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ExxonMobil Chemical Company 

3525 Decker Drive 

P.O. Box 100 

Baytown, Texas 77522-0100 

CERTIFIED MAIL 

October 21, 2014 

Ms. Penny Lassiter 

Office of Air Quality Planning and Standards (OAQPS) 

Sector Policies and Programs Division (E143-01) 

Refining and Chemicals Group Leader 

U.S. Environmental Protection Agency 

Research Triangle Park, NC 27711 

Re: Request for an Alternative Means of Emission Limitation for Pressure-Assisted 

Multi-Point Ground Flares (“MPGF”) at Baytown Olefins Plant and Mont Belvieu Plastics Plant 

Dear Ms. Lassiter: 

ExxonMobil Chemical Company (ExxonMobil) is writing to respectfully request the Environmental 

Protection Agency (“EPA”) provide an Alternative Means of Emission Limitation (“AMEL”) pertaining 

to the requirements of New Source Performance Standards (NSPS), 40 C.F.R. § 60.18, and National 

Emission Standards for Hazardous Air Pollutants (NESHAP), 40 C.F.R. § 63.11. As described below, 

providing the requested AMEL for Pressure-Assisted Multi-Point Ground Flares (“MPGF”) will further 

a technology that will promote significant environmental benefits without undermining any of the goals 

or purposes of the applicable NSPS and NESHAP regulations. The AMEL request is limited to one and 

only one element of the applicable NSPS and NESHAP standards: maximum tip velocity requirements 

in 40 C.F.R. § 60.18(c)(3),(4),(5) and 40 C.F.R. § 63.11(b)(6),(7),(8). 

ExxonMobil requests EPA provide the AMEL for MPGFs at two facilities – ExxonMobil’s Olefins 

Plant in Baytown, Texas (referred to as “Baytown Olefins Plant” or “BOP”) and the ExxonMobil 

Plastics Plant in Mont Belvieu, Texas (referred to as “Mont Belvieu Plastics Plant” or “MBPP”).1

 The 

 

1

 ExxonMobil BOP located in Baytown, Harris County, Texas received New Source Review (NSR) permit (NSR 102982) 

in February 2014 from the Texas Commission on Environmental Quality (TCEQ), and a Greenhouse Gas (GHG) 

Prevention of Significant Deterioration (PSD) permit (PSD-TX-102982-GHG) in May 2014 from EPA, for authorization 

of a new BOP ethylene unit. ExxonMobil received an NSR permit (NSR 103048) from the TCEQ in October 2013, as 

well as a GHG PSD permit (PSD-TX-103048-GHG) on September 5, 2013 from EPA, for authorization of a new MBPP 

polyethylene unit. The GHG PSD Permits are under review at EPA per EPA Memorandum from Janet G. McCabe, 

Acting Assistant Administrator, Office of Air and Radiation and Cynthia Giles, Assistant Administrator, Office of 

Enforcement and Compliance Assurance to Regional Administrators, Regions 1-10, Next Steps and Preliminary Views 

on the Application of Clean Air Act Permitting Programs to Greenhouse Gases Following the Supreme Court’s Decision 

in Utility Air Regulatory Group v. Environmental Protection Agency (July 24, 2014). 
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Subparts of NSPS in 40 C.F.R. Part 60 and of NESHAP in 40 C.F.R. Parts 61 and 63 that apply to the 

MPGFs as control devices at BOP and MBPP are provided in Attachment 1. Based on a review of the 

MPGF design cases and comparison to publicly available data, the MPGFs meet these requirements with 

the exception of maximum tip velocity. As required by the applicable AMEL statutory and regulatory 

provisions, this AMEL application provides the technical justification to demonstrate that, even when 

operating at exit velocities greater than 400 feet per second (fps), the MPGFs will achieve equivalent 

emission reductions to those required by flare performance specifications. We believe that maintaining 

a Lower Heating Value (LHV) greater than 800 Btu/scf or a Lower Flammability Limit (LFL) less than 

6.5% achieves equivalency to the destruction efficiencies represented by 40 C.F.R. § 60.18 and/or 40 

C.F.R. § 63.11(b), as applicable. 

Background

In directing EPA to promulgate NSPS and NESHAPs under Sections 111 and 112 of the Clean Air Act 

(“CAA”), Congress envisioned that promulgated emission standards might not address all available 

means of emission control and provided a mechanism for regulated entities to request and EPA to 

authorize “alternative means of emission limitation” under any given standard. 42 U.S.C. §§ 7411(h), 

7412(h)(3). The statute authorizes such AMELs if, after public notice and opportunity for comment, 

EPA determines that the requested alternative will achieve emission reductions at least equivalent to 

those required by the applicable standard. EPA has incorporated these authorities into its regulations. 

Attachment 1 identifies EPA’s statutory and regulatory authority to approve ExxonMobil’s AMEL 

request. 

