Receipt of Approval Requests for the Operation of Pressure-Assisted Multi-Point Ground Flare Technology, 8023-8030 [2015-03064]
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Federal Register / Vol. 80, No. 30 / Friday, February 13, 2015 / Proposed Rules
TABLE 5—PM2.5 DESIGN VALUES—Continued
Year
2008–2010
North Birmingham ............................................................................................
2009–2011
29
2010–2012
27
2011–2013
26
24
1997 Annual PM2.5 NAAQS: 15 μg/m3.
2006 24-hour PM2.5 NAAQS: 35 μg/m3.
Given the current PM2.5
concentrations and downward trend of
these concentrations in the Area and the
results of Alabama’s mobile source
modeling, EPA has preliminarily
determined that a change to 9.0 psi RVP
fuel in the Birmingham Area would not
interfere with maintenance of the 1997
Annual PM2.5 NAAQS or the 2006 24hour PM2.5 NAAQS in the Area.11
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d. Noninterference Analysis for the 2010
NO2 NAAQS
On February 17, 2012, EPA
designated all counties in Alabama as
unclassifiable/attainment for the 2010
NO2 NAAQS. See 77 FR 9532. Based on
the technical analysis in Alabama’s
November 14, 2014, SIP revision, the
potential increase in NOX emissions
associated with the change to 9.0 psi
RVP fuel in the Birmingham Area is
approximately 24 tons during high
ozone season. As discussed in section
V.a, above, the slight projected increase
in mobile source NOX emissions due to
the fuel switch will be negated by a
decrease in tailpipe emissions due to
fleet turnover. Given the current
unclassifiable/attainment designation
and the results of Alabama’s mobile
source modeling, EPA has preliminarily
determined that a change to 9.0 psi RVP
fuel in the Birmingham Area would not
interfere with maintenance of the 2010
NO2 NAAQS in the Area.
VI. Proposed Action
EPA is proposing to approve the State
of Alabama’s noninterference
demonstration, submitted on November
14, 2014, in support of the State’s
request that EPA change the Federal
RVP requirements for the Birmingham
Area from 7.8 psi to 9.0 psi.
Specifically, EPA is proposing to find
that this change in the RVP
requirements for the Birmingham Area
will not interfere with attainment or
maintenance of any NAAQS or with any
other applicable requirement of the
CAA.
11 EPA has also preliminarily determined that a
change to 9.0 psi RVP fuel in the Birmingham Area
would not interfere with maintenance of the
Annual PM10 NAAQS of 150 mg/m3 given the
results of Alabama’s mobile source modeling and
the fact that the Area is currently attaining the PM10
standard. Because PM2.5 is a component of PM10,
this preliminary determination is further supported
by the downward trend in PM2.5 identified above.
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EPA has preliminarily determined
that Alabama’s November 14, 2014, SIP
revision, containing the noninterference
demonstration associated with the
State’s request for the change of the
Federal RVP requirements is consistent
with the applicable provisions of the
CAA. EPA is not proposing action today
to remove the Birmingham Area from
the Federal 7.8 psi RVP requirement.
Any such proposal will occur in a
separate and subsequent rulemaking.
VII. Statutory and Executive Order
Reviews
Under the CAA, the Administrator is
required to approve a SIP submittal that
complies with the provisions of the Act
and applicable federal regulations. 42
U.S.C. 7410(k); 40 CFR 52.02(a). Thus,
in reviewing SIP submissions, EPA’s
role is to approve state choices,
provided that they meet the criteria of
the CAA. Accordingly, this proposed
action merely proposes to approve state
law as meeting Federal requirements
and does not propose to impose
additional requirements beyond those
imposed by state law. For that reason,
this proposed action:
• Is not a significant regulatory action
subject to review by the Office of
Management and Budget under
Executive Orders 12866 (58 FR 51735,
October 4, 1993) and 13563 (76 FR 3821,
January 21, 2011);
• does not impose an information
collection burden under the provisions
of the Paperwork Reduction Act (44
U.S.C. 3501 et seq.);
• is certified as not having a
significant economic impact on a
substantial number of small entities
under the Regulatory Flexibility Act (5
U.S.C. 601 et seq.);
• does not contain any unfunded
mandate or significantly or uniquely
affect small governments, as described
in the Unfunded Mandates Reform Act
of 1995 (Pub. L. 104–4);
• does not have Federalism
implications as specified in Executive
Order 13132 (64 FR 43255, October 7,
1999);
• is not an economically significant
regulatory action based on health or
safety risks subject to Executive Order
13045 (62 FR 19885, April 23, 1997);
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• is not a significant regulatory action
subject to Executive Order 13211 (66 FR
28355, May 22, 2001);
• is not subject to requirements of
Section 12(d) of the National
Technology Transfer and Advancement
Act of 1995 (15 U.S.C. 272 note) because
application of those requirements would
be inconsistent with the CAA; and
• does not provide EPA with the
discretionary authority to address, as
appropriate, disproportionate human
health or environmental effects, using
practicable and legally permissible
methods, under Executive Order 12898
(59 FR 7629, February 16, 1994).
In addition, the SIP is not approved
to apply on any Indian reservation land
or in any other area where EPA or an
Indian tribe has demonstrated that a
tribe has jurisdiction. In those areas of
Indian country, the rule does not have
tribal implications as specified by
Executive Order 13175 (65 FR 67249,
November 9, 2000) nor will it impose
substantial direct costs on tribal
governments or preempt tribal law.
List of Subjects in 40 CFR Part 52
Environmental protection, Air
pollution control, Incorporation by
reference, Intergovernmental relations,
Nitrogen dioxide, Ozone, Particulate
matter, Reporting and recordkeeping
requirements and Volatile organic
compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: February 4, 2015.
V. Anne Heard,
Acting Regional Administrator, Region 4.
[FR Doc. 2015–02942 Filed 2–12–15; 8:45 am]
BILLING CODE 6560–50–P
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Parts 60, 61, and 63
[EPA–HQ–OAR–2014–0738; FRL 9922–91–
OAR]
Receipt of Approval Requests for the
Operation of Pressure-Assisted MultiPoint Ground Flare Technology
Environmental Protection
Agency.
ACTION: Request for comments.
AGENCY:
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Federal Register / Vol. 80, No. 30 / Friday, February 13, 2015 / Proposed Rules
On August 5, 2014, The Dow
Chemical Company (Dow) requested an
Alternative Means of Emission
Limitation (AMEL) under the Clean Air
Act (CAA) in order to operate pressureassisted multi-point ground flares at its
Propane Dehydrogenation Plant and its
Light Hydrocarbons Plant at its Texas
Operations site located in Freeport,
Texas. On October 21, 2014,
ExxonMobil Chemical Company
(ExxonMobil) requested an AMEL under
the CAA for its pressure-assisted multipoint ground flares at its’ Olefins Plant
in Baytown, Texas, and its’ Plastics
Plant in Mont Belvieu, Texas. In this
document, the Environmental
Protection Agency (EPA) is soliciting
comment on all aspects of the AMEL
requests and the resulting alternative
operating conditions that are necessary
to achieve a reduction in emissions of
volatile organic compounds (VOC) and
hazardous air pollutants (HAPs) at least
equivalent to the reduction in emissions
required by various standards in 40 CFR
parts 60, 61 and 63 that apply to
emission sources controlled by these
pressure-assisted multi-point ground
flares. These standards point to the
operating requirements for flares in the
General Provisions to parts 60 and 63,
respectively, to comply with the
emission reduction requirements.
Because pressure-assisted multi-point
ground flares cannot meet the velocity
requirements in these General
Provisions, Dow and ExxonMobil are
seeking an AMEL.
SUMMARY:
Comments. Written comments
must be received on or before March 30,
2015.
Public Hearing. If requested by
February 18, 2015, we will hold a public
hearing on March 2, 2015, from 1:00
p.m. [Eastern Standard Time] to 5:00
p.m. [Eastern Standard Time] at EPA’s
Campus located in Research Triangle
Park, NC. We will provide details on the
public hearing on our Web site at:
https://www.epa.gov/ttn/atw/
groundflares/groundflarespg.html. To be
clear, a public hearing will not be held
unless someone specifically requests
that the EPA hold a public hearing
regarding these requests. Please contact
Ms. Virginia Hunt of the Sector Policies
and Programs Division (E143–01), Office
of Air Quality Planning and Standards,
Environmental Protection Agency,
Research Triangle Park, NC 27711;
telephone number: (919) 541–0832;
email address: hunt.virginia@epa.gov; to
request a public hearing, to register to
speak at the public hearing or to inquire
as to whether or not a public hearing
will be held. The last day to pre-register
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DATES:
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in advance to speak at the public
hearing will be February 25, 2015.
ADDRESSES: Submit your comments,
identified by Docket ID No. EPA OAR–
2014–0738, by one of the following
methods:
• https://www.regulations.gov. Follow
the on-line instructions for submitting
comments.
• Email: a-and-r-docket@epa.gov.
Attention Docket ID Number EPA–HQ–
OAR–2014–0738.
• Fax: (202) 566–9744. Attention
Docket ID Number EPA–HQ–OAR–
2014–0738.
• Mail: U.S. Postal Service, send
comments to: EPA Docket Center (EPA/
DC), Attention Docket ID Number EPA–
HQ–OAR–2014–0738, U.S.
Environmental Protection Agency,
Mailcode: 28221T, 1200 Pennsylvania
Ave. NW., Washington, DC 20460.
• Hand Delivery: U.S. Environmental
Protection Agency, EPA WJC West
Building, Room 3334, 1301 Constitution
Ave. NW., Washington, DC 20004.
