Technical Memorandum

Date: March 3 1 , 2011

Subject: Summary of U.S. EPA MACT Floor and Beyond

- the

- Floor Options for the Group I Polymers and Resins Portion of the 2010 RTR Proposal/Supplemental Proposal

From: Nick Parsons, EPA/OAR/OAQPS/SPPD/RCG

The purpose of this memorandum is to summarize EPA’s calculations of the MACT floor and the beyond

- the

- floor options for control of emissions from facilities in the National Emission Standards for Hazard Air Pollutants (NESHAP) for Polymers and Resins I (4 0 CFR part 63, subpart U), specifically for the Neoprene Rubber, Nitrile Butadiene Rubber, Epichlorohydrin Elastomer, Ethylene Propylene Rubber and Butyl Rubber Production source categories.

1. Neoprene Rubber Production. We identified in the provisions of the Group I Polymers and Resins MACT standard that apply to the Neoprene Rubber Production source category the absence of a standard for a significant emissions source in the category. Specifically, there are no back

- end process operation emission lim its for this source category. As these processes are major sources of emissions for the one facility in the source category, we are setting standards for back

- end process operations under CAA sections 112(d)(2) and (3)

. As there is only one facility in t he source category, the emissions level currently being achieved by this facility represents the MACT floor. The annual emissions from the back

- end process operations at this facility are approximately 33 TPY. There are 11 separate dryer vents
collective ly emitting around 33 TPY of toluene. None of the vents are controlled. Therefore, we
have determined that the MACT floor for the back

- end process is 33 TPY based on stripping and HAP recovery, given current production levels, but which would fluctuate p roportionally with an increase or decrease in production levels. As part of our beyond

- the

- floor analysis, we considered alternatives more stringent than the MACT floor option. We identified one option using add

- on emission controls that would require the ducting of emissions from the back

- end process operations to a control device, such as an incinerator. This option would also require an initial performance test of the incinerator and continuous parameter monitoring averaged daily. The capital costs of this option are estimated to be approximately $1,300,000 and the total annual costs are estimated approximately $4,800,000 per year. We estimate that an incinerator would achieve an emissions reduction of
98 percent, resulting in a HAP decrease of app roximately 32

. 3 TPY, with a cost

- effectiveness of approximately $ 149,000 per ton. Table 1 .1 summarizes the impacts of the se options. In addition to the cost and emission reduction impacts shown in Table 1 .1, we estimate that the beyond

- the

- floor option w ill result in increases in criteria pollutant and carbon dioxide emissions (PM

– 0.8, SO 2 – 0.2 TPY, NO
x – 55 TPY, CO

– 10 TPY, and CO 2 – 33,000 TPY) and an increase in energy use of approximately 560,000 million BTU/year at a cost of approximately $159,00 0/year. We believe that the costs and other impacts of this beyond

- the

- floor option are not reasonable, given the level of emission reduction. Therefore, we are setting an emission standard that reflects the MACT floor option

.Table 1.1. Neoprene Rubber Production Facility Back

- End Option Impacts

Regulatory Alternatives HAP emissions (TPY) Capital

Cost (million$) Annual

Cost (million$/yr) Cost

- Effectiveness as

Compared to Baseline ($/ton HAP removed)

Baseline 33

-- -- --

1 (MACT floor) 33 0 0

--
2 (Beyond

- the

- floor) 0. 7 1.3 4.8 149 ,000

2. Nitrile Butadiene Rubber Production. We identified the absence of a standard for a significant emissions source in the category in the provisions of the Group I Polymers and Resins MACT standard that apply to the Nitrile Butadiene Rubber Production source category. Specifically, there are no back

- end process operation emission limits for this source category. As these processes are major sources of emissions for the one facility in the source category, we are setting standards for back

- end process operations under CAA section 112(d)(2) and ( d)(3)

. As there is only one facility in the source category, the emissions limitation achieved by this facility is the MACT floor. The annual emissions from the back

- end process operations at this 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 o f the acrylonitrile emissions, but no control of 1,3

