## North Carolina Department of Environment and Natural Resources Division of Air 

### Quality Beverly Eaves Perdue Governor Sheila C. Holrnan Director 

### February 7,2011 Gwen Keyes Fleming Regional Administrator USEPA Region 4 Atlanta Federal Center 6

### 1Forsyth Street, SW Atlanta, GA 30303-8960 Dee Freeman Secretary



### Dear Ms. Fleming: In response to your stafrsrequest for additional information with respect to the North Carolina Regional Haze State Implementation Plan (SIP),please find attached a copy of the reasonable progress analysis prepared by PCS Phosphate (PCS)located in Aurora, North Carolina, for the two sulfuric acid plants S-5 and S-6. The North Carolina Division of Air Quality (NCDAQ) received the analysis on October 8,2010. In the analysis, PCS evaluatedthe technical and economic feasibilityof various options for reducing sulfur dioxide (SO2) emissions from the plants, includingreplacement of the existing vanadium catalyst in the fourth and final catalystbeds with cesium-promoted catalyst. The evaluations are based on informationprovided by MECS, Lnc., a company that designs sulfuric acid plants. Design and cost information providedby MECS, Inc. is included in Appendix A ofthe attachment. The most costeffective control scenariosPCS identified in its analysis are summarized below: Sulfuric Acid Plant S-5 is currently only using about 90% of its catalyst load capacity. The plant can reduce the SO2emission rate from 3.81pounds per ton (lbslton) acid (thehighest 3-hour average emission rate from 2009) to 3.5 lbslton acid by increasingthe actual amount of vanadium catalyst in Beds 1-3 and replacing the catalyst in Bed 4 with cesium-promoted catalyst. Under this scenario,PCS can maintain the existing SOzstrength (1

### 1.5%)in the converter inlet stream sothat there is no production penalty. Acid production increases slightly due to improved SO2conversion. This scenario would result in an SO2emissionsreduction of 165 tons S021yearat an estimated cost of $3,456/ton. Table 4 

### of the PCS submittalprovides a cost analysis of this scenario. The NCDAQ re-evaluatedthe cost of control with minor changes, including elimination of the costs of administration, property taxes, and insurance. The revised cost of control was estimated to be $2,879/ton. Sulfuric Acid Plant S-6 is currentlyusing 100% of its catalyst load capacity. The plant can reduce the SO2emission rate from 3.89 lbslton acid (thehighest 3-hour average emission rate from 2009) to 2.0 lbslton acid by replacing some of the vanadium catalyst in Beds 1-3with fresh vanadium catalyst and replacing all of the catalyst in Bed 4 with cesium-promoted catalyst. PCS would have to reduce the SO2strength in the converterfrom 11.5%to 10.5%to achieve the lower production rates,

1641 Mait Serv~ce Center, Rale~gh, NorthCarolma 27699-1641 2728 Capitat Blvd., Raleigh, NorihCarolina 27604 Phone: 919-733-3340 I FAX 919-71 5-7175I Internet: www.ncalr.org An EqualOpportunityIAffirmat~ve Actton Employer

### -50% RecycledilO% Post Consumer PaperMs. Fleming February 7,2011 Page 2


### which would result in a production penalty. This production penalty would be offset slightly due to improved SO2conversion. This scenario would result in an SO2emissions reduction of 1,I 11 tons S02lyear at an estimated cost of $1 1,414lton. Table 8 

### of the PCS submittal provides a cost analysis of this scenario. TheNCDAQ re-evaluated the cost of control with minor changes, including elimination of the costs of administration, property taxes, and insurance. The revised cost of control was estimated to be $1 1,347lton. Currently, Swanquarter is below the glidepath for visibility improvement. As part of the reasonable progress analysis, PCS performed CALPUFFmodeling to estimate the changein visibility that would occur at Swanquarter if the emission rates from both S-5 and S-6

### were reduced from4.0 Ibs S02/tonacid to 3.0lbs S02/tonacid.' The average change in visibility was estimated to be 0.16 deciviews for a 3-year period. This is farbelow the BART significance level of 

### 0.5 deciviews. The cost of compliance estimates are higher than what the NCDAQ used in the Regional Haze 

### SIPto determine if the cost was reasonable ($9 12to $1,922per ton of SO2 removed) for the 2018 Reasonable Progress Goals. Therefore, the NCDAQ believes that the initial assessment for PCS continues to be valid; there are no cost-effective controls available for these units at this time within the cost threshold established for this reasonable progress assessment. The NCDAQ has notified the company that although additional controls are not being required this planning period, future-planning periods may require controls to be installed. If you have any questions regarding this information, please contact Laura Boothe at I,aura.Boot he @

### ncdcnr.gov - 

### or (919) 733-1488

### or Fern Paterson at Fern.Paterwn @ncdenr..gov 

### or 

### (919) 

### 7 15-6242. Sincerely, 

# %[. Shei a C. Holman

Attachment cc: Michael Abraczinskas, NCDAQ Donald van der Vaart, NCDAQ Laura Boothe, NCDAQ Fern Paterson, NCDAQ Dick Schutt, USEPA Lynorae Benjamin, USEPA

1 The reductions represented in the modeling (i.e., 1.0Ihslton at both S-5 and S-6)are not identical to the reductions summarized in this memorandum (i.e.,0.31 Ibslton reduction at S-5 and 1.89Ibslton reduction at S-6). Rather, the modeling is intended to show that changes in visibility resulting from the approximate SO2reductions being evaluated are well below the significance level.

# PotashCorp" HelpingNature Provide



### October 5. 3010 PCS Phosphate- Aurora



### VIA 

### FEDERAL EXPRESS Donald 

### R. van der 

### Vaart North Carolina Departnlent of Environnlent and

### fiatiiral Resources 

## @%q, Divlsion of Air Quality $pi. %Y 

### 2733 Capital Boulevard Pa @$ 

### w&p 

# =?o@ Raleigh. NC 37604 

### "%.Q&

-I 

### lie: 

### PCS Phosphdte Reasonable Progress Anaiysis Dear Dr. van der Vaart: As you 

### requested. 

### I have 

### enclosed a copy ofthe independent

### reasonable progress control tecimoiogy evaluation 

### of SulhicAcid 

### Planis 

### 5 and 6 

### that PCS Phosphate Company, Inc. ("PCS") conducted for the facility 

### located near Aurora. 

### North Carolina (the "Reasonable Progress Analysis"'). The 

### attached Reasonable 

### Progress Analysis differs from the anaiysis that was previously pro~ided lo you on July 

### 15.201

### 0 in that: ji) 

### predicted actual annual emission reductions were calculated as described 

### in 

### footnote jb) 

### on page 

### 1-2of the Analysis: and 

### iii)the 

### cost eslimates used to calculate cosl effectiveness have been updated for consistency with 

### the inforination provided to 

### PC3by 

### MECS. This 

### updated Reasonable Progress Analysis replaces the one 

### previously provided to 

### you. Tile 

### Reasonable I'rogress Analys~s demoimrates that additiotlal controIs and/or switchmg catalysts are 

### not cost effective. North Carolina has ample authority to require only cost effective measures 

### in pursuit ofthe reasonable progress requirement of

### EPA's Regional 

### Haze rules. Those rules assign North Carollna significant discretion to 

### determine what nieasures to include in the Regional

### Haze SIP. 

### EPA will have 

### little choice but 

### to approve a 

### Regional Haze 

### SIPthat 

### is based on a 

### valid exercise 

### ofXorth Carolinassdiscretion 

### in weighing 

### the relevant factors. 

### I. Background Gnder 

### the authority 

### ofthe Clean Air Act I"CAA"j, the 

### United States Environmental ProtectionAgency ("EPA") 

### issued the "Regional 

### Haze Regulations and Guidelines for Best 

### Available Retroi3techno log^. 

### Derem~imions" (the'-Regional 

### Haze Rule"). 

### 70 Fed. 

### Reg. 39,104 (July 

### 6, 2005j. 

### The Regional 

### I-Iaze Rule

### requires that certain states, includingNorth Carolina, develop programs to 

### assure "reasonable progress" toward a national goal of

### preventing any future: and remedying 

### any existing. visibility 

### impairment at 

### nearly 

### 156federally protected parks and m~ilderness areas 

### over an 

### approximately fifty-year period. 

### 42 U.S.C. 

### 6 7491.

- 1530NC Hy 306 South,Aurcra, NC USA 27806 T (252)322-8266 

## '1252)322-8061

PES PhmphateCwnpany, Inc ] www.potashcorp.com

### Donald 

### R. van der Vaart 

### October 5,301

### 0 Page 

### 2 The Regional Haze Rule ft11t11er requires that certain sources of air pollutaiits itlstalI 

### B,MT to control regulated emissions. 40 

### C.F.R. 

## 5 5 

### 1.302. Section 169-4of the 

### C.4A requires that states determine the appropriate level of' 

### BART control by 

### considering: (ij 

### the tecl~nology available; (ii)theus 

### OFcon~pliance; jiii) the 

### energy and non-air quality 

## e~i~o~u~~~~t~~,ans of con~pliance: (iv) 

### any existiiw ~ollutioi~ con~rol technoioa in use at 

### the source; (-v) 

### the remaining useful life 

### of the 

### source; and (vi j 

### the degree of iniprcwsment in 

### visibility that may reasonably be expected as 

### a result of such technology. 40 

### C.F.R. 

## 6 5 1.308(e)(l jCii)!A,l. 

### The statutory factors in a reasonable progress a~ialysis are similar. They include: (i) the 

### ~t of compliance; 

### (ii)thetime 

# - nece,ssaryfor 

### compliance; (iii)

### the energy and non-air quality envirorunental impacts 

### of complia~zce: and iiv)

### the remainin_cusefid 

### life of the emissions unit. 

# 46 C.F.R.

## 5 51.308(d)(l )(i)(A). 

### Each unit must be uniquely evaluated uslng statutor? and regulatory factors 

### in making 

### BART and reasonable 

### progress determinattons. 

### EPA has recognized that. 

### in considering 

### the statutory factors. "States are frce to 

### determine the welght and 

### significance to be assigned to each factor." 70 

### Fed. Reg. at 339,130 

### TheNorth Carolina Department 

### ofEnvironment 

### and Natural 

### Resources. Division 

### of Air 

### Quairty i 

### "NCDENK-DAQ" ) 

### has determined. and the enclosed Reasonable Progress AnaJysls suppons, that rt 

### is nor 

### cost effective to install additional controls and/orswitch from vanadium to 

### cesium catalyst in the final 

### bed of Sulfuric Acid Plants No. 

### 5 and No. 6. 

### The lack of cost effectiveness give?

### NCDEI\;K-DAQ ample authority not to require additional controls or catalyst replacement because, as noted above, cost is one of

### the sratutoq factors 

### a Statemust consider 

### in making BART and reasonable propssdeterminations. noted 

### in 

### the North -.------ 

### Carolina --O---~-.-.---o--~- 

### Renional Haze ...---.

### State ..-.. 

### Implementation ---- .... 

### Plan .._-,,-.._.--.--, 

### submitted 

### ..-_.----_.. 

### to 

### EPA on December 

### 17,2007.North Carolina will remain on

### t~~li&de~t,h~na~~r?~~$bility without --__ 

# _ ,__ I--..--- "-,".-"-,--- 

### re@&gadditio~zaI 

### ~ontr_o&?_1:.~~~_c~$a~!;gre~J-~~lng~~-qd_the Staie. 

### .-

## ----

not 

### EPA, 

# - ------- has the authority to make 

### BART and reasonable progress determinations under the Regional 

### Haze Rule.
+ 

### _ .I--- -"..-.."-.-LI-.L------.-------"- ---, ".__I____"-

---. 