Attention Docket ID Number EPA–HQ–
OAR–2014–0738. Such deliveries are
only accepted during the Docket’s
normal hours of operation, and special
arrangements should be made for
deliveries of boxed information.
Instructions. Direct your comments to
Docket ID Number EPA–HQ–OAR–
2014–0738. The EPA’s policy is that all
comments received will be included in
the public docket without change and
may be made available online at
https://www.regulations.gov, including
any personal information provided,
unless the comment includes
information claimed to be confidential
business information (CBI) or other
information whose disclosure is
restricted by statute. Do not submit
information that you consider to be CBI
or otherwise protected through https://
www.regulations.gov or email. The
https://www.regulations.gov Web site is
an ‘‘anonymous access’’ system, which
means the EPA will not know your
identity or contact information unless
you provide it in the body of your
comment. If you send an email
comment directly to the EPA without
going through https://
www.regulations.gov, your email
address will be automatically captured
and included as part of the comment
that is placed in the public docket and
made available on the Internet. If you
submit an electronic comment, the EPA
recommends that you include your
name and other contact information in
the body of your comment and with any
disk or CD–ROM you submit. If the EPA
cannot read your comment due to
technical difficulties and cannot contact
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you for clarification, the EPA may not
be able to consider your comment.
Electronic files should not include
special characters or any form of
encryption and be free of any defects or
viruses. For additional information
about the EPA’s public docket, visit the
EPA Docket Center homepage at:
https://www.epa.gov/dockets.
Docket. The EPA has established a
docket for this rulemaking under Docket
ID Number EPA–HQ–OAR–2014–0738.
All documents in the docket are listed
in the regulations.gov index. Although
listed in the index, some information is
not publicly available, e.g., CBI or other
information whose disclosure is
restricted by statute. Certain other
material, such as copyrighted material,
is not placed on the Internet and will be
publicly available only in hard copy.
Publicly available docket materials are
available either electronically in
regulations.gov or in hard copy at the
EPA Docket Center (EPA/DC), EPA WJC
West Building, Room 3334, 1301
Constitution Ave. NW., Washington,
DC. The Public Reading Room is open
from 8:30 a.m. to 4:30 p.m., Monday
through Friday, excluding legal
holidays. The telephone number for the
Public Reading Room is (202) 566–1744,
and the telephone number for the EPA
Docket Center is (202) 566–1742.
FOR FURTHER INFORMATION CONTACT: For
questions about this proposed action,
contact Ms. Brenda Shine, Sector
Policies and Programs Division (E143–
01), Office of Air Quality Planning and
Standards (OAQPS), U.S.
Environmental Protection Agency,
Research Triangle Park, North Carolina
27711; telephone number: (919) 541–
3608; fax number: (919) 541–0246; and
email address: shine.brenda@epa.gov.
SUPPLEMENTARY INFORMATION:
Acronyms and Abbreviations
We use multiple acronyms and terms
in this document. While this list may
not be exhaustive, to ease the reading of
this document and for reference
purposes, the EPA defines the following
terms and acronyms here:
AMEL alternative means of emission
limitation
BOP Baytown Olefins Plant
Btu/scf British thermal units per standard
cubic feet
LFL lower flammability limit
LFLcz combustion zone lower flammability
limit
LHC Light Hydrocarbons Unit
LRGO Linear relief gas oxidizer
MACT maximum achievable control
technology
MBPP Mont Belvieu Plastics Plant
MPGF multi-point ground flare
NESHAP national emission standard for
hazardous air pollutants
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Federal Register / Vol. 80, No. 30 / Friday, February 13, 2015 / Proposed Rules
NHV net heating value
NHVcz combustion zone net heating value
NSPS new source performance standards
OAQPS Office of Air Quality Planning and
Standards
PDH Propylene Dehydrogenation Unit
PFTIR passive fourier transform infrared
SKEC steam-assisted kinetic energy
combustor
B. Alternative Means of Emission
Limitation
II. Requests for Alternative Means of
Emission Limitation
A. Dow AMEL
B. ExxonMobil AMEL
C. EPA’s Analysis of MPGF Burner
Emission Tests
III. AMEL for Pressure-Assisted MPGF
IV. Request for Comments
Organization of This Document. The
information in this document is
organized as follows:
I. Statutory and Regulatory Background
8025
requirements in 40 CFR parts 60, 61 and
63 that will apply to the different vent
gas streams that will be collected and
routed to their pressure-assisted multipoint ground flares (MPGF) at each
plant. These requirements are included
in Table 1.1 In all cases, these rules
reference the flare operating
requirements located in 40 CFR 60.18
and 40 CFR 63.11.
A. Flare Operating Requirements
In their requests, Dow and
ExxonMobil cite various regulatory
I. Statutory and Regulatory Background
A. Flare Operating Requirements
TABLE 1—SUMMARY OF APPLICABLE RULES THAT MAY APPLY TO VENTS STREAMS CONTROLLED BY PRESSURE-ASSISTED
MULTI-POINT GROUND FLARES
Dow propane
dehydrogenation
(PDH) plant
Dow light
hydro-carbons
(LHC) plant
Exxon-Mobil
Baytown Olefins
plant
Exxon-Mobil Mont
Belvieu plastics
plant
Emission reduction
required and
rule citation
Provisions for
alternative means
of emission
limitation
NSPS Subpart Kb.
..............................
X
X
..............................
X
X
X
..............................
NSPS Subpart DDD.
..............................
..............................
..............................
X
NSPS Subpart NNN.
X
X
X
X
NSPS Subpart RRR.
X
X
X
X
60.112b(a)(3)(ii)—Reduce VOC inlet emissions by 95%; If a
flare is used as a
control device, flare
must meet requirements of 60.18.
60.482–10a—Reduce
VOC emissions by
95% or greater; flare
used to comply with
subpart must meet
requirements of
60.18.
*Note—Under Dow
PDH Plant column,
NSPS subpart VVa
applies, but DOW is
opting to comply with
40 CFR part 63, subpart H (as referenced
by Miscellaneous Organic
NESHAP(MON)
which should satisfy
requirements in subpart VVa.
60.562–1—Reduce
emissions of Total
Organic Carbon
(TOC) by 98%, or
combust in a flare
that meets the requirements of 60.18.
60.662- Reduce emissions of TOC by
98%, or combust in a
flare that meets the
requirements of
60.18.
60.702—Reduce emissions of TOC by
98%, or combust in a
flare that meets the
requirements of
60.18.
60.114b allows for
AMEL.
NSPS Subparts VV/
Vva.
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Applicable
rules with
vent streams
going to
control
device
1 EPA prepared Table 1 using the information
provided in the requests, corrected as appropriate
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based on its own review of the regulations.
However, the EPA has not independently verified
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60.484(a) allows
for AMEL
CAA section
111(h)(3) allows
for AMEL.
CAA section
111(h)(3) allows
for AMEL.
CAA section
111(h)(3) allows
for AMEL.
whether Table 1 includes all of the regulatory
requirements with which these plants must comply.
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Federal Register / Vol. 80, No. 30 / Friday, February 13, 2015 / Proposed Rules
TABLE 1—SUMMARY OF APPLICABLE RULES THAT MAY APPLY TO VENTS STREAMS CONTROLLED BY PRESSURE-ASSISTED
MULTI-POINT GROUND FLARES—Continued
Dow propane
dehydrogenation
(PDH) plant
Dow light hydrocarbons (LHC)
plant
Exxon-Mobil
Baytown Olefins
plant
Exxon-Mobil Mont
Belvieu plastics
plant
Emission reduction
required and
rule citation
Provisions for
alternative means
of emission
limitation
NESHAP
Subpart V.
..............................
..............................
X
..............................
..............................
X
X
..............................
NESHAP
Subparts
F, G.
..............................
..............................
X
..............................
NESHAP
Subpart H.
X
..............................
X
..............................
NESHAP
Subpart
SS.
X
X
X
X
NESHAP
Subpart
UU.
..............................
X
..............................
..............................
NESHAP
Subpart
XX.
..............................
X
..............................
..............................
NESHAP
Subpart
YY.
..............................
X
X
..............................
NESHAP
Subpart
EEEE.
..............................
..............................
X
X
61.242–11(d)—flares
used to comply with
subpart V must comply with 60.18.
61.349(a)—reduce organic emissions vented to control device
by 95%; a flare shall
comply with the requirements of 60.18.
63.102, 63.113,
63.126—Reduce
emissions of Total
Organic HAP
(TOHAP) by 98%, or
combust in a flare
that meets the requirements of
63.11(b).
63.120—Combust in
flare meeting 63.11.
63.139—Reduce
emissions of TOHAP
by 95%, or combust
in a flare that meets
the requirements of
63.11(b). 63.145(j)—
Points to sections of
63.11(b) for flare control.
63.172—Reduce organic HAP or VOC
by 95%; flares used
to comply must meet
requirements of
63.11(b).
63.982(b) and
63.987(a) require that
a flare meets the requirements in
63.11(b).
63.1034—Nonflare control devices shall reduce emissions by
95%; flares shall
comply with subpart
SS.
63.1091 requires compliance with subpart
FF, which requires
compliance with
60.18.
Table 7 references subpart SS, which requires compliance
with 60.18.
63.2378(a) references
subpart SS, which requires compliance
with 60.18.
61.244 allows for
AMEL; also see
61.12(d).
NESHAP
Subpart
FF.
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Applicable
rules with
vent streams
going to
control
device
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61.353 allows for
AMEL; also see
61.12(d).
63.102(b) allows
for AMEL.
63.177 allows for
AMEL.
CAA section
112(h)(3) allows
for AMEL.
63.1021 allows for
AMEL.
61.353 allows for
AMEL; also see
61.12(d).
63.1113 allows for
AMEL.