The BOP unit will consist of eight new cracking furnaces and associated recovery equipment to produce 

ethylene. The recovery equipment includes a quench tower, caustic wash facilities, a process gas 

compressor and interstage coolers, chiller train, refrigeration system, deethanizer, ethylene/ethane 

splitter, and demethanizer. The MBPP unit will be used to produce polyethylene in low-pressure, gasphase fluidized bed reactors. Catalyst, monomer, co-monomer, and inert chemicals are fed to the 

reactors. The polymer produced by the reactors is in the form of granules suspended by circulating 

gases. Product from the reactors goes through a series of polymer separation and purging stages, and is 

ultimately extruded into pellets. The pellets are transferred to storage silos and are packed in bags and 

containerized for shipping. 

MPGF is a proven technology that has been in use for more than 40 years around the world. The 

modern and state of the art evolution of the technology provides advantages from environmental, 

business and public perspectives. Although it is a more expensive design than traditional flares, MPGFs 

operate with greater emissions control, lower energy requirements, and less community impact. Greater 

emissions control translates into lower post-combustion emission rates for hydrocarbons. Smokeless 

operation over the entire operating range without any assist medium minimizes energy consumption and 

results in lower greenhouse gas generation. Less low frequency noise and less flame visibility in low 

profile designs like those at BOP and MBPP reduce the effect on the surrounding community. 

Despite the different plant operations, the MPGFs at both BOP and MBPP are substantially similar in 

purpose, design, and operation. Both flares will be designed as an integral part of a larger control 

system that will control waste gases in stages. At both facilities, vent gases are captured back into the 

process and/or fuel systems to the maximum extent practicable. Vent gases that are unable to be 

collected are directed to a control system with two separate dispositions: a High Pressure (HP) 

disposition and a Low Pressure (LP) disposition. Simplified schematics depicting each system are 
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provided in Attachment 2. At MBPP, the LP dispositions are three Flameless Thermal Oxidizers and an 

elevated flare. At BOP, the LP disposition is an elevated flare. The elevated flares at BOP and MBPP 

will comply with 40 C.F.R. § 60.18 and/or 40 C.F.R. § 63.11 (as applicable). 

The two plant systems are designed to route waste gases to the MPGF above a set pressure. Each MPGF 

is itself a multi-staged flare system designed to operate with multiple pressure-assisted burners to 

facilitate the optimal mixing of the combustion materials. No assist medium is required to maintain 

consistent flame stability and proper combustion. The multi-staged design allows efficient operation 

(with no assist medium such as air or steam) over a wide range of flowrates. The MPGF’s design 

utilizes the pressure energy inherent within the high pressure relief gas to entrain sufficient quantities of 

combustion air resulting in flare tip exit velocities that will exceed VMAX as specified in 40 C.F.R. 

§60.18(c)(3),(4),(5) or 40 C.F.R. § 63.11(b)(6),(7),(8). 

Requested Alternative Means of Emission Limitation 

Attachment 1 details both the NSPS and NESHAP regulatory provisions that are applicable to the 

MPGFs at BOP and MBPP, along with the statutory and regulatory provisions that authorize EPA to 

review and implement AMELs. The list of potentially applicable regulations is intentionally broad 

reflecting the overlap between regulations and the complexity of plant designs. As described in Table 1 

below, the MPGFs require an approved alternative to NSPS and NESHAP flare performance 

specifications for maximum tip velocity. See 40 CFR §63.11(b)(6). At the same time, the AMEL 

technical justification provides supporting performance test data to demonstrate that MPGFs achieve 

equivalent emission reductions even when operating above 400 fps. Thus, EPA’s granting of the 

proposed AMEL will not result in increased emissions or undermine any of the goals or purposes of the 

applicable NSPS and NESHAP regulations. 

 
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Table 1 

NSPS and NESHAP Flare Specifications 

Flare specifications in 40 C.F.R. §63.112 MPGFs compared to 40 C.F.R. §63.11 

(a) Applicability 

(1) The applicability of this section is set out in 

§ 63.1(a)(4). 

(2) This section contains requirements for control devices 

used to comply with applicable subparts of this part. 

The requirements are placed here for administrative 

convenience and apply only to facilities covered by 

subparts referring to this section

(a) Applicability 

(1) As detailed in Attachment 1, 40 C.F.R. §63.11 and 

40 C.F.R. § 60.18 are applicable to MPGFs that 

ExxonMobil is proposing to use at its BOP and 

MBPP facilities. 

(b) Flares 

(1) Owners or operators using flares to comply with the 

provisions of this part shall monitor these control 

devices to assure that they are operated and maintained 

in conformance with their designs. Applicable subparts 

will provide provisions stating how owners or 

operators using flares shall monitor these control 

devices. 

(b) Flares 

(1) The MPGFs will comply with 40 C.F.R. § 63.11 

and 40 C.F.R. § 60.18, as applicable including 

monitoring requirements. 

(2) Flares shall be steam-assisted, air-assisted, or nonassisted.(2) The MPGFs will be pressure assisted. 

(3) Flares shall be operated at all times when emissions 

may be vented to them. 

(3) The MPGFs will be operated at all times when 

emissions are vented to the flare. 

