### 1 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 Ole fins Plant and Mont Belvieu Plastics Plant

Dear Ms. Lassiter:

ExxonMobil Chemical Company (ExxonMobil) is writin g to respectfully request the Environmental Protection Agency (“EPA”) provide an Alternative Means of Emission Limita tion (“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 (NES HAP), 40 C.F.R. § 63.11. As described below, providing the request ed AMEL for Pressure-Assisted Multi-Poin t Ground Flares (“MPGF”) will further a technology that will promote significant environmen tal benefits without undermining any of the goals or purposes of the applicable NSPS and NESHAP re gulations. 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) an d 40 C.F.R. § 63.11(b)(6),(7),(8).

ExxonMobil requests EPA provide the AMEL for MP GFs at two facilities – ExxonMobil’s Olefins Plant in Baytown, Texas (referred to as “Bayto wn 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 Sour ce Review (NSR) permit (NSR 102982) in February 2014 from the Texas Commission on Envi ronmental 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 Comp liance 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).ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 2 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 provi ded in Attachment 1. Based on a review of the MPGF design cases and comparison to publicly availa ble data, the MPGFs meet these requirements with the exception of maximum tip velocity. As required by the applicable AMEL st atutory and regulatory provisions, this AMEL application pr ovides 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 thos e required by flare performance specifications. We believe that maintaining a Lower Heating Value (LHV) greater than 800 Btu/scf or a Lower Fl ammability Limit (LFL) less than 6.5% achieves equivalency to the destruction effici encies 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 addre ss all available means of emission control and provided a mechanis m for regulated entities to request and EPA to

authorize “alternative mean s of emission limitation” under any give n 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 re ductions at least equivalent to those required by the appli cable standard. EPA has incorporated th ese authorities into its regulations. Attachment 1 identifies EPA’s statutory and re gulatory authority to approve ExxonMobil’s AMEL

request.

The BOP unit will consist of eight new cracking furn aces 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 syst em, 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 se paration 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 us e for more than 40 years around the world. The

modern and state of the art evolution of the technology provides advantag es from environmental, business and public perspectives. Although it is a more expensive design than traditional flares, MPGFs operate with greater emissions control, lower ener gy requirements, and less community impact. Greater emissions control translates into lower post-co mbustion emission rates for hydrocarbons. Smokeless operation over the entire operating range without any assist medium minimizes energy consumption and results in lower greenhouse gas ge neration. Less low frequency noise and less flame visibility in low profile designs like those at BOP and MBPP re duce the effect on the surrounding community.

Despite the different plant operati ons, the MPGFs at both BOP and MBPP are substantially similar in purpose, design, and operation. Both flares will be de signed as an integral pa rt 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 (L P) disposition. Simplified schematics depicting each system areExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 3 provided in Attachment 2. At MBPP, the LP dispositions are three Fl ameless Thermal Oxidizers and an elevated flare. At BOP, the LP disposition is an el evated 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 ga ses to the MPGF above a se t 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 ga s to entrain sufficient quantities of combustion air resulting in flare tip exit velocities that will exceed V MAX 

### 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 re gulatory provisions that are applicable to the MPGFs at BOP and MBPP, along with the statutory and re gulatory provisions that authorize EPA to review and implement AMELs. The list of potentially applicable regulations is intentionally broad reflecting the overlap between regula tions and the complexity of plant designs. As described in Table 1 below, the MPGFs require an approved altern ative 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 su pporting performance test data to demonstrate that MPGFs achieve equivalent emission reductions even when operati ng 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.ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 4 Table 1 NSPS and NESHAP Flare Specifications Flare specifications in 40 C.F.R. §63.11 2 

### 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.ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 5 AMEL Technical Justification

The MPGFs will control emissions during high pressu re / 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 ex perts 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 ro uted 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 heati ng 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 th e 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 im pact pressure-assisted burners by preventing them from entraining an adequate amount of air for mixing and proper co mbustion, 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 a ll 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. R outine and turnaround-level equipment maintenance activities (e.g., equipment clearing) were also identified. The cases al so represent malfunction scenarios such as partial and complete utility loss (e.g., cooli ng water or electric power). Emi ssions from unplanned events that cannot be recovered or routed to the LP dispositi on are also included. Exampl es include safety valve releases or other equipment malfunctions.

A review of operating cases identified key paramete rs for design of the flare including the maximum flowrate case, the case with the hi ghest propensity to smoke, and th e cases that determine the proper burner spacing.