63.2346(g) allows
for AMEL; also
see Table 12
which makes
63.6(g) applicable to this subpart.
Federal Register / Vol. 80, No. 30 / Friday, February 13, 2015 / Proposed Rules
8027
TABLE 1—SUMMARY OF APPLICABLE RULES THAT MAY APPLY TO VENTS STREAMS CONTROLLED BY PRESSURE-ASSISTED
MULTI-POINT GROUND FLARES—Continued
Applicable
rules with
vent streams
going to
control
device
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NESHAP
Subpart
FFFF.
Dow propane
dehydrogenation
(PDH) plant
Dow light hydrocarbons (LHC)
plant
Exxon-Mobil
Baytown Olefins
plant
Exxon-Mobil Mont
Belvieu plastics
plant
Emission reduction
required and
rule citation
Provisions for
alternative means
of emission
limitation
X
..............................
..............................
X
63.2450 requires compliance with limits in
Tables 1–7, which include reducing total
organic HAP in vent
streams by either
95% or 98%, and
provide an option for
control using a flare
meeting requirements
of 63.982(b) which
requires meeting
63.987, which requires a flare to meet
the requirements of
63.11(b).
63.2540 and Table
12 allow for
AMEL by making 63.6(g) applicable to this
subpart.
As shown in Table 1, the applicable
rules require that control devices
achieve destruction efficiencies of either
95 percent or 98 percent either directly,
or by reference, or allow control by
flares meeting the flare operating
requirements in 40 CFR 60.18 or 63.11.
The flare operating requirements in 40
CFR 60.18 and 63.11 specify that flares
shall be: (1) Steam-assisted air-assisted,
or non-assisted; 2 (2) operated at all
times when emissions may be vented to
them; (3) designed for and operated
with no visible emissions (except for
periods not to exceed a total of 5
minutes during any 2 consecutive
hours); and (4) operated with the
presence of a pilot flame at all times.
The flare operating requirements in 40
CFR 60.18 and 63.11 also specify
requirements for both the minimum
heat content of gas combusted in the
flare and the maximum exit velocity at
the flare tip.3 These provisions specify
maximum flare tip velocities based on
flare type (non-assisted, steam-assisted
or air-assisted) and the net heating value
of the flare vent gas (see 40 CFR
60.18(c)(3), 63.11(b)(6)). These
maximum flare tip velocities are
required to ensure that the flame does
not ‘‘lift off’’ or separate from the flare
tip, which could cause flame instability
and/or potentially result in a portion of
the flare gas being released without
2 While Dow and ExxonMobil describe their flares
as ‘‘pressure-assisted,’’ these flares qualify as ‘‘nonassisted’’ flares under 40 CFR 60.18(b) or 63.11(b)
because they do not employ assist gas.
3 These requirements are not all inclusive. There
are other requirements in 40 CFR 60.18 and 63.11
relating to monitoring and testing that are not
described here.
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proper combustion. Proper combustion
for flares is considered to be 98 percent
destruction efficiency or greater for
HAPs and VOCs, as discussed in our
recent proposal titled ’’Petroleum
Refinery Sector Risk and Technology
Review and New Source Performance
Standards,’’ 79 FR 36,880, 36,904–
36,912 (June 30, 2014).
The MPGF proposed by both Dow and
ExxonMobil are conceptually similar yet
inherently different in both flare head
design and operation than the more
traditional steam-assisted, air-assisted
and non-assisted flare types currently
able to comply with the flare operating
requirements in 40 CFR 60.18 or 63.11.
The MPGF technology operates by using
the pressure upstream of each
individual flare tip burner to enhance
mixing with air at the flare tip due to
high exit velocity, which allows the
MPGF to operate with smokeless
burning. The MPGF are constructed
differently than normal elevated flares
in that they consist of many rows of
individual flare tips which are
approximately 8 feet above ground
level. The ground flare staging system
opens and closes staging valves
according to gas pressure such that
stages containing multiple burners are
activated as the flow and pressure
increase or decrease in the header.
While information supplied by Dow,
and relied on by both Dow and
ExxonMobil, indicates that the flare tips
operate smokelessly and achieve high
destruction efficiencies, the MPGF
cannot meet the exit velocity
requirements in 40 CFR 60.18 and 40
CFR 63.11, which limit the exit velocity
at the flare tip to a maximum of 400 feet
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per second. The exit velocities from
MPGF typically range from 600 feet per
second up to sonic velocity (which
ranges from 700 to 1,400 feet per second
for common hydrocarbon gases), or
Mach =1 conditions. As a result, Dow
and ExxonMobil are seeking an
alternative means of complying with the
flare operating requirements in 40 CFR
60.18 and 63.11; specifically, the exit
velocity requirements in 40 CFR
60.18(c)(3), (c)(4), and (c)(5) and in 40
CFR 63.11(b)(6),(b)(7) and (b)(8).
B. Alternative Means of Emission
Limitation
As noted in Table 1, the specific rules
in 40 CFR parts 60, 61 and 63, or the
General Provisions for parts 60, 61 and
63 of the CAA 4 allow a facility to
request an AMEL. These provisions
allow the Administrator to permit the
use of an alternative means of
complying with an applicable standard,
if the requestor demonstrates that the
alternative achieves at least an
equivalent reduction in emissions. The
EPA must provide notice of the request
and an opportunity for a public hearing
on the request. After considering
comments received, the EPA will issue
a notice permitting the use of an
4 CAA section 111(h)(3) states: ‘‘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.’’ Section 112(h)(3)
contains almost identical language.
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alternative means of emission
limitation, if the Administrator
determines that the alternative will
achieve an equivalent reduction in
emissions.
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II. Requests for Alternative Means of
Emission Limitation
A. Dow AMEL
In its August 5, 2014, request, Dow
indicates that it plans to construct and
operate two new MPGFs at its Texas
Operations site in Freeport, TX. One
MPGF would be located at Dow’s
Propane Dehydrogenation Plant (PDH–
1), scheduled to start-up in early 2015
and whose primary product is
propylene. The other MPGF would be
located at Dow’s Light Hydrocarbons
Plant (LHC–9), scheduled to start-up in
early 2017 and whose primary product
is ethylene.
The flare systems proposed for use by
Dow at both plants consist of a staged
design concept. The first stage, which is
not at issue nor specifically part of the
notice requesting an AMEL because it
can meet the flare operating
requirements of 40 CFR of 60.18 and
63.11, is a steam-assisted ground flare
which has the primary function of
controlling waste gases during periods
of normal operation. The remaining
stages consist of arrays of pressureassisted flare tips (the MPGFs) and will
control waste gases during periods of
upset, maintenance, startup and
shutdown (high-pressure, high flow
periods). Pressure-assisted flares are
also known as sonic flares because the
exit velocity during periods of highpressure feeds is at sonic velocities.
At Dow, Stage 1 is the low pressure
stage in which the flare acts as a steamassisted flare. Stages 2 and beyond are
activated for high-pressure/high exit
velocity flows. The flare system is
surrounded by a panel type fence to
protect nearby workers from the radiant
heat from the flare system. At various
times ranging from 2 hours for startup
of processing equipment to 160 hours
for a complete plant shutdown, Dow
will have emissions from the MPGF for
the following maintenance, start-up and
shutdown (MSS) activities: Perform
plant start-up and shutdown, process
equipment startup and shutdown, offspec flaring, non-routine clearing and
commissioning of process equipment
and piping, fuel purging and flaring to
maintain pressure of the net-gas system.
Dow conducted testing on the two
types of individual flare tips in its
MPGF design to demonstrate that the
MPGF can achieve good combustion
efficiency under certain conditions and
has proposed operating requirements for
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these MPGF that can achieve the
emissions standards in the applicable
NSPS and NESHAP. These proposed
operating requirements are contained in
Dow’s request dated August 5, 2014,
located in the docket for this document.
A summary of test data and a complete
copy of the emission testing report and
appendices are available in the docket.
The tests were conducted on individual
flare tips because it is not possible to
test the full field of MPGF because of
the size and configuration of the fullscale MPGF installation (there are
approximately 300 flare tips in the
proposed array pattern that cover the
size approximately equivalent to that of
a football field in the actual
installations). Although two flare tip
types were tested during the effort, the
results of one burner type, a steamassisted flare burner, John Zink model
SKEC, are not discussed further as Dow
is not seeking an AMEL for this burner
because it operates at lower velocity
and, thus, can meet the existing flare
operating requirements.
B. ExxonMobil AMEL
In its October 21, 2014, request,
ExxonMobil indicates it plans to
construct and operate two MPGFs, one
at its Baytown Olefins Plant (BOP) in
Baytown, TX, and the other at its Mont
Belvieu Plastics Plant (MBPP) in Mont
Belview, TX. Both of the proposed
control strategies will be designed such
that vent gases are routed to either a low
pressure system, or in infrequent cases
where high-pressure/high flow events
occur, the high pressure MPGF. Both
low pressure control systems at the BOP
and MBPP consist of an elevated flare,
but the MBPP low pressure control
system also consists of three flameless
thermal oxidizers. The elevated flares at
both the BOP and MBPP will comply
with 40 CFR 60.18 and/or 40 CFR 63.11,
as applicable.
ExxonMobil did not supply any
additional test data, but rather is relying
on a series of publically available MPGF
emissions tests, among them the 2013
test submitted by Dow, a 2012 test done
by Marathon Petroleum Corporation, LP,
a 2006 pipeline burner test done by
Dow, and two earlier tests conducted by
the EPA in the 1980s. ExxonMobil
indicates that the BOP and MBPP
burner tip designs will have comparable
performance to the burners recently
tested and submitted December 14,
2014, supplemental application
containing additional information on
plans to use the John Zink LRGO
burners for the MPGF installation at the
MBPP, and ZEECO burners at the BOP.
