### 1 M EMORANDUM

DATE: July 19, 2010

SUBJECT: Regulatory Alternative Impacts for Group 1 Polymers and Resins Source Categories

FROM: Karen Marsh , EC/R Incorporated Phil Norwood, EC/R Incorporated

TO: Randy McDonald, EPA/OAQPS/SPPD/CCG Paula Hirtz, EPA/OAQPS/SPPD/CCG

The purpose of this memorandum is to present the estimated impacts of regulatory

alternatives iden tified to reduce hazardous air pollutant (HAP) emissions from five source categories that are subject to the Group 1 Polymers and Resins National Emission Standards for HAP (NESHAP)

– 40 CFR 63, subpart U. These source categories are Butyl Rubber Producti on, Epichlorohydrin Elastomers Production, Ethylene Propylene Rubber Production, Neoprene Production, and Nitrile Butadiene Rubber Production. The Butyl Rubber source category is separated into two subcategories, Butyl Rubber Production and Halobutyl Rubb er Production, and regulatory alternatives were evaluated independently for these two subcategories. These regulatory alternatives are being evaluated under EPA’s Risk and Technology Review program, which is addressing statutory requirements under section 112(d)(2), 112(d)(6) and 112(f)(3) of the Clean Air Act. Section 1 provides background information, followed by an identification of the regulatory alternatives in Section 2. Section 3 summarizes the estimated costs and HAP

emission reductions of the al ternatives, and Section 4 summarizes the secondary impacts.

1.0 BACKGROUND

Section 112 of the Clean Air Act (CAA) establishes a comprehensive regulatory process to address emissions of hazardous air pollutants (HAP) from stationary sources. In accorda nce with CAA section 112(c), EPA identifies categories and subcategories of major sources that emit one or more of the HAP listed in CAA section 112(b). CAA section 112(d)(2) then calls for EPA to promulgate national technology

- based emission standards fo r each listed category or subcategory of sources. For “major sources” that emit or have the potential to emit any single HAP at a rate of 10 tons or more per year or any combination of HAP at a rate of 25 tons or more per year, these technology

- based stan dards must reflect the maximum reductions of HAP achievable (after considering cost, energy requirements, and non

- air health and environmental impacts) and are commonly referred to as maximum achievable control technology (MACT)

standards. Section 112(d)( 6) then requires EPA to review the CAA section 112(d) technology

based standards and to revise them “as necessary, taking into account developments in practices, processes, and control technologies,” no less frequently than every 8 years. The residual ris k review is described in section 112(f) of the CAA. CAA section 112(f)(2) requires EPA to promulgate standards for each category or subcategory of CAA section 112(d) sources “if promulgation of such standards is required in order to provide an ample margi n of safety to protect public health . . . or to prevent, taking into consideration costs, energy, safety, and other

### 2 relevant factors, an adverse environmental effect. The Group 1 Polymers and Resins NESHAP (40 CFR 63, subpart U) regulates HAP emissions fr om nine source categories. In the current action, EPA is addressing five of the nine source categories

– Butyl Rubber Production, Epichlorohydrin Production, Ethylene Propylene Rubber Production, Neoprene Production, and

Nitrile Butadiene Rubber Productio n . Sources of HAP emissions from these processes include raw material storage vessels, front

- end process vents, back

- end process operations, wastewater operations, and equipment leaks. The process “front

- end” includes pre

- polymerization, reaction, stripp ing, and material recovery operations; and the process “back

- end” includes all operations after stripping (predominately drying and finishing). The emission sources regulated by the NESHAP for these source categories are storage tanks, front

- end process v ents, equipment leaks, and wastewater operations.