### 11. Technically Feasible ConlroI Technolotlies for 

### SA Plants 1 

### and 

### 2 Are 

### Not 

### Cost Effective The enclosed Reasonable Progress Analysis demonstrates that technically feasibie technologies far conrrolling 

### SO2enlissions from 

### Sulfuric Acid Plants 

### KO.5 

### and 6 

### would cost in the range of 

### $3.456

### to $452,598 per ton of 

### SO2 reduced. These teclmologizs are not cost effective. In the Reasonable Progress Analysis. 

### PCS e~aluated all technically feasible control technologies. including replacing the existing vanadium with cesium catalyst in the final bed 

### of the four-bed reacrors, at Sulftlric .4cid Plants No. 5 

### and 

### No. 6 

### as required by 

### the Regional Haze Rule. In one scenario exraluated b!, 

### PCS for Sulfuric Acid Piant No. 

### 6 (Scenario 1j, 

### an atmual emission reduction was assumed solelj-for purposes of calculating a cost effectiveness value.

### Doizald 

### R. van der 

### Vaart October 

### 5, 3010 

### Page 3



### For each ofthe evaluated scenarios: it would cost 

### inthe range of $3,436

### to $26,484

### per ton of 

### SO2 reduced for SA

### Plant 

### No. 5 

### and 

### in the range of $I 1,4 

### 14

### to $452,598

### per ton 

### of SO? reduced for SA

### Plant 

### No. 6 

### to inslall, operate and mainrain the evaluatedtechnology. As 

### detailed in 

### the Reasonable Proyress Analysis, the cost effectiveness calculatiolls consider: 

### (i) 

### the cost ofpurchasing, installing. operating and 

### maintaining cesium catalyst; (ii)the Iikely 

### change in actual 

### SO2emissions tililt would occur with the 

### ttse of cesium catalyst; and (iii)

### other costs, such asproductio~l penalties and capital equipmeat costs. that would 

### be assoc,iatedwith 

### the 

### use of the evaluated control tec1xiology. EPA has been 

### clear that '-States

### have flexibility 

### in how they calculate costs." 

### 70Fed. Reg at 39.2

### 1

### 7.39,I 

### 53. Where possible, cost estimates should be conducted in accordance with the Office ofAir Quality Planning and 

### Smdard's ('-OAQPS") Cost Control Manual. 70

### Fed. Reg at 39,166. 

### AdditmnaIly, "[tfhe cost analysis should also take into account any site-specific design or other conditions



### . . .that affect the cost of a particular 

### BART technology option." 

### Id. PCS performed the cost estlmatcs m ~ts 

### Reasonable Progress Analys~s in accordance with 

### the OA

### QPS Cost Control Manual wh~le _talag

### ~ni~c~~~_sr>gclf~f&~ns. The Keasonable Progress Anal

### ysls demonstrates that the costs associated ~71th the iechnrcall

### y feasible control options at Plant\ 5 

### and 

### 6 are unseasonably high 

### inlight of the actual enlission reductions, 

### if 

### an). that could be 

### achieved 

### PCS 

### is aware that 

### EPA lm

### evaluated canvenmg tocesium catalyst and has provided a different cost effectiveness calculation for 

### thts scenario. 

### The EPA 

### calculatron does not include consideration of three cost elemer~ts that must be considered: 

### (i ) 

### average cost effectiveness using the full -- 

### cost of

### re&aqgment of the current catalyst. (ii) 

### production penalties, and 

### (iii) capital
..-- 

### equipment costs. 

## d

L 

### YCS. om the other kmd. evaluated a number of plant-specific scenarios under which the cesium catalyst would be 

### replaccd in 

### the final bed of 

### the reactor to achieve EPA's target - 

### emission rate. 

### Ln each of these scenarios. 

### PCS 

### ~1_s&$_e-_c_o~o_21a~m_~7.~te~n~~arge of cesium

-'.s.-7---.. 

### cataiyst 

### in determining 

### .- ., 

### averap-cost __." 

### effectiveness.

-,.-% _._-.-- 

### EPA
-.,- 

### ca&uk~onk&$n-~ eJf$&.~eness 

### of ce~~u~m,,.~~!~~yst-~~~t~.\~e.t~~,v~~adiun? 

### ca_1.&1st. The 

### EPA approach is wrong under its 

### own guidance. Both average and 

### incremental costs should be 

### considered in any cost analysis. 70 

### Fed. Reg. at 

### 39,127. : n 

### EPA's use 

### of only 

### incremental costs underestimates the actuai cosrs that PCS wodd incur 

# / in switching io cesium 

### catalyst. PCS 

### does not 

### replace 

### all of

### the catalyst 

### in a 

### hed 

### unless there has -I._IXI__-_l_^l-,. -I--- '----*--'~-.---".-.14 -""...
l,. ' ,.. I 

### been

_

## ____ some


### _processjssue that has damaged 

### tht. 

### catalyst. 

### PCS insread screens 

### or scalps certain -- - ---- . . _"._. ..._ ' 

### beds during 2-year t&narounds. ana%en adds new 

### catalyst to the top of

### the bed 

### to replace li~e



### lost quantity. The 

### first beds. 

### which have a h~giier duty 

### than the 

### final beds. are fully replaced 

### over 

### 6 lo 8 years. The 

### finai beds are replaced less frequentljr.

### Donald 

### K. van der 

### Vaart October 

### 5. 3010 

### Page 4


### EPA incorrectly assumes that both ofthe final beds require a whole new charge of catalyst and thcn calculalcs the differe~lce between the 

### cosl of cesium catalyst and the cost of vanadium catalyst This 1s a 

### false choice. The real choice is between the cost of two entirely newbeds of cesium catalyst or the cost 

### ofreplacing the port1011 of 

### the vanadium catalyst bed that 

### is screened during turnarounds. Therefore, the full cost 

### of new beds of cesium catalyst should be included when est~lnating the average cost 

### of control. This cost isreflected 

### in the attached Analysis. The 

### PCS cost effectiveness calcuiaiions acc.ount 

### for-another factor that 

### EPA missed in its, 

## cafculation--a production penaitv that would be 

### incurred 

### if cesium catalyst is used with a 

### lower 

### SO2 gas stsen.gthto meet the 

### lower emission levels. 

### The OAQPS Cost Control Manual provides for consideration 

### of this 

### factor. -'In

### many systems, the insertion of a pollution control device causes the system to lose productive capacity. This can be caused by the device creating obstructions in the 

### flue. temperame losses that create imbalances, or other physical changes that affect performance. These losses 

### are collectively tenned 'parasitic power' losses." 

### QAQPS Cost Control Maiual at 

### 2-35 n.b. 

### A catalvst replacement can only achieve the lower

# emi&ossirafeadvocated 

### bj 

### EPA when i 

### the plant is operated at the appropriate residence time for 

### the cesium catalyst or sign31cant * 

### capital equipment upgrades aqe_ulstdled. ----------I-Y__j- .eS. 

### the necessary residence time can 

### only be

w.. 

### aclueveah\.e~ucmg the feed rate. and hence.goductionrate~aa&ue&puurrurre_n~~



### . I 

# - --** 

# --eM

### achieve the desired res~'-ifs,

### a catalvst replacement 

### will cause a 

### lower production rate. 

### NCDENRDAQ properly considered the ioss-in as part 

### oftl~r cosl of

### compliance. 

### EPA did not consider this factor at all 111 

### its cost effectiveness calcul~tion.

/--7 \

### I As 

### NCDENR-DAQ also notes: 

### I'CS faces significant additional costs associated with the \ 

### State's CIean Smokestack Act ("CSA"). 

### PCS is the largest single consumer 

### of electricity on the ! 

### ' Progress Energy System and will bear-considerable additional costs through increased electricity 

# I i rates resulting from compliance by 

### Progress 

### Energy wit11 

### the 

### CSA. 

### NCDENR-DAQ can 

# 1 coiisider these additional costs ii? 

### determining what ineasures are reasonable to require in the 

## !' Regional Haze 

### SIP.
L----- 

### This discussion illustrates that 

### PCS provided a 

### complete and 

### thorough evaluatron that

considered all relevant factors 

### while EPA ignored its own guidance to 

### provide a results-oriented number. In addition to 

### considering cost per ton of SO: controlled. the Regional 

### Haze Rule also requires that 

### NCDENR-DAQ consider the cost of control 

### in relation to the visibilitjr improvementsthat are achievable 

# - Per 

### the 

### NCDENR-DAQ 

### SIP submiital. replacmg the exlsting 

### vanadium pentoxide catalyst 

### with ceslum catalyst ~tould 

### result in 

### oni) neghgible (ifany)visibil~ty improvement Calpufi'modeling ofthe plant was 

### used to estiinate the assocxatecl change in deciviews from the current 4 

### 0 

### lbiton 

### W?SOJto 2.0 

### Ibllon W2S01 

### The avcrage change was 

### 0.16 deciviews for the

### Donald 

### R. v,m den Vaan October 

### 5,201 0 Page 

### 5

covered three year period. Th~s 

### change 

### is far less than the 

### 0.5 deciview significance level used 

### in 

### BART. and when coupled with the 

### high costs associated 

### with a catalyst conversion. leads to the conchion that thc conversion 1snot cost effect~ve 

### for purposes 

### of determining 

### BART. 

### 111. North Carolina's 

### SIP Complies 

### with all Stan~torv Reqpirements As written. North Carolina's 

### SIP complies with

### the 

### Regional Haze 

### Rule. and the State will remain on the glide path to natusal visibility 

### by 

### 2064 without requiring a catalyst replacexnent at the 

### PCS Aurora facilih. 9,

## - +xqxxs-e's reasonab1e rate ofprowess need onl~ be 

### consistent 

### with the statutory factors, not as fa2t 

### as possible In the
^.pm 

### final Conference agreement, Congress changed what had been the 

### "maximum feasible progress" to "reasonable progress" when referring to the States' goals. 

### H.R.

### REP. No 95-564 

### at 1536 Thus. the Stateneed 

### not proceed at the masimuni rate feasible. 

### EP.4 has recognized that "the CAA 

### national visibility goal and 'reasonable progress' provisions do not mandate specific 

### raws 

### ofprogress, but instead 

### call for 'reasonable progress' toward the 

### ultimate goal 

### ofreturning to natural backpound conditions." 

### 64 

### Fed. Reg. 

### 35,714. 35,73 

### 1 (July 1, 

### 1999). States developing reasonableprogress goals (,"RPGs") are directed to identify the ~rniform rate 

### of progress necessary to 

### attain natural back~ound conditions by 

### 2064 and 

### then identify the amount of 

### progress that 

### would result 

### if tile State achieved the uniform

### rate of progress during the period of the first regional haze implementation 

### plan. The 

### uniform rate of progress is the "default giide path." 

### 70 Fed. 

### Reg. at 

### 39,143.

t 

### Once the glide path IS 

### established, 

### the 

### State identiiies and analyzes the emissron control

measures 

### needed to achieve suchprogress for the period covered 

### by the long-term strategy and cietem~ines whether those measures are leasonable based on the statutorj factors. 64 Fed. Reg. at 35.732. -'ll'tlie State determines that the amounl 

### of progress 1s reasonable based upon 

### the statutory factors,the State sl-ioulddenl lily 

### this amount of progress as its 

### [WG]


## . . 

## .unless 

### it determines that 

### addmonai progress is aIso 

### reasonable " 

### Id 

### If additional plogress IS 

### reasonable 

### ku~cd on 

### the ~/atutory ~LIC~OTJ. 

### the State should adopt that 

### amountofprogress as ~ts 

### RPG. Id (emphasisadded).

/- 

### Here, 

### NCDENR-DAQ has determined the uniform rate of progress necessary to achieve

natural background conditions by 

### 2064 and 

### has andyed the statutory factors. The Statehas decided that the 

### uniform ratc of progress 

### is reasonable and achievable by 301

### 8 without requiring a catalyst replacement at 

### the 

### PC3 Aurora plant. 

### NCDENR-DAQ rcjected additional controls at 

### the Aurora facility as unreasonably costly after considering the 

### statutory factors. 

### NCDENRDAQ's co~iclusion is suppotred by 

### PCS's own Keasonabk Progress .4nalysis. NCDENR-DAQ's 

### BART and 

### RPG detenl-iinstionsare reasonable. 

### and its 

### SIP complies 

### with the Regional 

### Haze Rule.

### Donald 

### R.van der Vmrt October 

### 5.20 

### 10 Page 

### 6

I. 