- butadiene. The collection of 10 uncontrolled vents emit around 0.8 TPY of 1,3

- butadiene and 0.9 TPY of acrylonitrile. Therefore, we have determined that the MACT floor for these processes is 2 TPY
base d on the current level of HAP stripping and recovery, given current production levels, but which would fluctuate proportionally with an increase or decrease in production levels. As part of our beyond

- the

- floor analysis, we considered alternatives more stringent than the MACT floor option. We identified one option using add

- on emission controls that would require the ducting of emissions from the currently uncontrolled back

- end process operations emission source to a control device, such as an incinerat or. This option would also require an initial performance test of the incinerator and continuous parameter monitoring averaged daily. The capital costs of this option are estimated to be approximately $1,600,000 and the total annual
costs are estimated t o be approximately $11,400,000/year. We estimate that an incinerator would achieve an emissions reduction of 98 percent, resulting in a HAP decrease of approximately 1.7 TPY, with a cost

- effectiveness of approximately $6,700,000/ton. Table 2.1
summarizes the cost and emission reduction impacts of the se options. In addition to the cost and emission reduction impacts shown in Table 2.1, we estimate that the beyond

- the

- floor option will result in increases in criteria pollutant and carbon dioxide
emissions (PM

– 2 TPY, SO 2 – 0.4 TPY, NO
x – 133 TPY, CO

– 23 TPY, and CO 2 – 80,000 TPY) and an increase in energy use of approximately 1,400,000 million BTU/year at a cost of approximately $385,000/year. We believe that the costs and other impacts of this beyond

- t he

- floor option are not reasonable, given the level of emission reduction. Therefore, we are setting an emission standard that reflects the MACT floor option . However, in order to incorporate process emissions variability (e.g., the emissions rate may va ry with product mix, in addition to production level) we are applying a variability factor to the MACT floor level. The facility in this source category submitted several years of additional emissions data, suggesting that the emissions rate in 2008would be more representative of expected future production rates. We found that the emissions

rate from 2008 was 42 percent higher than that in 2009. In order to incorporate this emissions

rate variability, we have applied a 42 percent variability factor to the facility’s baseline emissions, which results in a MACT floor of 2.4 TPY.

Table 2.1. Nitrile Butadiene Rubber Production Facility Back

- End Option Impacts

Regulatory
Alternatives HAP

Emissions (TPY) Capital

Cost (million $) Annual

Cost (million $/ yr) Cost

- Effectiveness as

Compared to Baseline (million $/ton HAP removed)

Baseline 1.7

-- -- --

1 (MACT floor) 2.4 0 0

--
2 (Beyond

- the

- floor) 0.04 1.6 11.4 6.7

3 . Epichlorohydrin Elastomers Production.
We identified the absence of a limit for a significant emissions source within the provisions of the Group I Polymers and Resins MACT standard that apply to the Epichlorohydrin Elastomers Production source category. Specifically, there are no back

- end process operation emission limits for this sou rce category. As these processes are major sources of emissions for the one facility in the source category, we are set ting standards for back

- end process operations under CAA section 112(d)(2) and (d)(3). As there is only one facility in the source ca tegory, the emissions level currently being achieved by this facility represents the MACT floor. The annual HAP emissions from the back

end process operations at this facility are approximately 36 TPY of toluene. There are two separate dryer vents, one e mitting around 24 TPY of toluene, and the other emitting around 12 TPY of toluene. Neither of these vents is controlled. Therefore, we have determined that the
MACT floor for these processes is 36 TPY based on the current level of HAP stripping and

recov ery, given current production levels, but which would fluctuate proportionally with an increase or decrease in production levels. As part of our beyond

- the

- floor analysis, we considered alternatives more stringent than the MACT floor option. We identif ied one option using add

- on emission controls that would require the ducting of emissions from the back

- end process operations to a control device, such as an incinerator. This option would also require an initial performance test of the incinerator
and c ontinuous parameter monitoring averaged daily. The capital costs of this option are estimated to be approximately $600,000 and the total annual costs are estimated to be approximately $1,100,000. We estimate that an incinerator would achieve an emissions
reduction of 98 percent, resulting in a HAP decrease of approximately 35 TPY, with a cost

effectiveness of approximately $31,000/ton. Table 3 .1 summarizes the cost and emission
reduction im pacts of these options. In addition to the cost and emission reduction impacts shown in Table 3 .1 , we estimate that the beyond