ExxonMobil asserts that the ZEECO
burner design provides equivalent
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combustion efficiency and flame
stability as that of the John Zink burners
tested, although ExxonMobil has not
supplied any data or information that
could confirm this assertion of
equivalency. We are requesting
comment on this assertion as well as
specifically soliciting data and
comments from the public on burner
design and performance of these MPGF
burners.
C. EPA’s Analysis of MPGF Burner
Emission Tests
Dow and ExxonMobil are proposing
to follow all of the flare operating
requirements contained in either 40 CFR
60.18 or 63.11, except for the exit
velocity requirements. They are
proposing to operate their high pressure
MPGFs at higher velocity than the
current requirements because their data
indicate that these burners can operate
with a stable flame at higher velocities
and still achieve good combustion and
destruction efficiencies. Instead of
complying with the exit velocity
requirements in 40 CFR 60.18 and
63.11, Dow and ExxonMobil are
requesting that EPA grant their AMEL
requests to allow them to operate the
high pressure sections of their MPGFs
such that the vent gas flowing to the
flare tips is maintained with a net
heating value that has been
demonstrated to be equal to or greater
than the values that were determined to
achieve a reduction in emissions of
pollutants being controlled by a steamassisted, air-assisted or non-assisted
flare complying with the requirements
of either 40 CFR 63.11(b) or 40 CFR
60.18(b) during the burner emission
tests.
In the emission tests, the high
pressure burners were subjected to a
number of different operating
conditions, and each set of conditions
represented a separate test series. For
purposes of this discussion, the relevant
test results are those from Dow’s 2013
test report, which are comprised of runs
from test series P1 through P4 and were
tested on John Zink’s pressure assisted
flare burner model LRGO–HC, as well as
emissions data reported in Marathon’s
2012 test report, which are from test
series PA1 and PA2 and were tested on
John Zink’s pressure assisted flare
burner model LRGO–D. These tests used
the analytical technique of passive
fourier transform infrared (PFTIR)
spectroscopy to assess combustion
efficiency. Dow’s 2013 test report also
presents data collected using an
extractive method where flue gas was
extracted from a collection hood that
was suspended above the burner tip and
analyzed using standard EPA methods.
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The Marathon 2012 test report (see
‘‘Performance Test of Steam-Assisted
and Pressure-Assisted Ground Flare
Burners with Passive FTIR—Garyville’’)
and the Dow 2013 test report (see
‘‘Report on Emissions Testing of
Pressure Assisted LRGO–HC and Steam
Assisted SKEC Burners’’) are provided
in the docket.
The results of the PFTIR testing
indicated that when a flame was present
on the pressure-assisted flare burners
tested that an average combustion
efficiency of 99 percent or greater was
always achieved. Each set of operating
conditions tested by both Dow and
Marathon for both combustion
efficiency and flame stability generally
consisted of a series of triplicate runs.
In all, a total of 34 test runs were
analyzed from these two tests (21 from
Dow’s P1 through P3 test series and 13
from Marathon’s PA1 and PA2 test
series). For test series P4, which was
conducted as part of Dow’s 2013 test
using a 90 volume percent hydrogen/10
volume percent natural gas mixture, no
combustion efficiency test was
conducted; instead, a qualitative
indication that the flame was stable at
the conditions tested was made. We
note that in Dow’s 2013 test report that
three of the 21 test runs were aborted
because of loss of flame (which we refer
to as flameout); only two of the three
test runs (one in the P2H series and one
in the P2L series) produced enough
information before flameout to be
analyzed in more detail. We requested
more detailed information from Dow on
the conditions that resulted in this loss
of flame as it informs us of the
conditions that would create a failure of
the burners to sustain a stable flame and
achieve good combustion. This
document is included in the docket
titled ‘‘Supplement 1 to Dow report.’’
Additionally, we also note that in
Marathon’s 2012 test report that two of
the 13 test runs also experienced loss of
flame (test PA1 Runs 4(2) and 4(4)). The
results of all of these test runs are
discussed in the memorandum titled
‘‘Review of Available Test Data on
Multipoint Ground Flares,’’ located in
the docket.
There are two general conclusions
from these test reports that are
consistent with the earlier EPA 1985
study done on pressure-assisted flares
(see conclusions on pages 2–19 and 2–
22 in September 1985 EPA report titled
‘‘Evaluation of the efficiency of
industrial flares: Flare head design and
gas composition’’). The first is that
‘‘flare head design can influence the
flame stability curve.’’ This is evident in
Figures 2–3 and 2–5 of the 1985 EPA
report where different stability curves
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were generated for the different flare
heads (burners) tested over a range of
differing exit velocities and flare gas net
heating values. When comparing the
current maximum flare tip velocity
requirements in the general provisions
with those tested on pressure-assisted
flare burners, this conclusion still holds
true. The agency’s current requirements
would require that flares meet an
increasing minimum net heating value
with increasing velocity, all the way up
to a minimum waste gas net heating
value of 1,000 BTU/scf and maximum
velocity of 400 feet per second.
However, the recent test reports on
pressure-assisted burners show that
flame stability can be achieved at
significantly higher velocities (i.e., sonic
velocity) with waste gas net heating
values below 1,000 BTU/scf. The second
general conclusion made from EPA’s
1985 study is that ‘‘stable flare flames
and high (>98–99) combustion and
destruction efficiencies are attained
when flares are operated within
operating envelopes specific to each
flare burner and gas mixture tested.
Operation beyond the edge of the
operating envelope can result in rapid
flame de-stabilization and a decrease in
combustion and destruction
efficiencies.’’ The data where flameout
of the burners occurred from test runs
in both the Marathon 2012 test report
and the Dow 2013 test report showed
that the flare operating envelope was
different for the different gas mixtures
tested. Additionally, it was observed
that combustion degradation beyond the
edge of the operating envelope for
pressure-assisted MPGF burners was so
rapid that when a flame was present, the
flare would still achieve a high level of
combustion efficiency right up until the
point of flameout.
In order to assess the proper operating
envelope for these flare types, the EPA
evaluated both the net heating value (in
BTU/scf), which is how the 40 CFR part
60 and 63 General Provisions currently
address combustion zone properties, as
well as the lower flammability limit
(LFL) because the LFL may be a better
indicator of performance than net
heating value for some flare vent gas
streams, notably those with the
potential for high hydrogen content.
Hydrogen is relatively flammable, but
its net heating value is low on a BTU/
scf basis when compared to other
hydrocarbons. By using LFL, we
eliminate the need to correct the
hydrogen heat content or to select a
lower BTU/scf limit for high hydrogen
cases. Although Dow has requested
operating limits in the form of BTU/scf
and has presented the test data in BTU/
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8029
scf, we believe it is important to
consider both types of operating limits.
Our review indicates that the LRGO
burners tested achieve a high level of
combustion efficiency when the lower
flammability limit of waste gases burned
in the flare is less than 6.5 volume
percent (vol%) LFL or above 800 BTU/
scf. We suggest the 6.5 vol% LFL based
on the flammability of the stream during
the flame out conditions experienced
during the high pressure test run P2H1
(at 6.6 vol% LFL). The corresponding
BTU content of the waste gas at this
value was 789 BTU/scf (according to
Dow, the gas chromatograph analysis
indicated this value was 746 BTU/scf,
although the John Zink report based on
measured flow rates indicated it was
789 BTU/scf). Dow’s proposed operating
conditions included startup/shutdown
cases where the waste gas heat content
could be as low as 690 BTU/scf and as
high as 6.9 vol% LFL, and data from
these tests indicate that good
combustion can occur at these
conditions. However, to establish the
alternative operating requirements at a
level that ensures good combustion and
flame stability at all times under all
operating conditions, we believe it is
reasonable to establish the heat content
requirements for BTU/scf above which
there were no flame out observations.
For LFL, that level would be set below
which there are no flame out
observations. This is because gas
mixtures with a relatively high LFL are
less flammable when released to the air
than mixtures with a relatively low LFL.
A gas mixture with a relatively high LFL
requires a larger volume of the mixture
to burn in a specific volume of air, than
would a mixture of gases with a
relatively low LFL being combusted in
that same volume of air. We believe the
flame out observations establish the
limiting case because a flameout is a
complete failure of the burner,
indicating zero-percent combustion.
Because of the quantity of waste gases
potentially flared in the high-pressure
zones of these MPGF, we believe it
would be prudent to establish limits on
the conservative side to prevent air
emissions of unburned waste gas.
We also reviewed whether we should
consider velocity or burner operating
pressure in describing conditions that
should be met during the MPGF
operation and whether we should
require some testing to ensure that the
individual burners will ignite properly
when a new stage goes into service. Dow
provided information on its process
control system and indicated that crosslight testing (testing of burner ignition
from pilots) of individual burners at its
off-site test facility has been conducted
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and the burners performed as expected.
This discussion, titled ‘‘Process control
system overview-multipoint ground
flare system,’’ is in the docket for this
action. At this time, we are not
considering any requirements for
additional process control or ignition
testing. However, we believe it would be
important to require that cameras are
installed and operated such that
operators have a visual indication of
flames from the flare at all times that the
MPGF is operating and that this footage
be available for inspection by the
permitting agency, along with
operational records of the waste gas
flowrate, pressure in header and stages,
pilot and waste gas composition.
Because these flares are located at
ground level, it is possible that ambient
concentrations of pollutants could be
higher than they would be under an
alternative scenario where waste gases
would be flared in an elevated flare,
enabling greater dispersion and
potentially lessening the impact to
neighboring communities. To that end,
we are soliciting comment on whether
additional ambient monitoring is
warranted to provide for immediate
notification to emergency planning
officials and the community during
significant events and malfunctions of
the system.
