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 Pollutants (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-thefloor” (BTF) regulatory options to determine MACT. Unlike 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 the 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 Phosphoric 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 sources, 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 MORE STRINGENT CONTROLS FOR EXISTING 

SOURCES

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 information:

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 

emission 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 anticipated. 

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 studies1

, a FB carbon adsorption 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). 

The incremental emission reductions 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 installing an ACI system were also determined.

3.0 SELECTION OF MORE STRINGENT 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 significant 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 METHODOLOGY USED TO ESTIMATE COSTS AND EMISSION 

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 annual 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 

Production 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). Ontariohydro data was used for the Risk Assessment because this method provides speciated 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 numerical 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 that 

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. Although 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 for 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. Because 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 yield 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 associated 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 carbon 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 count 

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 adsorb as readily on nonimpregnated 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 nonvolatile.

Due to the large size and number of vessels 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 steel 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 2013 dollars. Since the exhaust 

stream flow rate was the driving factor, the 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, with 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 

modified 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 an 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).

Costb = Costa * (Flowa / Flowb)

0.6 (Eq. 2)

Where:

Costa = 1,350,000

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

boiler

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

The variable Flowa was estimated as the low end of exhaust flow rates for utility boilers 

(since the 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 Costb. When estimating costs for the phosphate rock calciners, Costb

(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 rate0.81 (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 bag 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 annualized 

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 developed (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 carbon 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 from the ACI. See 

Attachment B for the calculations for ACI capital and annual costs, with and without fabric 

filters.

5.0 RESULTS

Applying 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. Applying BTF control to reduce Hg emissions from phosphate rock calciners is expected 

to result in a total annualized 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, the 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 costeffective. 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 $4,900,000 $1,200,000 145 $8,000

ACI with Existing WESP $6,500,000 $1,800,000 145 $12,100

ACI with Fabric Filter $16,500,000 $2,500,000 145 $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. 24 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 New Stationary Sources and Emission 

Guidelines for Existing Sources: Sewage Sludge Incineration Units, Final Rule. March 

2011. EPA-HQ-OAR-2009-0559-0148.

8. EPA, 2011b. Standards of Performance for New Stationary Sources and Emission 

Guidelines for Existing Sources: Sewage Sludge Incineration Units, Summary of Public 

Comments and Responses. March 2011. EPA-HQ-OAR-2009-0559-0171.

9. TIGG, 2008. TIGG MRA, Vapor Phase Mercury Removal Activated Carbon. TIGG 

Corporation. February 2008. http://www.tigg.com/PDF/TIGG_MRA.pdf.

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 Field 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 specific 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 * Lduct / 100

d. Velocity Pressure (in H2O) VP = (ut / 4016)^2

e. Friction Loss from Elbows (in H2O) Fc = Elb90 * k90 * VP + 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 + CostDamp

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; Max 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 * 0.31

i. Total Capital Investment TCI = CostPurch + CostInst + CostIndInst

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 * 1.08

g. Carbon Replacement Labor CostRepLab = Mct * 0.05 * CRFcarb

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 + CostProp + CostIns + CostCRF

9. Annual Cost

a. Total Annual Cost TAC = TAC_Dir + TAC_Ind
A-2: Fixed-Bed Carbon Adsorption Costs to comply with phosphate rock calciner mercury limit (structural costs included)

Facility Emission Point Hg Conc. (ppmvd) Hg Limit (ppmvd) Hg Inlet Rate, 

mHg (lb/hr)

Hg Inlet Rate, 

mHg (lb/yr)

Flowrate 

(acfm)

Superficial 

Velocity 

(ft/min)

% Reduction

Initial Carbon 

Requirement, 

Mc (lbs)

PCS Aurora Calciners 3.84E-03 5.44E-04 2.95E-02 169.5 385,518 85 90% 86,269

Bed Surface 

Area, 

Required (ft2)

Bed Surface 

Area, Actual 

(ft2)

Vessel Length 

(ft)