2.0 REGULATORY ALTERNATIVES

Regulatory alternatives were evaluated for the process “front

- end” for Butyl Rubber Production, Halobutyl Rubber Production, and Ethylene Propylene Rubber Production to red uce hydrochloric acide (HCl) emissions. Two “front

- end” process regulatory alternatives were

identified. The first alternative was to establish an emissions limit based on the current level of HCl emissions. This option did not require the installation of any additional controls, only that HCl emissions be maintained at the current level. The second alternative was to require a 99 percent reduction of the HCl created from the combustion of chlorinated organic compounds. In each case, the HCl is generat ed by the combustion of chlorinated organic compounds in a flare. Since it is not possible to install an add

- on device to reduce these HCl emissions following the flare, the impacts are based on the replacement of the flares currently in use with incinera tors followed by scrubbers that will achieve 99 percent reduction in the HCl emissions.

Regulatory alternatives were also identified for the process “back

- end” for: Butyl Rubber Production, Epichlorohydrin Production, Halobutyl Rubber Production, Neopre ne Production,

and Nitrile Butadiene Rubber Production. Two alternatives were considered for each source category/subcategory. The alternative was to establish an emission limit based on the current HAP emissions levels considering existing levels of HAP stripping and recovery plus any existing controls. This option did not require the installation of any additional controls, only that emissions be maintained at the current level. The second regulatory alternative identified was to reduce the organic HA P emissions by requiring a 98 percent reduction in organic HAP

emissions.

3.0 RELEVANT EMISSION POINTS AND BASELINE EMISSIONS

Information about emission points and emissions were provided by the industry in response to a questionnaire distributed by th e EPA using their authority under section 114 of the

CAA.

3.1 Front

- End Emissions

There are two facilities that reported emissions of HCl from the flaring of chlorinated organic compounds present in front

- end process vent emissions, one producing Buty l Rubber and one producing Halobutyl Rubber and Ethylene Propylene Rubber. There are two other

### 3 operating facilities in the Ethylene Propylene Rubber source category, but neither reported any HCl emissions due to the combustion of chlorinated organic comp ounds.

The two facilities are in compliance with the current MACT standards, which requires that organic HAP emissions from continuous group 1 front

- end process vents be reduced by

98 percent, or by using a flare. The relevant “front

- end” emission point s and emissions are provided in Table 1, along with the flow rates at the flare exits.

Table 1: “Front

- End” Process Vents and Baseline Emissions

Source Category Emission

Point ID Pollutant Emissions (tpy) Flow Rate (ft3/sec)

Butyl Rubber FS12 Hydrochlor ic Acid 30.09 205.98

Methyl Chloride 0.779

Hexane 6.53

1,3 Butadiene 0.001

Xylenes 0.0002

Total Organic HAP 7.31 Ethylene Propylene Rubber M

- 07B Hydrochloric Acid 19.77 459.4

Hexane 0.188

Total Organic HAP 0.188

Halobutyl Rubber M

- 07 Hydrochloric Acid 76.8 459.43 Methyl Chloride 0.53

M

- 07A Hexane 0.06 459.43

Total Organic HAP 0.59



### 3.2 Back

- End Process Emissions

Following are summaries of the back

- end process emissions from each of the source categorie s/subcategories. There is only one facility in each source category/subcategory.

The emissions from the back

- end process operations at the butyl rubber facility are approximately 54 TPY. There are two separate dryer vent streams at the butyl rubber faci lity, with one stream controlled. The controlled stream emits around 28 TPY of hexane, while the uncontrolled stream emits around 26 TPY of hexane. The regenerative thermal oxidizer used to control emissions achieves approximately 98 percent control.

The emissions from the back

- end process operations at the halobutyl rubber facility are approximately 5 3 TPY. There are four separate dryer vents at the halobutyl facility and only one

vent is controlled. The controlled vent emits around 18 TPY of hexane and 0.04 TPY of hydrochloric acid. The regenerative thermal oxidizer used to control emissions achieves approximately 97 percent control of the hexane emissions. The three uncontrolled vents collectively emit around 35 TPY of hexane.

The annual emissions f rom the back

- end process operations at the Epichlorohydrin Elastomers facility are approximately 36 TPY. There are two separate dryer vents, one emitting

### 4 around 25 TPY of toluene and the other emitting around 11 TPY. Neither of these vents is

controlled.