III. AMEL for Pressure-Assisted MPGF
Considering the above requests from
both Dow and ExxonMobil, we are
seeking the public’s input on the
operating requirements for the proposed
pressure-assisted MPGFs that would be
used by both companies which would
establish an AMEL that will achieve a
reduction in emissions at least
equivalent to the reduction in emissions
being controlled by a steam-assisted, airassisted or non-assisted flare complying
with the requirements of either 40 CFR
63.11(b) or 40 CFR 60.18(b). Information
provided in the AMEL requests and the
available emissions test data from the
test reports described above indicate
that the following list of operating
requirements for pressure-assisted
MPGF result in destruction efficiencies
at least equivalent to destruction
efficiencies expected from complying
with the requirements of 40 CFR
63.11(b) and 40 CFR 60.18(b) for the
pressure-assisted MPGF being proposed
for use by both Dow and ExxonMobil:
1. The flare system must be designed
and operated such that the net heating
value of the combustion zone gas
(NHVcz) for the pressure assisted flare
burners meets a minimum heating value
of 800 BTU/scf or a lower flammability
limit of the combustion zone gas (LFLcz)
of less than or equal to 6.5 percent by
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volume under all conditions. We would
expect owners or operators to calculate
NHVcz and LFLcz in a manner similar to
those in the currently proposed
requirements of 79 FR 36980–40 CFR
63.670(l)–(m).
2. The flare system must be operated
with a flame present at all times when
in use. Each row of flare burners must
have at least one pilot with a constant
pilot flame. The pilot flame(s) must be
continuously monitored by a
thermocouple. The time, date and
duration of any loss of pilot flame must
be recorded. Each monitoring device
must be maintained or replaced at a
frequency in accordance with the
manufacturer’s specifications.
3. The flare system must be operated
with no visible emissions except for
periods not to exceed a total of 5
minutes during any 2 consecutive
hours. A video camera can be used in
order to conduct visible emission
observations since operating personnel
cannot enter the fenced area while the
MPGF is operating.
4. The operator must install and
operate an on-line vent gas flow meter
and an on-line gas chromatograph to
measure the flow and composition of
the vent gas to each flare. We would
expect the operator to comply with
similar monitoring and testing
requirements and recordkeeping and
reporting requirements for these
monitoring systems as currently
proposed in 79 FR 36980–40 CFR
63.670(i)–(j) and (l)–(m).
5. The operator should install and
operate pressure and/or flow monitors
on each stage of the flare. We would
expect the operator to comply with
similar applicable monitoring and
testing requirements and recordkeeping
and reporting requirements for these
monitoring systems as currently
proposed in 79 FR 36980–40 CFR
63.670(i).
IV. Request for Comments
We solicit comments on all aspects of
these requests for an AMEL. We
specifically seek comment regarding
whether or not the potential alternative
operating requirements listed in section
III above would be adequate for
ensuring that the MPGF will achieve
good combustion at all times and enable
the facilities to meet their applicable
emission standards. Additionally,
several other entities have indicated to
us that they intend to make similar
requests for the ability to operate
pressure-assisted MPGFs. We are also
soliciting comment on whether the
requirements listed above, if followed
by these other entities, could enable
these other facilities to receive approval
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of their own AMELs. As noted in
section II.B above, we also solicit
comment and data on other pressureassisted flare burner types. Commenters
should include data or specific
examples in support of their comments.
Dated: February 3, 2015.
Janet G. McCabe,
Acting Assistant Administrator.
[FR Doc. 2015–03064 Filed 2–12–15; 8:45 am]
BILLING CODE 6560–50–P
DEPARTMENT OF HEALTH AND
HUMAN SERVICES
National Institutes of Health
42 CFR Part 11
[Docket Number NIH–2011–0003]
RIN 0925–AA52
Clinical Trials Registration and Results
Submission
National Institutes of Health,
Department of Health and Human
Services.
ACTION: Proposed rule; extension of
comment period; request for comments.
AGENCY:
The Department of Health and
Human Services (HHS) is extending the
public comment period for the Notice of
Proposed Rulemaking (NPRM) on
Clinical Trials Registration and Results
Submission. The proposed rule was
published on November 21, 2014 (79 FR
69566) with a deadline for public
comments of February 19, 2015. The
comment period is being extended to
provide additional time for commenters
to prepare their responses. The
comment period will close at 5 p.m.
Eastern Standard Time (EST) on March
23, 2015.
DATES: Comments on the NPRM must be
received before 5 p.m. EST on March 23,
2015 in order to ensure we will be able
to consider the comments when
preparing the final rule and policy.
ADDRESSES: Individuals and
organizations interested in submitting
comments on the NPRM, identified by
RIN 0925–AA52 and Docket Number
NIH–2011–0003, may do so by any of
the following methods:
• Electronic Submissions: Use
Federal eRulemaking Portal: https://
www.regulations.gov. Follow the
instructions for submitting comments.
NIH is no longer accepting comments
submitted directly by email. The NIH
encourages you to continue to submit
electronic comments by using the
Federal eRulemaking Portal: https://
www.regulations.gov.
SUMMARY:
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]]>Agencies
[Federal Register Volume 80, Number 30 (Friday, February 13, 2015)]
[Proposed Rules]
[Pages 8023-8030]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2015-03064]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 60, 61, and 63
[EPA-HQ-OAR-2014-0738; FRL 9922-91-OAR]
Receipt of Approval Requests for the Operation of Pressure-
Assisted Multi-Point Ground Flare Technology
AGENCY: Environmental Protection Agency.
ACTION: Request for comments.
-----------------------------------------------------------------------
[[Page 8024]]
SUMMARY: On August 5, 2014, The Dow Chemical Company (Dow) requested an
Alternative Means of Emission Limitation (AMEL) under the Clean Air Act
(CAA) in order to operate pressure-assisted multi-point ground flares
at its Propane Dehydrogenation Plant and its Light Hydrocarbons Plant
at its Texas Operations site located in Freeport, Texas. On October 21,
2014, ExxonMobil Chemical Company (ExxonMobil) requested an AMEL under
the CAA for its pressure-assisted multi-point ground flares at its'
Olefins Plant in Baytown, Texas, and its' Plastics Plant in Mont
Belvieu, Texas. In this document, the Environmental Protection Agency
(EPA) is soliciting comment on all aspects of the AMEL requests and the
resulting alternative operating conditions that are necessary to
achieve a reduction in emissions of volatile organic compounds (VOC)
and hazardous air pollutants (HAPs) at least equivalent to the
reduction in emissions required by various standards in 40 CFR parts
60, 61 and 63 that apply to emission sources controlled by these
pressure-assisted multi-point ground flares. These standards point to
the operating requirements for flares in the General Provisions to
parts 60 and 63, respectively, to comply with the emission reduction
requirements. Because pressure-assisted multi-point ground flares
cannot meet the velocity requirements in these General Provisions, Dow
and ExxonMobil are seeking an AMEL.
DATES: Comments. Written comments must be received on or before March
30, 2015.
Public Hearing. If requested by February 18, 2015, we will hold a
public hearing on March 2, 2015, from 1:00 p.m. [Eastern Standard Time]
to 5:00 p.m. [Eastern Standard Time] at EPA's Campus located in
Research Triangle Park, NC. We will provide details on the public
hearing on our Web site at: https://www.epa.gov/ttn/atw/groundflares/groundflarespg.html. To be clear, a public hearing will not be held
unless someone specifically requests that the EPA hold a public hearing
regarding these requests. Please contact Ms. Virginia Hunt of the
Sector Policies and Programs Division (E143-01), Office of Air Quality
Planning and Standards, Environmental Protection Agency, Research
Triangle Park, NC 27711; telephone number: (919) 541-0832; email
address: hunt.virginia@epa.gov; to request a public hearing, to
register to speak at the public hearing or to inquire as to whether or
not a public hearing will be held. The last day to pre-register in
advance to speak at the public hearing will be February 25, 2015.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA OAR-
2014-0738, by one of the following methods:
https://www.regulations.gov. Follow the on-line
instructions for submitting comments.
Email: a-and-r-docket@epa.gov. Attention Docket ID Number
EPA-HQ-OAR-2014-0738.
Fax: (202) 566-9744. Attention Docket ID Number EPA-HQ-
OAR-2014-0738.
Mail: U.S. Postal Service, send comments to: EPA Docket
Center (EPA/DC), Attention Docket ID Number EPA-HQ-OAR-2014-0738, U.S.
Environmental Protection Agency, Mailcode: 28221T, 1200 Pennsylvania
Ave. NW., Washington, DC 20460.
Hand Delivery: U.S. Environmental Protection Agency, EPA
WJC West Building, Room 3334, 1301 Constitution Ave. NW., Washington,
DC 20004. Attention Docket ID Number EPA-HQ-OAR-2014-0738. Such
deliveries are only accepted during the Docket's normal hours of
operation, and special arrangements should be made for deliveries of
boxed information.
Instructions. Direct your comments to Docket ID Number EPA-HQ-OAR-
2014-0738. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
online at https://www.regulations.gov, including any personal
information provided, unless the comment includes information claimed
to be confidential business information (CBI) or other information
whose disclosure is restricted by statute. Do not submit information
that you consider to be CBI or otherwise protected through https://www.regulations.gov or email. The https://www.regulations.gov Web site
is an ``anonymous access'' system, which means the EPA will not know
your identity or contact information unless you provide it in the body
of your comment. If you send an email comment directly to the EPA
without going through https://www.regulations.gov, your email address
will be automatically captured and included as part of the comment that
is placed in the public docket and made available on the Internet. If
you submit an electronic comment, the EPA recommends that you include
your name and other contact information in the body of your comment and
with any disk or CD-ROM you submit. If the EPA cannot read your comment
due to technical difficulties and cannot contact you for clarification,
the EPA may not be able to consider your comment. Electronic files
should not include special characters or any form of encryption and be
free of any defects or viruses. For additional information about the
EPA's public docket, visit the EPA Docket Center homepage at: https://www.epa.gov/dockets.
