### TECHNICAL MEMORANDUM

TO: Tina Ndoh , U

. S

. EPA/OAQPS/SPPD

- Minerals and Manufacturing Group

FROM: Eastern Research Group, Inc.

DATE: May 20, 2014

SUBJECT: Beyond

- the

- Floor Analysis for Phosphate Rock Calciners at Phosphoric Acid Manufacturing Plants

1.0 INTRODUCTION

The U.S. Environmental Protection Agency (EPA), under section 112 of the Clean Air Act (CAA), is required to establish emissions standards for Hazardous Air Pollu tants (NESHAP) emitted from phosphoric acid and phosphate fertilizer production facilities. The complete set of HAP is listed under CAA section 112(b). EPA must also examine more stringent “beyond

- the

floor” (BTF) regulatory options to determine MACT. Unli ke the minimum stringency requirements of the floor, EPA must consider various impacts of the more stringent regulatory options such as costs and emissions reductions in determining whether MACT standards are to reflect BTF requirements.

Upon review of th e phosphoric acid and phosphate fertilizer source categories in conjunction with the risk and technology review, EPA identified emission sources that do not have MACT standards for all pollutants emitted. As a result, the EPA determined MACT

standards for mercury (Hg) and hydrogen fluoride from the phosphate rock calciners. However, the emissions of Hg from the phosphate rock calciners are the largest source of Hg emissions from this industry and comprise approximately 80 percent of the Hg emissions from the combined source categories Phosp horic Acid Manufacturing and Phosphate Fertilizer Production. As a result, BTF options were identified for phosphate rock calciners that would be more stringent than the MACT floor level of control

. .

This memorandum describes the cost and emissions reductions for phosphate rock calciners achieved by applying BTF regulatory options for Hg.

Sections 2.0 and 3.0 discuss the selection of more stringent controls or emissions levels than the floor level reviewed for this analysis for existing and new sour ces, respectively. Section 4.0 discusses the methodology used to estimate costs and emissions reductions of the more stringent controls and Section 5.0 summarizes the results of the BTF analysis.

1

### 2.0 IDENTIFICATION OF MO RE STRINGENT CONTROL S FOR EXISTING

SOURC ES

The MACT floor analysis for existing sources results in emissions levels that each existing phosphate rock calciner is required to meet. The emissions reductions and costs of the MACT floor level of control for Hg were estimated based on the following i nformation:

1. Test data were only available from two phosphate rock calciners, as only one facility operates phosphate rock calciners in the production of phosphoric acid; therefore, the two phosphate rock calciners set the MACT floor limit and no Hg

emissio n reductions are expected as a result.

2. The cost of the one facility to meet the Hg MACT floor for phosphate rock calciners was estimated based on periodic testing and associated recordkeeping and reporting requirements. No additional controls were anticip ated.

For existing phosphate rock calciners it was determined that emissions reductions of Hg could be achieved by routing the phosphate rock calciner exhaust through a Hg control device,

such as a fixed

- bed (FB) carbon adsorption system, activated carbon injection (ACI) prior to the existing wet electrostatic precipitators (WESP), or ACI installed after the existing WESP followed by a fabric filter. Based on a review of vendor supplied information and previous control technology studies 1 

### , a FB carbon adso rption system would achieve at least a 90 percent reduction of the Hg in the calciner exhaust stream. Similar emissions reductions are anticipated with ACI followed by the WESP or a fabric filter (EPA, 1997; Jones, 2007).

T he incremental emission reductio ns and costs for installing a FB carbon adsorption
system to control Hg emissions from the six phosphate rock calciners in operation were

determined

. As an alternative to a FB carbon adsorption system, incremental emission reductions

and costs for installi ng an ACI system were also determined.

3.0 SELECTION OF MORE ST RINGENT CONTROLS FOR NEW SOURCES

Data from two phosphate rock calciners were available to EPA to establish the existing and new source MACT floor emission limits for Hg. By rounding up to two signi ficant figures, the new source floor was equivalent to the existing source floor. As a result, the same BTF options available for existing phosphate rock calciners are available for new phosphate rock

calciners.

4.0 M ETHODOLOGY USED TO ESTIMATE COS TS AND EMI SSION

REDUCTIONS

Emissions reductions of Hg from application of the BTF controls relative to the current performance were calculated for the six phosphate rock calciners at the PCS Aurora facility using the following procedure. First, baseline Hg emissions were estimated using the facility reported test data and operating hours for one of the tested calciners. Then emissions were estimated for the other five calciners by calculating a ratio of annual operating hours for each

1 Refer to vendor information from Calgon Carbon Corporation (Calgon, 2006, Calgon, 2012a, Calgon 2012b), APC Technologies, Inc (APC, 2011), and EPA’s Mercury Study Report to Congress (EPA, 1997).