The annual emissions from the back

- end process operations at the Nitrile

- Butadiene Rubber facility are approximately 2 TPY. There are 11 separate dryer vents; one is controlled,

while the others are uncontrolled. The controlled vent emits around 0.003 TPY of 1,3

- butadiene and 0.002 TPY of acrylonitrile. The regenerative thermal oxidizer used on this vent achieves approximately 96 percent control of the acrylonitrile emissions, but no control of 1,3

- butadiene.

The collection of 10 uncontrolled vents em it around 0.8 TPY of 1,3

- butadiene and 0.9 TPY of acrylonitrile.

The annual emissions from the back

- end process operations at the Neoprene Rubber facility are approximately 23 TPY. There are 11 separate dryer vents collectively emitting

around 6.5 TPY of chloroprene and 16.5 TPY of toluene. None of the vents are controlled.

The baseline uncontrolled “back

- end” emission points and emissions are listed in

Table 2. The shaded emissions points are small contributors to the total HAP emissions and

were no t included in the impacts analyses discussed in the following sections.

Table 2: Uncontrolled “Back

- End” Process Vents and Baseline Emissions

Source Category Emission

Point ID Pollutant Emissions (tpy) Flow Rate (ft 3 

### /sec)

Butyl Rubber BPBFINISH Hexan e 26.19 213

Total 26.2 213

Halobutyl Rubber M

- 58 Hexane 0.24 441

V

- 127 Hexane 23.76 253

V

- 131 Hexane 10.91 201

Total 34.7 454
Epichlorohydrin

Elastomers ABKEND Toluene 24.77 154.5

BBKEND Toluene 11.2 154.5

Total 36.0 309

Neoprene EWBDRY Chlo roprene 2.325 256.5 Toluene 0.382

WWBDRY Toluene 2.325 256.5 Chloroprene 0.382

EHDRY Toluene 11.894 476 Chloroprene 1.955

WHDRY Chloroprene 1.894 476 Toluene 1.955

EDRYC1 Toluene 0.001 343 Chloroprene 0.001

WDRYC1 To luene 0.001 343 Chloroprene 0.001

EDRYC2 Toluene 0.001 343 Chloroprene 0.001

WDRYC2 Toluene 0.001 343

### 5 Table 2: Uncontrolled “Back

- End” Process Vents and Baseline Emissions

Source Category Emission

Point ID Pollutant Emissions (tpy) Flow Rate (ft 3 

### /sec)
Chloroprene 0.001

EMTNK1 Toluene 0.001 199 Chloroprene 0.001

EMTNK2 Toluene 0.001 199 Chloroprene 0.001

EMTNK3 Tol uene 0.001 199 Chloroprene 0.001

Total 23.1 1466

Nitrile Butadiene

Rubber DRYNCW 1,3

- Butadiene 0.00587 184 Acrylonitrile 0.0435

PBL1 1,3

- Butadiene 0.0587 193

PBL2 Acrylonitrile 0.176 193

PBL3 1,3

- Butadiene 0 275

PBL4 Acrylonitrile 0 275

PBL5 1,3

- Butadiene 0.119 550

PBL6 Acrylonitrile 0.357 550

SD1BLT Acrylonitrile 0.000215 9

SDN1 1,3

- Butadiene 0 275

SDN2 Acrylonitrile 0 275

SDNDR2 1,3

- Butadiene 0.0119 550 Acrylonitrile 0.0885

SDR1SD 1,3

- Butadiene 0.615 646 Acrylonitrile 0.247

SDR2SD Acrylonitrile 0.0165 610

T45678 1,3

- Butadiene 0.000177 75 Acrylonitrile 0.0000887

Total 1.74 3561



### 4.0 COSTS AND EMISSION REDUCTIONS OF REGULATORY ALTERNATIVES

4.1 Front

- End Process Vents

As noted in Section 2, there were two regulatory alternatives identified to address HCl

emissions from front

- end process vents from the Butyl Rubber, Ethylene Propylene Rubber, and Halobutyl Rubber source categories/subcategories. The first alternative would ensure that the current level of HCl emissions are maintained. The only impact of this alternative would be costs due to the labor costs associated with the calculations, records, and reports to demonstrate compliance. These costs are summarized in Table 3.