Docket. The EPA has established a docket for this rulemaking under
Docket ID Number EPA-HQ-OAR-2014-0738. All documents in the docket are
listed in the regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, is not placed on the Internet and will be
publicly available only in hard copy. Publicly available docket
materials are available either electronically in regulations.gov or in
hard copy at the EPA Docket Center (EPA/DC), EPA WJC West Building,
Room 3334, 1301 Constitution Ave. NW., Washington, DC. The Public
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the Public
Reading Room is (202) 566-1744, and the telephone number for the EPA
Docket Center is (202) 566-1742.
FOR FURTHER INFORMATION CONTACT: For questions about this proposed
action, contact Ms. Brenda Shine, Sector Policies and Programs Division
(E143-01), Office of Air Quality Planning and Standards (OAQPS), U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711; telephone number: (919) 541-3608; fax number: (919) 541-0246;
and email address: shine.brenda@epa.gov.
SUPPLEMENTARY INFORMATION:
Acronyms and Abbreviations
We use multiple acronyms and terms in this document. While this
list may not be exhaustive, to ease the reading of this document and
for reference purposes, the EPA defines the following terms and
acronyms here:
AMEL alternative means of emission limitation
BOP Baytown Olefins Plant
Btu/scf British thermal units per standard cubic feet
LFL lower flammability limit
LFLcz combustion zone lower flammability limit
LHC Light Hydrocarbons Unit
LRGO Linear relief gas oxidizer
MACT maximum achievable control technology
MBPP Mont Belvieu Plastics Plant
MPGF multi-point ground flare
NESHAP national emission standard for hazardous air pollutants
[[Page 8025]]
NHV net heating value
NHVcz combustion zone net heating value
NSPS new source performance standards
OAQPS Office of Air Quality Planning and Standards
PDH Propylene Dehydrogenation Unit
PFTIR passive fourier transform infrared
SKEC steam-assisted kinetic energy combustor
Organization of This Document. The information in this document is
organized as follows:
I. Statutory and Regulatory Background
A. Flare Operating Requirements
B. Alternative Means of Emission Limitation
II. Requests for Alternative Means of Emission Limitation
A. Dow AMEL
B. ExxonMobil AMEL
C. EPA's Analysis of MPGF Burner Emission Tests
III. AMEL for Pressure-Assisted MPGF
IV. Request for Comments
I. Statutory and Regulatory Background
A. Flare Operating Requirements
In their requests, Dow and ExxonMobil cite various regulatory
requirements in 40 CFR parts 60, 61 and 63 that will apply to the
different vent gas streams that will be collected and routed to their
pressure-assisted multi-point ground flares (MPGF) at each plant. These
requirements are included in Table 1.\1\ In all cases, these rules
reference the flare operating requirements located in 40 CFR 60.18 and
40 CFR 63.11.
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\1\ EPA prepared Table 1 using the information provided in the
requests, corrected as appropriate based on its own review of the
regulations. However, the EPA has not independently verified whether
Table 1 includes all of the regulatory requirements with which these
plants must comply.
Table 1--Summary of Applicable Rules That May Apply to Vents Streams Controlled by Pressure-Assisted Multi-Point Ground Flares
--------------------------------------------------------------------------------------------------------------------------------------------------------
Provisions for
Applicable rules with vent Dow propane Dow light hydro- Exxon-Mobil Exxon-Mobil Mont Emission reduction alternative means
streams going to control dehydrogenation carbons (LHC) Baytown Olefins Belvieu plastics required and of emission
device (PDH) plant plant plant plant rule citation limitation
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NSPS Subpart Kb................. .................. X X .................. 60.112b(a)(3)(ii)- 60.114b allows for
-Reduce VOC inlet AMEL.
emissions by 95%;
If a flare is
used as a control
device, flare
must meet
requirements of
60.18.
NSPS Subparts VV/Vva............ X X X .................. 60.482-10a--Reduce 60.484(a) allows
VOC emissions by for AMEL
95% or greater;
flare used to
comply with
subpart must meet
requirements of
60.18.
*Note--Under Dow
PDH Plant column,
NSPS subpart VVa
applies, but DOW
is opting to
comply with 40
CFR part 63,
subpart H (as
referenced by
Miscellaneous
Organic
NESHAP(MON) which
should satisfy
requirements in
subpart VVa.
NSPS Subpart DDD................ .................. .................. .................. X 60.562-1--Reduce CAA section
emissions of 111(h)(3) allows
Total Organic for AMEL.
Carbon (TOC) by
98%, or combust
in a flare that
meets the
requirements of
60.18.
NSPS Subpart NNN................ X X X X 60.662- Reduce CAA section
emissions of TOC 111(h)(3) allows
by 98%, or for AMEL.
combust in a
flare that meets
the requirements
of 60.18.
NSPS Subpart RRR................ X X X X 60.702--Reduce CAA section
emissions of TOC 111(h)(3) allows
by 98%, or for AMEL.
combust in a
flare that meets
the requirements
of 60.18.
[[Page 8026]]
NESHAP Subpart V................ .................. .................. X .................. 61.242-11(d)--flar 61.244 allows for
es used to comply AMEL; also see
with subpart V 61.12(d).
must comply with
60.18.
NESHAP Subpart FF............... .................. X X .................. 61.349(a)--reduce 61.353 allows for
organic emissions AMEL; also see
vented to control 61.12(d).
device by 95%; a
flare shall
comply with the
requirements of
60.18.
NESHAP Subparts F, G............ .................. .................. X .................. 63.102, 63.113, 63.102(b) allows
63.126--Reduce for AMEL.
emissions of
Total Organic HAP
(TOHAP) by 98%,
or combust in a
flare that meets
the requirements
of 63.11(b).
63.120--Combust in
flare meeting
63.11. 63.139--
Reduce emissions
of TOHAP by 95%,
or combust in a
flare that meets
the requirements
of 63.11(b).
63.145(j)--Points
to sections of
63.11(b) for
flare control.
NESHAP Subpart H................ X .................. X .................. 63.172--Reduce 63.177 allows for
organic HAP or AMEL.
VOC by 95%;
flares used to
comply must meet
requirements of
63.11(b).
NESHAP Subpart SS............... X X X X 63.982(b) and CAA section
63.987(a) require 112(h)(3) allows
that a flare for AMEL.
meets the
requirements in
63.11(b).
NESHAP Subpart UU............... .................. X .................. .................. 63.1034--Nonflare 63.1021 allows for
control devices AMEL.
shall reduce
emissions by 95%;
flares shall
comply with
subpart SS.
NESHAP Subpart XX............... .................. X .................. .................. 63.1091 requires 61.353 allows for
compliance with AMEL; also see
subpart FF, which 61.12(d).
requires
compliance with
60.18.
NESHAP Subpart YY............... .................. X X .................. Table 7 references 63.1113 allows for
subpart SS, which AMEL.
requires
compliance with
60.18.
NESHAP Subpart EEEE............. .................. .................. X X 63.2378(a) 63.2346(g) allows
references for AMEL; also
subpart SS, which see Table 12
requires which makes
compliance with 63.6(g)
60.18. applicable to
this subpart.
[[Page 8027]]
NESHAP Subpart FFFF............. X .................. .................. X 63.2450 requires 63.2540 and Table
compliance with 12 allow for AMEL
limits in Tables by making 63.6(g)
1-7, which applicable to
include reducing this subpart.
total organic HAP
in vent streams
by either 95% or
98%, and provide
an option for
control using a
flare meeting
requirements of
63.982(b) which
requires meeting
63.987, which
requires a flare
to meet the
requirements of
63.11(b).
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As shown in Table 1, the applicable rules require that control
devices achieve destruction efficiencies of either 95 percent or 98
percent either directly, or by reference, or allow control by flares
meeting the flare operating requirements in 40 CFR 60.18 or 63.11. The
flare operating requirements in 40 CFR 60.18 and 63.11 specify that
flares shall be: (1) Steam-assisted air-assisted, or non-assisted; \2\
(2) operated at all times when emissions may be vented to them; (3)
designed for and operated with no visible emissions (except for periods
not to exceed a total of 5 minutes during any 2 consecutive hours); and
(4) operated with the presence of a pilot flame at all times. The flare
operating requirements in 40 CFR 60.18 and 63.11 also specify
requirements for both the minimum heat content of gas combusted in the
flare and the maximum exit velocity at the flare tip.\3\ These
provisions specify maximum flare tip velocities based on flare type
(non-assisted, steam-assisted or air-assisted) and the net heating
value of the flare vent gas (see 40 CFR 60.18(c)(3), 63.11(b)(6)).
These maximum flare tip velocities are required to ensure that the
flame does not ``lift off'' or separate from the flare tip, which could
cause flame instability and/or potentially result in a portion of the
flare gas being released without proper combustion. Proper combustion
for flares is considered to be 98 percent destruction efficiency or
greater for HAPs and VOCs, as discussed in our recent proposal titled
''Petroleum Refinery Sector Risk and Technology Review and New Source
Performance Standards,'' 79 FR 36,880, 36,904-36,912 (June 30, 2014).
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\2\ While Dow and ExxonMobil describe their flares as
``pressure-assisted,'' these flares qualify as ``non-assisted''
flares under 40 CFR 60.18(b) or 63.11(b) because they do not employ
assist gas.