### 2

### phosphate rock calciner to the a nnual operating hours for the tested phosphate rock calciners; this ratio was then multiplied by the annual emissions for the tested calciners. See the memorandum “Emissions Data Used in Residual Risk Modeling: Phosphoric Acid and Phosphate Fertilizer

Prod uction Source Categories” for the baseline annual Hg emissions estimated for each phosphate rock calciner based on data from the Ontario

- Hydro test method (ERG 2012). Ontario

hydro data was used for the Risk Assessment because this method provides speciate d Hg results. However, Method 30B Hg data were used to calculate the BTF limit and facilities will use also use Method 30B to determine compliance. Therefore, baseline emissions and emissions

reductions for this memorandum are based on Method 30B data.

As previously described, it is assumed that Hg emission reductions of approximately 90 percent are possible with appropriate control technology. However, the BTF numerical limit of

1.4E

- 02 milligrams per dry standard cubic meter corrected to a three percent oxygen basis represents an 86 percent reduction because variability in the test data was taken into account when determining the proposed emissions limit. Therefore, annual emissions reductions as a result of the phosphate rock calciners meeting the BTF nu merical limit were calculated by multiplying the annual baseline emissions by the percent reduction necessary to comply with the BTF limit (86 percent).

In order to meet this BTF limit, two control options were initially evaluated; FB carbon adsorption and ACI with a fabric filter. FB carbon adsorption is currently used in multiple industrial applications (EPA 1997, Parsons 2002). A review of the Sewage Sludge Incinerators (SSI) preamble (EPA 2011a) and Response to Comments document (EPA 2011b) indicated th at ACI with a fabric filter may not be applicable to all emission points. It was noted in SSI documents that streams with high moisture would cause plugging of the fabric filter and thus

ACI followed by a fabric filter may not be feasible because the stack gas moisture content of each of the phosphate rock calciners is high (approximately 30 percent). However, because the phosphate rock calciners have a WESP in place, installation of ACI prior to the existing WESP was a third control option considered

. Alth ough there are no known applications with this combination of controls, there is control effectiveness information available for ACI followed by an electrostatic precipitator (ESP) (EPA 1997, Jones 2007), therefore this may be a potential control option fo r the calciners. We have assumed for this analysis that the WESP currently installed has the capacity to capture the additional particulate created by the ACI; however, data are not available to support this assumption. Costs and emissions reductions were estimated for each of the three control options. B ecause of the differences in the technologies to control Hg and the specific parameters of the PCS Aurora phosphate rock calciner operations , it was assumed that installation of FB carbon adsorption would y ield 90 percent reduction regardless of the BTF limit established, while the ACI carbon feed rate could be adjusted to achieve a range of percent reductions. However to be consistent, results pertaining to 90 percent reduction and the percent reduction ass ociated with meeting the BTF limit (86 percent) were evaluated for all three

control methods.

Fixed

- Bed Carbon Adsorption Cost

The cost of adding a FB carbon adsorption system for control of Hg from the phosphate

rock calciner exhausts was estimated. The cost algorithm for installing a FB carbon adsorption

3

### system is presented in Attachment A and is based on algorithms in the EPA Air Pollution

Control Cost Manual (EPA, 1999).

There are two key factors for determining c arbon adsorption costs; the exhaust stream flow rates and the inlet Hg concentration. Depending on the dataset either parameter can determine the number and size of adsorption vessels, but the high flow rate of the phosphate rock

calciner exhaust dictated the carbon adsorption costs in this instance. For the carbon adsorption cost algorithm, it was necessary to determine the size of the adsorption vessels and the number of vessels needed. The vessel length and width were adjusted manually until the vessel c ount approached a whole number; this was based on the vessels possessing enough surface area to

handle the exhaust flow rate at the velocity specified by the algorithm

. A maximum vessel size

of 30 feet by 10 feet was used as a design constraint . The number of vessels was then increased by one to account for repairs and flexibility in the adsorption system. Based on the amount of

activated carbon necessary to fill the vessels due to the large flow rate, there is sufficient activated carbon to control Hg for more than one year. For this cost estimate it was assumed the carbon bed would be changed every five years.

In order to capture Hg using carbon adsorption, impregnated carbon must be used (Calgon 2006, TIGG 2008) . This is due to the fact that Hg will not a dsorb as readily on non

impregnated carbon. For example, one vendor uses sulfur to enhance the Hg loading (Calgon 2006)

. Hg on the carbon reacts with sulfur to form mercury sulfide which is stable and non

volatile.

Due to the large size and number of vess els estimated to be installed for FB carbon adsorption, the cost estimate also includes installation of a steel structure. This structure allows for placement of vessels on a second story, reducing the overall footprint. The structure was

evaluated as a st eel structural frame and cost estimates for the structure were made using data from RSMeans online books ( RSMeans 2012). The cost estimate for this structure came to $179,000 and the details are provided in Attachment A. A 20 year life was assumed for any installed equipment. Capital recovery factors (CRF) were calculated using a seven percent discount rate. It was assumed that the facility has adequate space to install additional emissions control equipment if a two story steel structure was included, and connecting any process piping or ductwork could be performed during scheduled downtime for maintenance, thereby minimizing expected downtime. All costs were calculated as 201 3 dollars. Since the exhaust stream flow rate was the driving factor, t he cost of installing the FB carbon adsorption system was assumed to be the same whether the facility achieved the expected 90 percent reduction, or only reduced Hg emission levels to the BTF numerical limit.