### North Carolina, hot 

### EP-q. Has 

### thc Authorin: to Determine 

### BART and RPGs Tjnder the CAA. States. not the 

### EPA, have 

### authority to determine both 

### BART and 

### RPGs. Sec. 

### e.g.,43 

### U.S.C. 

### $6 7491(b)i2)(A)(sourcessubject to 

### BART "shail procure, install, and operate, as expeditiously 

### as practicable (andmaintain thereafter)the 

### [BART], as dedt.tcrmined171: 

### the Stuie 

### (or the Administrator in the case of 

### a plan promulgated under section 7410ic)of this title)


## . . . ."); 

### 43 U.S.C. 

## $5 7491 

### (g)(2)

### ("in deternlining [BART] 

### the Stale 

### (orthe Administrator in determining cmission limitations 

### which reflect such technology) shall take into consideration the costs of compliance. the energ>, and non-air quality eiwironmental impacts of compliance, 

### any existingpoIIution control technology in use at 

### the source, the remaining useful 

### life of the somce. and 

### the degree 

### of improvement in visibility which 

### may reasonably be anticipated to result from the use 

### of such technology.") (,en~phasis added). "The Haze Rule calls fcx states to play the lead 

### role in designing and implementing regional haze programs." Am. Corn 

### Growers 4ss 

### 'nI*.

### E. 

## PA.. 29 1 

### F.3d 1,

### 2 

### (D.C. Cir. 

### 3002) (reversing portion ofpreiiminaq. Regional 

### Haze Rule as '-inconsistent with the Act's 

### provisions giving the 

### states broad authority 

### over HART determinatioi~s.")J 

### Utilig: Air. 

### Regulator?' 

### Group I>. 

### E.P.,4

.. 

### 471 

### F.3d 1333, 

### 1336

### (D.C.Cis. 

### 2006) (thesecond step in a BART determination "requires 

### stumto determine the particular teclmologythat an individual source 'subject to 

### BART' must install.") (emphasis added). In addition to the stamtor> language and case 

### law granting Statesbroad authority 

### to make BART determ~natious, the leyislat~ve history 

### aiso supports this argument. 

### For example. Congress' intent that States 

### make 

### BART deterlnlnations was 

### evident in the Senate Debate adopting the 

### Conference Agreement: Mr. h4cCiure: Gnder the conference agreement, does 

### the State retain the sole authority for identificatioi; of sources for the purpose o-l'visibiiityissues under 

### this section? 

### Mr. Muskie: Yes; 

### the State, not the Administrator, identifies a 

### source that 

### may impair visibilrty and thereby 

### falls within the requirement 

### of section 

### 125. 

### Mr. McClure: And 

### does this also hold true for determination of "Best Available Retrofit Technologj."'? Mr. Muskie: Yes: here again it 

### i~ the State which determines 

### what constitu~es "Best 

### Available Retrofit Tecl-tnoiogj,," 

### as defined in section 

### 128.

. . 

### . . 

### 123CONG. 

### REC. S

### 13696, S 

### 1

### 3709 (1

### 977). 

### EPAhas 

### even stated that "the Statemust detemiine the appropriate level 

### of HART control for each source subject to 

### BART," 70 Fed. 

### Reg. at 39,107. 

### The Agency concedes that 

### "[iln some cases, the State may determine that a sourcehas already installed sufficiently stringent emission controis 

### for compliance with 

### other programs
. 

### . .

### Donald 

### R. van der Vaart 

### October 

### 5. 20 10 Page 7


### such that no additional controls would be needed f'or 

### complimce 

### with the 

### BART requirement." 64 

### Fed Reg. at 

### 35.740. The State, not 

### EPA has tile 

### authority to 

### make 

### BART and 

### RPG determinations. 

### NCDENR-DAQ's determination 

### of "no 

### additiod control" 

### is both reasoilabie 

### and consistent with the 

### CA4. PCS appreciates the opportunity to 

### provide this inforn~ation to 

### you. Please call 

### Ross 

### Smith at 

### 252-372-8270 if you have 

### an!; questions or 

### if you require any additional infommtion.

Sincerely.

Steven A.

### Beckel General 

### Manager Enclosure

cc: Ross 

### Smith, Manager. Environmental 

### A-I-fairs

## FIWAL REPORT 

## %-

, .@.



### v 

## %w 

# REGIONAL HAZE RULE %$ @& 

### */A+

% 

## r

"C~A b 

# REASONABLE PROGRESS 4% 

# CONTROL TECHNOLOGY EVALUATION FOR SULFURIC 

# ACID 

# PLANTS NO. 

# 5 

# AND NO. 6 

# PCS PHOSPHATE COMPANY, INC.

Preparedfor:



### PCS 

### Phosphate Company. 

### Inc. 1530

### NC 

### Highway 306 South 

### Aurora, North Carolina 37806 

### Prepared by:

URS Corporation -North Carolina 1600Perimeter Park Drive, Suite 100 Morrisville, North Carolina 27560 i919!461-1100 URS Projecr No. 31877076
October 

### 5,201(1

### Section 1

### Introduction



## ...........................

# .............................................................................. 1-1 1

### .1 Regulatory Background

.

### . 

## ...

## .. .

## .. . ..

### .

## .... ....

### . .. 

## ....

## ..

### . ..

### ... .

## ..

## ....

### . . ..

.

## ..

### . . . .. . . ...

### ....,.....

### . . .. 1 

## -1 1.2 Technical Conclusions



### ............................... .................................... 

### .........

### . 1-2 1.3 Contact lnformation

........................

### .......... ............... ..

### ............................. 1-3 

### Section 

### 2 

### ReasonableProgressAnalysis 

## .....................................,.......,............................ 2-1 

### 2.1 hntroductian..



### ...

### .. .

### . ......

### . .... .

### ...... . 

### .. 

### . . . .

### .

## .. ..

## . . . .. .

### . . . .. 

### .... ... .

### . . . .. . .2- 1 7.1.1 Step 1

### -Identify 

### All 

### Available Retrofit Control Technologies



### ............................................ 

### ................... 

### .......... ..... ..2-1 

### 2.1. Step 

### 2 

### -Identify Technically Feasible Retrofit Control Technologies



### . .

### ...... ..

### ....... 

### .

## .. ..

### . . . ....

### ...

## .

# .... . . .

## .... .

### ... . . .

### ..

### ..

### ....

### .. . .. . . .

### .. .. . . ... 

### ...

### .2-1 

### 2.1 Step 

### 3 

### -Evaluate TecknicalIy 

### Feasible Control Alternatives

.....

### ,...................... 

### .. ........................................ . 2-1 1.1.4 Step 3 

### -Evaluate Calculated and Reported Impacts



### ................... 2-3 2.2 

### RP Analysis for SA Plants 

### Nos. 5 and 6



### ..................................................2-3 '-3 

### 2.2.1 Identify A11 Available Retrofit Control 

### Technologies



### ................. , 3.2 Evaluation Cost Effectiveness of Control Scenarios

...................2-6 

### 3.3.3 Conclusion



### ......

### ..................................... ....

### ..................................2-1 1

Table 1: Summary of Sulfuric Acid Plant Parameters and Scenarios Table 

### 2: Summary 

### of Sulhric Acid Plant Control Cost Assessment 

### Table 3: Scenario la -Cost Analysis for 

### 3.8 lbiton 

### HzS04 - SuIfuric Acid 

### PIant No. 5 Table 4: Scenario 1 

### - Cost Analysis for 

### 3.5 Ib/ton 

### H~SOL 

### - Sulfiuic Acid 

### PlantNo. 5 Table 

### 5: Scenario 

### 3

## -Cost AnaIysis for 3.0 

### Iblton H2S04 (Includes Production Penalty) 

### - Sulfunc Acid 

### Plant lio.5 Table 

### 6: Scenario 

### 3 -Cost Analysis for 2.0 Ibiton H:S04 (Includes Capita1Equipment)

### - Sulfuric Ac~d Plant No. 5 Table 7: Scenario I 

### - Cost Analysis 

### for 

### 3.5 Ibiton I&S04 -Sulfunc Acid Plant No. b Table 

### 8: 

### Scenario 2 

## -Cost Analysis 

### for 3.0Ib/ton HlS04 (IncludesProduction Penalty) 

### - Sulfuric Acid Plant 

### No. 6 Table 

### 9: Scenario 

### 3 

## -Cost Analysis for 2.0 lb/ton 

### H2SO;r(Includes Capital 

### Equipment) 

### - Sulfuric Acid Plant No. 

### 6
APPEMDIXA: 

### MECS Design

### and Cost Information

### LIST 

### OF ACRONYMS LIDABBREVUTIONS

BACT DAQ 

### DENR EPA 

### H20 H2SO4 

### IbJton 

### NH3 NSPS 02 

### RBLC 

### RP S S



### A SP SO: 

## so3 

## so4 tQY 

### US Best Available Coatrol Technology Division 

### ofAir 

### Quality Department ofEnvironment and 

### ru'aturalResources Environmental Protection Agency Water Sulfuric Acid 

### Pounds 

### Per Ton Ammonia New Source Performance Standards Oxygen 

### RACTIBACTfLAER Clearinghouse Reasonable 

### Progress Sulfur Sulfuric Acid 

### State Implementation Plan Sulfur Dioxide Sulfur 

### Trioxide Sulfate Tons Per 

### Year United States

### PCS Phosphate Company, hc.

### (PCS Phosphate) owns and operates a 

### facility located 

### m Aurora. Beauforl 

### County. North Carolina. Beaufort County 1s located 

### in the eastern coastal reglon of North Carolina. 

### The PCS Phosphate Aurora 

### facilityfalls under the standard 

### North Amencan Industry CIassification System 

### (WAICS) codes 

### 212392 forphosphate rock rnming and 

### 335312 ibr phosphoric acid manufacturing 

### Suihcacid (SA) 

### is manufactured at the facility in order to react with phosphate rock and produce phosphoric acid. The sulfuric acid production area currently inchdes three sulfuric acid (Sh) plants (S.4 Plant

### No. 5. 

### No. 

### 6. and No. 

### 7), one cogeneration plant, and one auxiliary boiler. 

### SA Plant No. 5 began operation 

### in 19Eand 

### SA Plant 

### Kc. 6 began operation in 

### 1985. SA Plant No. 

### 7 began operation 

### in 2010. The two older 

### SAPiants No. 

### 3 and No. 4 shutdown after 

### SA Plant

### No. 

### 7 began operation in 201

### 0. At the request of the North Carolina Division of Au 

### Quality 

### (NCDAQ), 

### PCS Phosphate retained 

### URS Corporation to prepare an air emission control technology evaluation for SA Plants No. 

### 3 and No. 

### 6 consistent with 

### the requirements of 40 

### CFR 5 1. Appendix 

### Y.This report presents the results of the control technology evaluation. 

### 1.1 

### REGULATORY BACKGROUND The Clean Air Act (CAA) established goals for visibility 

### in many national parks 

### and wilderness areas. Through the 19?7 amendments to 

### the CAA, Congress set a national goal for visibility as 

### "the prevention of any future, and the remedying of any existing, impairment of visibility in mandatory Class 

### I Federal areas which impairmentresults from manmade air pollution." 

### The 

### CAA amendments of 

### 1390required 

### EPA to take regulatory action onregional 

### haze and on 

### July 1, 1999.

### EPA promulgated the 

### finalRegional Haze Regulation. The final Reponai Haze Regulation calls 

### for state and federal agencies to work together to @rove visibility 

### in I56 national parks and wilderness areas in the United States

### by developing and implementing long-tern air quality protection plans 

### to reduce the pollution that causes visibility impairment in these protected areas. 

### The Regional 

### Haze Regulation provides States flexibility in determining reasonable progress goals for protected areas by conducting 

### certain analyses to ensure that 

### they consider the possibility of setting an ambitious reasonable progress goal, one that is aimed at reaching natural background conditions by the year 

### 2064. The regulation requires States 

### to establish goals for each affected area. The Regional Haze replation also requires Statesto develop long-term strategies 

### including enforceable measures designed to meet reasonabieprogress goals. The first long-term strategy will cover 10to 

### 15years. with reassessment andrevision of those goals and snategies 

### in 201

### 8 and every 10years thereafter. State strategies 

### will address their contribution to visibilinr problems 

### in Class 

### 1areasboth within and outside the State. States were required 

### to develop and submit Regional Haze State Implementation Plans (SIPS)

### by the end of 2007. Theseincluded Best Available Retrofit Technology 

### (BART) evaluations for 

### emission units 

### that began operation between 

### 1962.and 

### 1977 

### aswell as reasonable progress evaluations for other emission units. 

### In December 

### 2007, the 

### NCDAQ subwtted 

### a ReglonaI Haze 

### SIPto the LTS 

### EPA, Reyon3 for the~r eview and approval. As 

### part of the 

### SLP submttal.the 

### NCDAQ ~ncluded a reasonable progress 

### (RP)control technology evaluation for several emlsslon umts located 

### In North Carohna 1-1including the 

### SA Plants 

### No. 

### 5 and KO.

### 6 located at the 

### PCS Phosphate facility. The 

### NCDAQ evaluation concluded that further emission controls for the SAPlants KO.

### 5 and No. 

### 6 were not cost effective and not reasonabIe at this time. During 

### the 

### EPA Region 4 review of 

### the NCDAQ 

### SIP, the 

### EPA quesrioned the 

### NCDAQ on their conclusions and asked whether further emission reductions could be achieved on SA Plants No. 5 and No. 