A total of 14 design cases at BOP and 12 design cas es at MBPP are represented in Attachment 3. Values and methodology for estimating LHV and LFL u tilized 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 fr om 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 acco rding to State of Texas regulations in 30 T.A.C. § 115 Subchapter H Division 1 (Highly-Reactive Volati le Organic Compounds – Vent Gas Control) andExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 6 Permit Special Conditions (NSR Permit 102982 issued February 19, 2014 for BOP and NSR Permit 103048 issued October 7, 2013 for MBPP). Th ese provisions can be summarized as:

 Flow monitoring

o Annual calibrations

o Temperature and pressure monitors used fo r 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 accordi ng 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 demonstrat e 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 estimat e hourly average values for LHV and LFL. Decreasing the averaging period likely results in additional monitoring facilities an d/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 publ icly available test reports, a review has been conducted of high MPGF tip velocity test runs (great er than 400 fps) that are either greater than 800 Btu/scf (LHV) or less than 6.5% LFL. Each of the analyzed test runs achie ved at least 98% DRE. Summary tables of test runs that meet the LHV or LFL criteria are incl uded in Attachment 4.

Table 2 MPGF Emissions Test Summary (1)

Test LHV LFL

DRE ≥ 98% (Btu/scf) (vol %)

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% LFLExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 7 Available emissions data includes bu rner 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 stoichio metric 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 BO P and MBPP are characterized by a spider-type design with multiple distinct burning poi nts. 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) greate r than 800 Btu/scf or a Lower Flammability Limit (LFL) less than 6.5% achieve s 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 le ss than 6.5% will achieve equivale nt emission reductions to those required by flare performance sp ecifications of 40 C.F.R. § 60.18 a nd/or 40 C.F.R. § 63.11(b) (as applicable). We respectfully request that EPA pr ovide for the AMEL through the following or similar language:

The multi-point ground flares shall be desi gned and operated such that the combined supplemental gas and waste stream to each fl are 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 va lue or NHV) or an hourly average lower flammability limit (LFL) less than 6.5%. Mo nitoring 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 (Highl y-Reactive Volatile Organic Compounds – Vent Gas Cont rol). Calculations of LFL vg 

### shall utilize the equation below from 79 FR 36984. Calculations of NHV vg 

### shall utilize the equation below from 79

FR 36983.ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 8ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



# Attachment 1

NSPS and NESHAP Applicability TablesExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 1-1 Table 1-1. NSPS and NESHAP Potentially Applicable to the Baytown Olefin Plant (BOP ) Ethylene Production Unit

Potentially Applicable NSPS and NE SHAP Requirements for the BOP MPGF and Implementing AMEL Provisions

NSPS Part AMEL Implementing Provision 3

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 Provision 4

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 estab lishes 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 opera tor of any source establishe s 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 th e source for purposes of compli ance with this section with respect to such pollutant.” 42 U.S.C. §7412(h)(3).ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 1-2 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 Provision 5

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 Provision 6

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 estab lishes 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 opera tor of any source establishe s 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 th e source for purposes of compli ance with this section with respect to such pollutant.” 42 U.S.C. §7412(h)(3).ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



# Attachment 2

Simplified Schematics of Control SystemsExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request2-1ExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request2-2ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



