source itself. 

Holcim only meant for the phrase "proper kiln design and operation" to serve as the 

baseline case of existing equipment operated to minimize NOx formation, and that any 

identified improvements would be clearly spelled out as retrofits to the existing system. 

EPA Comment #6 

•	 In addition to the installation of a fixed inlet to the clinker cooler and the installation of a low
 

NOx burner, Holcim should continue to consider mid-kiln firing and Selective Non-Catalytic
 

Reduction (SNCR) as viable BART control technologies for NOx emission reduction. Mid­


kiln firing is expected to achieve an emission reduction of45% or more (see H~en, Eric R
 

Technical Consultant, Cadence Environmental Energy Inc. "Staged Combustion for NOx
 

Reduction Using High Pressure Air Injection." IEEE2002). SNCR has been ap:plied to wet
 

kilns and can reliably attain a NOx emission rate of 800 mg/m3, and in most cases attain a
 

rate of 500 mg/m3 (see Scur, P. Cemex Ostzement, Red.ersdorf. Hoppe, Dr, Forchunginstitut
 

der Zementindustrie, Dusseldorf. "The Present State of NOx Abatement with the SNCR
 

Process.", Cement International No. 2/2006, Volume 4., ISSN 1610-6199 and Assessment of
 

NOx EmiSsions Reduction Strategies for Cement Kilns - Ellis County...,. Final Report.
 

Prepared by ERG, Inc.. for Texas Commission on Environmental Quality. TECQ Cotract No.
 

582-04-65589, Work Order No; 05..Q6. July 14,2006). Please provide additional analyses
 

and documentation for both ofthese potential control measures.
 

Holcim Response 

Mid-Kiln Firing of Tires 

Holcim wants to again emphasize that the use of tires is prohibited by Montana rule 

unless an air quality permit authorizing the incineration of tires is issued to Holcim. As 

detailed in the BART report, Holcim applied for such a permit in 2001, and it has yet to 

be issued. The permit is waiting for completion of a Montana Environmental Impact 

Statement by the Montana Department of Environmental Quality (DEQ). It appears that 

the probability of receiving a final permit free of legal challenges within the next few 

years is very low. Holcim cannot commit to the use of mid-kiln injection of tires, nor can 

Holcim commit to a lower NOx limit achieved through the use of tires. Therefore, Holcim 

believes any analysis of exactly how much NOx reduction can be achieved is irrelevant, 

since this system is not proposed as BART and cannot, by rule, be installed. 

Attachment A	 Page 10 
Selective Non-Catalytic Reduction (SNCR) 

Since the initial BART submittal in July of 2007 and at your suggestion, Holcim has 

continued to research the possibility of applying SNCR-type technology to its kiln 

operation at Trident. After considerable review as it applies to Trident and other 

installations, we have come to believe that indeed an SNCR-type of technology may be 

possible, at least on a trial basis, for the kiln at Trident. 

To that end, Holcim proposes to forgo an extensive re-analysis of BART for NOx for the 

kiln, and commit to install, on a trial basis, an SNCR system on the kiln. Holcim believes 

that an SNCR would offer at least a 30% NOx reduction, which would make it equal to 

or better than the best performing NOx reduction technology identified in Table 4-4 of 

Holcim's BART report. Holcim would install, operate and test the new SNCR system for 

a period of time (one year for example), analyze the actual NOx reductions achieved 

from that system, and then propose a new BART-derived limit for NOx for the kiln. 

As of the date of this document, Holcim has not chosen a specific SNCR system to 

install. Therefore, technical details of the proposed system will not be known until the 

required research is completed. Holcim is aware of two styles of SNCR which could be 

retrofitted to the kiln. One uses a solid pelletized form of urea, which could be 

mechanically introduced into the existing "dust scoops" mechanism. The other would 

involve a system to inject liquid urea into the proper temperature zone in the kiln. 

Holcim believes it can start the trial process by installing the necessary equipment to 

study the proper temperature zone in the kiln. This will be accomplished by installing a 

series of thermocouples in the kiln shell during the planned annual outage during April 

of 2009 

Following installation of the thermocouples to determine the proper temperature zone, 

Holcim will engineer and procure the associated equipment for installation of the trial 

SNCR in approximately April of 2010. Trials would occur over the next year with the 

intent of establishing an agreed upon reduction limit within one year, by April 2011. 