### 6 by replacing the vanadium catalyst in the final pass with cesium catalyst in order to reduce 

### SO2emission rates 

### to a ievel 

### of 2.0 lbsiton 

### H2S04.

### On June 

### 1,2010,the 

### NCDAQ sent a lette~ to 

### PCS Phosphate requesting that the company develop an independent 

### RP control technolow evaluation for 

### SAPlants No. 

### 5 and KO. 

### 6. 

### Ln response to the 

### NCDAQ request, 

### PCS Phosphate retained

### URS Corporation to 

### perform 

### a RP control technology evaluation for SA Piants 

### So.5 and 6. The statutory factors that arerequired 

### in evaluating reasonable progress for an emission unit include the costs. 

### the time necessary for compliance. the remaining useful life ofthe facility, and the energy and non-air environmental impacts ofthe control installation. Consistent with 

### the NCDAQ 

### RP evaluation methodology contained in the North Carolina Regional Haze 

### SIP, the cost of compliance was used as a screening tool to determine whether the emission units would require the full four-factor evaluation. The 

### derails of the 

### RP analysis and the concIusions reached are presented in this document.


### 1.2 TECHNICAL CONCLUSIONS A detailed control technology evaluation was performed following the 

### RP evaluation guidance 

### in



# - b.The emmionreductions are based the percent reduction %omthe maximum 3-hour emission rate in 2009 (Ibiton) to the larger emission rate (Ibiton)for each scenario rimes the maximum annual emisslon rate inpast ten years (tonsiyrt. c. Based on the tocal annualized costs divided by the annual emission reciuction. 40 

### CFR Part 51,Appendix 

### Y. The following presents a summary of the 

### RP evaluation cost effectiveness analyses for several emission reduction scenarios 

### for the SA Plants 

### No. 5 and No. 6. 

### Summary 

### of SulfuricAcid 

### Plant Control E\7aluation

Scenario la: Maximizing vanadium catalyst. Scenario 1 : Rlaxirn~ze vanadium catalyst and replace pass 4 with cesium cataly5t. Scenario 2: Maximize vanadium catalyst. replace pass 3 with ceslurn catalyst,and reduce SOzgas strength at the miet of the converter from 11.% to 10.5%. Cost Effec*iveness (Yton) "

$20.484 S3.456 $10.672 TotalAnnualized Costs 6&r) Capital Investment (%) r 

# 1 I 

# I Sulfuric Acid j Plant No. 5 

### / Scenario

Ii I 2.U 1 062 

### I %16.543.W0 

### i 

# 1 I 

# 1 i
I 1 I e 3.8 5 I 1 3.5 !6S I 1 2.0 ! 962 

### I !
Annual Emission 

# I Annual Emission Target Reduction (tonlyr) Gb SOZlton Acid) j

Si3.133.21 I $13.651 1
I

z.Based on MECS SO?em~ssion limt guaranree on a contrnuous basis. $2:?.??(: $2.024.45 : $2,024,451 Ji40.760 $569,490 SIC.266.485

## introduction

Scenario 3: Maximize vanadium catalyst replace pass 4 with cesium catalyst, repiace existing comvener with a new 48 kdiarnercr converter, and repiace No 1 superheater to obtain optimum temperature in Pass 3. 

### I
1 Annual Emission Capital investment 

## I Reduction jlon/yr) ($) I i i

a.Based on ,WECS SOzemission hmjt guarantee on a continuous basis. b The ermsslon reductions are based the percent reduct~on from the nlaxlmum 3-hour emlsslon rate In 3009 (Ibltoni to the tdrget enxsslon rate ilbitont for each scenarlotimes the max~mum annual em~sslon rate 111pst [enyears (tonstyr) c Basedon the total annuahzed costs drvlded by the annual ernlsston reductmn Scenario 1: Replace pass 3 with cesium catalyst and replace incremental amount of vanadium catalyst. Scenano 2:Replace pass 4 with cesim catalyst, and reduce SOZ gas strength at the inlet ofthe converter from 11.5% to 10.5?~0. Scenano 3: Replace pass 4 with cesium catalyst and replace existing converter with a new 48 ft diameter converter ,4s shown 

### in the tables above. the cost effectiveness terms of capitalinvestment and cost per ton of compound removed to achieve an SO?emission rate of 3.0 lb/ron

### H$OJ is higher than those that would be considered economically feasible for permitting under the EPA New Source 

### Review Regulation 

### for Best Available Control Technolojg [BACTj evaluations; the 

### EPA Regional 

### Haze Regulation for 

### Best Available Retrofit Technology 

### (BART) evaluations: and the criteria set forth by the 

### NCDAQ in the Regional Haze 

### SIP submittal. Therefore, the 

### RP evaluation concludes that further emission reductions 

### for SA Plants So.5 and No. 

### 6 are not cost effecrive 

### and thus not reasonable for the purpose of Regional 

### Haze reduction goals and confirms the conctusions contained 

### in the 

### NC Regional Haze 

### SIP dated December 

### 17,2007. Since no 

### cost effective control measures were identified, the remaining 

### three statutoly factors were not evaluated in this report. 

### 1.3 CONTACT 

### INFORMATlON Should the NCDAQ have 

### any questions or comments regarding this document,please contact Mr. 

### Ross Smith 

### of PCS Phosphate at 

### ((252)322-8270 or 

### Mr.Randy Taylor of 

### URS Corporation at (919)461-1520.

## ReasonabteProgress

## 8nahfsis

2.1 INTRODUCTION In performing the control technology evaluation, the following 4-step process used for Best Available Retrofit 

### (BART) and 

### RP evaluations were utilized to conduct the control evaluation as described in Appendix 

### Y to 40 

### CFR 51. The four steps are: 

### STEP i 

### - Identify 

### All Available Retrofit Control Technologies,

e STEP 7, 

### - Eliminate Technically Infeasible Options, STEP 

### 3 - Evaluate Control Effectiveness of Remaining Control Technologies, and STEP 4 

### -Evaluate Impacts and Document the Results.
Each of these steps is discussed in further detail in the sectionspresented below. 

### 2.1.1 Step 1

# - IdentifyAll Available 

### Retrofit ControlTechnoiogies Appendix 

### Y to 40 

### CFR 51 defines an available retrofit control option as 

### an air pollution control technology 

### with a practical potential for application to the emissions 

### unit and the regulated compoundunder evaluation. Technologies available for compliance with Best Available Control Technology 

### @ACT) or Lowest Achievable Emission Rate 

### (LL4ERj regulations were included as part of the 

### RP analysis. Furthermore, technologiesthat are evaluated should inctude exisiing controls for the source category in question as well as the transfer of controls that have been applied to similar source categories and gas streams. However, control technologies which have not yet been applied to full scale operations are not required to be inciuded in the evaluation. Potentially applicable control technologies canbe grouped into one of three categories: Pollution Prevention. As stated in the regulation this is "use qf inherentl~s lower-emitting processewjx-actices, including he use ofcontrol techniques

### /e.g., /ow-NOxburners) and wot-k practices thatprevent emisszonsand result in lower '~rou'zaction-specrftc" ernlssions." Add-on Control Technologies. "Use of 

### {andwhere alrea$y inplace, improvement in the pecformance 

### ojj add-on controls,such as scrzrbbel-s,,fabi-ic,filters, rhemal oxidizers and other devices that conrroi and reduce emissions afte~ they areproduced." Combinations 

### of the previous two categories. Sources that were used to determine the potentially applicable control technologies for the 

### PCS RP analysis include the Environmental Protection Agency's 

### RACT.BACT/LAER Clearinghouse (RBLC).control technology vendors, informat~on from 

### EPA consent decrees, and information from previous 

### BACT analyses performed at the facility.


### 2.1.2 

### Step 

### 2 

# - Identify 

### Technically Feasible Retrofit 

### Control Technologies Step 

### 1 of the 

### RP analysis identifies all ofthe control technologies that are potentially available for the SA Plants 

### No. 5 and No. 

### 6. 

### Ln step 

### 2 of the analysis, thslist is 

### further refined to include

## IleasonableProgress;Wnafitsis only those technologies 

### which are technically feasible. Appendix 

### Y of 40 

### CFR 51 defines 

### a technica1ly feasiblecontrol technology as follows: "Control technologies ar-e techrzical!t~.femibIe ?f

either 

### (1)the?,

### have been ir~talied ntld 

### opevafed successfui(~*.for rhe 

### &peofsourceunder review undersrrniiar-conditions,

### or 

### (2) the rechnoio~ couldbe uppized to thesource under rakttl. 

### Twokqv concepts are 

### iinportanz in determining wizerher 

### a rechnology could 

### be applied "wniEnbifi~>" und "applicahili~,. 

### "



### ...a technolop is considered "avai2ahie1' ifthe source owner mqobtain 

### ir through cornrneiAcial cizar~nels. 

### or it is otherwise available within the common sense meaning ojntbreterm.

### An availabk technology is "upplicahie" ifitcan reasonah(v 

### Be ivrstalleciand opera~ed 

### on the 

### source 

### ppe under consideration.A rechnoiogy that is mailable and applicable is technicai(~!.feasibie." Control technologies 

### that are demedtechnically infeasible in this step of 

### the evaluation

### must include specific data stating

### that the technology is either comrnercialIy unavailable or outline the specific circumstances which preclude its application. Facilities may demonstrate 

### that a particular techndogy is infeasible due to "unresoivable technical 

### di,!ficuitieswith 

### applying the conrrol to the source 

### (e.g.,size 

### ofthe uuit, location 

### oftheproposed site, operaringproblems related to spectfic circu?mlarzcesqfthesmrrcc, space constraints, reliabiiihi,and advcrse side effectson the resfuf~he.facilityi." The implication of cost effectiveness is not included 

### in thsstep of the analysis. 

### 2.1.3 Step 

### 3

# - EvaluateTechnically

### Feasible Cornlol 

### Alternatives Control technologies determined to be ~echnically feasible 

### in step 

### 2 of the anahysis 

### are 

### further evaluated in srep 3. As stated in the regulation. the two main issues in step 

### 2 ofthe process are as follows: 

### Ensuring that the degree of control is evaluated using a metric that ensures an '.apples to apples" comparison of emissions performance levels among options, and Giving appropriate treatment and consideration 

### of control techniques that can operate over a wide range 

### of emission performance levels. 

### The analysis is based on the maximum level of control that a technology is capable of achieving


### 2.1.4 

### Ste~ 4

# - Evaluate Calculated and 

### Reported lrnpacts Appendix 

### Y to 40 

### CFR 5 1presents detailed insrructions for conducting the 

### analysis of each potential 

### impact. For the control technologies determined to be commercially available and techcallyfeasible. the following four stamtory factors that would porentially result &omthe instaIIation ofa conno1technology are evaluated. lmpact analysis part 1 : Costs of compliance, lmpact 

### analysis part 

### 2: Energy impacts, 

### * Impact analysis part 

### 3: Non-air 

### quaiity environmental impacts, and
e Impact analysis 

### part 4: Remaking useful life.

# SEl!l‘l@HTW O Reasonable

## fsrogressAnafysis

Consistent with the 

### NCDAQ 

### W evaluationmethodology contained in 

### the North Carolina Regional Haze 

### SIP,the cost of compliance was used as 

### a screening tool to determine whether the emission units would require the full four-factor evaluation. 

### 2.2 RP

### ANALYSIS FOR 

### SA PLANTS

## NOS.5

## AND 6 The SAPlants Nos. 

### 5 and 

### 6 units already use the double absorption process to control SO2 and mist eliminators to control H2S04 mist 

### (PMlo) to meet 

### NSPS limits for SO2and 

### H2S04mist. The principal steps in the sulfuric acid production process consist of burning sulfur 

### (S)in air to form sutku dioxide (SOz), combining the sulfkr dioxide with oxygen 

### (O?)to form 

### sulfur trioxide 

### (SO?),and combining the 

### sulfurtrioxide with water 

### ('H20) to form a solution containing sulfuric acid (?&?SO4). Sulfur dioxide is 

### formed when elemental sulfur is sprayed into a horizontal spray-type burner. the sulfur dioxide gas exits the burner compartment at a higher temperature than the optimum for conversion and it enters a heat recovery boiler to be cooled 

### off. Upon exiting the recovery boiler, the sulfur dioxide rich gas enters the first converter where it is partially converted to SO,. 