(4) Flares shall be designed for and operated with no 

visible emissions, except for periods not to exceed a 

total of 5 minutes during any 2 consecutive hours. 

Test Method 22 in appendix A of part 60 of this 

chapter shall be used to determine the compliance of 

flares with the visible emission provisions of this part. 

The observation period is 2 hours and shall be used 

according to Method 22. 

(4) The MPGFs will meet the visible emission 

requirements. 

(5) Flares shall be operated with a flame present at all 

times. The presence of a flare pilot flame shall be 

monitored using a thermocouple or any other 

equivalent device to detect the presence of a flame.

(5) The MPGFs will operate with a flame present and 

presence of a pilot will be monitored using a 

thermocouple or equivalent device. 

(6) An owner/operator has the choice of adhering to the 

heat content specifications in paragraph (b)(6)(ii) of 

this section, and the maximum tip velocity 

specifications in paragraph (b)(7) or (b)(8) of this 

section, or adhering to the requirements in paragraph 

(b)(6)(i) of this section. 

(6) The MPGFs will operate in compliance with the 

heat content specification in paragraph (b)(6)(ii). In 

lieu of the maximum tip velocity specifications of 

40 C.F.R. § 63.11, ExxonMobil proposes a more 

stringent heat content specification of greater than 

800 Btu/scf (lower heating value or LHV) or a 

lower flammability limit (LFL) specification less 

than 6.5%. The combination of these two 

parameters will define a stable MPGF flame. 

 

2

 Table 1 focuses on 40 C.F.R. § 63.11 but the flare specifications are also applicable under 40 C.F.R. § 60.18. 
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Alternative Means of Emission Limitation Request 

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AMEL Technical Justification 

The MPGFs will control emissions during high pressure / high flow occasions. The MPGF technology 

has application to the petroleum refining and chemical processing industries due to its staging systems 

that ensure smokeless flames are maintained over the full operating range of the flare. The burner design 

utilizes pressure to assist combustion of waste gas by entraining an adequate amount of ambient air. 

Pressure-assisted flares are viewed by combustion experts as among the highest destruction and removal 

efficiency (DRE) flares available. Requirements in 40 C.F.R. § 60.18 and 40 C.F.R. § 63.11 limit the 

heating value and exit velocity of the waste streams routed to applicable flares to ensure the design and 

operation of these flares achieve the required destruction efficiency with the benefits of their particular 

assist methods. 

However, in establishing the heating value and exit velocity for 40 C.F.R. § 60.18 and 40 C.F.R. § 63.11, 

EPA did not address MPGF systems at the time. Therefore, there is a reasonable basis to provide an 

AMEL for the limit of maximum exit velocity for the proposed MPGFs. Establishing either a minimum 

heating value or maximum lower flammability limit will ensure good combustion of the waste gas. In 

contrast, limiting the exit velocity would adversely impact pressure-assisted burners by preventing them 

from entraining an adequate amount of air for mixing and proper combustion, and would not allow the 

flare to operate within its design conditions. 

Site-Specific Analysis 

In order to ensure proper operation of the MPGF at all times, a robust design process is used. Each of 

the design cases that represent the MPGF operating envelope are high pressure / high flow and occur 

infrequently. These cases included scenarios such as planned startup and shutdown at routine and 

turnaround activity levels. Routine and turnaround-level equipment maintenance activities (e.g., 

equipment clearing) were also identified. The cases also represent malfunction scenarios such as partial 

and complete utility loss (e.g., cooling water or electric power). Emissions from unplanned events that 

cannot be recovered or routed to the LP disposition are also included. Examples include safety valve 

releases or other equipment malfunctions. 

A review of operating cases identified key parameters for design of the flare including the maximum 

flowrate case, the case with the highest propensity to smoke, and the cases that determine the proper 

burner spacing. 

A total of 14 design cases at BOP and 12 design cases at MBPP are represented in Attachment 3. 

Values and methodology for estimating LHV and LFL utilized the Petroleum Refinery Sector Risk and 

Technology Review and New Source Performance Standards; Proposed Rule at 79 FR 36880. The 

following represent the key points from analysis of Attachment 3. 

 In each case, the LHV is greater than 800 Btu/scf or the LFL is less than 6.5%; 

 Speciation of gas to the MPGF is included; and 

 The unadjusted heating value for hydrogen has been used. 

Flare gas monitoring and recordkeeping will occur according to State of Texas regulations in 30 T.A.C. 