EPA Comment #7 

•	 Table 4-4 lists the efficiency for mid-kiln injection oftires as 30%. A value of40% for wet
 

kilns has been documented and we request that Holcim provide a revised analysis for this .
 

. control option using a value of40% for the wet kiln or an analysis of why 40% is pot
 

achievable (see NOx Control Technologies for the Cement Industry. Battye, R., SWalsh, J.
 

Lee-Greco, ECIR Incorporated prepared for U.S. EPA under contract No. 68-D-98-026.
 

September 19,2000. Table 5-7).
 

Holcim Response 

Obviously, Holcim does not have direct experience of expected NOx reductions from 

the use of TDF at the Trident facility. Rather, Holcim has relied on other studies of 

Attachment A	 Page 11 
actual installations elsewhere to estimate NOx reduction efficiency. Holcim used 30% 

as a conservative number taken from other studies. 

In examining the EPA referenced document, an average of 40.5% NOx reduction was 

reported in Table 5-7 on page 67, but the lowest value reported from the three wet kilns 

was a 27.5% reduction. Also, in Table 5-9 on page 75, which summarizes the NOx 

reductions cited for European kilns, a range of 20-40% reduction is listed. Given the 

variable nature of the existing data, the low number of similar installations and a lack of 

data on how mid-kiln injection of tires would actually perform at Trident, Holcim felt 

choosing a conservative but reasonable value of 30% was appropriate. 

Holcim feels that a 40% reduction may be achievable, but to base the entire BART 

analysis and a new NOx limit on 40% is foolhardy, as this number mayor may not 

actually be achieved in practice. 

In addition, as stated in the response to #6 above, Holcim will likely not be permitted to 

use TDF in the timelimes outlined in the BART regulations. Therefore, the use of TDF is 

not achievable and cannot be BART. 

EPA Comment #8 

•	 The document states that details ofthe cost analysis for low-NOx burners, and mid-kiln fuel
 

injection are included in Appendix C. However, Appendix C did /)ot include these analyses.
 

Please submit the details ofthe cost analysis for 10w-NOx burners and mid-kiln injection.'
 

Holcim Response 

Holcim was incorrect in stating that a cost analysis for either of these control 

technologies could be found in Appendix C. Section 4.4.4 of the report explains the 

details of the cost analysis for the annualized cost of LNB and mid-kiln firing conversion. 

As stated in Section 4.4.4, page 4-23 of the report, Holcim referenced the guidance 

document EPA NOx Control Technologies for Cement Industry Final Report, (9/19/00), 

Table 6-8 for costs of 10w-NOx burners and Table 6-10 for costs of mid-kiln fuel 

injection. Holcim used a 1.25607 CPI multiplier to adjust to 2006 dollars. 

Table 6-8 estimates an annualized cost of $389,000 (1997 dollars) for retrofit LNB 

installations for a 50 ton/hr long wet kiln. It is assumed this is a representative cost. The 

adjusted annualized cost was calculated to be $498,065. Table 6-10 estimates an 

annualized cost of $370,000 (1997 dollars) for mid-kiln firing conversion for a 50 ton/hr 

long wet kiln. It is assumed this is a representative cost. The adjusted annualized cost 

was calculated to be $473,738. 

EPA Comment #9 

•	 Using the permitted NOx emission rate to determine tons ofNOx removed is problematic.
 

The permitted value is very high relative to the actual emissions. The maximum NOx
 

Attachment A	 Page 12 
emission rate during the three year period of 2001-2003 was reported as 7841bslhour. The
 

permitted value is 1,568 Ibslhour, or twice the maximum value reported for the three year
 

period. Using the permitted value as the baseline could give a calculated post control
 

emission rate larger than the actual uncontrolled emissions. For example proposing a 20%
 

NOx reduction with a pennit limitation of 1,254 Ibslhour would allow an emission increase
 

from the currently reported maximum hourly rate of784Ibslhour..It is appropriate to use
 

actual emissions if those are representative of how Holcim has been operating in the past. In
 

addition, Holcim used actual emissions to model visibility for the BART analysis and the
 

emissions used in the modeling and the rest ofthe analysis need to be consistent. Please
 

t;evise the analysis using actual emissions.
 

Holcim Response 

We have reviewed your concern regarding the fact that the permitted emission rate for 

NOx (1,568 lb/hour) is higher than the actual reported rate (24-hour max) of 784 Ib/hour. 

We offer several observations and the rationale for our use of the permitted rate. 