### Yet all the 

### SOzis converted to 

### SO;; the conversion into SO; is a function of the catalyst and oxygen present during the reaction.


### 2.2.1 Identify All 

### Available Retrofit 

### Control Technoiogies As determined from recent 

### BACT determinations for 

### SO2emissions from sulfunc acid plants, the prevalent control technology 

### for SO2emissions from sulfuric acid plants 

### is a dual absorption system with a catalyst, which is employed at SA Plants Nos. 

### 5 and 

### 6. Other technologies have been identified as potentially applicable control technologies for 

### SOzemissions from sulfuric acid plants. 

### The following fechnologies are evaluated: Sodium SuEte-bisulfite scrubbing Regenerative Scrubbing Molecular sieve 

### Ammonia Scrubbing Dual absorption process with cesium catalyst Sodium 

### Sulfite-Bisulfite Scrubbing In the sodium sulfite-bisulfite scrubbing process, SO2is removed by scrubbing the exhaust gases with a sodium sulfite soiution. 

### The resulting sodium bisuIfite solution is 

### fed to a heated crystallizer where sodium sulfite crystals are fom~ed with the release of SOzand 

### water vapor. The crystals are separated from the mother liquor and dissolved in the recovered condensate 

### for recycling to the absorber. The recovered wet 

### SO: is recycled to the acid plant. 

### In all processes employing sulfite-bisulfite absorpfon even without regeneration, some portion of the sulfite is oxidized to sulfate, from which 

### SOzcannot be regenerated 

### in the heating sequence. Thssulfate must be purged from the system. Some thio-sulfate can also be formed 

### in the process. 

### The extent 

### of oxidation is dependent on several factors (somewhic'h 

### may be difficult to control) such as the oxygen content of the 

### gas stream,the temperature and residence time 

### ofthe liquor 

### in tne recovery sections, and the presence of conraminants that 

### may act 

### as oxidizing catalysts. The

## Reasonable

## ProgressAaabsis

formation of oxides, 

### which readily precipitate Erom solution. can result in plugging and operational probhns. Sincepromulgation 

### ofthe 

### NSPS for sulfuric acid manufacturing, only two piants have used the sodium sulfite-bisulfite control technoiogy. The sodium sulfitebisulfite system at one of the plants experienced operational difficulties and was subsequently replaced 

### by an ammonia scrubber. The other plant is a part 

### of an Arm); anmunition production faciliry and bas not been used since 1994. Sodium sulfite-bisulfite connol technology is rejected 

### from further conslderalion in this analys~s because if has not been demonstrated commercially as provldrng reliable emissions controt 

### of less than 

### 1.0lb SOzhon of 100percent &SO4 produced at a sulfur-bumlng sulfuric acid manufacrurmg plant. SA Plants 

### 5 and 

### 6 are currently limited to 4.0 Ib SQiton &SO, by 

### NSPS Subpart 

### H. Regenerative Scrubbing In general, regeneratwe scrubbers absorb 

### the compound to be removed In a liquid media whlch 1s then routed to a second vessei where the compound 1s recovered from the llquid med~a. 

### The "cleaned" liquid media is routed for reuse and the compound removed can either be disposed of or possibly returned to the process. 

### The technical feasibility ofregeneratix scrubbingthrough a propfietaw process called UmluSolv@~ has been evaluated. Literature 

### from CanSoTv@ provides the following process description: 

### I. The feed gas is first quenched and saturated in a waterpre scrubber. The pre scrubber des~gn is selected based ontotal solids and So3content 

### in the gas and the regulatory requirement to remove them 2. The gas is then contacted with the lean amine solution in a counter-current column where SO1is absorbed. Thetreated 

### gas exits the absorber with 

### an SO: content as low 

### as I0 ppmv, depending on design parameters. 

### 3. The 

### SO:-rich amine from the absorption column 1spumped to the regeneration coiulnn via leanirich arnine heat exchanger for energy recovery. 4. 

### The lean 

### amine solution is regenerated 

### by indirect steam strippmg and the SO?

### is recovered 

### as a pure, water-saturated product, 

### 5. The lean amine leaves the stripper reboiler and is pumped back to the absorption column via the 

### iew'rich amine heat exchanger and the lean alnine cooler. 

### 6. 

### A slipstream of 

### the arnine 1spurified to pre17ent accumuiatlon ofheat stabie salts, 

### 7 The by-product 

### SO. can be converted to vanous sulfurproducts such as liquid 

### SO., sulfuric acid. or sulfur. The CanSolveGLwebsite indicates that a regenerative scrubber unit has been instailed on a sulfuric acid plant operated 

### by Conoco-Phillips at their Wilmington, California 

### faciliv. The Wilmington operation is part of 

### a refining operation split between Carson, California and IViirnington, California. The Carson site operates 

### as the front end of the refining process, 

### using high sulfur crude oil as the feedstock. 

### The Wilmington, CaIifornia site operates as 

### the back-end 

### ofthe refining process upgrading the products. Overall. the site produces mostly transportation grade fuels such as gasoline. diesel, and jet fuel. The Wilmingtonplant is an acid regeneration

## ReasonableProgressAnalysis facility and its operation is different from the sulfur burning operation at the Aurora facility. Emissions are inherently lower from an acid regeneration plant because the inlet 

### gas concentration is lower (generally 

### 1 ON), thereby, resulting in lower SO: emissions. Additionally, the oxygen and 

### SO: concentrations may be controlled independently in the regeneration plant, allowing forbetter control and tower emissions. This type of control is not possible in a sulfur burning operation. Additionally, there will likely be degradation of the amine solution due to the acid mist in the exhaust stream. There will also be secondary increases in emissions of greenhouse gasesbecause of 

### the increased steam demand which will be achieved through the combustion of additional fossil heis. This technology was recently evaluated for the sulfuric acid plant at the 

### PCS Geismar, Louisiana facility and it was determined to be technically infeasible due to potential operating difficulties and expected cost associated with operating the technology. 

### EPA concurred with this conclusion for the Geismar sulfuric acid plant and focused on double absorptiontechnology with cesium catalyst in the final 

### pass as 

### the preferred technology approach. Molecular Sieves This process utilizes a proprietary molecular sieve system in which 

### SO: is adsorbed on synthetic zeolites. The adsorbed material is desorbed by purified hot tail gas from the operating system and sentback to the acid plant. Sincethe promulgation of the suffuric acid plant 

### NSPS, only one new unit was built with a molecular sieve system to control SO2. However, exrensive operational difficulties with the system caused this piant to be retrofitted with a dual absorption system for SOzcontrol. The dual absorption system was retrofitted inJanuary 1979and has operated satisfactorily since that time. Since molecuiar sieve control technology has not been commercially demonstrated and operational 

### difficulties are anticipated, this option is considered technically mfeasibie for further reducing 

### SO: emissions from S.4 Plants 

### 5 and 

### 6 and is rejected from further consideration. 

### Ammonia 

### Scrubbing The ammonia scrubbing process uses anhydrous ammonia 

### (NH3)and make-up water in 

### a twostaze scrubbing process to remove 

### SOz. The typical SO: removal efficiency qf this control technoiogy 

### is not as 

### high as conventional dual absorption technology; however, several facilities in the 

### U.S.have used this technology to meet the KSPS for sulfuric acid manufacturing plants. According to 

### MKS.Inc., sulfur-burning suifuric acid manufacturing plants that have used ammonia scrubbingtechnology have applied the technoiogy as a retrofit to "existing" plants that were based 

### on single absorption technology that had to improve emissions control to achieve the 

### XSPS limit of 4.0 lb S02/ton of 

### 100percent 

### H~SOS produced and comply with the more strmgent state limit of 

### 3.8 lb S02/ton 

### of 100percent 

### H2S04 produced. Due to operational difficulties and high costs associated with operating ammonia scrubbing systems, all but two single absorption piants using ammonia scrubbing technology have been shut down. and the two existing plants still in operatior,are required to meet 

### the both the 

### NSPS emission limit of4.0 lb S02/ton of 100 percent E12S04 produced and the state limit of 

### 3.8 lb Soziton of 100percent.

### H2S04produced. Consequently, ammonia scrubbing is rejected from this analysis because it is commercia11.y undemonstrated on dual absorption plants. because of operational difficulties thathave been experienced by other sulfuric acid manufacturers, and because it is unknown whether additional control of SO: emissions would be achieved by 

### a retrofit with this type of system. Furthermore. the ammonium 

### sulfateultimately 

### emitted is a leading contributor to visibility impaiment ofFederal Class 

### I areas and would 

### have adverse-impacts onthe state's Reasonable Further Progress goals in the Regional Haze Program under the C,leanAir Act. Additionally, not all ofthe ammonia entering the scrubber would be consumed 

### in the reactions described above. 

### This would result in excess ammonia being emitted through the stack 

### in a process termed "ammoniaslip." 

### Duaf Absorption Process 

### with 

### Cesium Promoted 

### Catalvst Dual absorption technology is widely accepted 

### as 

### BACT for sulfuric acid plants. ConceptuaIly, dual absorption is the addition of another converter and absorbing tower to the exhaust from a single absorption plant. Vanadium-based catalysts are used in virtually all existing dual absorption systems, including 

### SA 

### PlantsNos. 5 and 

### 0. Cesium-promoted catalysts have recently been used, and can provide higher leveis of control. There are no by-products or waste scrubbing materials produced 

### by the dual absorptionprocess. 

### Speni cataiyst 

### is not treated as hazardous waste. The cesium-promoted catalyst was developed specifically for lower temperature operations 

### which can lead to 

### greater SO1 conversion and hence lower 

### SO2emissions to the atmosphere. The cesium salt promoter reduces thr required operating temperature for the sulfuric acid caralystby as much 

### as 40°C (70°F). Higher 

### SO2conversion ispossible at tower temperatures as long as the catalyst is "active." The cesium-promoted catalysts are sufficiently active at these Iower temperatures (390 ro 410°Ci'735 to 

### 770°F) to 

### take advantage of this conversion "opportunity." Cesium catalyst is technically feasible and thus theoretical analyses based on this retrofit technology were perforined for SA Plants Nos. 