### 6 Table 3. Estimated Impacts for Front

- End Regulatory Alternative 1

Source Category Baseline

Emissions (tpy) Emission

Reduction (tpy) Capital Costs ($) Annual Costs ($/yr) Cost

Effectiveness ($/ton) Butyl Rubber 7.31 0 $0 $1,000 N/A Ethylene Propylene Rubber 0.1 88 0 $0 $1,000 N/A Halobutyl Rubber 0.59 0 $0 $1,000 N/A



### As noted in section 2, the organic HAP emissions from these front

- end vents are already controlled by the flare. The costs estimated are to replace the flare with an incinerator followed by a sc rubber. The costs were estimated using the standard OAQPS algorithms for thermal

incinerators and acid

- gas absorbers (scrubbers). In order to estimate the input organic HAP loading to the incinerator, the organic HAP emissions shown in Table 1 were divid ed by 0.02 to obtain the uncontrolled emissions. This assumes the flare is achieving a 98 percent reduction in organic HAP emissions. For example, there would be 365.5 TPY of organic HAP from the Butyl Rubber front

- end process that would routed to the in cinerator (7.31 ÷ 0.02 = 365.5). Because the flow rates shown in Table 1 are the flow rates for the flare, it would not be appropriate to assume those represent the flows that would be entering the incinerator. Based on information submitted by these fac ilities during the development of the original MACT standard, a flow rate of 3,500 scfm was used for all three processes.

Table 4 presents the costs based on the second regulatory alternative requiring 99 percent

reduction in HCl emissions. Since both th e Ethylene Propylene Rubber and Halobutyl Rubber source facilities are located at the same plant site, costs were estimated assuming a shared

incinerator/scrubber. This is shown in the last column of Table 4. Details of these costs estimates are provided in Attachment 1.

Table 4. Estimated Impacts for Front

- End Regulatory Alternative 2

Butyl Rubber Halobutyl Rubber Ethylene Propylene Rubber Halobuty and Ethylene Propylene

Combined

HCl Emissions at Baseline (tpy) 30.1 76.8 19.8 96.6

Incinerator
Capital $172,921 $404,703 $404,690 $481,264

Annual $109,533 $291,598 $289,700 $471,049

Scrubber
Capital $496,400 $580,177 $580,194 $639,136

Annual $125,779 $153,882 $133,912 $170,451

Total Capital $669,321 $984,881 $984,8 83 $1,120,400

Total Annual $235,312 $445,480 $423,612 $641,500

HCl Emission Reduction (tpy) 29.8 76.0 19.6 95.6

Cost Effectivenesss $7,899 $5,859 $21,643 $6,710

HCl after control (tpy) 0.3 0.8 0.2 1.0

### 7 4.2 Back

- End Process Operations

As noted in Section 2, there were two regulatory alternatives identified to address back

end emissions from the Butyl Rubber, Epichlorohydrin Elastomers, Halobutyl Rubber, Neoprene, and Nitrile Butadiene Rubber source categories/subcategories. The first alternati ve would ensure that the current level of emissions are maintained. The only impact of this alternative would be costs due to the labor costs associated with the calculations, records, and reports to demonstrate compliance. These costs are summarized in Table 5.