1. Applicability. 

To begin, the 24-hour maximum rate was used primarily, in our OpiniOn, for 

applicability purposes. The term applicability here refers to the determination of 

which sources are "BART-eligible sources" (those sources that primarily meet the 

requirements of 40 CFR 51, Appendix Y, Section II) in conjunction with those 

sources that are determined to be "subject to BART" (40 CFR 51, Appendix Y, 

Section 111.1). The "subject to BART" analysis was conducted by EPA and the 

results are summarized in your February 28, 2007 letter. The letter includes a 

summary of dispersion modeling results, including indirect references to the 

actual emission rates, and requesting Holcim to conduct BART engineering 

studies. 

To that end, the BART Guideline (40 CFR 51, Appendix Y) and the Montana 

"Modeling Protocol For Federal Mandatory Class I Areas,,1 require that the 

emission rate used in the dispersion modeling be the "24-hour average actual 

emission rate from the highest emitting day of the meteorological period, unless 

this rate reflects periods of start-up, shutdown, or malfunction."z 

Once an applicability determination is (was) made, then its use is not necessarily 

required for continuing analyses of defining an appropriate BART technology. 

That is not to say that the "actual" values would necessarily be ignored. However, 

we believe we have provided a more conservative approach to the NOx BART 

analysis by using the allowable emission rate in the technology analysis section 

of our July, 2007 submittal. Additional information is provided below. 

1 http://www.epa.gov/Region8/air/pdf/MontanaBARTProtocoI0906.pdf. 

2 40 CFR 51, Appendix Y, Section 11I.A.3. 

Attachment A Page 13 
2. Conservative Analysis. 

Your comment: 

"Using the permitted values as a baseline could give a 

calculated post control emission rate larger than the actual 

uncontrolled emissions. " 

This sentence appears to be misleading. The discussion intimates that any 

control technology that could be applied (to Holcim) will yield a larger emission 

reduction rate than starting the comparison from the actual emission rates. The 

statement is factually correct, but its implied impact (the selection of a BACT 

technology that is inappropriately weak) is not. 

The selection of BART is based on a number of factors. Once all of the infeasible 

or otherwise inappropriate technologies are eliminated, the selection of the "final" 

BART is based, in large part, on the cost-effectiveness of the remaining 

technologies coupled with visibility improvements, all other factors being equal. 

This analysis is typically expressed as an annualized cost of the alternatives 

divided by the reduction in emissions from each control. 3 

Once a particular technology is considered, the cost of that technology remains 

fixed within the parameters of this discussion regardless of the emission rate. 

The final cost-effectiveness figure depends on the denominator of the equation, 

the tons of emissions reduction. 

From that perspective, the selection of a less stringent BART technology would 

be favored by using the actual emission rate. If that were done, then the costeffectiveness of the control technologies would be about one-half the costeffectiveness of the same strategy if one uses the permitted figures (as Holcim 

has done). 

For the BART analyses conducted in the July 2007 submittal along with this 

document, Holcim has chosen to use the permitted emission rate for consistent 

analysis. Such a technique has led to an artificially low cost-effectiveness of 

available technologies. Therefore, the approach is a conservative one for the 

BART program. 

Regardless, it is clear both from the July 2007 submittal and this document that 

the use of either the actual or permitted values for NOx would not change the 

selected control technology. This submittal proposes to use the most effective 

feasible control technology for purposes of NOx control: 

3 See Steps 3 and 4 Section IV.D of Appendix Y (70 FR 69164, et seq.) 

Attachment A Page 14 
• fixed clinker cooler inlet; 

combustion system modification (low NOx burner); and 

• a demonstration project SNCR . 

Therefore, no additional analyses are necessary nor would they lead to an 

alternative technology selection. 

EPA Comment #10 

Particulate Matter Emissions and Controls 

•	 Holcim did not provide any design parameters for the existing PM control technologies on 

the ESP on the kiln and the baghouse on the clinker cooler. It is possible that BART for PM 

for these two sources could include additional controls and/or increased perfonnance of,the 

existing technologies. The BART Guidelines state that ~'For emission units subject to a 

BART review, there will often be control measures or devices already in place. For such 

emission units, it is important to include control options that involve improvements to 

existing cO!1trols and not to limit the control options only to thOse measures that involve a 

, complete replacement of control devices" (see 70 FR 39164, July 6, 2005). We ask that 

Holcim submit the design parameter information for PM controls on the kiln and clinker 

cooler and evaluate the possibility ofadditional controls and increased perfonnance ofthe 

existing equipment. ' 

Holcim Response 

The ESP on the kiln has a 99.9%+ control efficiency as estimated by Holcim and 

independently estimated by Montana DEQ (referenced in the BART report). The 

baghouse on the clinker cooler also has an estimated 99.9%+ control efficiency. Holcim 

believes these control system performance figures to be typical for modern installations. 