\3\ These requirements are not all inclusive. There are other
requirements in 40 CFR 60.18 and 63.11 relating to monitoring and
testing that are not described here.
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The MPGF proposed by both Dow and ExxonMobil are conceptually
similar yet inherently different in both flare head design and
operation than the more traditional steam-assisted, air-assisted and
non-assisted flare types currently able to comply with the flare
operating requirements in 40 CFR 60.18 or 63.11. The MPGF technology
operates by using the pressure upstream of each individual flare tip
burner to enhance mixing with air at the flare tip due to high exit
velocity, which allows the MPGF to operate with smokeless burning. The
MPGF are constructed differently than normal elevated flares in that
they consist of many rows of individual flare tips which are
approximately 8 feet above ground level. The ground flare staging
system opens and closes staging valves according to gas pressure such
that stages containing multiple burners are activated as the flow and
pressure increase or decrease in the header. While information supplied
by Dow, and relied on by both Dow and ExxonMobil, indicates that the
flare tips operate smokelessly and achieve high destruction
efficiencies, the MPGF cannot meet the exit velocity requirements in 40
CFR 60.18 and 40 CFR 63.11, which limit the exit velocity at the flare
tip to a maximum of 400 feet per second. The exit velocities from MPGF
typically range from 600 feet per second up to sonic velocity (which
ranges from 700 to 1,400 feet per second for common hydrocarbon gases),
or Mach =1 conditions. As a result, Dow and ExxonMobil are seeking an
alternative means of complying with the flare operating requirements in
40 CFR 60.18 and 63.11; specifically, the exit velocity requirements in
40 CFR 60.18(c)(3), (c)(4), and (c)(5) and in 40 CFR 63.11(b)(6),(b)(7)
and (b)(8).
B. Alternative Means of Emission Limitation
As noted in Table 1, the specific rules in 40 CFR parts 60, 61 and
63, or the General Provisions for parts 60, 61 and 63 of the CAA \4\
allow a facility to request an AMEL. These provisions allow the
Administrator to permit the use of an alternative means of complying
with an applicable standard, if the requestor demonstrates that the
alternative achieves at least an equivalent reduction in emissions. The
EPA must provide notice of the request and an opportunity for a public
hearing on the request. After considering comments received, the EPA
will issue a notice permitting the use of an
[[Page 8028]]
alternative means of emission limitation, if the Administrator
determines that the alternative will achieve an equivalent reduction in
emissions.
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\4\ CAA section 111(h)(3) states: ``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.'' Section 112(h)(3) contains almost identical language.
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II. Requests for Alternative Means of Emission Limitation
A. Dow AMEL
In its August 5, 2014, request, Dow indicates that it plans to
construct and operate two new MPGFs at its Texas Operations site in
Freeport, TX. One MPGF would be located at Dow's Propane
Dehydrogenation Plant (PDH-1), scheduled to start-up in early 2015 and
whose primary product is propylene. The other MPGF would be located at
Dow's Light Hydrocarbons Plant (LHC-9), scheduled to start-up in early
2017 and whose primary product is ethylene.
The flare systems proposed for use by Dow at both plants consist of
a staged design concept. The first stage, which is not at issue nor
specifically part of the notice requesting an AMEL because it can meet
the flare operating requirements of 40 CFR of 60.18 and 63.11, is a
steam-assisted ground flare which has the primary function of
controlling waste gases during periods of normal operation. The
remaining stages consist of arrays of pressure-assisted flare tips (the
MPGFs) and will control waste gases during periods of upset,
maintenance, startup and shutdown (high-pressure, high flow periods).
Pressure-assisted flares are also known as sonic flares because the
exit velocity during periods of high-pressure feeds is at sonic
velocities.
At Dow, Stage 1 is the low pressure stage in which the flare acts
as a steam-assisted flare. Stages 2 and beyond are activated for high-
pressure/high exit velocity flows. The flare system is surrounded by a
panel type fence to protect nearby workers from the radiant heat from
the flare system. At various times ranging from 2 hours for startup of
processing equipment to 160 hours for a complete plant shutdown, Dow
will have emissions from the MPGF for the following maintenance, start-
up and shutdown (MSS) activities: Perform plant start-up and shutdown,
process equipment startup and shutdown, off-spec flaring, non-routine
clearing and commissioning of process equipment and piping, fuel
purging and flaring to maintain pressure of the net-gas system.
Dow conducted testing on the two types of individual flare tips in
its MPGF design to demonstrate that the MPGF can achieve good
combustion efficiency under certain conditions and has proposed
operating requirements for these MPGF that can achieve the emissions
standards in the applicable NSPS and NESHAP. These proposed operating
requirements are contained in Dow's request dated August 5, 2014,
located in the docket for this document. A summary of test data and a
complete copy of the emission testing report and appendices are
available in the docket. The tests were conducted on individual flare
tips because it is not possible to test the full field of MPGF because
of the size and configuration of the full-scale MPGF installation
(there are approximately 300 flare tips in the proposed array pattern
that cover the size approximately equivalent to that of a football
field in the actual installations). Although two flare tip types were
tested during the effort, the results of one burner type, a steam-
assisted flare burner, John Zink model SKEC, are not discussed further
as Dow is not seeking an AMEL for this burner because it operates at
lower velocity and, thus, can meet the existing flare operating
requirements.
B. ExxonMobil AMEL
In its October 21, 2014, request, ExxonMobil indicates it plans to
construct and operate two MPGFs, one at its Baytown Olefins Plant (BOP)
in Baytown, TX, and the other at its Mont Belvieu Plastics Plant (MBPP)
in Mont Belview, TX. Both of the proposed control strategies will be
designed such that vent gases are routed to either a low pressure
system, or in infrequent cases where high-pressure/high flow events
occur, the high pressure MPGF. Both low pressure control systems at the
BOP and MBPP consist of an elevated flare, but the MBPP low pressure
control system also consists of three flameless thermal oxidizers. The
elevated flares at both the BOP and MBPP will comply with 40 CFR 60.18
and/or 40 CFR 63.11, as applicable.
ExxonMobil did not supply any additional test data, but rather is
relying on a series of publically available MPGF emissions tests, among
them the 2013 test submitted by Dow, a 2012 test done by Marathon
Petroleum Corporation, LP, a 2006 pipeline burner test done by Dow, and
two earlier tests conducted by the EPA in the 1980s. ExxonMobil
indicates that the BOP and MBPP burner tip designs will have comparable
performance to the burners recently tested and submitted December 14,
2014, supplemental application containing additional information on
plans to use the John Zink LRGO burners for the MPGF installation at
the MBPP, and ZEECO burners at the BOP. ExxonMobil asserts that the
ZEECO burner design provides equivalent combustion efficiency and flame
stability as that of the John Zink burners tested, although ExxonMobil
has not supplied any data or information that could confirm this
assertion of equivalency. We are requesting comment on this assertion
as well as specifically soliciting data and comments from the public on
burner design and performance of these MPGF burners.
C. EPA's Analysis of MPGF Burner Emission Tests
Dow and ExxonMobil are proposing to follow all of the flare
operating requirements contained in either 40 CFR 60.18 or 63.11,
except for the exit velocity requirements. They are proposing to
operate their high pressure MPGFs at higher velocity than the current
requirements because their data indicate that these burners can operate
with a stable flame at higher velocities and still achieve good
combustion and destruction efficiencies. Instead of complying with the
exit velocity requirements in 40 CFR 60.18 and 63.11, Dow and
ExxonMobil are requesting that EPA grant their AMEL requests to allow
them to operate the high pressure sections of their MPGFs such that the
vent gas flowing to the flare tips is maintained with a net heating
value that has been demonstrated to be equal to or greater than the
values that were determined to achieve a reduction in emissions of
pollutants being controlled by a steam-assisted, air-assisted or non-
assisted flare complying with the requirements of either 40 CFR
63.11(b) or 40 CFR 60.18(b) during the burner emission tests.
In the emission tests, the high pressure burners were subjected to
a number of different operating conditions, and each set of conditions
represented a separate test series. For purposes of this discussion,
the relevant test results are those from Dow's 2013 test report, which
are comprised of runs from test series P1 through P4 and were tested on
John Zink's pressure assisted flare burner model LRGO-HC, as well as
emissions data reported in Marathon's 2012 test report, which are from
test series PA1 and PA2 and were tested on John Zink's pressure
assisted flare burner model LRGO-D. These tests used the analytical
technique of passive fourier transform infrared (PFTIR) spectroscopy to
assess combustion efficiency. Dow's 2013 test report also presents data
collected using an extractive method where flue gas was extracted from
a collection hood that was suspended above the burner tip and analyzed
using standard EPA methods.
[[Page 8029]]
The Marathon 2012 test report (see ``Performance Test of Steam-Assisted
and Pressure-Assisted Ground Flare Burners with Passive FTIR--
Garyville'') and the Dow 2013 test report (see ``Report on Emissions
Testing of Pressure Assisted LRGO-HC and Steam Assisted SKEC Burners'')
are provided in the docket.
The results of the PFTIR testing indicated that when a flame was
present on the pressure-assisted flare burners tested that an average
combustion efficiency of 99 percent or greater was always achieved.