# Attachment 3

BOP & MBPP MPGF Design CasesExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request3-1Table 3-1. Baytown Olefins Plant (BOP) MPGF Design CasesCOMPONENT MWLHV[2]LFL[7]1 2 3 4 5 6 7 8 9 10 11 12 13 14(lb/lb-mol) (Btu/scf) (volume% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% )Nitrogen 28.01 0∞0.0 0.0 0.0 0.0 0.0 51.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.7Hydrogen 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 18.7 0.0 0.0 0.0Methane 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 3.4 0.0 89.3 89.3Acetylene 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 0.2 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 30.4 0.0 0.0 0.0Ethane 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 19.1 57.4 0.0 0.0Propylene 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 17.5 0.0 0.0 0.0Propane 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 0.1 0.0 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 0.2 0.0 0.0 0.0Butanes 58.122,957[3]1.8 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Benzene 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 0.2 0.0 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 10.2 42.6 10.7 0.0Hydrogen Sulfide 34.08595[4]4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Toluene 92.144,285[4]1.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 41.9 0.0 0.0 0.0 0.0 0.0 0.0Xylene 106.164,980[4]1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0Ethylbenzene 106.174,894[5]1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6.3 0.0 0.0 0.0 0.0 0.0 0.0Styrene 104.154,756[5]1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.8 0.0 0.0 0.0 0.0 0.0 0.0Higher HCs120.19[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 0.0 0.0 0.0 0.01,269 1,082 1,602 733 800 783 761 4,520 2,157 365 1,230 916 800 8003.1 3.5 3.0 4.6 5.2 6.1 5.4 1.1 2.4 4.1 3.3 5.2 5.6 5.6Notes: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 fromGas Engineers Handbook, The Industrial Press, 1965.5. LHV was obtained fromIntroduction 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 fromPerry's Chemical Engineers' Handbook (4th Ed.), Perry, Chilton, Kirkpatrick, McGraw-Hill, New York, 1963.8. LFL for "Higher HCs" represented as C9H12(cumene).BOP MPGF Design Cases7. 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 Gases and Vapors, Bulletin 627, 1965(Appendix A).Mixture LHV (Btu/scf)Mixture LFL (volume%)ExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request3-2Table 3-2. Mont Belvieu PlasticsPlant (MBPP) MPGF Design CasesCOMPONENT MWLHV[2]LFL[7]1 2 3 4 5 6 7 8 9 10 11 12(lb/lb-mol) (Btu/scf) (volume% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% ) (mol% )Hydrogen 2.02 274 4.0 2.4 0.8 0.0 1.1 0.0 3.9 0.0 2.1 0.0 6.7 0.0 2.7Nitrogen 28.01 0∞9.1 6.3 4.8 5.1 3.1 12.8 5.8 7.0 3.1 22.3 10.3 61.6Methane 16.04 896 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Ehtylene 28.05 1,477 2.7 73.7 80.5 84.0 84.9 89.5 64.1 80.6 80.8 89.5 37.5 65.5 23.8Ethane 30.07 1,595 3.0 1.7 0.9 0.5 0.9 0.3 2.6 0.6 1.4 0.3 4.5 1.0 0.21-Butene 56.113,033[3]1.6 5.1 1.7 0.0 2.2 0.0 8.2 0.0 4.0 0.0 14.2 0.0 0.0Butanes 58.122,957[4]1.8 2.7 2.6 2.6 1.7 1.7 3.3 3.1 1.8 1.7 5.8 5.5 2.0Pentanes 72.153,708[5]1.4[8]5.0 6.4 7.1 3.7 4.7 5.2 8.7 2.8 4.7 9.0 15.4 7.6Hexenes 84.164,206[6]1.2[9]0.2 0.6 0.8 0.3 0.6 0.0 1.0 0.0 0.6 0.0 1.8 1.2Other C6s[1]86.184,680[10]1.2 0.1 0.2 0.2 0.1 0.2 0.0 0.3 0.0 0.2 0.0 0.5 0.91,553 1,606 1,634 1,545 1,580 1,536 1,668 1,502 1,580 1,580 1,817 7962.7 2.6 2.6 2.7 2.6 2.8 2.6 2.7 2.6 2.8 2.5 5.6Notes: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 fromPerry'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 fromGas Engineers Handbook, The Industrial Press, 1965.6. LHV for hexenes represented as 1-hexene, and was obtained fromIntroduction to Chemical Engineering Thermodynamics (2nd ed.), Smith, Van Ness, McGraw-Hill, New York,1959.8. LFL for pentanes represented as n-pentane.9. LFL for hexenes represented as n-hexane.10. LHV for n-hexane obtained fromPerry'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 of Combustible Gases and Vapors,Bulletin 627, 1965 (Appendix A).Mixture LFL (volume%)MBPP MPGF Design CasesExxonMobil Chemical Company Alternative Means of Emission Limitation Request