Activated Carbon Injection Cost

Cost estimates for ACI, w ith and without a fabric filter, were derived from a Sargent & Lundy report which uses cost data based on industry experience (S&L 2011). The Sargent & Lundy report provided example calculations for coal utility boilers only, so their equations were

modifi ed in order to apply costs to non

- boiler applications. Since utility boilers typically have much higher exhaust flow rates than the phosphate rock calciners, a scaling factor was applied to decrease the base capital cost to a value more representative of a n ACI system which would be

4

### installed for the phosphate rock calciners. In the Sargent & Lundy report, the base cost for ACI (BMC) is calculated as shown in equation 1.

BMC = 1,350,000*Retrofit factor*(Carbon feed rate) 0.15 

### (Eq. 1)

The constant 1,350,000 in this equation will estimate a high capital cost, regardless of flow rate. To scale this constant down, the relationship in equation 2 was applied (Cooper 2002).

Cost b 

### = Cost
a 

### * (Flow

a 

### / Flow b 

### ) 0.6 

### (Eq. 2)

Where:

Cost
a 

### = 1,350,000

Flow

a 

### = 400,000 cubic feet per minute (CFM); the exhaust flow rate of a small utility

boiler

Flow b 

### = 65,000 CFM; The exhaust flow rate of the tested calciner at PCS Aurora

The variable Flow

a 

### was estimated as the low end of exhaust flow rates for utility boilers (since t he Sargent & Lundy report was based on cost data from utility boilers); this is the approximate flow rate for a 100 megawatt utility boiler. Solving equation 2 results in a rounded value of 460,000 for Cost b 

### . When estimating costs for the phosphate rock ca lciners, Cost b 

### (460,000) was then used in place of 1,350,000 in equation 1 when calculating the base cost (BMC).

Scaling factors were also applied to estimate the costs for fabric filter installation. Using

an air

- to

- cloth ratio of 4, the base cost for a baghouse (BMB) is calculated as shown in equation

3.

BMB = 476*Exhaust gas flow rate 0. 81 

### (Eq. 3)

The constant 476 in equation 3 will estimate a high capital cost for fabric filters. To scale this constant down, the relationship in equation 2 was applied. Applying equation 2 for the fabric filter cost estimate resulted in a value of 160, which was then used in place of 476 in equation 3.

It was also necessary to convert the annual ba g and cage replacement cost for fabric

filters from dollars per megawatt hour ($/MWh) to dollars per year ($/yr). The Sargent & Lundy report based their flue gas flow rates off the unit size (MW), gross heat rate (Btu/kWh), and type of coal (e.g., lignite or bituminous). The Sargent & Lundy data were used to calculate annualize d costs based on the flow rate. For this calculation, a gross heat rate of 9,500 Btu/kWh, the use of lignite coal, and 8760 operating hours were assumed. These assumptions provided a conservatively high cost estimate. From this data a relationship was deve loped (refer to equation 4) which was used for the BTF estimate. Data used to calculate this relationship are provided in

Attachment B.

Bag and Replacement cost ($/yr) = 0.3821 * Flow Rate (acfm) (Eq. 4 )

5

### To estimate the cost for six ACI systems, with and without fabric filters, (one for each phosphate rock calciner), the capital and annual costs were first calculated for one ACI system and then multiplied by 6.

The Sargent & Lundy reports states that for cases where an ESP is installed after the ACI,

a ca rbon feed rate of 5 pounds per million actual cubic feet is appropriate; this same feed rate was assumed to be appropriate for WESP particulate control. The cost estimate also assumed the existing WESP could handle the additional carbon particulate waste f rom the ACI. See Attachment B for the calculations for ACI capital and annual costs, with and without fabric

filters.

5.0 RESULTS

A pplying BTF control to reduce Hg emissions from phosphate rock calciners is estimated to result in a total capital investment (TCI) (2013$) of approximately $4.9 million for FB carbon adsorption, $6.5 million for ACI prior to the existing WESP, or $16.5 million for ACI with fabric

filters. A pplying BTF control to reduce Hg emissions from phosphate rock calciners is expected

to re sult in a total annual ized cost (TAC) (2013$) of $ 1.2 million for FB carbon adsorption, $1.8 million for ACI prior to the existing WESP, or $2.5 million for ACI with fabric filters. Reducing phosphate rock calciner emissions to the BTF limit (an 86 percent reduction) would achieve Hg

reductions of 145 pounds per year (based on the results of the U.S. EPA Method 30B test results). The cost

- effectiveness for FB carbon adsorption was estimated to be $ 8,000 per pound of Hg, t he cost

- effectiveness for ACI prior to the existing WESP was estimated to be $ 12,100 per pound of Hg, and the cost

- effectiveness for ACI with fabric filters was estimated to be $17,100 per pound of Hg. Table 5

- 1 presents a summary of the BTF analysis for phosphate rock calciners. The BTF Hg controls evaluated were technically feasible and considered to be cost

effective. As a result, it was determined that 90 percent Hg reduction is achievable and the proposed BTF limit for Hg is 10 percent of the calculated MACT limit.