### 5 and 

### 6.


### 2.2.2 

### Evaluation Cost 

### Effectiveness of 

### Control 

### Scenarios A major component ofthe 

### BART and 

### RP evaiuations

### is the determination of the annual operating costs associated with a particular technology. 

### In developing this evaluation: 

### MECS was contacted to provide total capital investment costs associated with each scenario. ,4ppendix A presents the 

### MECS design 

### and cost information for several control scenarios. To estimate annual operating expenses, the EPA's Cost Control Manual was also used to complete 

### the evaluation. For the SA Plants 

### No. 5 and 

### No. 6, a cost effectiveness evaluation was performed for several controI scenarios using cesium catalyst replacement 

### in the 

### final pass. 

### MECS, Inc. provided 

### four scenarios 

### (la. 1,

### 2. and 

### 3)for 

### SA Plant 

### No. 5 and three scenarios (1.3. and 

### 3) for SA Plant Yo. 

### 6. 

### The following presents the scenarios evaluated for each 

### plant. Sulfuric Acid 

### Plant No. 5 Base Scenario: SA Plant No. 

### 5has a total vanadium catalyst toad capacity of0.160kiloliters (kl) catalysh'ton &SO4 day. Current] y, the actual vanadmm catalyst load 1s 0.144 

### kl catalystiton H?S04day. Scenario la: Increase tlte actual capacity ofthe vanadium cataiyst load from 0.144to the maximum of 0.160 

### kl cataiyst/ton 

### H2S04 day. This scenario examines the cost of achieving 

### a 2.8 lblton H~SOJ short-term emission limit on a continuous basis. &Scenario 1: 

### This scenako examines the cost of achieving a 

### 3.5lbiton 

### H2S04 emission rate. For SA 

### No. 

### 5,this emissions rate 

### can be achieved on a continuous basis by increasing the actual capacity of thevanadium catalyst load up to maximum in beds 1 through 3. and replacing the cataiysr in bed 

### 4with cesium catalyst.Scenario 

### 2: This scenario examines the cost of achreving a 2.0 lbiton &SO4 emission rate on a continuous basis. This emissions rate could be achieved by adding vanadium 

### up to catalyst capacity in beds 

### 1 through 

### 3, repiacing the catalyst in bed 

### 4 with cesium, and reducing the 

### SO2 gas strength at the converter inlet to 10.5O/0. Thereduction of 

### SO2 gas strength at the inlet in order to achieve the 

### 2.0 lbiton 

### HzSO~ emission rate will result in a sizeabie production penalty. Scenario 3: As an alternative to Scenario 2, Scenario 

### 3 examines another method in which the emission rate oi'l.0 lbtton KzS04can be achieved on a continuous basis. PCS would add vanadium up to caialyst capacity in beds 1 through 

### 3, replacing the catalyst in bed 

### 4 with cesium, and installing a new converter and superheater. The installation of the new equipment allows the facility to avoid reducing the 

### SO?gas strength, while achieving the desired emission rate. Sulfuric Acid 

### Plant No. 

### 6 Controll 

### Scenarios Base Scenario: SAPlant No. 

### 6 has a totaI vanadium catalyst load capacity 

### of 0.150hloliters 

### (kli catalyst/ton H2S04 day. Currently, the actual vanadium catalyst load is 0.1

### 50 kl catalyst/ton H2S04 day and thus the maximum vanadium is currently used in the plant. Scenario 

### 1: This scenario examines the cost 

### of achieving a 

### 3.888 lb/ton emission rate. For SA

### No. 6, this emission rate can be achieved on a continuous basis by replacing the catalyst in bed 4 with cesium catalyst. 

### MECS also included replacing a fraction of the existing vanadium catalyst in each pass for this scenario. 

### It should be noted that 

### MECS has only guaranteed 

### an emission rate of 4.0 Ib/ton; however, this scenario has assumed 

### a 1tan emission reduction 

### (3.888 Ib/tonjin order to show some reduction for the purpose of calculating a cost effectiveness value. .)scenario 

### 2: Thsscenario axarninesthe cost of achieving a 2.0 lblton 

### H2S04emission rate on a continuous basis. This emission rate could be achieved by replacing the catalyst in bed 4 with cesium. and reducing the SO2 gas strength at the converter 

### inlet to 10.50/b. The reduction of SO. gas strength at the inlet will result in a sizeable production penaity. Scenario 

### 3: As an alternative to Scenario 

### 2, Scenario 

### 3 examines another method in 

### which the emission rate 

### of 2.0 lbiton can be achieved on a continuous basis. 

### PCS would replace the catalyst 

### in bed 4 with cesium and install a new converter. The installation of the new equipment allows the facility to avoid reducing the SO?

### gas strength, whIe achieving the desired emission rate. A summary of the SA Plant 

### KO. 5 and No. 

### 6 operatingparameters and associated scenarios arc presented in Table 

### I. Capital Recovery 

### Factor 

### In performing the cost evaluation for each ofthe scenarios, there are two types of 

### annual operating expenses, indirect costs and direct costs. The direct costs include cataiyst costs, screening costs. and catalyst disposal costs. Indirect expenses include adnlinistrative, depreciation for equipment, and SO2 recovery credit. The depreciation is calculated through the use of a capital recovery factor. The 

### EP-4 Cost Control Manual states the following in regards to the capital recovery factor: "Anabats 

### use the interest rate to estimate the time 

### vuiue ofnzonejs.It can he thought of as areturn oninvestment or the cost 

### ofborrowing. Tile interest rate employed in this 

### A,fununl diflers~jkom that 

### used in nor?-governmenral.jirzanriai 

### anulyses. 11represenn

### a

## ReasonalleProgressAnalysis

social interesi rate established by the OfficeofManagement and Budget (0MB)jorthe comparison of publicpolicy issues. OMBsets the social interestrarejbrgovernmental ana&ses and it 

### is currenthset ai seven percent. However, the social rate ofinterest 

### is not appropriate for industry. Whet7choosing between alternative air pollution control devices, the industrialplanner musfnot.onlj> take intoconsideration the costs 

### of each device, the?> musr also understand how the cost 

### ofeach device fits into the financial structure 

### oftheir business. Furthermore, a nzmmber 

### of air regulations allow sources ofpollurion topetitioiz.for exrensionson deadlines, var.iances~from the regulation, or exemptionjkom installing control dmices, based upon the economic impact that equipment would have upon the source. In these cases, the sowee majjJind it useful POapply their own interest rate to the calculationofcontrol costs. Common itzievestrates 

### used by indust? 

### and accepted by 

### the 

### EPA.for

### source petitions include thebusiness' current borrowing rate, the current prime rate, and other acceptableindustpialrates 

### ofreturn. " For the reasons stated above. the application of a 

### 7% interest rate is not appropriate for this analysis. Furthermore, the EPA Cost Conrrol Manual does not require the use of 

### 7%. A 15% rate is being used to account for the project costs as well as for the lost capital available for funding otherprojects that could have positive return on investment at the facility. This rate is appropriatebecause the return on investment target for projects at the Aurora facility is 15%. 

### Calcuilationof Annual 

### Emission Reductions and Cost Effectiveness 

### In performing the cost effectiveness, the total annualized cost is divided by the estimated annual emission reductions associated with each scenario. The emission reductions arebased the percent reduction from the maximum 3-hour emission rate in 

### 2009 (IbJton)to the target emission rate (Ib/ton)for each scenario times the maximum annual emission rate in past ten years (tonsiyr). Theuse of the baseline actual production data to establish an emissions baseline for cost effectiveness calculations is in accordance with a recent EPA determination. See 

### 74 Fed. Reg. at 44,321 (Aug.28, 2009). In connection with EPA's review of the cost effectiveness analyses for the Salt River Project 

### ("SRP") Navajo Generating Station 

### in Anzona, 

### EPA found that SRP's use of "the same 24-hour average actual emission rate from the highest emitting day used for its modeling inputs7' used for 

### BART modeling was incorrect. Id. 

### EPA revised SRP's calculations accordingly "by starting with baseline emission rates for 

### NOx averaged over 2004- 

### 2006

. . 

### . ." Id. EPA's determination in the 

### SRP context is in line with the agency's requirement that baseline emissions "represent a realistic depiction of anticipated annual emissions 

### for the source." 

### 70 Fed. Reg. at 

### 39,167 (July 6.2005). Using actual baseline emissions instead of the 

### BART modeling baseline leads to a more accurate-and higher--cost effectiveness estimate for control options being evaluated. As pointed out by 

### EPA, using the 

### BARTmodeiing baseline to calculate cost effectiveness overestimates actual emissions and does not provide a realistic estimate of anticipated annual emissions from each source. 

### h this evaluation, the maximum production rate during the 

### PSD actual baseline period for each unit is used to perform 

### the cost effectiveness evaluation. The 

### maximum production rare during the baseline period is multiplied by the percent reduction from the maximum 3-hour emission rate in 2009 (Iblton)to the target emission rate (Ib!ton).

## Reasonable

# Pmoress8naMsis
Cost Effectiveness Evaluation Results The following presents the details ofthe cost effectiveness evaluation for 

### SA Plants No. 5 and No. 

### 6. Table 

### 2 presents the basis for the cost evaiuatjon and cost effectiveness for each the scenarios. 

### Sulfuric Acid 

### Plant No. 

### 5 For Scenario 

### la,there would be a one-time direct cost of $237,720 for maximizingvanadium catalystto capacity in beds 1through 

### 4. 

### This would allow 

### the plant to continuously achieve a short-term emission rate of 

### 3.8 Ib SOz/ton&SO4 or a 5 tordyear emisstonreduction. The cost per ton of SO: rernoval will be $26,4X4/ton. Thts value is not considered cost effective. Table 

### 3 presenrs the detailed calculations for Scenario la. For Scenario 1,there would be a one-time direct cost of $2,024,45

### 1 for S,4 PlantNo. 5 including the cost of additional vanadium 

### in beds 

### I through 

### 3,the total costs ofreplacing bed 

### 4 with cesium, additional screening costs, and used catalyst disposal. This wouId allow the plant to continuously achieve a short-term emission rate of 3.5 

### lb SOdtonH2SOs or 165tonsiyear emission reduction. The cost per ton 

### of 

### SOzremoval will be $3,456/ton. This value 

### is not considered cost effective. Table 

### 4 presents the detailed calculations for Scenario 

### 1. For Scenario

### 2, there would be a one-time direct cost of $2,034,451 for 

### SA Plant No. 

### 5 including the cost of additional vanadium in beds 

### 1 through 3> the total costs 

### ofreplacing bed 4 with cesium?additional screening costs, and used catalyst disposal. 

### This scenariowill also include recurring direct annual costs from a production penalty resulting in $9,778,087 of lost product. This would alowthe plant to continuously achieve 

### a short-term emissionrate of2.0

### Ib SOz/ton 

### H2SOdor 

### 962 tonsiyear 

### emisston reduction. The costper ton of SO2removal will be $1O,67Yton. This value is not considered cost effective. Table 

### 5 presents the detailed calculations for Scenario 7 

### -. For Scenario 3,there would be a one-time direct cost of $16,543,000 for 

### SA 

### PlantNo. 

### 5 inciuding the cost of additional vanadium in beds 

### 1 through 3. the total costs ofreplacingbed 4 with cesium, additional screening costs, andused catalyst disposal, a new convener, and a new superheater. Furthermore, 

### since the installation of the new converter and superheaterwould require approximately 10months for completion, there would be a production loss at the facility due to reduced steam generation from the 

### sulfuric acid plant and a cost for lost cogeneration. The one-time production and cogeneration penalty would be approximately$45,276.986. This would allow the plant to continuously achieve a short-term emission rate of2.0 

### lb S02/ton H2S04or 962 tondyear emission reduction. Thus, the cost per ton 

### of SOZ removal will be $13,65l/ton. Tlsvalue is not considered cost effective. Table 

### 6 presents the detailed calculations for Scenario 

### 3. The following tabie summarizes 

### the cost effectiveness analyses for each of the SA Plants No. 5 scenarios described above.

# ReasonableProgress:Anahis

- b.The emission reductions are based tihe percent reduction fiom the miximum 3-hour emission rate in 2009 (lbtton) to the target ernmion rate (Ib/ton)for each scenario times the maximum annual emssion rate in past ten years itonsly-) c. Based on the total annual~zed costs divided by the annual emission reduction. - - ! 1

Scenario l a: Maxrmmg vanadium catalyst. Scenano 1: Maximize vanadium catatyst and replace pass 4 with cesium cataiyst, Scenano2: Maximize vanadium catalyst. repiace pass 3 with ceslum catalyst. and reduce SO2gas strength at the inlet ofthe converter from 11.% to 10.5'3'0. Scenario3:Maximize vanadrum catalyst. replace pass 4 with cesium catalyst.repiace existing converrer with a new 48 ft diameter converter. and replace No. 1 superheater to obrain optimwn temperature In Pas2 I