Table 5. Estimated Impacts for Back

- End Regulatory Alternative 1

Source Category Baseline

Emissions (tpy) Emission

Reduction (tpy) Capital Costs ($) Annual Costs ($/yr) Cost

Effectiveness ($/ton) Butyl Rubber 54 0 $0 $981.84 N/A Epichlorohyd rin 36 0 $0 $981.84 N/A Halobutyl Rubber 5 3 0 $0 $981.84 N/A Neoprene 23 0 $0 $981.84 N/A

Nitrile Butadiene Rubber 2 0 $0 $981.84 N/A



### Table 6 presents the costs based on the second option of requiring a 98 percent reduction in organic HAP emissions. The costs were estimated using the standard OAQPS algorithm for

thermal incinerators. Some of the back

- end streams are already controlled. Further emission reductions for the controlled streams were not considered. Instead, the cost impacts were

calcul ated based on the control of the uncontrolled streams that were not shaded in Table 2. Since the flow rates shown in Table 2 represent the flow rates of the uncontrolled streams, they

were used as the inlet flow rates for the incinerators. Details of the se costs estimates are provided in Attachment 2.

Table 6. Estimated Cost and Emission Reductions for Back

- End Regulatory Alternative 2

Source Category Baseline

Uncontrolled

Emissions (tpy) Emission

Reduction (tpy) Capital Costs ($) Annual Costs ($/yr) C ost
Effectiveness ($/ton)

Butyl Rubber 26.2 25.7 $234,589 $180,628 $7,038 Epichlorohydrin 36.0 35.3 $614,071 $1,104,543 $31,334 Halobutyl Rubber 34.7 34.0 $951,419 $1,606,579 $47,285
Neoprene 23.1 22.6 $1,275,414 $4,816,013 $212,630

Nitrile Butadien e Rubber 1.7 1.7 $1,592,255 $11,403,862 $6,687,697



### 5.0 SECONDARY ENVIRONMENTAL IMPACTS

While the primary impact of the regulatory alternatives is to address HCl emissions on

the front

- end and organic HAP emissions on the back

- end, the application of t he control technologies that would be required under the second regulatory alternatives can also have other environmental effects. These impacts can be positive, such as a reduction in non

- HAP volatile organic compound air emissions; or negative, such as the generation of additional wastewater or energy consumption. In this section the secondary impacts on air pollution, water pollution, and

### 8 energy are discussed. The methodologies used to calculate secondary impacts can be found in

documentation for the MACT standard. 1



### Air Pollution

For the sources included in this project, the secondary air pollution impacts are the increased criteria pollutant emissions caused by the on

- site combustion of organic HAPs and

fuels. This combustion results in the emiss ion of nitrogenous oxides (NO

x 

### ), carbon monoxide (CO), particulate matter (PM), and sulfur dioxide (SO 2 

### ). In addition to these five criteria pollutants, emissions of carbon dioxide (CO 2 

### ) are also expected. Table 7 presents the estimated secondary air imp acts for regulatory alternative 2 for the front

- end process vents, and Table 8 presents those for back

- end process vents. The total criteria pollutant emissions for the front

- end are estimated to be around 7 tpy, with NO

x 

### emissions from incinerators accou nting for 6 tpy. The total criteria pollutant emissions for the back

- end are estimated to be around 267 tpy, with

NO

x 

### emissions from incinerators accounting for 225 tpy. The CO 2 

### emissions are estimated to be around 2,607 tpy and 131,086 tpy for front

- end and back

- end, respectively.

Table 7. Secondary Air Impacts for Front

- End Regulatory Alternative 2

Source Category Emissions (tpy)

PM SO 2 NOx CO CO 2

Butyl Rubber 0.004 0.001 2 0.05 162

Halobutyl Rubber 0.03 0.006 2 0.40 1,233
Ethylene Propylene

Ru bber 0.03 0.006 2 0.40 1,219

Combined HBR

AND EPR 0.06 0.012 4 0.70 2,445

Table 8. Secondary Air Impacts for Back

- End Regulatory Alternative 2

Source Category Emissions (tpy)

PM SO 2 NOx CO CO 2

Butyl 0.01 0.003 8 0.2 593

Halobutyl 0.25 0.05 17 3 10 ,160

Epichlorohydrin 0.17 0.03 12 2 6,891

Neoprene 0.83 0.20 55 10 33,045

Nitrile Butadiene

Rubber 2.01 0.40 133 23 80,397

1 Memorandum. Estimated Regulatory Alternative Impacts fo r Elastomer Production Facilities (Polymers and Resins I). Norwood, P., EC/R, to Evans, L., EPA/OAQPS/ESD/OCG. May 10, 1995. Contained in Hazardous Air Pollutant Emissions from Process Units in the Elastomer Manufacturing Industry

-- Supplementary Informa tion Document for Proposed Standards. EPA

- 453/R

- 95

- 005a. May 1995.

