1 TECHNICAL MEMORANDUM

TO: Tina Ndoh, U.S. EPA/OAQPS/SPPD - Minerals and Manufacturing Group

FROM: Eastern Research Group, Inc.

DATE: July 21, 2015

SUBJECT: Beyond-the-Floor Analysis for Phosphate Rock Calciners at Phosphoric Acid Manufacturing Plants – Final Rule

1.0 INTRODUCTION

The U.S. Environmental Protection Agency (EPA), under section 112 of the Clean Air Act (CAA), is required to esta blish national emissions standard s for Hazardous Air Pollutants (NESHAP) emitted from phosphoric acid and phospha te fertilizer production facilities. The complete set of HAP is listed under CAA secti on 112(b). EPA must also examine more stringent “beyond-the-floor” (BTF) regulatory options to determine MACT. Unlike the minimum stringency requirements of the fl oor, EPA must consider various impacts of the more stringent regulatory options such as co sts and emissions reductions in determining whether MACT standards are to reflect BTF requirements.

Upon review of the phosphoric acid and phos phate fertilizer sour ce categories in conjunction with the risk and t echnology review, the EPA identifie d emission sources that do not have MACT standards for all pollutants emitted. As a result, the EPA determined that MACT

standards should be established for mercury (Hg) and total fl uoride from the phosphate rock calciners. We then evaluated BTF options for Hg and total fluoride. For total fluorides we were unable to identify any cost effective BTF technol ogies. 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 Produc tion. BTF options for Hg emissions were identified for phosphate rock calciners that woul d be more stringent than the MACT floor level

of control.

This memorandum documents the phosphate rock calciner BTF evaluation for total

fluorides and describes the cost and emissions reductions for phosphate rock calciners achieved by applying BTF regulatory options for Hg. S ection 2.0 presents the total fluorides BTF

evaluation. Sections 3.0 and 4.0 disc uss the identification of more st ringent Hg controls that were reviewed for this analysis for existing and new sources, respectively. Section 5.0 discusses the methodology used to estimate costs and emissions reductions of the more stringent Hg controls,

and Section 6.0 summarizes the resu lts of the Hg BTF analysis.2 2.0 BTF EVALUATION FOR TOTAL FLUORIDES

Each of the six phosphate rock calciners cu rrently controls emi ssions with a venturi

scrubber and wet electrostatic precipitator (WESP). Therefore, the phosphate rock calciners currently employ technology that will control total fluoride emi ssions. However, we evaluated the addition of a packed bed scrubber for addition al total fluoride contro l for the BTF analysis. Test data were available from one phosphate rock calciner, which set the MACT floor limit. Using this data, we determined that installation of an additional scrubber to control total fluoride emissions was not cost effective, and thus we did not set a BTF limit for total fluorides from phosphate rock calciners. Of note, phosphate rock calciner total fl uoride emissions are comparable to total fluoride emissions from ot her controlled emission points at phosphoric acid manufacturing and phosphate fert ilizer production fac ilities and are not a significant source of

total fluoride emissions.

3.0 IDENTIFICATION OF MORE STRI NGENT MERCURY CONTROLS FOR

EXISTING SOURCES

The emissions reductions and costs of the MA CT floor level of control for Hg were estimated based on the following information:

1. Hg test data were only av ailable from two phosphate ro ck calciners, as only one facility operates phosphate rock calcine rs in the production of phosphoric acid; therefore, the two phosphate rock calciners set the Hg MACT floor limit.

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 additi onal controls were anticipated.

For existing phosphate rock calciners it was de termined 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 or activated carbon inj ection (ACI). Based on a review of vendor supplied information and previous control technology studies 1 , a FB carbon adsorption system would achieve at least a 90 per cent reduction of the Hg in the calciner exhaust

stream. Similar emissions reductions are antic ipated with ACI (EPA, 1997; Jones, 2007).