### Sulfuric Acid 

### Plant No. 6 

# I

For Scenario 

### 1,there would be a one-time direct cost of 

### $1

### ,go?,% 1 for SAPlant Yo. 

### 6 including the cost of additional vanadium 

### in beds 1 through 3? the total costs ofreplacing bed 4 with cesium, additional screening costs, and used catalyst disposal. This would allow the plant to continuously achieve a short-term emissionrate of 

### 3.888lb SOliton H2S04. 

### It should be noted that 

### MECS has only guaranteed an emission rate of 4.0 lb!ton; however. this scenario has assumed a 

### 3.888 Ib/ton

### (1.O toniyr reduction) 

### in order to show some reduction for the purpose of calcuIating a cost effectiveness value. Thus, 

### the cost per ton 

### of 

### SO- removal will be $452,59Wton. 

### This value is 

### not considered cost effective. Table 

### 7 presents 

### he detailed calculations for Scenario 

### I. For Scenario 3, there would be a one-time direct cost of $1,907,93 1 for SA PlantNo. 

### 6 inciuding the cost 

### of additional vanadium in beds 

### 1 through 

### 3? the total costs ofreplacing bed 4 

### with cesium, additional screening costs, and used catalyst disposal. This scenario 

### will also include recurring direct annual costs from 

### a production penalty resulting in $13.232.609 of iosl product. 

### This would allow the 

### plaut to continuously achieve a short-rem emission rate of 2.0 Ib SOz/ton 

### H2SOdor 1.1 11 tons~year emissionreduction. 

### Tne cost per ton of SO. removal will be $11,4i4hon. This value is not considered cost effective. Table 

### 8presents the detailed calculationsfor Scenano 2. 

# I

For Scenario 

### 3. there would be 

### a one-time direct cost 

### of $14,125.000 for 

### SA Plant 

### Eo. 6 includingthe cost of additional vanadium in beds 1 through 

### 3, the total costs ofreplacing bed 4 with cesium, additional screening costs?and used catalyst disposal, a new converter. 

### and 

### anew superheater. Furthermore. since the installation of the new converter would require approximately 10 months for completion. there would be a production loss at the facility due to reduced steam generation fiom the sulfuric acid plant and cost 

### for lost cogeneration, 

### The one

### 2-10 SulfuricAcid Annual Emission Ptnnt No. 5 Target 

# 1 Annual Emission Capital Investment Total Annualized Costs Cost EfCectiseness

Scenario 

# I (lb SOZhnAdd) * Reduction (ton~vr) b. ($1 6S/_vri (Siton)', I 

# I 

# I j 

### 1 I r~ 1a 3 8 I ! >.5 165 $2.03.45 I $5~9.490 $3.456 I 1 2.0 I 962 

### 1 $2.024.45 1 

### I 10266.4XL [ 51 0,672 1 

### 1 2.0 

### 1 96'1 ) $1b.543.000 

### 1 S !3.1?2.11 7 

### I 13.65: 

# I

a.Based on h4ECS SO- ernisslon hit euaranree on a conrinuous basis.

# SH!TI@W'PWO ReasonableProgresAnafysis time production and cogeneration penalty would 

### be approxrrnateiy $53,687,154. 

### This would aliow the plant to continuousiy achieve a short-term emission rate of 

### 2.0 lb SO2/ton 

### H.SO.4 or 1,111 tons/year emission reduction. Thus, the cost per ton of SOzremoval 

### will be $13.816/ton. Thls value is not considered cost effective. Table 9 presents the detailed calcuiations for Scenario 

### 3. The foIlowing table summarizes the cost effectiveness analyses for each ofthe SA Plants So.

### 6 scenarios described above.

a. Based on MECS SO2emission limn ,pirantee on a continuous basis b The emlsslon reducfions are based the percent reductmn from the maximum 3-hour emission rate m 1009 (lblton) to the rarget emission rate (Ibitoni for each scenarlo lmes the maxlmum annual ermsslon rare In past ren years (tonsyr)

. c Based on the total annuaiized costs dlv~ded by tile annulemissron reauct~on. Scenano 1 Replace pass 4 with ceslum catalyst and replace incremental amount ofvanadlum catalyx Scenano2 Replace pass 4 wlth cesium catalyst, and reduce SO: gas strength at the inlet of the converter from !1 5O.o to 10550 Scenano 3 Replace pass w~th ceslum catafyst and replace exlsting converter with a new 48 fi dlarneter converter


### 2.2.3 

### Conclusion URS performed a detailed control technology evaluation following the 

### RP evaluation guidance in 

### 40 CFR Part 51. Appendix 

### Y. Under various scenarios for SAPlant 

### KO. 5 and 

### No. 

### 6,the cost per ton of compound removed under all ofthe evaluated scenarios 

### is higher than those that would be considered cost effective. Therefore, the evaluatioi~ concludes that further emission reductions for SA Plants 

### No,

### 5 and No. 6 are not cost effective and not reasonable for the purpose of Regional Haze reduction goals and confirms the conclusions contained 

### in the 

### NC Reglonal Haze 

### SIP dated December 17,2007. Since

### no cost effective control measures were identified, the remaimng three statutory factors were not evaluated in this report.

## TablesTABLE 3 SCENARIO Ia

### - COST ANALYSIS FOR 3.8 LBRON HZS04

## - SULFURJC ACID PLAiiT NO. 5 MAXIMUM VASADIUM CATALYST PCS PHOSPHATE COMPANY URS PROJECT YO.31827076
Basis: lj MECS Inc. 2) MECS -Cesium and vanadium catalyst cost. CPCSPholphate ~n~rnetlnngnd 

### in-^

, ,pressurt:
Dtrect Costs Max Vanadium BasislCommene,

Cos! of ies~urn Catalyst Replacerntnr Cost (Bed 4 crslum, SO Addinonal catalyst (9 43 kl catalystttmw cost of Cost of Addrtiond Vanadrum Caraiyst (Bed 1.1.3.4j $237.720 vanadium (94.00!1 I Addmonal screening cost $0 Us& catalyst dispo~i con(9 0 1XILI %n
Total Capital Cost $237.720
Dirert Aauual costs Elccrnclt): 15" increased pressure drop $0.05 iKwi IndirectAnnual Coats kdmtnis~nt~oa PromTaxes Insulilnc~ hp~tal Reco\ery (CwumCatalyst) Capmi Rwovrry (Vanadlun~ Catalyst 6 Additional acreentag and D~sposol i Credir for ac~d recoverv
Total Annual Cost

Maximum baselme actual cmlssion rase

Lrnpmvcd Conrrol Eficrenc) Over Baselrnt

CostAon oTSOI removai 34.754 2% TCC: van Nuswnd Rcmhoid $2.377 1% TCC van NostrandRernhoid $2.377 I?," TCC van Nostrand Reinhold 60 (1590 rare ot mumand 10 vr equipment litel
Si7.366 (!5% rate of return and 10yr qurpment lrli')

($383) lncrea~ed sulEur ii~oxtde conventon I@ S47/to!i acid

2.025 tpy (based on rnaxtrnm nnnuai etn~aslons)T.4BLE4 SCENARlO 1

### - COST ANALYSIS FOR 3.5 LB/TON H2S04- SULFURIC ACID PLAh'T NO. 5 CESIUM CATALYST IN 4TH PASS

PCS PHOSPHATE COMPANP' URS PROJECT NO. 31827076

P_ 

# - -. Basis: I\ MECS Sns. 2) MECS- Cesium and vanadium catalyst cost

Direct Cost$

Cost of Cesrum CatalystReplacelnenr Cost (Bed4 ;esrum i

Catalvst. Remove. Ke~nstail and Saees C$taiysrFrerght
Ciuaiu Total Capital Cosl
Direcr AnnuaI cosm Eteccncirv (5" rncreaseti pressure drop $005 ,Xwi Annual produciion loss due w reduced SU: Suer& at convener inie?ilons P,O,I\TJ Cosi of annual prcnJuLtinn ioss dur ro reduced SO: Sl~~ngh at conwrter inlet
IndirectAnnual Costs Adm~nism~on Propenylax& Insurmct Capml Recovery (Ces~urn Catalyst, Caprtal Recoven, (Vanadturn Catalyst B Add~ucnai screening and Dlsposaii Credl: foracid rwovm

hlaximum baaelme actual em1salon rare

Improved Conlroi FfficimcvOwr Baseline Cesium Catalyst Retrofit Total of wrsiysr mad of t 81.2ki csralys~ tines costof piacingvanadlm wtth cesium ($8 00n)
Addnional caialvs?ijq33 kl catalm itrneswsr of \anadrum (94.00~11

MGCS MECS MECS

$40 489 2% TCC urn goswndKernhold $20.245 I % TCC van Koswnd Urlnhold $20.24: IS, TCC vat1 Nostrand bmhold $288.836 1IS?+raw ofrrlwn md 10 y: equipment lifcj $1 04.315 (15%mie of rerum and I0 yr equipmcnl life1 (%I I.8581 increued sulfur droxidc convemon (3 $4711011ard

8.1 YO ((based3 i ih SO;!!on acrdt

CosthnofSO, removulTABLE S SCENARIO 2

## - COST ANALYSIS FOR 2.0 LBITON H2S04

## - SULFURICACID PLANT 30.5 CESlCM CATALYSTIN 4TH PASSAND REDUCE SO2 GAS STRENGTH TO CONlrERTER PCS PHOSPHATE COMPANY URS PROJECT NO.31827076

e Basis: 11 MECS he. 2) MECS

### - Cesium and vanadium cstalystcost.

Direct Costs

Cost of Ccsrum Catalyst Repiacmicnt Cost (Bed 4 cesium)

Cost of Addlaonai Vanad~urrr Cntaivsl (Bed 1.3.31 Ca!alvst, Remove, Re~nsull and Screcn Cablyst Frergh~ Quart.
Total Capital Cost
Direct Ann~nl costs Eiccmcxy (5" ~ncrwscd pressure drop 50.05 Kw i

Annuai production loss duc to reduced SO2Strength at convener inie~ (tonsP,Og).ri
Cost of annual product~on loss duc to reduced SO2Skrcngth at convcncrinld
Isdirect .4nnual Costs
Admin~strauon Properiy Faxes insurance Cnpiwl Recovcry iCes1um Catalyst) Cap~tal Recovery iVanadru~n Catalyst & Additlolial sc~ue~l~ng anti D~sposiilj Crcditfor prlc recnvnv

lmproved Control Eflicmcy Uvcr baselme
Emisslori Reduction
Costiton ol'SO-, removal Ces~urn Catalyst Retrefrt
Totai of cntaIy8t load of 181.2k! calalysTtlmcs cost of rcolacing vanadium with cenum (58.W11)
Addibonal catalyst 159.43kl catalp?tunes cost oT vmaaun (%4.00;% MECS

EPA-450'3-85-0 13 (acfm- 2 10,660) Reducrng SO?gas srrcngth from 11.to 10.58,3b results In 40 TPD pmriucnon penalty umes 358 davs pcr vear (9890ut~lmlion) Hiwed mi average grosrnarpn of S2Ol;ron PIC;, r.roduced~soiJ

2% TCC vnn Nosnand Ranhold )%TCC ran Nosvend Reinhold I?b TCC var, NusnndRcrnhoki (15% rate of return nud 10 yr cquipmenl hie) (15% meolrcturn and 10yr cqulpment iifc)

rp) Ibased on manmum annual emisszonsITABLE6 SCENARJO3 -COST ANALYSZS FOR 1.0 LEITONH2S04

### - SULFURIC ACID PLANT NO.5 CESIUM CATALYST IR lTH PASS AHD ADDITIONAL EQUlPiMENT CAPITAL PCS PHOSPHATE COMPANY Ulds PROJECTNO. 31827076

2i MECS- Caiumand vaaadiom cn:alvst mat 3) Eruting cooveier is rcpiaced with a new 48 11 diameter msvener and pan4 i. rrpi~fed with SCX-Z(WO cstltvst. No. 1 Superhester ir rrplaced to obtain