Vessel 

Diameter (ft) # Vessels # Vessels (Rounded) Vessel Surface Area (ft2) Total Carbon (lb)

PCS Aurora Calciners 4536 4800 30 10 15.12 16 1100 144,000

Vessel Cost Carbon Cost

Adsorber 

Equipment 

Cost

Ductwork Cost Equipment 

Cost

Total Adsorber 

Equipment 

Cost

Total 

Purchased 

Equipment 

Cost

Direct 

Installation 

Costs

I

PCS Aurora Calciners $1,462,977 $432,000 $1,993,347 $370,025 $2,363,372 $2,486,057 $2,933,547 $880,064 

Including Structural 

Electricity 

(System Fan)

Operating 

Labor

Supervisory 

Labor

Maintenance 

Labor

Maintenance 

Materials

Carbon 

Replacement

Carbon 

Replacement 

Labor

Carbon 

Disposal

T

PCS Aurora Calciners $211,555 $46,013 $6,902 $46,013 $46,013 $113,790 $1,756 $878 

Overhead Administrative 

Charges Property Tax Insurance Capital Recovery Total Indirect Costs

PCS Aurora Calciners $86,965 $94,460 $47,230 $47,230 $401,099 $676,984 $1,149,904

Including Structural Steel Frame $1,166,775

% Reduction 

to Meet Limit

Annual Hg 

Emissions 

(lb/yr)

Hg Emissions 

Reduced 

(lb/yr) 

(Meeting 

Limit)

Hg Reduction 

Cost Meeting 

Limit ($/lb)

PCS Aurora Calciners 86% 169.5 145.4 $8,022

Facility Emission Point

PCS Aurora Calciners Combined all calciners to do analysis. 6 calciners will share the carbon beds.

Total Annual 

Cost

STREAM DATA

Facility Emission Point

Note

Facility Emission PointFacility Emission PointFacility Emission PointFacility Emission Point

COST EFFECTIVENESS (ANNUAL COST BASIS)

VESSEL AND CARBON DETAILS

VESSEL AND CARBON CAPITAL COSTS ($2013)

ANNUAL COSTS ($2013) - DIRECT COSTS

ANNUAL COSTS ($2013) - INDIRECT COSTS
A-3: Ductworks Costs for Fixed-Bed Carbon Adsorption

Facility Emission Point Flow Rate (ft3/min) Number of ducts Duct diam. (ft) Duct diam. (in) Length of Duct (ft) Friction losses, Fd (in H2O) velocity pressure, VP (in H2O) Fc, friction loss from elbows (in H2O) Tot

Frict

(=Sta

Pressu

Fd+

PCS Aurora Calciners 385,518 16 2.96 35.52 300 1.08 0.76 1.88 2.9

Facility Emission Point

Total 

Straight 

duct cost, 

galvanized

Total 

Elbow cost

Total 

Damper 

cost

Material 

Ductwork 

Cost for 

ONE duct

Total 

Material 

Ductwork 

Cost

Duct 

Installation 

Cost

Material + 

Installation 

cost 

(TOTAL)

2013 

Material + 

Installation 

cost (TOTAL)

PCS Aurora Calciners $7,525 $2,507 $1,517 $11,548 $184,766 $69,287 $254,054 $370,025

DUCTWORK COSTS

DUCTWORK COSTS
A-4: Structural Steel Frame Costs for Fixed-Bed Carbon Adsorption

Structural 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 vessel

Total structure dimensions equal 72 ft x 64 ft

STRUCTURAL COSTS

Item Length/Area Units Count RSMeans Line # Unit Cost Cost Units Total 

x-axis Beams 16 ft 32 051223174650 1,446 $ $/Beam 46,256 $ Structural 

y-axis Beams 18 ft 10 051223174650 1,879 $ $/Beam 18,792 $ 

Structural 16ft price 

z-axis Beams 14 ft 25 051223174600 826 $ $/Beam 20,638 $ Structural Decking 1968 Sq. Ft -- 053113503560 4.26 $ $/Sq ft 8,384 $ 16 gauge Railing 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 Methodology
B-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 facility

d. PM Emissions (ton/hr) PM Value specific to facility

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_lb / 1000000

b. Carbon Waste Rate (lb/hr) Car_WR = Car_FR

c. Total Waste Rate (ton/hr) TWR = Car_FR + (PM / 2000)