Table 5

- 1. Summary of Beyond

- the

- Floor Analysis Results for Phosphate Rock Calciners

BTF Scenario TCI (2013 $) TAC [1] (2013 $) Hg Emissions

Reduction (pounds/year) Cost

Effectiveness ($/pound of Hg)

Carbon Adsorption $ 4

, 9 00,000 $1, 2 0 0,000 145 $ 8,000

ACI with Existing WESP $ 6 ,500,000 $1, 8 00,000 145 $ 12,100

ACI with Fabric Filter $ 16

, 5 00,000 $ 2,5 00,000 145 $ 17,100

[1]

– Calculated using a 7 percent discount factor.

BTF

– Beyond

- the

- floor

TCI

– Total capital investment for the BTF option

TAC

– Total annual cost for the BTF option $/pound

– Dollars per pound



### 6

### 6.0 REFERENCES

1. Calgon, 2006. “HGR ® 

### for Mercury Removal Granular Activated Carbon.” Calgon Carbon Corporation. CPM

- PB1047

- 0406. http://www.calgoncarbon.com/carbon_products/documents/HGRforMercuryRemoval.pdf

2. Calgon, 2012a

. “Fixed bed for wet exhaust streams, 10,000 SCFM, CCC Ref# Hg050412

- 1.” Calculation sheet prepared by Calgon Carbon Corporation for ERG. 5 May, 2012. Docket ID: EPA

- HQ

- OAR

- 2012

- 0522

.

3. Calgon, 2012b. “Fixed bed for wet exhaust streams, 200,000 SCFM, CCC Ref # Hg050412

- 1.” Calculation sheet prepared by Calgon Carbon Corporation for ERG. 5 May, 2012. Docket ID: : EPA

- HQ

- OAR

- 2012

- 0522

.

4. APC, 2011. “Air Emission Control Systems and Service MercPure Series Merucry Emission Control Systems.” APC Technologies, Inc. 2 4 October, 2011. http://www.apctechnologies.net/pdf/APC

- MercPure.pdf

5. EPA, 1997. “Mercury Study Report to Congress Volume VIII: An Evaluation of Mercury Control Technologies and Costs.” U.S. Environmental Protection Agency. December

1997. Publication Number EPA

- 452

- R

- 97

- 010.

6. EPA, 1999. U.S. Environmental Protection Agency. EPA Control Cost Manual. Section 3.1: VOC Recapture Controls Chapter 1: Carbon Adsorbers. September 1999. Publication

Number EPA/452/B

- 02

- 001.

7. EPA, 2011a. Standards of Performance for Ne w Stationary Sources and Emission Guidelines for Existing Sources: Sewage Sludge Incineration Units, Final Rule. March

2011. EPA

- HQ

- OAR

- 2009

- 0559

- 01 48.

8. EPA, 2011b. Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sou rces: Sewage Sludge Incineration Units, Summary of Public Comments and Responses. March 2011. EPA

- HQ

- OAR

- 2009

- 0559

- 01 71.

9. TIGG, 2008. TIGG MRA, Vapor Phase Mercury Removal Activated Carbon. TIGG Corporation. February 2008. http://www.tigg.com/PDF/TIGG_MRA.p df

.

10. Parsons, 2002. The Cost of Mercury Removal in an IGCC Plant. Parsons Infrastructure and Technology Group Inc; prepared for U.S. DOE, National Energy Technology Laboratory. September 2002.

11. Jones, 2007. DOE/NETL’s Phase II Mercury Control Technology Fiel d Testing Program, Updated Economic Analysis of Activated Carbon Injection. Jones, A., Hoffmann, J., Smith, D., Feeley III, T., Murphy, J.; prepared for U.S. DOE, Office of Fossil Energy, National Energy Technology Laboratory. May 2007.

7

### 12. S&L 2011. IPM Model

– Revisions to Cost and Performance for APC Technologies: Mercury Control Cost Development Methodology (Project 12301

- 009). Sargent & Lundy

. March 2011.

13. RSMeans 2012. RSMeans online cost books. 2012. http://www.meanscostworks.com/

.

