(194c) Flare Emissions Regulatory Update

ABSTRACT

“Flare Emissions Regulatory Update”

by Kevin Leary, John Zink Hamworthy
Combustion

Several
new regulations have been recently published by the US EPA that will have
significant effects on the design and operation of industrial flares.  This paper will provide a brief summary of
the new requirements that will impact the design and operation of flare systems
typically used in the petrochemical industry.

Proper
control of assist steam, assist air and enrichment fuel gas is required to
ensure smokeless flaring of hydrocarbons with good combustion efficiency.  Historically the EPA requirements to comply
with EPA air emissions standards were focused on designing for a maximum exit
velocity based on the net heating value of the gas stream and controlling the
steam or air assist medium to prevent smoke formation.  Testing has shown that improper control of
the steam or air assist rates can cause emissions outside the EPA standards for
flares.  Based on this testing the EPA
has issued revision of the standards required for flare operation. 

In
December 2015 the EPA published a final rule entitled “Petroleum Refinery
Sector Risk and Technology Review and New Source Performance Standards” under
40CFR Parts 60 and 63.  This standard
adopted several new requirements for the operation of flares for petroleum
refineries.  These new performance
standards add significant changes to the monitoring and control of refinery
flares that is required to ensure compliance with applicable emissions
standards.  Although this ruling only
currently applies to petroleum refineries, many within the petrochemical
industry believe that similar requirements will be implemented in their sector
in the near future.  This paper will
summarize the new measurement and control devices required to properly operate
a flare system to meet these new standards.

In
addition, Multi-Point Ground Flares (MPGFs) have been used for many years as an
effective flare design to minimize the impact of flaring and to allow design
for very high smokeless capacities that are not feasible with conventional
elevated flares.  The EPA requirements
for flare design contained in 40CFR60.18 and 40CFR 63.11 are focused on steam
assisted, air assisted and non-assisted flares. 
These requirements do not allow for the use of high pressure MPGF’s as a
method to comply with EPA air emissions standards since these flares operate at
much higher exit velocity than is allowed in these regulations.  However, recent testing has shown that these
flares can provide high destruction efficiency and very large smokeless
capacity.

In
order to facilitate use of this technology, in August 2105 the EPA published a
notice entitled “Notice of Final Approval for the Operation of Pressure-Assisted
Multi-Point Ground Flares at The Dow Chemical Company and ExxonMobil Chemical
Company and Notice of Receipt of Approval Request for the Operation of a
Pressure-Assisted Multi-Point Ground Flare at Occidental Chemical Corporation”.  In this notice the EPA announced approval of
an AMEL (Alternate Means of Emissions Limitation) for the operation of MPGF’s
at several US sites.  In this same notice
the EPA published a proposed framework for a streamlined approval process for
future AMEL’s using MPGF technology in new flare systems.  Several operators in the petrochemical
industry are proposing using similar MPGF for their new sources.  This paper will discuss the benefits of using
MPGF’s in new petrochemical facilities and summarize the requirements of this
EPA proposed streamlined approval process of AMEL’s to use this flare
technology.