In the most recent stack testing on each source, the ESP tested at a total particulate 

emission rate of 0.0146 gr/dscf (Sept 2007), and the clinker cooler baghouse tested at 

0.0139 gr/dscf (Oct 2006). These emission rates are consistent with sources at similar 

facilities, and represent the highest level of control that is achieved in practice with the 

same device; therefore, the existing controls were chosen as BART and were not 

further analyzed. 

In Holcim's opinion, the phrase that reads "it is important to include control options that 

involve improvements to existing controls" means that a system not performing to 

modern standards could be rebuilt for improved performance. For example, an existing 

older S02 scrubber achieving a 70% S02 reduction could be brought up to modern 

standards and be made to achieve a 90 or 95% reduction. In this case, Holcim is not 

aware of any improvements that could be made to increase the performance of the 

existing systems. 

Methods to improve the performance of the existing ESP and baghouse were not 

evaluated because the BART Guideline states that, "if a source commits to a BART 

determination that consists of the most stringent controls available, then there is no 

need to complete the remaining analyses in this section." 

Attachment A	 Page 15 
EPA Comment #11 

Overall Comments 

•	 Your analysis did not include a conversion from a wet kiln to a semi-dry or dry kiln. Several
 

documents in the literature indicate that both of these demonstrated options would offer
 

substantial emissions reductions at' potentially reasonable costs (see Assessment ofNOx
 

Emissions Reduction Strategies for Cement Kilns - Ems Co.unty - Final Report. Prepared by
 

ERG, Inc. for Te~as Commission on Environmental Quality. TECQ Cntract No. 582-04­


65589, Work Order No. 05-06. July 14,2006 and A Unique Approach. Menke, T., Jepsen.
 

O.L., and Keefe, B.P. Review No. 136. Reprint from IEEE-IASIPSCA 2001 Cement
 

industry Technical Conference May 2001 and published in International Cement Review,
 

July 2001). Please include an analysis that addresses a conversion from a wet kiln to a semi­


dry or dry kiln.
 

Holcirn Response 

As mentioned in the response to comment #5, Holcim believes changing the kiln to 

another design, such as a pre-heater, pre-calciner or dry kiln would lower NOx emission 

rates on a pound per ton of clinker produced basis. There are no major technical 

challenges to convert the plant to one of those designs. The challenges come in the 

economic realities of such a change. 

To modify the kiln design would actually require a re-configuration of much of the rest of 

the plant as well. Holcim converted its Devils Slide, Utah plant to a dry kiln in 1998. 

Holcim reported the total cost at $133 million. In todays dollars, that figure exceeds 

$200 million. 

Furthermore, Holcim and its competitors already serve a market that is smaller than its 

capacity. The Portland Cement Association projects that the Montana market demand 

will not exceed capacity for approximately 20 years. Therefore, the market demand 

simply does not exist at this time to satisfy the construction a plant with the capacity of 

the Devil's Slide plant, the smallest of any Holcim plants recently constructed. To 

construct a dry plant the size of the existing Trident plant simply to reduce NOx 

emissions (other BART related criteria pollutants would be nearly the same) would 

simply be uneconomical. 

Holcim believes that a reconstruction of the kiln and supporting plant structure goes far 

beyond what is meant by a "retrofit technology" under the meaning of the BART 

program. The BART program is meant to apply a retrofit technology to an existing 

source (constructed 1962 to 1977), not to replace the source itself. If the kiln were redesigned and replaced, the kiln would be a new or re-constructed source, and would fall 

outside of the authority of the BART program. The kiln would be permitted under the 

Montana PSD permitting process, which would then address modeling and visibility 

issues at Class I and other areas. 

Attachment A	 Page 16 
EPA Comment #12 

There are also several locations in the document that may have typographical errors. 

•	 On page 3-3 in Section 3.3 it states that the BART modeling analysis perfonned for
 

Holcim used the pennitted NOx PTE to establish the baseline visibility impacts. The
 

pennitted value is given as 1,568 Ibslhr on a rolling 30-day average (6,868 tons/year). As
 

provided in Table 3-2, the rate that was modeled is 784 lbslhour. . .
 