8

### Attachment A

Fixed

- Bed Carbon Adsorption Cost Methodology

Structural Steel Frame Costs

### A-1: Fixed-Bed Carbon Adsorption Cost Algorithm

Parameter/Cost Variable Equation/Value 1. Inputs a. Hg Conc. in Exhaust Stream (ppmvd) HgConc Value specif ic to facility b. Hg Inlet Rate (lb/hr) MHgHr Value specific to facility c. Hg Inlet Rate (lb/yr) MHgYr Value specific to facility d. Exhaust Flowrate (acfm) FL Value specific to facility e. Superficial Velocity (ft/min) SV 85 f. Carbon Bed Life (yrs) BedL 5 g. Adsorption Time (hrs) AdsT = 8760 * 5 = 43800 h. Hg Adsorption Potential on Carbon (lb Hg adsorbed/lb carbon) AdsPot 0.015 i. Carbon Bed Density (lb/ft3) Dens 30 j. Operating Hours per Year OpHrs 8760 k. Operating Labor Rate Labor 84.04 l. Electricity Cost ($/kW-hr) Elec 0.0682 m. Capital Recovery Factor (20 yrs, 7%) CRF = (0.07*(1+0.07)^20)/((1+0.07)^20-1) = 0.09439 n. Bed Depth (ft) Depth 1 o. Carbon Cost ($/lb) CarbCost 3 p. Carbon Disposal Cost ($/ton) Disp 50 q. Capital Recovery Factor for Carbon Replacement CRFcarb = (0.07*(1+0.07)^5)/((1+0.07)^5-1) = 0.24389 2. Ductwork Inputs a. Duct Pressure Drop deltaP = 0.03679 * SV + 0.0001107 * SV^2 * Depth b. ut (ft/min) ut 3500 c. Number of 90 Degree Elbows Elb90 5 d. k Value for 90 Degree Elbows k90 0.33 e. Number of 45 Degree Elbows Elb45 5 f. k Value for 45 Degree Elbows k45 0.165 g. Material Factor, Galvanized Carbon Steel a1 0.322 h. Material Factor, Galvanized Carbon Steel b1 1.22 i. Material Factor, Galvanized Carbon Steel a2 30.4 j. Material Factor, Galvanized Carbon Steel b2 0.0594 k. Material Factor, Galvanized Carbon Steel a3 45.5 l. Material Factor, Galvanized Carbon Steel b3 0.0597 m. Number of Dampers Damp 4 n. Length of Duct (ft) LDuct 300 3. Cost Index Values (CEPCI)

a. 1998 CEPCI 98CEPCI 389.5

b. 1999 CEPCI 99CEPCI 390.6

c. 2013 CEPCI 13CEPCI 567.3 4. Ductwork Capital Cost a. Duct Diameter (ft) Diam_ft =1.128 * (FL / V# / ut)^0.5 b. Duct Diamter (in) Diam_in = Diam_ft * 12 c. Friction Losses (in H2O) Fd = 0.136 * (1 / Diam_ft)^1.18 * (ut / 1000)^1.8 * Ld uct / 100 d. Velocity Pressure (in H2O) VP = (ut / 4016)^2 e. Friction Loss from Elbows (in H2O) Fc = Elb90 * k90 * V P + Elb45 * k45 * VP f. Total Friction, Static Pressure Ft = Fd + Fc g. Straight Duct Cost, Galvanized CostStrDu = a1 * (Diam_ in^b1) * LDuct h. Elbow Cost CostElb = a2 * exp(b2 * Diam_in) * (Elb90 + Elb45) i. Damper Cost CostDamp = a3 * exp(b3 * Diam_in) * Damp j. Material Duct Cost CostMat = CostStrDu + CostElb + CostD amp k. Total Material Duct Cost CostTotMat = CostMat * V#

l. Duct Installation Cost CostInstDu = 0.375 * CostTotMat m. Total Material and Installation CostDuct = (CostTotMat + CostInstDu) * (13CEPCI / 98CEPCI)

### A-1: Fixed-Bed Carbon Adsorption Cost Algorithm

Parameter/Cost Variable Equation/Value

5. Vessel and Carbon Info a. Initial Carbon Requirement (lb) - Based on enough carbon to control mercury content of

stream Mci = MHgHr / AdsPot * AdsT b. Bed Surface Area, Required (ft2) SAr = FL / SV c. Vessel Length (ft) VL Variable, dependent on flow; Ma x of 30 feet d. Vessel Diameter (ft) VD Variable, dependent on flow; Max of 10 feet e. Number of Vessels V# = SAr / (VL * VD) + 1 Bed Surface Area, Actual (ft2) SAa = VL * VD * V# g. Vessel Surface Area (ft2) VSA = **π** * VD * (VL + VD/2) h. Total Carbon, to fill vessels Mct = Dens * Depth * Saa [Must be greater than Mci] 6. Vessel and Carbon Capital Costs a. Vessel Cost CostV = 271 * (VSA^0.778) * V# * (13CEPCI / 99CEPCI)

b. Carbon Cost CostC = Mct * CarbCost c. Adsorber Equipment Cost CostAds = 5.82 * (FL^-0.133) * (CostV + CostC) d. Equipment Cost CostEq = CostAds + CostDuct e. Total Adsorber Equipment Cost CostTotAds = 5.82 * (FL ^-0.133) * CostEq f. Total Purchased Equipment Cost CostPurch = CostTotAds * 1 .18 g. Direct Installation Costs CostInst = CostPurch * 0.3

h. Indirect Installation Costs CostIndInst = CostPurch * 0.3 1 i. Total Capital Investment TCI = CostPurch + CostInst + C ostIndInst