- the

- floor option would result in increases in criteria pollutant and carbon dioxide emissions (PM

– 0.2 TPY, SO 2 – 0.03 TPY, NO
x – 12 TPY, CO

– 2 TPY, an d CO 2 – 7,000 TPY), and an increase in energy use of approximately 117,000 million British thermal units (BTU)/year at a cost of approximately $33,000/year. We believe that the costs and other impacts of this beyond

- the

- floor option are not reasonable, gi ven the level of emission reduction. Therefore, we are setting an emission standard that reflects the MACT floor option. However, in order to incorporate process emissionsvariability (e.g., the emissions rate may vary with product mix, in addition to pr oduction level)

we are applying a variability factor to the MACT floor level. While historical emissions data for the facility in this source category submitted were not available, the owner of the facility (which
also owned the one facility in the NBR so urce category) noted that the back

- end processes for this facility were very similar to those of the NBR facility

. We agreed with the owner that the expected variability in emissions from the Epichlorohydrin Elastomers facility would be similar
to that of the NBR facility. In order to incorporate this emissions rate variability, we have applied a 42 percent variability factor to the facility’s baseline emissions, which results in a
MACT floor of 51 TPY.

Table 3.1. Epichlorohydrin Elastomer Production Fa cility Back

- End Options Impacts

Regulatory Alternatives HAP
Emissions (TPY HAP) Capital

Cost ($million) Annual

Cost ($million/yr) Cost

- Effectiveness as

Compared to Baseline ($/ton HAP removed)

Baseline 36

-- -- --

1 (MACT floor) 51 0 0

--

2 (Beyond

- the

- floor) 1 0.6 1.1 31,000

4 . Ethylene Propylene Rubber Production. We identified in the provisions of the Group I Polymers and Resins MACT standard that apply to the Ethylene Propylene Rubber Production source category the absence of a standard for a significant emissions source in the category. Specifically, the rule re quires that emissions from Group 1 front

- end process vents be routed to a control device that achieves 98 percent reduction in organic HAP emissions but does not require the control of hydrogen halides and halogens
from the outlet of combustion devices. A ll four currently

- operating facilities in this source category control the organic HAP emissions in accordance with the requirements in the rule (i.e., reduce organic HAP emissions by 98 percent). This represents the MACT floor for this source category. However, one facility routes a chlorinated organic compound to a flare, which results
in emissions of HCl that were not regulated by the original MACT requirements. Due to the level of HCl emissions resulting from the combustion of chlorinated organic com pounds in Group 1 streams, we proposed to require control of these HCl emissions for the Ethylene Propylene Rubber Production source category. As each facility in this source category currently complies with the existing MACT standard for organic HAP emi ssions, this represents the MACT floor. As part of our beyond

- the

floor analysis, we considered alternatives to reduce these HCl emissions, which are more stringent than the MACT floor option. We identified the option of eliminating the exemption
from th e requirement to control hydrogen halides and halogens from the outlet of combustion devices. The one facility reports 24.1 TPY of HCl emissions in 20 05 resulting from the combustion of chlorinated organic compounds in a flare. The other three facilities indicated that they do not emit any HCl emissions resulting from the combustion of chlorinated organic compounds. We estimated that the capital costs for the facility to replace the flare with an incinerator followed by a scrubber to reduce th e HCl would be approximately $ 1,900,000 and the total annual costs are estimated to be approximately $ 441,000 per year. While there would be no additional reduction in organic HAP from this requirement, the HCl emissions would be reduced by 99 percent, or 19.2 TPY. The cost

- effectiveness of this option would be approximately $ 19 ,000 per ton. Table 4 .1 summarizes the impacts of the proposed options.In addition to the cost and emission reduction impacts shown in Table 4 .1, we estimate

that the beyond

- the

- floor option will result in increases in criteria pollutant and carbon dioxide emissions (PM