During the comment period for the proposed ru le PCS Aurora (the one facility with phosphate rock calciners) contracted with URS to review our Hg control technology evaluation. The complete evaluation is available in thei r commenter letter, docket item EPA-HQ-OAR2012-0522-0037. As a result of this additional info rmation, the EPA agreed that a traditional fixed-bed carbon adsorption system and ACI installe d prior to or after the existing WESP are not technically feasible for phospha te rock calciners. However, in formation in the PCS Aurora

comment letter noted that certain other contro l technologies would be feasible: use of ACI installed upstream of the existing venturi sc rubber and the Gore Mercury Control System (GMCS). We have, therefore, re vised the BTF analysis for Hg based on installing ACI upstream

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).3 of the existing venturi scrubber a nd installing GMCS. See section V.C.3.a.i of the final preamble for the EPA’s complete response regarding Hg control devices and the BTF Hg limit.

4.0 IDENTIFICATION OF MORE STRI NGENT MERCURY 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 exis ting source floor. As a result, the same BTF options available for existing phosphate rock calciners are av ailable for new phosphate rock

calciners.

5.0 METHODOLOGY USED TO ESTI MATE COSTS AND EMISSION

REDUCTIONS FOR MERCURY CONTROLS

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. Fi rst, 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 calcu lating a ratio of annual operating hours for each phosphate rock calciner to the annual operating hour s for the tested phosphat e rock calciners; this ratio was then multiplied by the annual emissions for the tested calciners. See the memorandum

“Emissions Data Used in Residual Risk Modeli ng: Phosphoric Acid and Phosphate Fertilizer Production Source Categories” for the annual Hg emissions estimated for each phosphate rock

calciner based on data from the Ontario-Hydro test method (ERG 2014). Ontario-hydro data was

used for the Risk Assessment because this me thod provides speciated Hg results. However, Method 30B Hg data were used to calculate th e BTF limit and facilities will use also use Method 30B to determine compliance. Therefore, baselin e emissions and emissions reductions for this

memorandum are based on Method 30B data. The to tal Hg baseline emissions using Method 30B for the six phosphate rock calci ners equals 169 pounds per year.

As previously described, it is assumed that Hg emission reductions of approximately 90 percent are possible with appropriate cont rol technology. However, the BTF Hg numerical limit of 1.4E-02 milligrams per dry standard c ubic 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 emission limit. Theref ore, annual Hg emissions reductions as a result of the phosphate rock calciners meeti ng the BTF numerical limit were calculated by multiplying the annual Hg baseline emissions by th e percent reduction necessary to comply with the BTF Hg limit (86 percent). This results in Hg emissions reductions of approximately 145 pounds per year.

Using the site-specific costs that were provide d in the PCS Aurora commenter letter (see docket item EPA-HQ-OAR-2012-0522-0037) , costs were determined fo r the BTF Hg analysis.

Gore Mercury Control System

The cost of adding GMCS for control of Hg from the phosphate ro ck calciner exhausts

was estimated in the PCS Aurora comment letter a nd we are maintaining their cost estimate for4 our BTF Hg analysis. Capital costs for GMCS were based on vendor data provided by W.L. Gore & Associates to URS, on behalf of PCS Aurora. Capital costs for the GMCS are enumerated in Figure 10 of Attachment A in the PCS comment letter. Annual costs for GMCS are presented in Appendix B-4 of Attach ment A in the PCS comment letter.

Activated Carbon Injection Cost

The cost estimate for installing ACI prior to the existing venturi scrubber was estimated based on data provided in the PCS Aurora comme nter letter. ACI capita l costs were based on vendor data provided by ADA to URS, on behalf of PCS Aurora ; see Figure 6 of Attachment A

in the PCS comment letter. Annual costs for ACI are presented in Appendix A-4 of Attachment A in the PCS comment letter. However, we ar e revising their annual co st estimate by applying carbon injection rates of 5 lb/ MMacf and 10 lb/MMacf, instead of 30 lb/MMacf. The rationale for using lower carbon injection rate s is provided in section V.C.3.a .i of the final preamble. See

Attachment A for the revised ACI annual cost calculations.