§ 115 Subchapter H Division 1 (Highly-Reactive Volatile Organic Compounds – Vent Gas Control) and 
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Permit Special Conditions (NSR Permit 102982 issued February 19, 2014 for BOP and NSR Permit 

103048 issued October 7, 2013 for MBPP). These provisions can be summarized as: 

 Flow monitoring 

o Annual calibrations 

o Temperature and pressure monitors used for compensation that are calibrated annually 

o Calibration to within 5% at 30%, 60% and 90% of monitor full scale 

 On-line analyzer system 

o Analysis at least once every 15 minutes to within 5% of molecular weight and LHV 

o Representative samples including supplemental gas 

o Quarterly CEMS calibration according to Performance Specification 9 

o Weekly calibration checks 

o 95% availability 

o Manual sampling and analysis during monitor downtime 

 One-hour averaging for flowrate 

 One-hour averaging for LHV 

 Recordkeeping 

o Quality Assurance Plan to demonstrate measurement accuracy and reliability 

o Hourly records of flow and on-line analysis 

o Manual sampling records 

o Calibrations and calibration checks 

The on-line analyzer data will be used to estimate hourly average values for LHV and LFL. Decreasing 

the averaging period likely results in additional monitoring facilities and/or procedures that have no net 

environmental benefit. 

Existing MPGF Emissions Test Data 

There are at least five publicly available test reports where post-combustion emission measurements 

have been made for MPGFs. For each of the publicly available test reports, a review has been 

conducted of high MPGF tip velocity test runs (greater than 400 fps) that are either greater than 800 

Btu/scf (LHV) or less than 6.5% LFL. Each of the analyzed test runs achieved at least 98% DRE. 

Summary tables of test runs that meet the LHV or LFL criteria are included in Attachment 4. 

Table 2 

MPGF Emissions Test Summary (1)

Test 

LHV LFL 

(Btu/scf) (vol %) DRE ≥ 98% 

Dow 2013 Test 2,133 - 2,145 2.4 Yes 

Marathon 2012 Test 908 - 912 4.5 - 4.6 Yes 

Dow 2006 Test 828 - 2,150 2.4 - 6.2 Yes 

EPA/EER 1985 Test 828 - 870 5.7 - 6.0 Yes 

EPA/CMA 1982 Test 2,150 2.4 Yes 

(1) Test runs greater than 400 fps and greater than 800 Btu/scf (LHV) or less than 6.5% LFL 
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Available emissions data includes burner tests of natural gas, propane, propylene and nitrogen. We have 

compared our design case components in Attachment 3 to key flame properties from the existing tests. 

Based on similarities between our design cases and the flame properties of existing emissions test data, 

we believe that our design cases will achieve similar DREs. Charts portraying key flame properties such 

as flammability limits, flame speeds across stoichiometric combustion ranges, and flame speeds for 

various components are shown in Attachment 5. The BOP and MBPP burner tip designs (Linear Relief 

Gas Oxidizer type or equivalent) will have comparable performance to the burners tested in the five 

publicly available test reports. Individual burners selected for BOP and MBPP are characterized by a 

spider-type design with multiple distinct burning points. Dividing the individual burner flow into 

multiple burning points at high velocity will entrain adequate air for good mixing. 

In summary, we believe that maintaining a Lower Heating Value (LHV) greater than 800 Btu/scf or a 

Lower Flammability Limit (LFL) less than 6.5% achieves equivalency to the destruction efficiencies 

represented by 40 C.F.R. § 60.18 and/or 40 C.F.R. § 63.11(b). 

Conclusion and Request 

Based on review of the design cases and comparison to five publicly available tests, maintaining a LHV 

greater than 800 Btu/scf or LFL less than 6.5% will achieve equivalent emission reductions to those 

required by flare performance specifications of 40 C.F.R. § 60.18 and/or 40 C.F.R. § 63.11(b) (as 

applicable). We respectfully request that EPA provide for the AMEL through the following or similar 

language: 

The multi-point ground flares shall be designed and operated such that the combined 

supplemental gas and waste stream to each flare meets the requirements of 40 C.F.R. § 

60.18 and 40 C.F.R. § 63.11, with the exception of maximum tip velocity requirements in 

40 C.F.R. § 60.18(c)(3),(4),(5) and 40 C.F.R. § 63.11(b)(6),(7),(8). In lieu of the 

maximum tip velocity specifications of 40 C.F.R. § 60.18 and 40 C.F.R. § 63.11, the flares 

shall maintain an hourly average heat content of greater than 800 Btu/scf (lower heating 

value or LHV, also called net heating value or NHV) or an hourly average lower 

flammability limit (LFL) less than 6.5%. Monitoring and recordkeeping of the combined 

supplemental gas and waste stream to each flare shall occur according to State of Texas 

regulations in 30 T.A.C. § 115 Subchapter H Division 1 (Highly-Reactive Volatile 

Organic Compounds – Vent Gas Control). Calculations of LFLvg shall utilize the equation 

below from 79 FR 36984. Calculations of NHVvg shall utilize the equation below from 79 

FR 36983. 
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ExxonMobil Chemical Company 

Alternative Means of Emission Limitation Request 

Attachment 1 

NSPS and NESHAP Applicability Tables 
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Table 1-1. NSPS and NESHAP Potentially Applicable 

to the Baytown Olefin Plant (BOP) Ethylene Production Unit 

Potentially Applicable NSPS and NESHAP Requirements for the BOP MPGF 

and Implementing AMEL Provisions 

NSPS Part AMEL Implementing Provision3

40 C.F.R. Part 60, Subpart Kb; Section 

60.112b(a)(3)(ii) 