7. Direct Annual Costs a. Electricity (System Fan) CostElec = 0.00025 * FL * (1 + deltaP) / 1.341 * OpHrs * Elec b. Operating Labor CostLab = Labor * 0.5 * 3 * 365 c. Supervisory Labor CostSup = CostLab * 0.15

d. Maintenance Labor CostMaint = Labor * 0.5 * 3 * 365

e. Maintenance Materials CostMaintMat = Labor * 0.5 * 3 * 365 f. Carbon Replacement CostCarbRep = CostC * CRFcarb * 1.0 8 g. Carbon Replacement Labor CostRepLab = Mct * 0.05 * CR Fcarb h. Carbon Disposal CostDisp = Mct * Disp / 2000 * CRFcarb

i. Total Direct Costs TAC_Dir = CostElec + CostLab + CostSup + CostMaint + CostMaintMat + CostCarbRep + CostRepLab + CostDisp

8. Indirect Annual Costs

a. Overhead CostOH = 0.6 * (CostLab + CostSup + CostMaint + CostMaintMat) b. Administrative Charges CostAdm = 0.02 * TCI c. Property Tax CostProp = 0.01 * TCI

d. Insurance CostIns = 0.01 * TCI

e. Capital Recovery CostCRF = CRF * (TCI - (CostCarbRep / CRFcarb) - (CostRepLab / CRFcarb)) f. Total Indirect Costs TAC_Ind = CostOH + CostAdm + CostP rop + CostIns + CostCRF

9. Annual Cost

a. Total Annual Cost TAC = TAC_Dir + TAC_IndA-2: Fixed-Bed Carbon Adsorption Costs to comply with phosphate rock calciner mercury limit (structural costs included)FacilityEmissionPointHg Conc.(ppmvd)Hg Limit(ppmvd)Hg Inlet Rate,mHg(lb/hr)Hg Inlet Rate,mHg(lb/yr)Flowrate(acfm)SuperficialVelocity(ft/min)% ReductionInitial CarbonRequirement,Mc (lbs)PCS AuroraCalciners3.84E-035.44E-042.95E-02169.5385,5188590%86,269Bed SurfaceArea,Required (ft2)Bed SurfaceArea, Actual(ft2)Vessel Length(ft)VesselDiameter (ft)# Vessels# Vessels(Rounded)Vessel SurfaceArea (ft2)Total Carbon(lb)PCS AuroraCalciners45364800301015.12161100144,000Vessel Cost Carbon CostAdsorberEquipmentCostDuctwork CostEquipmentCostTotal AdsorberEquipmentCostTotalPurchasedEquipmentCostDirectInstallationCostsIndirectInstallationCostsTotal CapitalInvestmentPCS AuroraCalciners$1,462,977$432,000$1,993,347$370,025$2,363,372$2,486,057$2,933,547$880,064$909,400$4,723,011Including Structural Steel Frame$4,901,744Electricity(System Fan)OperatingLaborSupervisoryLaborMaintenanceLaborMaintenanceMaterialsCarbonReplacementCarbonReplacementLaborCarbonDisposalTotal DirectCostsPCS AuroraCalciners$211,555$46,013$6,902$46,013$46,013$113,790$1,756$878$472,920OverheadAdministrativeChargesProperty Tax InsuranceCapitalRecoveryTotal IndirectCostsPCS AuroraCalciners$86,965$94,460$47,230$47,230$401,099$676,984$1,149,904Including Structural Steel Frame$1,166,775% Reductionto Meet LimitAnnual HgEmissions(lb/yr)Hg EmissionsReduced(lb/yr)(MeetingLimit)Hg ReductionCost MeetingLimit ($/lb)PCS AuroraCalciners86%169.5145.4$8,022FacilityEmissionPointPCS AuroraCalcinersCombined all calciners to do analysis. 6 calciners will share the carbon beds.Total AnnualCostSTREAM DATAFacilityEmissionPointNoteFacilityEmissionPointFacilityEmissionPointFacilityEmissionPointFacilityEmissionPointCOST EFFECTIVENESS (ANNUAL COST BASIS)VESSEL AND CARBON DETAILSVESSEL AND CARBON CAPITAL COSTS ($2013)ANNUAL COSTS ($2013) - DIRECT COSTSANNUAL COSTS ($2013) - INDIRECT COSTSA-3: Ductworks Costs for Fixed-Bed Carbon AdsorptionFacilityEmissionPointFlow Rate(ft3/min)Number ofductsDuct diam.(ft)Duct diam.(in)Length ofDuct (ft)Frictionlosses, Fd (inH2O)velocitypressure,VP (in H2O)Fc, frictionloss fromelbows (inH2O)TotalFriction(=StaticPressure) =Fd+FcPCS AuroraCalciners385,518162.9635.523001.080.761.882.96FacilityEmissionPointTotalStraightduct cost,galvanizedTotalElbow costTotalDampercostMaterialDuctworkCost forONE ductTotalMaterialDuctworkCostDuctInstallationCostMaterial +Installationcost(TOTAL)2013Material +Installationcost (TOTAL)PCS AuroraCalciners$7,525$2,507$1,517$11,548$184,766$69,287$254,054$370,025DUCTWORK COSTSDUCTWORK COSTSA-4: Structural Steel Frame Costs for Fixed-Bed Carbon AdsorptionStructural costs for supporting carbon adsorption vesselsVessels are 30 ft x 10 ft diam.Structure adds a 2nd story at 14 ft high; Vessel arrangement is 4 x 2 per story; 3 ft walkway around each vesselTotal structure dimensions equal 72 ft x 64 ftSTRUCTURAL COSTSItemLength/AreaUnitsCountRSMeans Line #Unit CostCost UnitsTotalNotesx-axis Beams 16 ft 32 051223174650 1,446$ $/Beam 46,256$ Structural steel framingy-axis Beams 18 ft 10 051223174650 1,879$ $/Beam 18,792$Structural steel framing. Increased16ft price by 30%z-axis Beams 14 ft 25 051223174600 826$ $/Beam 20,638$ Structural steel framingDecking 1968 Sq. Ft -- 053113503560 4.26$ $/Sq ft 8,384$ 16 gauge deckingRailing 552 ft -- 055216500020 36.42$ $/L.F. 20,104$Kick Plate 552 ft -- 055216500200 5.45$ $/L.F. 3,008$Stairs -- -- 96 055119500020 375.65$ $/Riser 36,062$Earthwork 512 sq. yard 312216100012 3.61$ $/sq. yd. 1,848$Concrete 179.2 cubic yard 033105350150 110.00$ $/cubic yd. 19,712$Lay Slab 179.2 sq. yard 033105704650 21.93$ $/sq. yd. 3,930$178,733$16,871$TOTALANNUALIZED COST (20-yr, 7%)