6.0 MERCURY BTF ANALYSIS RESULTS

Applying BTF control to reduce Hg emissions from the six existing phosphate rock

calciners is estimated to result in a total capital investment (T CI) (2014 dollars) of approximately $21.15 million for ACI installed upstream of the existing venturi scrubber or $32 million for GMCS. Applying BTF control to reduce Hg emis sions from the six existing phosphate rock calciners is expected to result in a tota l annualized cost (TAC) (2014$) ranging from $4.32 million (using a carbon injection ra te of 5 lb/MMacf) to $5.28 m illion (using a carbon injection rate of 10 lb/MMacf) for ACI installed upstream of the existing venturi scrubber or $5.78 million for GMCS. 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 effectiven ess for ACI installed up stream of the existing venturi scrubber was estimated to range from$29,800 to $36,400 per pound of Hg and the costeffectiveness for GMCS was estimated to be $39,800 per pound of Hg. Table 5-1 presents a summary of the BTF analysis for existing phos phate rock calciners. The BTF Hg controls evaluated were technically feasible. Because AC I installed upstream of the existing venturi scrubber was the lower cost option, only this control technology was c onsidered regarding the economic impact and cost-effectiveness of the BT F limit. GMCS data are presented in Table 5-1 for completeness.

Table 5-1. Summary of Hg Beyond-th e-Floor Analysis Results for Existing Phosphate Rock Calciners

BTF Control Technology

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

Reduction (pounds/year) Cost

Effectiveness ($/pound of Hg)

ACI (Installed Upstream of the Existing Venturi Scrubber) – Carbon Injection Rate of 5 lb/MMacf $21,150,000 $4,320,000 145 $29,8005 ACI (Installed Upstream of the Existing Venturi Scrubber) – Carbon Injection Rate of 10 lb/MMacf $21,150,000 $5,280,000 145 $36,400

GMCS $32,000,000 $5,780,000 145 $39,800

[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

After consider the economic impact to PCS Aurora, we determined the BTF limit for existing phosphate rock calciners would impose a significant economic impact to PCS Aurora, and as such, we are not finalizing the BTF Hg li mit for existing phosphate rock calciners. We are finalizing a MACT floor Hg lim it of 0.14 mg Hg/dscm @ 3% O 2 for existing phosphate rock calciners and do not anticipate that any facilities w ill need to install a new control device to meet the existing phosphate rock calciner Hg limit.

We also evaluated the BTF Hg limit for new phosphate rock calciners. We estimated the costs and emission reductions for installing a ne w phosphate rock calciner; see Table 5-2. These estimates were based on the same costs pr ovided by PCS Aurora, and assumes the new phosphate rock calciner has similar emissions as the existing phosphate ro ck calciners at PCS Aurora. Installing ACI upstream of the existing ve nturi scrubber was considered to be cost

effective for new sources and facilities should be be tter able to plan for the costs of controls. As a result, it was determined that 90 percent Hg reduction is achievable and the new source BTF limit for Hg is 10 percent of th e calculated MACT limit. We are finalizing the proposed BTF Hg limit (i.e., 0.014 mg Hg/dscm @ 3% O 2 ) for new phosphate rock calcin ers. We are not aware of any new phosphate rock calciners that are under development, and therefore, there will not be

near-term costs for this limit. See section V.C.3.a .i of the final preamble for the complete BTF Hg limit response and discussion.

Table 5-2. Summary of Hg Beyond-th e-Floor Analysis Results for New Phosphate Rock Calciners

BTF Control Technology

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

Reduction (pounds/year) Cost

Effectiveness ($/pound of Hg)

ACI (Installed Upstream of the Existing Venturi Scrubber) – Carbon Injection Rate of 5 lb/MMacf $3,500,000 $720,000 24 $29,800

ACI (Installed Upstream of the Existing Venturi Scrubber) – Carbon Injection Rate of 10 lb/MMacf $3,500,000 $880,000 24 $36,400

[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 pound6 7.0 REFERENCES

APC, 2011. “Air Emission Control Systems and Service MercPure Series Mercury Emission Control Systems.” APC Technologies, Inc. 24 October, 2011. http://www.apctechnologies .net/pdf/APC-MercPure.pdf

Calgon, 2006. “HGR ® for Mercury Removal Granular Activated Carbon.” Calgon Carbon Corporation. CPM-PB1047-0406. http://www.calgoncarbon.com/carbon_products/ documents/HGRforMercuryRemoval.pdf

Calgon, 2012a. “Fixed bed for wet exhaust streams, 10,000 SCFM, CC C Ref# Hg050412-1.” Calculation sheet prepared by Calgon Carbon Corporation for ERG. 5 May, 2012. Docket ID: EPA-HQ-OAR-2012-0522.