Holcim Response 

Section 3.3 of Holcim's BART report is correct; the permitted limit of 1,568 Ibs per hour 

was used by Holcim for NOx reduction modeling and associated visibility analysis. 

Table 3-2 refers to the initial applicability test and modeling performed by EPA, where 

the highest actual 24-hour rate of 784 Ibs/hr was used. See response to Comment #9 

for further information. 

EPA Comment #13 

-.	 On page 4-11 the secOnd technology analyzed 'wet S02 scrubber impacts' begins with a 

(c) rather than a (b). Is there a missing analysis? 

Holcim Response 

No, this is a typographical error. It should read (b) Wet 502 Scrubber Impacts. 

EPA Comment #14 

•	 On p~ge 4~23 the web address for the CPI multiplier does not work. 

Holcim Response 

This link was successfully used after reading this comment. It is 

http://www.rninneapolisfed.org/research/data/us/calc/. 

Attachment A	 Page 17 
----

---

Appendix 8 

-CONFIDENTIAL- Trident Plant A<;tual Emissions 

S02 Emissions (lpy) 543 

Airflow (acfm) 172959 

Production (tpd) 957.6 

Direct Costs 

Purchased Equipment Cost· Scrubber $2.073,683 xponentJal scaling using an exponent of 0.7 and ratio of Trident Kiln to Model Plant B flowrate of 238.800 acfm in PCA Rep

I 

xponential scaling using an exponent of 0.2 and ratio of Trident Kiln to Model Plant B f\Owrate of 238,800 acfm in PCA Rep

Purchased Equipment Cos! - Waste Water Treatment Plant $750,018 IE 

I xponential scaling using an exponent of 0.7 and ratio of Trident Kitn to Model Plant B fIowrate 01 238,800 acfm in PCA Rep

Total Cost of Scrubber and New Stack $6,223,444 t ased their value on sum of Purchased Equipment Cost, Direct Installation Cost, Total Direct Cost arld Totallrldired Cost 

Total Cost of Waste Water Treatment Plant $1,875,045 I xponent\aJ scaling using an exponent of 0.2 and ratio of Trident Kiln to Model Plant B flowrale of 238,800 acfm in PCA Rep

Total Capital Investment (TCI) $8,098,489 

Direct Annual Costs 

Hours per Year 7,680 I xpected annual operation for PCA cost estimates 

OperatinQ Labor
 

Operator $219,150
 I stimate from PCA
 

Suoervisor (15% of ooeratorl $32,873
 (CCM (and PCA) 

Subtotal, Operating Labor $252,023 

Maintenance
 

Maintenance (labor and materials) 20% of Purchasing Cost $564,74[
 

Subtotal, Maintenance $564,74'
 

Lost Production if:;, I? ((Of, Cost of Lost Production @ $30/ton $317,7
 

Subtotal, Lost Production $317,;
 

_.. ~- -;i-"'-­ Utilities
 

Electricity
 3 

Pump (kW)
 

Fan (kW)
 

Cost ($lkW-hr) $[ r (' ~f
 

Subtotal, Electricity $4' ./ / 

Water 

Amount Required (Iblhr) 

Cost 

Subtotal, Water 

Reagent (NaOH)
 

Amount Required (tpy) "c,
 

$5'J() 1R1 NaOH Cost (50% liq. Caustic soda. $300rr)) 

$5 

Subtotal, Reagent 

Acid Wash (,i-<.~~ Amount Required (ton/yr) T ?rcf' Ir Ie' 9 

Cost ($Iton) ! ,....,-1/ 'i 0 , Subtotal, Acid Wash 

, 01f/C/ Waste Water Disposal (Slurry) 

Amount Required (tpy) , " 

Cost ($Iton) ----, Subtotal, Waste Disposal (Slurry)

7 ~~. 'I <~,~ Blowdown Disposal Costs
 

Amount Required (ton/yr)
 f 3/!l73,V 0 9 4",,!\4 Cost($lton) 

Subtotal, WasIe Disposal (Solids) -~--=---:--L&rfLj ~/~C;D(p 

Subtotal, Utilities ( 

Total Dired Annual Costs 

Indirect Annual Costs 

Overhead (60% of sum of operating, supervisor, maintenance labor & matenals) $490,058 PCA report agreed wi OAQPS CCM percentage
 