# Attachment 4

Publicly Available MPGF Emissions Test DataExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request4-1Table 4-1. Dow 2013 Test[1]Test No. ComponentLHV LFL[2]DRE≥98%Exit Velocity(Btu/scf) (vol %) (fps)P1H 3-Run Average Propylene 2,145 2.4 Yes 880P1L 3-Run Average Propylene 2,133 2.4 Yes 597Maximum DRE 99.99%Notes:[1] Data obtained from John Zink,Test Report, Flue Gas Emission Testing Support of A TCEQ Alternate Means of Control (AMOC)Application From A Pressure Assisted Process Flare And A Steam Assisted Process Flare, Preparedfor John Zink Company, LLC, AndTheDow Chemical Company Texas Operation, TRC Project No. 199009, November 2013 and John Zink,Test Protocol for The Determinationof 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).ExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request4-2Table 4-2. Marathon 2012 Test[1]Test No. Component[2]LHV LFL[3, 4]DRE≥98%[6]Exit Velocity(Btu/scf) (vol %) (fps)68 98.4% Natural Gas, 1.6% Nitrogen 909 4.5 Yes 1,37774 98.8% Natural Gas, 1.2% Nitrogen 911 4.5 Yes 1,34975 98.7% Natural Gas, 1.3% Nitrogen 910 4.5 Yes 1,36065 98.4% Natural Gas, 1.6% Nitrogen 910 4.6 Yes 77766 98.4% Natural Gas, 1.6% Nitrogen 911 4.6 Yes 77667 98.4% Natural Gas, 1.6% Nitrogen 908 4.6 Yes 7776 98.3% Natural Gas, 1.7% Nitrogen 912 4.6[5]Yes 3,531[7]24 98.3% Natural Gas, 1.7% Nitrogen 912 4.6[5]Yes 3,543[7]38 98.3% Natural Gas, 1.7% Nitrogen 912 4.6[5]Yes 3,520[7]70 98.3% Natural Gas, 1.7% Nitrogen 912 4.6[5]Yes 3,559[7]79 98.3% Natural Gas, 1.7% Nitrogen 912 4.6[5]Yes 3,483[7]Maximum DRE 100%Notes:[1] Data obtained from Clean Air Engineering,Performance Test of Steam-Assisted and Pressure Assisted Ground Flare Burners withPassive 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 CombustibleGases and Vapors, Bulletin 627, 1965 (Equation 41 on page 26). A standarderror of estimate of 0.53 was added to the calculated valuefor 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 conservatism in thenatural gas LFL calculations.[6] Combustion Efficiency (CE) for each testwas obtained from the test report, and 1.5% was added to the CE to calculate theDRE.(Per USEPA Office of Air QualityPlanning and Standards (OAQPS),Parameters for Properly Designed and Operated Flare, April2012, 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.ExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request4-3Table 4-3. Dow 2006 Test[1]Test No. Component[2]LHV[3, 4]LFL[5]DRE≥98%Exit Velocity(Btu/scf) (vol %) (fps)Test 1 R1 & R2Propylene with Nitrogen Leakage(56% C3H6, 44% N2) 1,201 4.3 Yes 819Test 1 R3 Propylene 2,150 2.4 Yes 810Test 1a Propylene 2,150 2.4 Yes 827Test 2 70% Propylene, 30% Nitrogen 1,496 3.4 Yes 880Test 3 Propylene 2,150 2.4 Yes 797Test 4 39% Propylene, 61% Nitrogen 828 6.2 Yes 912Maximum DRE 99.99%Notes:[1] Data obtained from John Zink,Report on Emissions Testing of Pressure Assisted Flare Burners (John Zink LRGO Type), Preparedfor The Dow Chemical Company, Test Conducted - October 2006, March 2007, and John Zink,Test Protocol for The Determination ofDestruction 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 component wasbackcalculated 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, orHigher Heating Value (HHV))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 per equationfrom 79 FR 36984.ExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request4-4Table 4-4. EPA/EER 1985 Test[1]Test No. ComponentLHV LFL[2]DRE≥98%Exit Velocity(Btu/scf) (vol %) (fps)218 35.2% Propane, 64.8% Nitrogen 828 6.0 Yes 470221 36.6% Propane, 76.1% Nitrogen 870 5.7 Yes 907Maximum DRE 99.7%Notes:[1] Data obtained from Table 2-2 in USEPA Research and Development,Evaluation of The Efficiency of Industrial Flares: FlareHead 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 equationfrom 79 FR 36984.ExxonMobil Chemical CompanyAlternative Means of Emission Limitation Request4-5Table 4-5. EPA/CMA 1982 Test[1]Test No. ComponentLHV[2]LFL[2]DRE≥98%[3]Exit Velocity[4](Btu/scf) (vol %) (fps)1 through 59 Crude Propylene 2,150 2.4 Yes 903Maximum 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 testwas obtained from the test report, and 1.5% was added to the CE to calculate theDRE.(Per USEPA Office of Air QualityPlanning and Standards (OAQPS),Parameters for Properly Designed and Operated Flare, April2012, a 1.5% difference between DRE and CE (DRE - 1.5% = CE) is a reasonable assumption.)[4] Estimated based on fuel flowrate atburner and burner tip cross-sectional area.[5] All 59 tests achieved 100% DRE.ExxonMobil Chemical Company Alternative Means of Emission Limitation Request



# Attachment 5

Flame PropertiesExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 5-1 Plot 5-1. Demonstration that the flammability limits of ethylene ar e wider than propylene

( Zabetakis M. G., “Flammability Characteristics of Comb ustible Gases and Vapors,” Bu reau 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 Zi nk - 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 60Fuel(VolumePercent)

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 3LaminarFlameSpeed(cm/s)

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

PropyleneExxonMobil Chemical Company Alternative Means of Emission Limitation Request



### 5-2 Plot 5-3. Demonstration that propylene has a representative flame speed for a range of

chemicals