– 0.0 03 TPY, SO 2 – 0.00 1 TPY, NO
x – 0.4 TPY, CO

– 0. 0 4 TPY, and CO 2 – 136 TPY), the generation of approximately 9 million gallons/year of wastewater, and an incre ase in energy use of approximately 140 ,000 million BTU/year at a cost of approximately $ 2,800 /year. We believe that the costs and other impacts of this beyond

- the

- floor option are not reasonable, given the level of emission reduction. Therefore, we are s etting an emission standard that reflects the MACT floor option. However, in order to incorporate process emissions variability (e.g., the emissions rate may vary with product mix, in addition to production level) we are applying a variability factor to t he MACT floor level. The facility in this source category submitted several years of emissions data for our consideration. We found that the emissions rate varied up to 26 percent higher than that in 2005 ( 39 percent higher than that in 2010 )

. This variability was based on the difference between the facility’s average emissions rate and the average emissions rate plus two standard deviations. In order to incorporate this emissions rate variability, we have applied a 26 percent variability facto r to the facility’s baseline emissions in 2005 (39 percent variability factor to the facility’s baseline emissions in 2010) , which results in a
MACT floor of 30.5 TPY in 2005

.

Table 4 .1. Ethylene Propylene Rubber Production Facility Front

- End Options Imp acts

Regulatory
Alternatives HAP Emissions

(TPY HAP) Capital

Cost ($million) Annual

Cost ($million/yr) Cost

- Effectiveness as

Compared to Baseline ($/ton HAP removed)

Baseline 24.1

-- -- --

1 (MACT floor) 30.5 0 0

--
2 (Beyond

- the

- floor) 0.2 1.9 0.4 19 ,000

5 . Butyl Rubber Production. We identified in the provisions of the Group I Polymers and Resins MACT standard that apply to the Butyl Rubber Production source category the absence of standards for two significant emissions sources in this source category . Specifically, these situations are HCl
emissions from front

- end process vents and emissions from back

- end process operations. The rule requires that emissions from Group 1 front

- end process vents be routed to a
control device that achieves 98 p ercent reduction in organic HAP emissions but does not require the control of hydrogen halides and halogens from the outlet of combustion devices. Both
facilities in this source category control the organic HAP emissions in accordance with the requirement s in the rule (i.e., reduce organic HAP emissions by 98 percent). This represents the MACT floor for these subcategories. However, these facilities route a chlorinated organic compound to a flare, which results in emissions of HCl that were exempted from the original MACT requirements. Due to the level of HCl emissions resulting from the combustion of chlorinated organic compounds in Group 1 streams, we proposed to require control of these HCl
emissions. As each facility in this source category is curr ently subject to the same standard and complying the same way, the existing level of control for organic HAP emissions represents the
MACT floor

. The two facilities in this source category reported combined HCl emissions of
10 1.6 TPY in 2006 . Therefore, we have determined that the MACT floor for these processes iseach facility’s individual HCl emissions , given current production levels, but which would

fluctuate proportionally with an increase or decrease in production levels. As part of our beyond

- th e

- floor analysis, we considered alternatives to reduce the HCl emissions, which are more stringent than the MACT floor option. For front

- end process vents, we identified the option of eliminating the exemption from the requirement to control hydrogen
hali des and halogens from the outlet of combustion devices. Since scrubbers could not be installed on the outlet of these combustion devices to reduce the HCl emissions by 99 percent,
the facilities would need to install new recuperative thermal oxidizers fol lowed by scrubbers to comply with this beyond

- the

- floor requirement. We estimate that the capital costs for this would be $ 4,500,000 for both facilities . The total annual costs would be around $ 1,200,000 per year for
both facilit ies . Since there would b e no additional reduction in organic HAP emissions from what is being achieved by the current controls, the only emission reduction would a 99 percent reduction in HCl emissions, or 100.5 TPY . Thus, the cost

- effectiveness of these beyond

- the

floor options would be approximately $ 12,000 per ton. Table 5 .1 summarize s the impacts of
these options. In addition to the cost and emission reduction impacts shown in Table 5 .1, we estimate that the beyond

- the

- floor option will result in increases in criteria pollutant and carbon dioxide emissions (PM