### Attachment B

Activated Carbon Injection Cost MethodologyB-1: ACI & Fabric Filter Cost Algorithm

Parameter/Cost Variable Equation/Value 1. Inputs a. Exhaust Gas Flow Rate (acfm) ExF Value specific to facility b. Operating Hours Ophrs 8760 c. Hg Concentration (ppmv) Hg Value specific to facil ity d. PM Emissions (ton/hr) PM Value specific to facilit y

e. Carbon Feed (lb/MMacf) Car_lb 5 lb/Mmacf for WESP;

2 lb/MMacf for fabric filter

f. Modified Initial Base Cost ModB 460000 g. Modified Baghouse Base Cost ModBH 160

h. 2013 CEPCI 13CEPCI 585.7

i. 2009 CEPCI 09CEPCI 521.9 j. Capital Recovery Factor (7%, 20 yr) CRF = (0.07*(1+0.07)^20)/((1+0.07)^20-1) = 0.09439 k. Carbon Cost ($/ton) Carb 1500 l. Waste Disposal Cost ($/ton) WDC 50 m. Monitor Capital Costs (per monitor) MonCC = 140900 n. Monitor Annual Costs (per monitor) MonAC = 33100

2. Waste Calcs a. Carbon Feed Rate (lb/hr) Car_FR = ExF * 60 * Car_l b / 1000000 b. Carbon Waste Rate (lb/hr) Car_WR = Car_FR c. Total Waste Rate (ton/hr) TWR = Car_FR + (PM / 200 0) 3. Capital Costs a. Base Cost for ACI BMC = ModB * (Car_FR^0.15) b. Base Cost for Baghouse BMB = ModBH * (ExF^0.81) c. Engineering and Construction Management

Costs ECM = 0.05 * (BMC + BMB) d. Labor adjustment Lab = 0.05 * (BMC + BMB) e. Contractor Profit and Fees ConP&F = 0.05 * (BMC + BMB) f. Capital, Engineering, and Construction Cost

Subtotal CECC = BMC + BMB + ECM + Lab + ConP&F g. Owners Costs OC = 0.05 * CECC h. Baghouse Construction Funds BH = 0.06 * (CECC + OC )

i. Total Project Costs TCI = (CECC + OC + BH) * (11CEPCI / 09CEPCI) +

MonCC

4. Annual Cost - Fixed O&M

a. Maintenance Material and Labor Main&Lab = 0.005 * (TCI - Mon)

b. Administrative Labor Admin = 0.03 * 0.4 * Main&Lab c. Capital Recovery CR = CRF * (TCI - Mon)

d. Total Fixed O&M FOM = (Main&Lab + Admin + CR) * (11CEPCI / 09CEPCI)

5. Annual Cost - Variable O&M a. Carbon Sorbent Sorb = Car_FR * Carb / 2000 * Ophrs b. Waste Disposal WD = TWR * WDC * Ophrs c. Bags and Cages BC = 0.3821 * ExF d. Total Variable O&M VOM = (Sorb + WD + BC)* (11CEPC I / 09CEPCI)

6. Total Annual Cost TAC = FOM + VOM + MonAC

ACI costs for 6 calciners To determine costs for ACI on 6 calciners - Multipl y costs for 1 ACI by 6B-1: ACI & Fabric Filter Cost Algorithm (cont.)