40 C.F.R. § 60.114b 

40 C.F.R. Part 60, Subpart VV; Section 60.482-10(d) 40 C.F.R. § 60.484 

40 C.F.R. Part 60, Subpart VVa; Section 60.482-

10a(d) 

40 C.F.R. § 60.484a 

40 C.F.R. Part 60, Subpart NNN; Sections 60.662(b), 

60.664(d) 

42 U.S.C. §7411(h)(3) 

40 C.F.R. Part 60, Subpart RRR; Sections 60.702(b), 

60.704(c) 

42 U.S.C. §7411(h)(3) 

NESHAP Part AMEL Implementing Provision4

40 C.F.R. Part 61 Subpart V; Section 61.242-11(d) 40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

40 C.F.R. Part 61 Subpart FF; Sections 

61.349(a)(2)(iii), 61.354(c)(3), 61.356(f)(2)(i)(D) 

40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

40 C.F.R. Part 63 Subpart F; Section 63.103(a) 40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

40 C.F.R. Part 63 Subpart G; Sections 

63.113(a)(1)(i), 63.116(a)(2), 63.116(a)(3), 

63.119(e), 63.120(e)(1) through (4), 

63.126(b)(2)(i), 63.128(b), 63.139(c)(3), 

63.139(d)(3), 63.145(j) 

40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

40 C.F.R. Part 63 Subpart H; Sections 63.172(d), 

63.180(e) 

40 C.F.R. § 63.6(g); 40 C.F.R. § 63.177; 42 U.S.C. 

§7412(h)(3) 

40 C.F.R. Part 63, Subpart SS; Section 63.987 

(NOTE: SS is referenced through YY and EEEE) 

40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

40 C.F.R. Part 63, Subpart YY 40 C.F.R. § 63.1113 

40 C.F.R. Part 63, Subpart EEEE; Sections 

63.2378(a), 63.2382, 63.2398 

40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

 

 

3

 The federal Clean Air Act allows the Administrator to implement AMELs for NSPS compliance purposes, “If after 

notice and opportunity for public hearing, any person establishes to the satisfaction of the Administrator that an 

alternative means of emission limitation will achieve a reduction in emissions of any air pollutant at least equivalent to 

the reduction in emissions of such air pollutant achieved under the requirements of paragraph (1), the Administrator shall 

permit the use of such alternative by the source for purposes of compliance with this section with respect to such 

pollutant.” 42 U.S.C. § 7411(h)(3). 

4

 The federal Clean Air Act also allows the Administrator to implement AMELs for NESHAP compliance purposes, “If 

after notice and opportunity for comment, the owner or operator of any source establishes to the satisfaction of the 

Administrator that an alternative means of emission limitation will achieve a reduction in emissions of any air pollutant 

at least equivalent to the reduction in emissions of such pollutant achieved under the requirements of paragraph (1), the 

Administrator shall permit the use of such alternative by the source for purposes of compliance with this section with 

respect to such pollutant.” 42 U.S.C. §7412(h)(3). 
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Table 1-2. NSPS and NESHAP Potentially Applicable 

to the Mont Belvieu Plastics Plant (MBPP) Polyethylene Unit 

Potentially Applicable NESHAP Regulations for the MBPP MPGF 

and Implementing AMEL Provisions 

NSPS Part AMEL Implementing Provision5

40 C.F.R. Part 60, Subpart DDD; Sections 60.562-1 

(a)(1)(i)(C); 60.564(f)-(g) 

42 U.S.C. § 7411(h)(3) 

40 C.F.R. Part 60, Subpart NNN; Sections 60.662(b); 

60.664(d) 

42 U.S.C. § 7411(h)(3) 

40 C.F.R. Part 60, Subpart RRR; Section 60.702(b); 

60.704(c) 

42 U.S.C. § 7411(h)(3) 

NESHAP Part AMEL Implementing Provision6

40 C.F.R. Part 63, Subpart SS; Section 63.987 

(NOTE: SS is referenced through EEEE) 

40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

40 C.F.R. Part 63, Subpart EEEE; Sections 

63.2378(a), 63.2382, 63.2398 

40 C.F.R. § 63.6(g); 42 U.S.C. §7412(h)(3) 

40 C.F.R. Part 63, Subpart FFFF; Section 63.2450(f) 40 C.F.R. §63.6(g); 42 U.S.C. §7412(h)(3) 

 

5

 The federal Clean Air Act allows the Administrator to implement AMELs for NSPS compliance purposes, “If after 

notice and opportunity for public hearing, any person establishes to the satisfaction of the Administrator that an 

alternative means of emission limitation will achieve a reduction in emissions of any air pollutant at least equivalent to 

the reduction in emissions of such air pollutant achieved under the requirements of paragraph (1), the Administrator shall 

permit the use of such alternative by the source for purposes of compliance with this section with respect to such 

pollutant.” 42 U.S.C. § 7411(h)(3). 