Calgon, 2012b. “Fixed bed for wet exhaust st reams, 200,000 SCFM, CC C Ref# Hg050412-1.” Calculation sheet prepared by Calgon Carbon Corporation for ERG. 5 May, 2012. Docket ID: EPA-HQ-OAR-2012-0522.

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

Publication Number EPA-452-R-97-010.

ERG, 2014. “Emissions Data Used in Residual Ri sk Modeling: Phosphoric Acid and Phosphate

Fertilizer Production Source Ca tegories.” Eastern Research Group, Inc. August 2014. EPA–HQ–

OAR–2012-0522.

Jones, 2007. DOE/NETL’s Phase II Mercury Co ntrol 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.Attachment A

Annual ACI Cost and Cost Effectiveness For Each Carbon Injection Rate**Attachment A: Annual ACI Cost and Cost Effectivenes s For Each Carbon Injection Rate** **Parameter Cost for Carbon** **Injection Rate of 5 lb/MMacf** **Cost for Carbon Injection Rate** **of 10 lb/MMacf Cost for Carbon** **Injection Rate of 30 lb/MMacf** **1 Notes** **Total Capital Investment $21,149,568** **$21,149,568 $21,149,568** Same as PCS2**Direct Annual Costs (DAC)**Operating LaborOperator$142,403$142,403$142,403Same as PCS3Supervisor$21,360$21,360$21,360Same as PCS3MaintenanceLabor$160,714$160,714$160,714Same as PCS3Activated Carbon (PAC)Carbon Feed Rate (lb/MMacf)**5 10** **30**Exhaust gas flow rate per calciner (acfm)64,25364,25364,253Carbon Sorbent Cost ($/lb)$1$1$1Same as PCS3Operating Hours830083008300Same as PCS3Carbon Feed Rate (lb/hr/calciner)19.338.6115.7= (Carbon Feed Rate (lb/MMacf)) * (Exhaust gas flowrate percalciner (acfm)) * (60 min/hr) / (1,000,000 acf/MMacf)Carbon Sorbent Cost ($/yr/calciner)$159,990$319,980$959,940=(Carbon Feed Rate (lb/hr/calciner)) * (Carbon Sorbent Cost($/lb)) * (Operating Hours)Total Carbon Sorbent Cost ($/yr)$959,940$1,919,880$5,727,000= (Carbon Sorbent Cost ($/yr/calciner)) * 6**Total DAC $1,284,417** **$2,244,357 $6,051,477** **Indirect Annual Costs (IAC)**Overhead$194,686$194,686$194,686Same as PCS3Administrative Charges$422,991$422,991$422,991Same as PCS3Property tax$211,496$211,496$211,496Same as PCS3Insurance$211,496$211,496$211,496Same as PCS3Total Capital Recovery Cost$1,996,370$1,996,370$1,996,370Same as PCS3**Total IAC $3,037,039** **$3,037,039 $3,037,039** **Total Annual Cost $4,321,455** **$5,281,395 $9,088,516** = Total DAC + Total IAC**Annual Hg Emissions (lb/yr)**169 169 169**Hg Emissions Reduced (lb/yr) (Meeting Limit, 86% Reduction)** 145 145 145**Cost Effectiveness (Meeting Limit) ($/lb) $29,803** **$36,423 $62,679** = (Total Annual Cost) / (145 lb/yr)**Notes:**1. The costs for a carbon injection rate of 30 lb/MMacf are identical to those provided in Appendix A-4 of Attachment A in the PCS comment letter, for reference only (seedocket item EPA-HQ-OAR-2012-0522-0037).2. The total capital cost was not revised, same asFigure 6 of Attachment A in the PCS comment letter(see docket item EPA-HQ-OAR-2012-0522-0037).3. This cost item was not revised, same as AppendixA-4 of Attachment A in the PCS comment letter (seedocket item EPA-HQ-OAR-2012-0522-0037).