Administrative (2% TCI) $161,970
 PGA report agreed wi QAQPS CCM percentage
 

Property Tax (1% TCI) $80,985
 PGA report agreed wI OAQPS GCM percentage
 

Insurance (1 % TCI) $80,985
 PCA report agreed wi OAQPS CCM percentage
 

Ca ital Recovery (10 year life, 7 percent interest) $1,153,043
 PCA report agreed wi OAQPS CCM recovery equation 

Total Indirect Annual Cost $1,967,040 

,002 Price Total Annualiz.ed Cost (2002 $) $4,606,451 

Scaled based on inflation to represent 2007 values (PCA used 2002). Consumer Price Index Annual Avg from 2002 = 179.9 

Total Annualiz.ed Cost (2007 $) $5,334,982,21 

Used actual emissions from 2002 Pollutant Emission Rate Prior to Scrubber (tons SQyr) S43 L
 

Pollutant Removed (tons SQ/yr) assuming 95% removal 516
 

Cost Per Ton of Pollutant Removed $10,342
 
Subject to Confidentiality Claim
 
Attachment C 

- CONFIDENTIAL ­

Trident Facilitv Fuel Consumotion Scenarios 

40% Pet Coke/60% Coal BASELINE 

Sulfur Perc"nt -. 0 

content offu"l Emissions 

Pet Coke 28,700 metric Ions @ 5.30% 40% 1521 Ions of uncontrolled sulfur 78% 

Currenl Coal 53,000 metric Ions @ 0.80% 60% 424 Ions of uncontrolled sulfur 22% 

TOTAL 81,700 1945 lolal sulfur = 3890 tons of S02 I Estimated fuel consumption based off of producing 289,953 metric tons of clinker per year.
 

6,613.9 E.G (joulesJMton c1inker))II 289,953 (Mton clinker/yr)" 1.9155 E+15 (Joulesfyr)
 

=>1.9155E+15 lJoules/yr) J 1055.06 (JOUles/Btu) '"' 1.818 E.12 (Btulyr)
 

"'''>14,000 {Btu/lb coke) x 2,000 (Ib/Stan coke)" 2.8 E+7 (Btu/Stan coke)
 

........>1.818 E+12 (Btu/yr) / 2.8 E+7 (Btu/Stan coke) • (64,916 Ston coke/yr) x (1 Mton ( 1.1023 Ston) '"' 71,557 Mton coal x (40%) • 28,662 Metric ton coke per year
 

..........> 9,350 (Btu/lb coal) x 2,000 (Ib/Ston coal)- 1.87 E+7 (Btu/Ston coal)
 

"""""=>1.818 E+12 (Btulyr) 11.87 E+7 (BtU/Stan coal) • (97,200 Ston coal/yr) x (1 Mton 11.1023 Stan) • 88,400 Mton coal yr)( (60%) = 53,040 Metric ton coal per year
 

0% Pet Coke/1 00% Coal Scenario 

Pel Cok.e o melric tons @ 5.30% 0% 0 Ions of unconlrolled sulfur 0% 

Current Coal 92,000 melrlc Ions @ 0.80% 100% 736 Ions of uncontrOlled sulfur 100% 

TOTAL~ 92.000 736 lolal sulfur :: 1472 tons of S02 I 25% Pet Coke/75% Coal Scenarios 

5.3% 5 Pet Coke 

Currenl Pel Coke 14,500 metnc Ions @ 5.30% 25% 769 tons of uncontrolled sulfur 58% 

Current Coal 70,000 metric tons @ 0.80% 75% 560 Ions of unconlrolled sulfur 42% 

TOTAL: 84,500 1329 lotal sulfur - 2657 tons of S02 1 

3.5% S Pet Coke 

Current Pel Coke 14,500 metric Ions @ 3.50% 25% 508 tons of uncontrolled sulfur 48% 

Currenl Coal 70,000 metric tons @ 0.80% 75% 560 tons of uncontrolled sulfur 52% 

TOTAL: 64,500 1068 lolal sulfur '" 2135 tons of 502 1 

2.9% 5 Pet Coke 

Currenl Pel Cok.e 14,500 metnc Ions @ 2.90% 25% 421 tons or uncontrolled sulfur 43% 