6

 The federal Clean Air Act also allows the Administrator to implement AMELs for NESHAP compliance purposes, “If 

after notice and opportunity for comment, the owner or operator of any source establishes to the satisfaction of the 

Administrator that an alternative means of emission limitation will achieve a reduction in emissions of any air pollutant 

at least equivalent to the reduction in emissions of such pollutant achieved under the requirements of paragraph (1), the 

Administrator shall permit the use of such alternative by the source for purposes of compliance with this section with 

respect to such pollutant.” 42 U.S.C. §7412(h)(3). 
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Attachment 2 

Simplified Schematics of Control Systems 
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Attachment 3 

BOP & MBPP MPGF Design Cases 
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Table 3-1. Baytown Olefins Plant (BOP) MPGF Design Cases 

COMPONENT MW LHV [2] LFL [7] 1 2 3 4 5 6 7 8 9 10 1

(lb/lb-mol) (Btu/scf) (volume% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mo

Nitrogen 28.01 0 ∞ 0.0 0.0 0.0 0.0 0.0 51.3 0.0 0.0 0.0 0.0 0

Hydrogen 2.02 274 4.0 21.5 22.3 0.0 26.0 10.4 0.0 9.8 0.0 0.0 85.4 18Methane 16.04 896 5.0 4.0 4.1 1.3 4.4 1.6 0.3 1.7 0.0 0.0 14.6 3Acetylene 26.04 1,404 2.5 0.0 0.2 0.0 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0Ethylene 28.05 1,477 2.7 37.5 34.1 0.0 24.1 10.6 0.0 9.6 0.5 0.0 0.0 30Ethane 30.07 1,595 3.0 28.2 20.1 94.7 14.9 36.8 47.3 35.3 0.4 0.0 0.0 19Propylene 42.08 2,150 2.4 7.5 6.7 0.0 0.4 0.3 0.0 0.2 0.1 95.0 0.0 17Propane 44.10 2,281 2.1 0.1 0.1 3.5 0.1 0.3 1.1 0.4 0.0 5.0 0.0 01,3-Butadiene 54.09 2,690 2.0 0.3 0.3 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0Butanes 58.12 2,957 [3] 1.8 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0

Benzene 78.11 3,591 1.3 0.0 0.0 0.0 0.3 0.0 0.0 0.0 20.8 0.0 0.0 0Water 18.02 0 ∞ 1.0 12.0 0.5 29.4 40.0 0.0 42.9 0.0 0.0 0.0 10

Hydrogen Sulfide 34.08 595 [4] 4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0

Toluene 92.14 4,285 [4] 1.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 41.9 0.0 0.0 0Xylene 106.16 4,980 [4] 1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.0 0.0 0.0 0Ethylbenzene 106.17 4,894 [5] 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6.3 0.0 0.0 0Styrene 104.15 4,756 [5] 1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.8 0.0 0.0 0Higher HCs 120.19 [1] 5,869 [6] 0.9 [8] 0.0 0.0 0.0 0.0 0.0 0.0 0.0 21.2 0.0 0.0 0

1,269 1,082 1,602 733 800 783 761 4,520 2,157 365 1,2

3.1 3.5 3.0 4.6 5.2 6.1 5.4 1.1 2.4 4.1 3

Notes:1. Molecular weight for "Higher HCs" represented as C9H12 (cumene).

2. LHV was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule), when available.3. LHV for butanes represented as iso-butane from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule). 4. LHV was obtained from Gas Engineers Handbook , The Industrial Press, 1965.

5. LHV was obtained from Introduction to Chemical Engineering Thermodynamics (2nd ed.) , Smith, Van Ness, McGraw-Hill, New York, 1959.

6. LHV for "Higher HCs" represented as cumene. LHV for cumene was obtained from Perry's Chemical Engineers' Handbook (4th Ed.), Perry, Chilton, Kirkpatrick, McGraw-H

8. LFL for "Higher HCs" represented as C9H12 (cumene).

BOP MPGF Design Cases

7. LFL was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule), or U.S. Dept. of the Interior, Bureau of Mines, Flammability Characteristics of Combustible G

(Appendix A).

Mixture LHV (Btu/scf)

Mixture LFL (volume%)
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3-2 

Table 3-2. Mont Belvieu Plastics Plant (MBPP) MPGF Design Cases 

COMPONENT MW LHV [2] LFL [7] 1 2 3 4 5 6 7 8 

(lb/lb-mol) (Btu/scf) (volume% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (m

Hydrogen 2.02 274 4.0 2.4 0.8 0.0 1.1 0.0 3.9 0.0 2.1 Nitrogen 28.01 0 ∞ 9.1 6.3 4.8 5.1 3.1 12.8 5.8 7.0 

Methane 16.04 896 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Ehtylene 28.05 1,477 2.7 73.7 80.5 84.0 84.9 89.5 64.1 80.6 80.8 8Ethane 30.07 1,595 3.0 1.7 0.9 0.5 0.9 0.3 2.6 0.6 1.4 1-Butene 56.11 3,033 [3] 1.6 5.1 1.7 0.0 2.2 0.0 8.2 0.0 4.0 