Cost of CcsburnCaraipsr Rcphcmnrl Cost ftlM 4 ccsburn! Cesium Cntalyst Basis:Commenrs Krtrufit
Tnulofcalsly~ ioad of22s 2 ki iati!yt tmes iost of SI.S'.5,6(K, repiacmg vanadrum w~th ccsiurn (S8 00111

Calalyi, Rcmovc.Rcnmali and Sacos $285.813 MECS

Ncw C'onvurler S10.575.783 MECS

ioral New Equcomcnr J13.6.3j57S3 MKS
Tc~ral Capttnl Casr 516,543,OMl

mrccr Annual mklr

SjI(O.Xh(l ?",. TCC van Nusmlki Rcinhoiil klG,+l?O 1% TCC'van Nmmnd Rcmho!d 1165.430 1':. TCC van Nw~mui Rcinirold S.X.755 t 15':. rare ofretunand Illyr wulpmem hfcj

Maxtrnum badrncactual muaslunmre 2.025 rpy fbascdon maxunum anoual LmlsrlunsjTABLE 7 SCENARIO 'i -COST ANALYSIS FOR 3.89 LBtTOX H2S04

## - SULFURIC ACID PLAKT NO. 6 CESIUM CATALYST IS 4TW PASS

PCS PHOSPHATE COMP-tNY URS PROJECT YO. 31827076 

## - Bask 1) MECS lnr. 21 MECS

### - L'wunl and vanadium catalyst cost.

Direct Cctsts

Cocr of.4ddmonal Vanadium Cawivst iaed i.2.3) Cataiyxr, Remove, Remnuall and Screen Catalyst Freigni C)uLm
Total Capitat Cost
Direct Annual cow Electricity 1

### '" increased pressure drop 40 05 ~Ku)
Annunl producnon loss due to reduced SO-, Strcngtlr st converter inleiiloos f20,:yri Cost ofannual pmd~tion loss due lo rcouced SO, Strength at umvmer mlet
lndirecr Aonuol Cwls

Cap~tal Recovery (Vanadium Catnlysr & Add~t~ondl screeuvlg and Dlspo.;tIi Credl: tor ac~d recover).
Total Annual Cov

Lmpn~ed Control Efficlmcy Over Basetlnc Cesium Catalyst Retrofit Total of catalyst load of Ih83 kl cataiys tmes coat o! repiac~ng vn~dlwn w~th ceslum ($8 c)O/l) Add~ttonai catalyst - 60 04 ki t~mer, cosi of aanadlum catalyst ($1 0O:it
MECS MECS MECS

2%TCC van Nosrrand Remhold I80 TCC van Kosrmnd Re~uhold I"/" TCC van Nosirand Re~nhold (15% raw ofre:m and :(I yr yurpment iiki
115% rate of ream al~d 10 )Tcqumpmcnt hiej
Increased suhrdtoriLir canverswn I:$ f47;ron actd

tpy (based on maximum annwl emlss1onL)TABLE 8 SCENARIO 2 

### - COST ANALYSIS FOR 2.0 LBfrON H2S04

### - SULFURK ACID PLANT YO. 6 CESlLrM CATALYST IN 4TH PASS AND REDUCE SO2 GAS STRENGTHTO CONVERTER PCS PHOSPHATE COMPANY URS PROJECT NO.31827076 

## - 

# - Basts: 1) MECS lnc. 21 Haldor Topsw. Lnc. 

### - Cesium and vnnadium catalyst cost.

pirect Costs

Cost of Cestum Catziyst Replamrncnf Cat(Bcd4 ceslrirn i

Cosr ofAdditional Vanadium Catalyst (l3cd 1.2.3) Caulyst. Removc, Rcinatall and Scrcon Catalyst Fretgl~t Qwm
Total Capital Cost
Dirwt Annual costs Elccmc~rs (5" lncrcaacdpressurc hop $0.05 ,F;iv!

Annuai product~on loss due !o reduced 50, Sucngth at umvcner tnle: (tunsP,O&rl
Cost o<annuaiproductton iuss dueu) rtauced SO: Strcngtii atcunvcrtcr inlet
Indirect Annual Costs Admintstrat~on Prupeny Tams insurar~ce Capnai Rccove~y ((lcsium Cataiystl Capttak Remvcr)i Waitad~uni Cataiyst& Addmonai screening and D~spusai~ Crcditfor ad rccovm
Total Annual Cost

Maxtmum bascilne WNal emission rdlc

CosWion of SO?removal Cesium Catafyst Retrofit Total uf catalyst load of 168.3 ki mraiysr times cost or repimng vnnad~un~ with Lesum (S8.Wfi) Addltronai catalyst - biJ.09 ii:tjmcs cost of ana ad run^ caiolyst tS4.OO!I) MECS MECS MCS

EPb.45013-85-0 12. tach= 110.660) Reducing SO, gas strength &om 1 !.5 to 10.5% rcsults in 500 n'D prductroo penally ilrnes 358 days per year (98%utrIir.auon) Based on avuagcyossmargin oFSZOl/;on P20, protiuccd~sold

240TCC vw Noshilnd RetnhoId 1% TCC van NoswndRe~nhold I% TCC van Nosnand Remhoid 15% ratc of return 2nd 10yr equprncnt Ifd ii5%ratc olrcnim and 10yr cqurpmcntItk:
in~~cuscd sulfur dlox~de mnvcrsioti i:n; Fj71tori ad

tpy (bas& on maximum altnual emtssrons)

k (baser! 2.0 ib SOyron ac~d) lpy (baed on 2.0 Ib SD,/mn ac~dlTABLE 9 SCENARIO3 -COST ANALYSIS FOR 2.0 LBrrON HZSO4 -SULFURIC ACIDPLANT NO. 6 CESIUM CATALYST IN 4TH PASS AND ADDITIONAL EQUIPMENT CAPITAL PCS PHOSPHATE COMPANY URS PROJECT NO. 31827076
Basis: I) MECS Inc 2) iisldorZopscre. Inc

### - Cerium and vanadium ntnlysr con JfEriahnpnccd with a new 48 ft diameter converter f
Cesium Calaiyst Retrofit
Toel orcalalyst ioad of248.1kl wtnlvst ltmus cost of r~qlacmg vanadturn with crsturn (58 M):l)
Addruonal catalvst- 181 ki llmcs cuut oiv~tdlurn Caldlyst (41M)iil
MECS
MECS
MECS ,MECS Cost ofCesatm Catalyst Replacanent Cost (Bed 4 cmrwnl

Cost of Aditrronal Vanamum Catalyn (Red 11,3) SetaiysL Remove. Retnstatl md.keen

New Convcmr Ncw Supehcnlcr
lolal Capitsl Cost

Aununi productrun lors duc ui 10month dcwnttrne lo udd new cqulpmenl Ironsf'2i)5iyr~

huai producrtvn luss dw iorcdilccd SO Slrcngth atconvcrrw rnlct lrona \O.:yrt Cwt ofUNZM~ producriun loss due to reduck SO SIC~~L$I at convrrtcr ltilcl ~aaal Costs Ahtn~wmon Propcny Taxer losurdnw Caprrdl Kccovcrv (CesiumCaldysll 2% TCCvan Nostrand Remhoid I%

TCC ranNuahond RnnLold I"% TCC van "lostrand Rutniioid 115%rate olrctum and I0yr eqmprnml I& Capital Rccovcry (Vannd~um Catalvsi addthonai sncentng aird Utspowl. rlew converter ad sepcrhca%cr, andone lllnc prudilcr~un loss and cogennntlmloss) C~drl tor aidre~~vcq (15% rate airamand 10pr rqutpment hie)

increased aulfur d~oxidc cmvmmn 157Sii7:lon acid

'futal Annual Cml

ipy ibdicdon nuximum annual cmw~om]

Improved Conrrol Effic~ncy CvcrBascitne

## APPEMDMA 

## MECS DESl6tl

## AND COST

## IHFQRMBTII11

## Catalyst 

## Designs for PCS Aurora

Dastgcs are based on 3 year turnarounds 

# I PLANT 5 

# I PLANT 6 

# I

Scenario 1: What is the lowest $02 Wonem15sion rate that can be continuously achieved ona 3hour average basis, without lowering the 502gas strength (i.e. production penal%y) and significant capital? Pass 4 isreplacedwlth SCX-2000 catalyst for both plants SO2 rant 115% Pbnt Rate 3400 STPD SO2 Erntss~ons 3 5 lbllon Temperature (deg F!

Bed Type Volume (Ll inle: Outiel

1 XLP-220 117.800 794 1156 2 XLP-110 123.400 907 1025 3 XLP-!I0 155,000 845 911 4 SCX-2000 18:,200 734 787 TOTAL 577,400 (170 LJT) SO2 conc 11 5% Plant Rate 3700 STPO SO2 Emlsswns 4 0 bfion Temperature (deg Fi

Bed Type Volume (Li inlet Outlet

1 XLP-220 130.000 785 112d 2 XLP-$10 122,100 8il 937 3 XLP-ll0 14E.30 833 910 4 SCX-2O[M 168.300 734 790 TOTAL 568.900 (154 UT)

Scenario 2: Inorder to achieve a 2.0 fbfton emlsslon rate continuouslyona f-hour average basis, what would be the SO2 gas strength and associated productlon penalty, without slgnififant capital? Pass 4 is repieced with SCX-2000 catatysi for both plants.
so2COW 10 5% Planl Rate 3000 STPD SO2 Emrsslons 2 0 lblton

Bed Type Vdume (L) Inlet Outkt

1 XLP-220 117.8CC 794 1"1? 2 XLP-110 123.4IM 907 1011 3 XLP-110 155.000 &15 896 4 SCX-2MIO IS1.2W 734 769 TOTAL 577,400 SO2 Conc '0 5% Plant Rate 3200 STPD SC2 Emswans 2 0 bitor Temoerature ldeo Fi

Bed Type Voiume <:'I lnlel Outiet

I XLP-220 130.M1G 783 1141 2 XLP-110 122 100 811 932 3 XLP-110 148500 833 871 4 SCX-ZOOC 168 300 734 763 TOTAL 568 900

Scenario 3. Inorder to achieves 2.0 lblton erniss~on rats continuously on a 3-hour average basis, what modifications would be required and what would the capital cost6 be loachieve the emission level? PIant 5 exWngconveter is replacad with a new 46 f! diameter wnverter and paas 4 is replaced with SCX-ZOO0 cataiyst. No. 1 Superheater IS replaced to &tam optimum temperature In pass 2. SO2 Conc 11 5% Plant Rate 3400 STPD SO2 Ernrss~ons 2 0 IbAon Ternperatwe (degF)

Bed Type Vdurne (1: Me? Out!et

1 XLP-220 322.600 734 1156 2 XLP-110 :56.6@2 824' 975 3 XP-110 201,000 845 887 4 SCX-ZOOC 228,200 734 775 TOTAL 708.4OC (206 UT) Plant 6 emsting conveter is replaced with a new 48 ft diameter converter and pass 4 is replaced with SCX-ZOO0 catalvst.
so2 Ccnc 115% Plant Rate 3700 STPD SO2 Ernrsslans 2 0 IbIIon Temoerabre ideaFi

6ed Type Volume {L: lniet 0uiet

1 XLP-220 133.400 783 1131 2 XLP-110 170,600 811 971 ? XLP-110 216,60@ 833 @-32 4 SCX-2OW248.200 734 773 TOTAL 770.800 (208LJr)
Nore that new SuperheaterISreoulrsdClient: PC§ Description: Catalyst Options Location: Aurora, NC

Scenario I: Plant 5 Catalyst, Remove, Reinstall and Screen *

includes New SCX-2000 and Make-up XLP Plant 6 Catalyst. Remove. Reinstall and Screen *

lnciudes New SCX-ZOO0 and Make-up XLP

Scenario 2: Plant 5 Catalyst, Remove, Reinstall and Screen '

Includes New SCX-2000 and Make-upXLP Plant 6 Catalyst, Remove, Reinstall and Screen *

includes New SCX-2000 and Make-upXLP

Scenario 3: Plant 5 NewConverter incl Catalyst Replacement New Superheater Plant 6 New Converter incl Catalyst Replacement Rev: 0 Project #: By: 

### SGK Date: 

### 25-Jun-18 Estimate Type: 

### +/- 25%

" Screening includes all beds.

-

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