Current Coal 70,000 metrIC Ions @ 0.80% 75% 560 tons of uncontrolled sulfur 57%
 

TOTAL; 64.500 981 tolal sulfur = 1961 tons of 502 I
 

lpy 

13042 10"' or S02 rcom coke 

848 Ions of 802 from coal 

I 0 100' or S02 rcom coke 

1472 Ions of 502 from coal 

1'537 10" of S02fcom coke 

1120 tons of S02 from coal 

I' 015 lon' of S02fcom coke 

1120 tons of S02 from coal 

1'41 Ion"f S02fcom coke 

1120 Ions of S02 from coal 

Current Cost of 5.3% Sulrur Pet Coke from Billings = $27.83 IMT <---Current 

Conoco 3.5% Sulfur Pet Coke from California :; $123 IMT <---Option 1 

Chevron 2.9% Sulfur Pel Coke Salt Lake City;: $233 IMT <---0 tion 2 Subject to Confidentiality Clairn Cost of 0 8% Sulfur coal from E Montana =I $41.22 1ST -I $37.39 IMT 

40'/D Coke 60% Coal Ontion BASELINE 

Consumption Sulfur Annual 502 from Reduction Reduction 

E5timated Fuel of coke Content Cost fuel in 502 in 502 

Consumotion Fuel metric tons/vr % CostiMT Baseline Ito, IlonlY'\ 1%\ Estimated Baseline Coke Pet Coke 28,700 530% $27.83 798.721 3042 

Esllmaled Basehne Coal Coal 53.000 080% $37.39 I 1,981.890 848 

Estimated Total Fuel Annualized Cost $ 2,780,611 

25% Coke 75% Coal ODtions 

Ootions Fuel 

Consumption 

of coke 

(metric 

tons/yr) 

Sullur 

Content 

(%\ C05VMT 

Annual 

Coke Cost 

S021rom 

luel 

(tpy) 

Reduction 

in 502 

(ton/yr) 

Reductio 

n 

inS02 

(%) 

Coke Ootion 1 Pet Coke 14.500 5.30% $27.83 $403.535 2657.0 0 0% 

Coke Ootion 2 Pet Coke 14,500 3.50% $123.00 $1,783.500 2135.0 522.0 20% 

Coke Option 3 Pet Coke 14,500 290% $233.00 $3,378,500 1961.0 696.0 26% 

Note. Annualized Cost of75 Yo coal =70,000 metnc tons/yr)( $37.39/MT -- $2,617,591/yr. ThIS cost IS In additIon to the coke cost above and is included in the cost analysis table below. 

0% Coke 100% Coal Ontions 

Consumption Sulfur S02 from Reduction Reduction 

of coal Content Annual fuel in 502 in 502 

Ootions Fuel (metric tons/yr) (%j Cost/MT Fuel Cost (tpy) (ton/yr) (%) 

Coal Option 1 Coal 92,000 0.80% $ 37.39 $3,440,262 1472.0 0 0% 

Cost Analvsis for Fuel Switchina Qations 

Gates of the Mountains 

ControlODtion 

Annualized 

Cost1 Effieienev f% \ 

502 

Ib/hr\ 

502 

(lOY) 

Tons 

Removed 

Cost 

($/ton) 

Incremental 

($/ton) 

502 

Imoact 

DeCiviews 

I r24 hr - ~I

Cost 

I$/de) 

Incremental 

($/de) Using 100% Coal $659,651 62% 5 22 35 $18,637 -$357,090 1290 0.0065 $101,065,920 -$1,936.447,863 Option 3 USing 25% 

CoKe Wlth a 2.9% Sulfur 

Contenl 

$3.215.480 50% 7 29 28 $113.874 $626.276 1291 0.0052 $617,520.160 $3.396.206.349 

Option 2' USing 25% 

Coke With a 3 5% Sulfur 

Canten! 

$1.620.480 45% 7 31 26 $63,077 $180,614 1.292 0.0047 $342.057.878 $979,445.328 

Option 1 Using 25% Coke 

With a 5 3% Sulfur 

Canlent 

$240.515 32% 9 39 18 $13,325 -­ 1.293 0.0033 $72.258.780 -­

Baseline' USing 40% 

Coke wilh a 5 3% Sulfur $0 0% 13 57 0 -­ -­ 1.297 -­ -­ -­ Content 

Annualized cost = Option Cost Baseline Cost 

2The baseline is based off the 2007 CEM's data that averaged 13.1 lbs/hr of S02. This is calculated to be 57 tons/yr, which is 89.5% lowever than the permitted limit.