Butanes 58.12 2,957 [4] 1.8 2.7 2.6 2.6 1.7 1.7 3.3 3.1 1.8 Pentanes 72.15 3,708 [5] 1.4 [8] 5.0 6.4 7.1 3.7 4.7 5.2 8.7 2.8 

Hexenes 84.16 4,206 [6] 1.2 [9] 0.2 0.6 0.8 0.3 0.6 0.0 1.0 0.0 Other C6s [1] 86.18 4,680 [10] 1.2 0.1 0.2 0.2 0.1 0.2 0.0 0.3 0.0 

1,553 1,606 1,634 1,545 1,580 1,536 1,668 1,502 1

2.7 2.6 2.6 2.7 2.6 2.8 2.6 2.7 

Notes:1. Molecular weight, LHV, and LFL for "Other C6s" represented as n-hexane.2. LHV was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule), when available.3. LHV obtained from Perry's Chemical Engineers' Handbook (4th Ed.), Perry, Chilton, Kirkpatrick, McGraw-Hill, New York, 1963.4. LHV for butanes represented as iso-butane.5. LHV for pentanes represented as iso-pentane, and was obtained from Gas Engineers Handbook , The Industrial Press, 1965.

6. LHV for hexenes represented as 1-hexene, and was obtained from Introduction to Chemical Engineering Thermodynamics (2nd ed.) , Smith, Van Ness, McGraw

8. LFL for pentanes represented as n-pentane.9. LFL for hexenes represented as n-hexane.10. LHV for n-hexane obtained from Perry's Chemical Engineers' Handbook (4th Ed.), Perry, Chilton, Kirkpatrick, McGraw-Hill, New York, 1963.

Mixture LHV (Btu/scf)

7. LFL was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule), or U.S. Dept. of the Interior, Bureau of Mines, Flammability Characteristics oBulletin 627, 1965 (Appendix A).

Mixture LFL (volume%)

MBPP MPGF Design Cases
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Attachment 4 

Publicly Available MPGF Emissions Test Data 
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4-1 

Table 4-1. Dow 2013 Test [1]

Test No. Component 

LHV LFL [2]

DRE ≥ 98% 

Ex

(Btu/scf) (vol %) 

P1H 3-Run Average Propylene 2,145 2.4 Yes 

P1L 3-Run Average Propylene 2,133 2.4 Yes 

Maximum DRE 99.99% 

Notes: [1] Data obtained from John Zink, Test Report, Flue Gas Emission Testing Support of A TCEQ Alternate Means of Control Application From A Pressure Assisted Process Flare And A Steam Assisted Process Flare, Prepared for John Zink Company

Dow Chemical Company Texas Operation, TRC Project No. 199009, November 2013 and John Zink, Test Protocol for The D

of Destruction Efficiency of Pressure-Assisted and Steam Assisted Flare Burners, July 30, 2013. [2] LFL was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule). 
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4-2 

Table 4-2. Marathon 2012 Test [1]

Test No. Component [2]

LHV LFL [3, 4]

DRE ≥ 98% [6]

Ex

(Btu/scf) (vol %) 

68 98.4% Natural Gas, 1.6% Nitrogen 909 4.5 Yes 74 98.8% Natural Gas, 1.2% Nitrogen 911 4.5 Yes 75 98.7% Natural Gas, 1.3% Nitrogen 910 4.5 Yes 65 98.4% Natural Gas, 1.6% Nitrogen 910 4.6 Yes 66 98.4% Natural Gas, 1.6% Nitrogen 911 4.6 Yes 67 98.4% Natural Gas, 1.6% Nitrogen 908 4.6 Yes 

6 98.3% Natural Gas, 1.7% Nitrogen 912 4.6 [5] Yes 

24 98.3% Natural Gas, 1.7% Nitrogen 912 4.6 [5] Yes 38 98.3% Natural Gas, 1.7% Nitrogen 912 4.6 [5] Yes 70 98.3% Natural Gas, 1.7% Nitrogen 912 4.6 [5] Yes 79 98.3% Natural Gas, 1.7% Nitrogen 912 4.6 [5] Yes 

Maximum DRE 100% 

Notes: [1] Data obtained from Clean Air Engineering, Performance Test of Steam-Assisted and Pressure Assisted Ground Flare BPassive FTIR - Garyville, March 21, 2013. [2] Natural gas mole percent for each test was calculated based on the nitrogen mole percent indicated in the test report. [3] LFL for natural gas was calculated per U.S. Dept. of the Interior, Bureau of Mines, Flammability Characteristics of CoGases and Vapors, Bulletin 627, 1965 (Equation 41 on page 26). A standard error of estimate of 0.53 was added to the cal

for conservatism, with a pressure assumption of 1 atm. [4] Mixture LFL was calculated per equation from 79 FR 36984 (Proposed Refinery Sector Rule). [5] Fuel pressure at burner was not indicated in the test report. A minimum pressure of 4 psig was assumed for conservatinatural gas LFL calculations. [6] Combustion Efficiency (CE) for each test was obtained from the test report, and 1.5% was added to the CE to calculate 