Each set of operating conditions tested by both Dow and Marathon for
both combustion efficiency and flame stability generally consisted of a
series of triplicate runs. In all, a total of 34 test runs were
analyzed from these two tests (21 from Dow's P1 through P3 test series
and 13 from Marathon's PA1 and PA2 test series). For test series P4,
which was conducted as part of Dow's 2013 test using a 90 volume
percent hydrogen/10 volume percent natural gas mixture, no combustion
efficiency test was conducted; instead, a qualitative indication that
the flame was stable at the conditions tested was made. We note that in
Dow's 2013 test report that three of the 21 test runs were aborted
because of loss of flame (which we refer to as flameout); only two of
the three test runs (one in the P2H series and one in the P2L series)
produced enough information before flameout to be analyzed in more
detail. We requested more detailed information from Dow on the
conditions that resulted in this loss of flame as it informs us of the
conditions that would create a failure of the burners to sustain a
stable flame and achieve good combustion. This document is included in
the docket titled ``Supplement 1 to Dow report.'' Additionally, we also
note that in Marathon's 2012 test report that two of the 13 test runs
also experienced loss of flame (test PA1 Runs 4(2) and 4(4)). The
results of all of these test runs are discussed in the memorandum
titled ``Review of Available Test Data on Multipoint Ground Flares,''
located in the docket.
There are two general conclusions from these test reports that are
consistent with the earlier EPA 1985 study done on pressure-assisted
flares (see conclusions on pages 2-19 and 2-22 in September 1985 EPA
report titled ``Evaluation of the efficiency of industrial flares:
Flare head design and gas composition''). The first is that ``flare
head design can influence the flame stability curve.'' This is evident
in Figures 2-3 and 2-5 of the 1985 EPA report where different stability
curves were generated for the different flare heads (burners) tested
over a range of differing exit velocities and flare gas net heating
values. When comparing the current maximum flare tip velocity
requirements in the general provisions with those tested on pressure-
assisted flare burners, this conclusion still holds true. The agency's
current requirements would require that flares meet an increasing
minimum net heating value with increasing velocity, all the way up to a
minimum waste gas net heating value of 1,000 BTU/scf and maximum
velocity of 400 feet per second. However, the recent test reports on
pressure-assisted burners show that flame stability can be achieved at
significantly higher velocities (i.e., sonic velocity) with waste gas
net heating values below 1,000 BTU/scf. The second general conclusion
made from EPA's 1985 study is that ``stable flare flames and high (>98-
99) combustion and destruction efficiencies are attained when flares
are operated within operating envelopes specific to each flare burner
and gas mixture tested. Operation beyond the edge of the operating
envelope can result in rapid flame de-stabilization and a decrease in
combustion and destruction efficiencies.'' The data where flameout of
the burners occurred from test runs in both the Marathon 2012 test
report and the Dow 2013 test report showed that the flare operating
envelope was different for the different gas mixtures tested.
Additionally, it was observed that combustion degradation beyond the
edge of the operating envelope for pressure-assisted MPGF burners was
so rapid that when a flame was present, the flare would still achieve a
high level of combustion efficiency right up until the point of
flameout.
In order to assess the proper operating envelope for these flare
types, the EPA evaluated both the net heating value (in BTU/scf), which
is how the 40 CFR part 60 and 63 General Provisions currently address
combustion zone properties, as well as the lower flammability limit
(LFL) because the LFL may be a better indicator of performance than net
heating value for some flare vent gas streams, notably those with the
potential for high hydrogen content. Hydrogen is relatively flammable,
but its net heating value is low on a BTU/scf basis when compared to
other hydrocarbons. By using LFL, we eliminate the need to correct the
hydrogen heat content or to select a lower BTU/scf limit for high
hydrogen cases. Although Dow has requested operating limits in the form
of BTU/scf and has presented the test data in BTU/scf, we believe it is
important to consider both types of operating limits.
Our review indicates that the LRGO burners tested achieve a high
level of combustion efficiency when the lower flammability limit of
waste gases burned in the flare is less than 6.5 volume percent (vol%)
LFL or above 800 BTU/scf. We suggest the 6.5 vol% LFL based on the
flammability of the stream during the flame out conditions experienced
during the high pressure test run P2H1 (at 6.6 vol% LFL). The
corresponding BTU content of the waste gas at this value was 789 BTU/
scf (according to Dow, the gas chromatograph analysis indicated this
value was 746 BTU/scf, although the John Zink report based on measured
flow rates indicated it was 789 BTU/scf). Dow's proposed operating
conditions included startup/shutdown cases where the waste gas heat
content could be as low as 690 BTU/scf and as high as 6.9 vol% LFL, and
data from these tests indicate that good combustion can occur at these
conditions. However, to establish the alternative operating
requirements at a level that ensures good combustion and flame
stability at all times under all operating conditions, we believe it is
reasonable to establish the heat content requirements for BTU/scf above
which there were no flame out observations. For LFL, that level would
be set below which there are no flame out observations. This is because
gas mixtures with a relatively high LFL are less flammable when
released to the air than mixtures with a relatively low LFL. A gas
mixture with a relatively high LFL requires a larger volume of the
mixture to burn in a specific volume of air, than would a mixture of
gases with a relatively low LFL being combusted in that same volume of
air. We believe the flame out observations establish the limiting case
because a flameout is a complete failure of the burner, indicating
zero-percent combustion. Because of the quantity of waste gases
potentially flared in the high-pressure zones of these MPGF, we believe
it would be prudent to establish limits on the conservative side to
prevent air emissions of unburned waste gas.
We also reviewed whether we should consider velocity or burner
operating pressure in describing conditions that should be met during
the MPGF operation and whether we should require some testing to ensure
that the individual burners will ignite properly when a new stage goes
into service. Dow provided information on its process control system
and indicated that cross-light testing (testing of burner ignition from
pilots) of individual burners at its off-site test facility has been
conducted
[[Page 8030]]
and the burners performed as expected. This discussion, titled
``Process control system overview-multipoint ground flare system,'' is
in the docket for this action. At this time, we are not considering any
requirements for additional process control or ignition testing.
However, we believe it would be important to require that cameras are
installed and operated such that operators have a visual indication of
flames from the flare at all times that the MPGF is operating and that
this footage be available for inspection by the permitting agency,
along with operational records of the waste gas flowrate, pressure in
header and stages, pilot and waste gas composition.
Because these flares are located at ground level, it is possible
that ambient concentrations of pollutants could be higher than they
would be under an alternative scenario where waste gases would be
flared in an elevated flare, enabling greater dispersion and
potentially lessening the impact to neighboring communities. To that
end, we are soliciting comment on whether additional ambient monitoring
is warranted to provide for immediate notification to emergency
planning officials and the community during significant events and
malfunctions of the system.
III. AMEL for Pressure-Assisted MPGF
Considering the above requests from both Dow and ExxonMobil, we are
seeking the public's input on the operating requirements for the
proposed pressure-assisted MPGFs that would be used by both companies
which would establish an AMEL that will achieve a reduction in
emissions at least equivalent to the reduction in emissions being
controlled by a steam-assisted, air-assisted or non-assisted flare
complying with the requirements of either 40 CFR 63.11(b) or 40 CFR
60.18(b). Information provided in the AMEL requests and the available
emissions test data from the test reports described above indicate that
the following list of operating requirements for pressure-assisted MPGF
result in destruction efficiencies at least equivalent to destruction
efficiencies expected from complying with the requirements of 40 CFR
63.11(b) and 40 CFR 60.18(b) for the pressure-assisted MPGF being
proposed for use by both Dow and ExxonMobil:
1. The flare system must be designed and operated such that the net
heating value of the combustion zone gas (NHVcz) for the
pressure assisted flare burners meets a minimum heating value of 800
BTU/scf or a lower flammability limit of the combustion zone gas
(LFLcz) of less than or equal to 6.5 percent by volume under
all conditions. We would expect owners or operators to calculate
NHVcz and LFLcz in a manner similar to those in
the currently proposed requirements of 79 FR 36980-40 CFR 63.670(l)-
(m).
2. The flare system must be operated with a flame present at all
times when in use. Each row of flare burners must have at least one
pilot with a constant pilot flame. The pilot flame(s) must be
continuously monitored by a thermocouple. The time, date and duration
of any loss of pilot flame must be recorded. Each monitoring device
must be maintained or replaced at a frequency in accordance with the
manufacturer's specifications.
3. The flare system must be operated with no visible emissions
except for periods not to exceed a total of 5 minutes during any 2
consecutive hours. A video camera can be used in order to conduct
visible emission observations since operating personnel cannot enter
the fenced area while the MPGF is operating.
4. The operator must install and operate an on-line vent gas flow
meter and an on-line gas chromatograph to measure the flow and
composition of the vent gas to each flare. We would expect the operator
to comply with similar monitoring and testing requirements and
recordkeeping and reporting requirements for these monitoring systems
as currently proposed in 79 FR 36980-40 CFR 63.670(i)-(j) and (l)-(m).
5. The operator should install and operate pressure and/or flow
monitors on each stage of the flare. We would expect the operator to
comply with similar applicable monitoring and testing requirements and
recordkeeping and reporting requirements for these monitoring systems
as currently proposed in 79 FR 36980-40 CFR 63.670(i).
IV. Request for Comments
We solicit comments on all aspects of these requests for an AMEL.
We specifically seek comment regarding whether or not the potential
alternative operating requirements listed in section III above would be
adequate for ensuring that the MPGF will achieve good combustion at all
times and enable the facilities to meet their applicable emission
standards. Additionally, several other entities have indicated to us
that they intend to make similar requests for the ability to operate
pressure-assisted MPGFs. We are also soliciting comment on whether the
requirements listed above, if followed by these other entities, could
enable these other facilities to receive approval of their own AMELs.
As noted in section II.B above, we also solicit comment and data on
other pressure-assisted flare burner types. Commenters should include
data or specific examples in support of their comments.
Dated: February 3, 2015.
Janet G. McCabe,
Acting Assistant Administrator.
[FR Doc. 2015-03064 Filed 2-12-15; 8:45 am]
BILLING CODE 6560-50-P