– 0.0 5 TPY, SO 2 – 0.01 TPY, NO
x – 5.2 TPY, CO

– 0. 53 TPY, and CO 2 – 1 ,823 TPY), the generation of approximately 90 million gallons/year of wastewater, and an increase in energy use of around 2

, 8 00 million BTU/year at a cost of approximately $ 56 ,000/year. We believe that the costs and other impacts of these beyond

- the

- floor options are not reasonable, given the level of emission reduction. Therefore, we are setting an emission standard
that reflects the MACT floor option. However, in order to incorporate process emissions variability (e.g., the emissions rate may vary with product mix, in addition to production level) we are applying a variability factor to the MACT floor level. The facilities in this source

cate gory submitted several years of additional emissions data for our consideration. We found that the emissions rate varied up to 190 percent higher than that in 2006 ( 74 percent higher than
that in 2010 )

. This variability was based on the difference betwee n the facility’s average emissions rate and the average emissions rate plus two standard deviations. In order to incorporate this emissions rate variability, we have applied a 190 percent variability factor to
each facility’s baseline emissions in 2006 (a 74 percent variability factor to each facility’s baseline emissions in 2010) , which results in a MACT floor of 294.6 TPY in 2005.

Table 5.1. Butyl Rubber Production Facility Front

- End Options Impacts

Regulatory
Alternatives HAP

Emissions (TPY HAP) Capital

Cost ($million) Annual

Cost ($million/yr) Cost

- Effectiveness as Compared to Baseline ($/ton HAP removed)

Baseline 101.6

-- -- --

1 (MACT floor) 294.6 0 0

--
2 (Beyond

- the

- floor) 1.0 4.5 1.2 12,000

We also noted that there are no back

- end process operation emission limits for the Butyl
Rubber Production source category

. As each facility in this source category is currently subject to the same standard and complying the same way, the existing level o f control for organic HAP emissions represents the MACT floor. The annual emissions from the uncontrolled back

- end process operations from the Butyl Rubber source category are 6 7.5 TPY in 2006

. Therefore, wehave determined that the MACT floor for these processes is each facility’s individual organic

HAP emissions , given current production levels, but which would fluctuate proportionally with an increase or decrease in production levels. As part of our beyond

- the

- floor analysis, we considered alternatives more stringent than the MACT floor option. We identified one option using add

- on emission controls that would require the ducting of emissions from the uncontrolled back

- end process oper ations to a control device, such as a regenerative thermal oxidizer . This option would also require an initial performance test of the thermal oxidizer and continuous parameter monitoring averaged daily.
We estimated that the capital costs of this option to be approximately $ 3,500,000 and the total annual costs are estimated to be approximately $ 1,500,000

. We estimate that a thermal oxidizer
would achieve an emissions reduction of 98 percent, resulting in a HAP decrease of approximately 66.2 TPY. The as sociated cost

- effectiveness values would be approximately $ 23 ,000 per ton for Butyl Rubber source category. Table 5.2 summarize s the impacts of the proposed options. In addition to the cost and emission reduction impacts shown in Table 5.2 , we estimate that the beyond

- the

- floor option will result in increases in criteria pollutant and carbon dioxide emissions (PM

– 0. 18 , SO 2 – 0.0 4 TPY, NO
x – 63 TPY, CO

– 2 TPY, and CO 2 – 7,111 TPY) and an increase in energy use of approximately 11 ,000 million BTU/year a t a cost of approximately $ 223 ,000/year. We believe that the costs and other impacts of these beyond

- the

- floor options are not reasonable, given the level of emission reduction. Therefore, we are setting an emission standard
that reflects the MACT floor option. However, in order to incorporate process emissions variability (e.g., the emissions rate may vary with product mix, in addition to production level) we are applying a variability factor to the MACT floor level. The facilities in this source categ ory submitted several years of additional emissions data for our consideration. We found that the emissions rate varied up to 45 percent higher than that in 2006 ( 35 percent higher than
that in 2009 )

. This variability was based on the difference between the facility’s average emissions rate and the average emissions rate plus two standard deviations. In order to incorporate this emissions rate variability, we have applied a 45 percent variability facto r to each facility’s baseline emissions in 2006 ( 35 percent variability factor to each facility’s baseline
emissions in 2009), which results in a MACT floor of 164 .6 TPY in 200 6.