(Per USEPA Office of Air Quality Planning and Standards (OAQPS), Parameters for Properly Designed and Operated Fla

2012, a 1.5% difference between DRE and CE (DRE - 1.5% = CE) is a reasonable assumption.) [7] Velocity was likely at speed of sound instead of 3,000+ fps. 
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4-3 

Table 4-3. Dow 2006 Test [1]

Test No. Component [2]

LHV [3, 4] LFL [5]

DRE ≥ 98% 

E

(Btu/scf) (vol %) 

Test 1 R1 & R2 

Propylene with Nitrogen Leakage 

(56% C3H6, 44% N2) 1,201 4.3 Yes 

Test 1 R3 Propylene 2,150 2.4 Yes 

Test 1a Propylene 2,150 2.4 Yes 

Test 2 70% Propylene, 30% Nitrogen 1,496 3.4 Yes Test 3 Propylene 2,150 2.4 Yes Test 4 39% Propylene, 61% Nitrogen 828 6.2 Yes 

Maximum DRE 99.99% 

Notes: [1] Data obtained from John Zink, Report on Emissions Testing of Pressure Assisted Flare Burners (John Zink LRGO Typfor The Dow Chemical Company, Test Conducted - October 2006, March 2007, and John Zink, Test Protocol for The DeteDestruction Efficiency of Pressure-Assisted Flare Burners, Revised June 2006. [2] For tests with propylene and nitrogen mixture (including nitrogen contamination runs), mole percent of each componencalculated based on the heating values for propylene and the mixture obtained from the test report. [3] Mixture LHV for each test was calculated based on the mixture Gross Heating Value (GHV, or Higher Heating Value obtained from the test report, and application of a 1.07 GHV/LHV ratio for propylene. [4] LHV was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule). [5] LFL was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule), and the mixture LFL was calculated pfrom 79 FR 36984. 
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4-4 

Table 4-4. EPA/EER 1985 Test [1]

Test No. Component 

LHV LFL [2]

DRE ≥ 98% 

Exit V

(Btu/scf) (vol %) (

218 35.2% Propane, 64.8% Nitrogen 828 6.0 Yes 4221 36.6% Propane, 76.1% Nitrogen 870 5.7 Yes 

Maximum DRE 99.7% 

Notes: [1] Data obtained from Table 2-2 in USEPA Research and Development, Evaluation of The Efficiency of Industrial FlaHead Design and Gas Composition, EPA-600/2-85-106, September 1985. [2] LFL was obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule). Mixture LFL was calculated per efrom 79 FR 36984. 
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4-5 

Table 4-5. EPA/CMA 1982 Test [1]

Test No. Component 

LHV [2] LFL [2]

DRE ≥ 98% [3]

Exit Ve

(Btu/scf) (vol %) (f

1 through 59 Crude Propylene 2,150 2.4 Yes 9

Maximum DRE [5] 100% 

Notes: [1] Data obtained from February 17, 1984 John Zink letter to USEPA RTP, Test 81 Test Data Summary. [2] LHV and LFL were obtained from 79 FR 36993 Table 12 (Proposed Refinery Sector Rule). [3] Combustion Efficiency (CE) for each test was obtained from the test report, and 1.5% was added to the CE to calculat

(Per USEPA Office of Air Quality Planning and Standards (OAQPS), Parameters for Properly Designed and Operated Fl

2012, a 1.5% difference between DRE and CE (DRE - 1.5% = CE) is a reasonable assumption.) [4] Estimated based on fuel flowrate at burner and burner tip cross-sectional area. [5] All 59 tests achieved 100% DRE. 
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Attachment 5 

Flame Properties 
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5-1 

Plot 5-1. Demonstration that the flammability limits of ethylene are wider than propylene 

(Zabetakis M. G., “Flammability Characteristics of Combustible Gases and Vapors,” Bureau of Mines, Bulletin 627) 

Plot 5-2. Demonstration that ethylene has a higher flame speed than propylene across the 

stoichiometric combustion range. 

(Baukal, Charles E. "Appendix C, Table C.11." The John Zink - Hamworthy Combustion Handbook. 2nd ed. Vol. 1. Boca 

Raton, FL: CRC, 2012. 580.) 

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60

Fuel (Volume Percent)

Additional Nitrogen in Fuel (Volume Percent)

Ethylene

Propylene

Air % = 100 ‐ Fuel % ‐ Nitrogen %

0

10

20

30

40

50

60

70

80

0 0.5 1 1.5 2 2.5 3

Laminar Flame Speed (cm/s)

Stoichiometric Ratio (vol air / vol fuel / Stoichiometric Air Requirement)

Ethylene

Propylene
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5-2 

Plot 5-3. Demonstration that propylene has a representative flame speed for a range of 

chemicals