Modified Costs

Cost_b = Cost_a*(Size_b/Size_a)^e e = Cost exponent = 0.6

Modified Base Costs (ModB) (For calculating BMC) Size_a = 400,000 Size_b = 65,000 Cost_a = 1,350,000 Cost_b = 453,780 Cost_b (rounded) = 460,000

Modified Base Baghosue Costs (ModBH) (For calculat ing BMB) Size_a = 400,000 Size_b = 65,000 Cost_a = 476 Cost_b = 160 Cost_b (rounded) = 160B-1: ACI & Fabric Filter Cost Algorithm (cont.)

Unit Size (Gross) Gross Heat Rate Heat Input Flue Gas Rate Bag and Cage Cost (MW) (Btu/kWh) (Btu/hr) (acfm) ($/yr)

A B = A * B * 1000 = A * B * 0.362 = 0.15 * A * 8760 10 9500 95,000,000 34,390 $13,140 20 9500 190,000,000 68,780 $26,280 35 9500 332,500,000 120,365 $45,990 50 9500 475,000,000 171,950 $65,700 75 9500 712,500,000 257,925 $98,550 100 9500 950,000,000 343,900 $131,400 As discussed in the beyond-the-floor memo it was ne cessary to convert the annual bag and cage replacem ent cost for fabric filters from dollars per megawatt hour ($/MWh) to d ollars per year ($/yr). The Sargent & Lundy report based their flue gas flow rates off the unit size (MW), gross heat rate (Btu/ kWh), and type of coal (e.g., lignite or bituminous ). The Sargent & Lundy

data were used to calculate annualized costs based on the flow rate. For this calculation, a gross hea t rate of 9,500 Btu/kWh, the use of lignite coal, and 8760 operating hours w ere assumed.

y = 0.3821x
R2 = 1

$20,000 $40,000 $60,000 $80,000 $100,000 $120,000 $140,000Annual Bag and Cage Cost

Bag and Cage cost = .3821 * Flow rate

$0 $20,000

0 75,000 150,000 225,000 300,000 375,000

Flow Rate, acfmB-2: ACI Costs to comply with phosphate rock calciner mercury limitFacilityIDEmissionPointExhaust gasflow rate(acfm)Operating Hours Hg Conc. (ppm) Hg Limit (ppmvd)Filterable PMEmissions(ton/hr)Carbon Feed Rate(lb/hr)Carbon Waste Rate(lb/hr)ParticulateWaste Rate(ton/hr)Total WasteRate (ton/hr)ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa1 Calciner64,25387603.8E-035.4E-043.1E-0219.319.30.03150.041ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa1 Calciner64,25387603.8E-035.4E-043.1E-027.77.70.03150.035Base Cost forACI (BMC)Base Cost forBaghouse (BMB)Engineering andConstructionManagementcostsLabor adjustmentfor 6 x 10 hourshift premium,per diem, etc.Contractorprofit and feesCapital,Engineering andConstruction CostSubtotal (CECC)Owners costs includingall 'borne office" costs(owners engineering,management, andprocurement activities)BaghouseConstructionFundsMonitorCapital CostsTotal ProjectCost ($2013)ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa1 Calciner$716,985$0$35,849$35,849$35,849$824,533$41,227$0$140,200$1,081,272PCS Auroa6 Calciners$6,487,629ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa1 Calciner$624,912$1,254,624$93,977$93,977$93,977$2,161,467$108,073$136,172$140,200$2,755,185PCS Auroa6 Calciners$16,531,111Maintenancematerial andlabor costs($/yr)Administrativelabor costs($/yr)Capital Recovery(7%, 20-yr)Total Fixed O&Mcosts ($/yr)($2011)CarbonSorbent ($/yr)Waste Disposal($/yr)Bags and Cages ($/yr)Total VariableO&M ($/yr)($2011)ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa1 Calciner$4,705$56$88,830$101,734$126,643$17,997$0$157,222$34,100$293,055PCS Auroa6 Calciners$1,758,333ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa1 Calciner$13,075$157$246,836$282,691$50,657$15,464$24,551$98,560$34,100$415,351PCS Auroa6 Calciners$2,492,105% Reduction toMeet LimitAnnual HgEmissions(lb/yr)Hg EmissionsReduced (lb/yr)(Meeting Limit)Hg Reduction CostMeeting Limit($/lb)Hg ReductionCost with 90%Reduction($/ton)ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa6 Calciners86%169.5145.5$12,089$24,177,504ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa6 Calciners86%169.5145.5$17,134$34,267,045INPUTCalculatedCOST EFFECTIVENESS (ANNUAL COST BASIS)Capital CostAnnual Cost - Fixed O&M CostAnnual Cost - Variable O&M CostAnnualMonitoringCostTotal AnnualCost ($/yr)($2013)FacilityIDEmissionPointFacilityIDEmissionPointFacilityIDEmissionPoint