Table 5.2

. Butyl Rubber Production Subcategory Facility Back

- End Option Impacts

Regulatory Alternatives HAP Emissions (TPY HAP) Capital

Cost ($million) Annual

Cost ($million/yr) Cost

- Effectiveness as

Compared to Baseline ($/ton HAP removed)

Baseline 113.5

-- -- --

1 (MACT floor) 1 64.6 0 0

--
2 (Beyond

- the

- floor) 47.3 3.5 1.5 23,000

6

. Shutdown Standards.
We received a comment from facilities in the Ethylene Propylene Rubber and Butyl Rubber source categories that organic HAP emissions that are required to be sent to emissions control equipment (i.e., flares) may not be able to comply with the MACT standards during periods of shutdown. The commenter stated that they may not always be able to route some of
their continuous front

- end process vents to a flare during periods of shutdown due to the lowpressure or low heating value in the process vent. EPA agree d with the commenter that it is not

possible to comply with the applicable sta ndard during periods of shutdown, and developed an alternative standard app licable during these times. As part of our analysis of this alternative standard, EPA found that the facilities in this source category currently route their emissions to a flare until either the concentration of organic HAP in the process vent falls belo w 50 ppmv (at which point it no longer has enough heat content to be burned in the flare) or the pressure in the process vent falls below 15 psig (at which point it no longer has enough pressure to be pumped into the flare). As these events occur infreque ntly (estimated to be 1

- 3 times per year), emissions were estimated assuming a 50 ppmv HAP content stream emitting for 48 hours annually. We found that sources in the Butyl Rubber source category are estimated to emit 0.15 TPY and in the Ethylene Propylen e Rubber source category to emit 0.09 TPY. Therefore, we have determined
that these values represent the MACT floor for these process vents during periods of shutdown. As part of our beyond

- the

- floor analysis, we considered alternatives more stringent th an the MACT floor option. We identified one option using additional pumps to send the waning process vent stream to the flare once the organic HAP content fell below 50 ppmv or the pressure fell below 15 psig. For the Butyl Rubber source category, w e est imated that the capital costs of this option to be approximately $ 4,300 and the total annual costs are estimated to be approximately $ 19 ,000. We estimate that the flare would achieve an emissions reduction of
98 percent, resulting in a HAP decrease of app roximately 0.14 TPY. The associated cost

effectiveness values would be approximately $ 130 ,000 per ton for Butyl Rubber source category. For the Ethylene Propylene Rubber source category, we estimated that the capital costs of this option to be approximately $ 2,100 and the total annual costs are estimated to be approximately $ 4

, 8 00. We estimate that the flare would achieve an emissions reduction of 98 percent, resulting in a HAP decrease of approximately 0.09 TPY. The associated cost

- effectiven ess values would be approximately $ 53 ,000 per ton for Ethylene Propylene Rubber source category. Table s 6.1
and 6.2 summarize the impacts of the proposed options. We believe that the costs and other impacts of these beyond

- the

- floor options are not

reaso nable, given the level of emission reduction. Therefore, we are setting an emission standard that reflects the MACT floor option.

Table 6.1 . Butyl Rubber Production Subcategory Facility Front

- End Shutdown Option Impacts

Regulatory Alternatives HAP Emiss ions (TPY HAP) Capital

Cost ($ thousand ) Annual

Cost ($ thousand /yr) Cost

- Effectiveness as

Compared to Baseline ($/ton HAP removed)

Baseline 0.15

-- -- --

1 (MACT floor) 0.15 0 0

--
2 (Beyond

- the

- floor) 0.003 4.3 19 130,000Table 6.2

. Ethylene Propylene Rubber Production Subcategory Facility Front

- End

Shutdown Option Impacts

Regulatory Alternatives HAP Emissions (TPY HAP) Capital

Cost ($ thousand ) Annual

Cost ($ thousand /yr) Cost

- Effectiveness as

Compared to Baseline ($/ton HAP removed)

Baseline 0.09

-- -- --

1 (MACT floor) 0.09 0 0

--
2 (Beyond

- the

- floor) 0.002 2.1 4.8 53,000