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)* (11CEPCI / 09CEPCI)

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

ACI costs for 6 calciners

To determine costs for ACI on 6 calciners - Multiply costs for 1 ACI by 6
B-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 calculating BMB)

Size_a = 400,000 

Size_b = 65,000 

Cost_a = 476 

Cost_b = 160 

Cost_b (rounded) = 160
B-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 necessary to convert the annual bag 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 annualized 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.

y = 0.3821x

R2 = 1

$20,000 

$40,000 

$60,000 

$80,000 

$100,000 

$120,000 

$140,000 

Annual 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, acfm
B-2: ACI Costs to comply with phosphate rock calciner mercury limit

FacilityID Emission Point Exhaust gas flow rate 

(acfm)

Operating Hours Hg Conc. (ppm) Hg Limit (ppmvd)

Filterable PM 

Emissions 

(ton/hr)

Carbon Feed Rate 

(lb/hr)

Carbon Waste Rate 

(lb/hr)

Part

Was

(to

ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa 1 Calciner 64,253 8760 3.8E-03 5.4E-04 3.1E-02 19.3 19.3 0.ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa 1 Calciner 64,253 8760 3.8E-03 5.4E-04 3.1E-02 7.7 7.7 0.

Base Cost for 

ACI (BMC)

Base Cost for 

Baghouse (BMB)

Engineering and 

Construction 

Management 

costs

Labor adjustment 

for 6 x 10 hour 

shift premium, 

per diem, etc.

Contractor 

profit and fees

Capital, 

Engineering and 

Construction Cost 

Subtotal (CECC)

Owners costs including 

all 'borne office" costs 

(owners engineering, 

management, and 

procurement activities)

Bag

Const

Fu

ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa 1 Calciner $716,985 $0 $35,849 $35,849 $35,849 $824,533 $41,227 PCS Auroa 6 Calciners ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa 1 Calciner $624,912 $1,254,624 $93,977 $93,977 $93,977 $2,161,467 $108,073 $13PCS Auroa 6 Calciners 

Maintenance 

material and 

labor costs 

($/yr)

Administrative 

labor costs 

($/yr)

Capital Recovery 

(7%, 20-yr)

Total Fixed O&M 

costs ($/yr) 

($2011)

Carbon 

Sorbent ($/yr)

Waste Disposal 

($/yr) Bags and Cages ($/yr)

Total 

O&M 

($2

ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa 1 Calciner $4,705 $56 $88,830 $101,734 $126,643 $17,997 $0 $15PCS Auroa 6 Calciners ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa 1 Calciner $13,075 $157 $246,836 $282,691 $50,657 $15,464 $24,551 $9PCS Auroa 6 Calciners 

% Reduction to 

Meet Limit

Annual Hg 

Emissions 

(lb/yr)

Hg Emissions 

Reduced (lb/yr) 

(Meeting Limit)

Hg Reduction Cost 

Meeting Limit 

($/lb)

Hg Reduction 

Cost with 90% 

Reduction 

($/ton)

ACI Costs - Installed Prior to Existing WESP (No Fabric Filter)PCS Auroa 6 Calciners 86% 169.5 145.5 $12,089 $24,177,504ACI and Fabric Filter Costs - Installed After Existing WESPPCS Auroa 6 Calciners 86% 169.5 145.5 $17,134 $34,267,045

INPUT Calculated

COST EFFECTIVENESS (ANNUAL COST BASIS)

Capital Cost

Annual Cost - Fixed O&M Cost Annual Cost - Variable O&M Cost

FacilityID Emission PointFacilityID Emission PointFacilityID Emission Point