### 9 Water Pollution

The only impact on water pollution for the second regulatory alternatives identified in

Section 2.0 is associ ated with the incinerator/scrubber system for control of HCl from the front

end process vents. Control of organic HAP emissions using combustion only does not result in any significant increase in wastewater discharge, since no water effluents are generat ed by the

thermal incinerator.

In the scrubber control system, water is used to remove the acid gas contained in the thermal oxidizer outlet stream. The amount of wastewater generated is equal to the amount of water needed by the scrubber to absorb th e acid gas leaving the incinerator. It is estimated that about 90 million gallons of wastewater will be generated annually from acid scrubbers at Butyl Rubber, Halobutyl Rubber, and Ethylene Propylene Rubber facilities. Almost 60 million of this

total is from the Halobutyl and Ethylene Propylene Rubber facility. The same assumptions were used for this analysis as those used in the MACT. 2 

### Table 9 presents the water pollution impacts

from front

- end regulatory alternative 2.

Table 9. Water Pollution Impac ts from Front

- End Regulatory Alternative 2

Source Category Flow Rate to Scrubber (scfm) Operating Hours (hr/yr) Water Flow Rate (1000 gal/yr)

Butyl Rubber 3,750 8,000 30,600

Halobutyl Rubber 3,608 8,000 29,441

Ethylene Propylene Rubber 3,607 8,000 29,433

Combined HBR AND EPR 7,214 8,000 58,866



### Energy Impacts

The energy demands associated with the control technologies for the second regulatory alternatives include the need for additional electricity and natural gas. The total nationwide

energ y demands that would result from implementing regulatory alternative 2 for front

- end and

back

- end process vents are presented in Tables 10 and 11, respectively. Overall, the controls would require approximately 1.0 x 10 9 

### Btu electricity and 4.4 x 10 10 

### Btu natural gas annually for

front

- end process vent control. Back

- end process vents would require approximately 3.7 x 10 10


### Btu electricity and 2.2 x 10 12 

### Btu natural gas annually. More details about the methodologies

used can be found in the MACT documentat ion. 3

2 See footnote 1

3 See footnote 1

### 10 Table 10. Energy Requirements for Front

- End Regulatory Alternative 2

Incinerator Scrubber

Source Category Annual Electricity

Cost Electricity (10 6
BTU/yr) Natural Gas Use (1000

ft 3 /yr) Natural Gas (10 6
BTU/yr) Annual Electricity

Cost Electricit y (10 6
BTU/yr) Natural

Gas Use

(1000

ft 3 /yr) Natural Gas (10 6
BTU/yr)

Butyl Rubber $1,665 96 2,708 2,708 $1,283 74 0 0

Halobutyl

Rubber $6,309 365 20,546 20,546 $477 28 0 0

Ethylene Propylene

Rubber $6,308 365 20,309 20,309 $478 28 0 0

Combin ed

HBR AND

EPR $12,617 730 40,755 40,755 $1,290 75 0 0

Table 11. Energy Requirements for Back

- End Regulatory Alternative 2

Source Category Annual Electricity

Cost Electricity (10 6
BTU/yr) Natural Gas Use (1000

ft 3 /yr) Natural Gas (10 6
BTU/yr)

But yl $6,080 352 9,889 9,889

Halobutyl $49,137 2,844 169,328 169,328

Epichlorohydrin $33,442 1,936 114,852 114,852

Neoprene $158,683 9,185 550,748 550,748

NBR $385,458 22,311 1,339,949 1,339,949