MEMORANDUM  SEQ CHAPTER \h \r 1    

TO:		Melanie King, EPA OAQPS/SPPD/ESG

FROM:	Bradley Nelson, EC/R, Inc.

DATE:		January 15, 2010

SUBJECT:	Summary of the October 20, 2009 Teleconference with Exterran
and the U.S. Environmental Protection Agency to discuss the Proposed
NESHAP for Existing Stationary Spark Ignition Reciprocating Internal
Engines

1.0	INTRODUCTION

Exterran requested this teleconference with EPA to discuss the proposed
national emission standards for hazardous air pollutants (NESHAP) for
existing stationary reciprocating internal combustion engines (RICE). 
The main focus of the discussion was on the proposed emission standards
for two-stroke lean burn (2SLB) engines.  This meeting summary will be
available in the docket for this rulemaking (Docket ID No.
EPA-HQ-OAR-2008-0708).  The proposed NESHAP for existing stationary RICE
was published in the Federal Register on March 5, 2009 (74 FR 9698).  

2.0	ATTENDEES

U.S. Environmental Protection Agency

Melanie King, OAQPS/SPPD/ESG

Michael Horowitz, OGC

Exterran

Mike Wasson

Bill Bowes

James Harrison 

Kyle Jantzen 

Bracewell & Giuliani

Jeff Holmstead

Rebecca Rentz

JW Power Co.

John Dutton

Compressor Systems Inc.

David O’Leary

EC/R Incorporated

Bradley Nelson

3.0	SUMMARY OF MEETING

Exterran stated that it has approximately 1,000 stationary 2SLB engines
operating in the field.  Nearly all of these 2SLB engines are
manufactured by Ajax, and none are equipped with oxidation catalyst. 
Exterran believes that the emission standard for 2SLB engines should not
be based on the use of an oxidation catalyst because it is not cost
effective.  In addition, Exterran believes that there are technical and
reliability issues with retrofitting an existing 2SLB engine with an
oxidation catalyst in the field.  Exterran estimated the cost per ton of
using an oxidation catalyst on a 2SLB engine to be $120,000 per ton of
HAP removed.  This value was calculated using vendor cost data and
assuming 90 percent reduction of hazardous air pollutants (HAP). 
Exterran stated that oxidation catalysts typically only achieve 60-70
percent HAP reduction.  EPA asked if Exterran could provide the vendor
costs.  Exterran responded that they would provide the cost information
to EPA. 

Exterran stated that Cooper, Clark, and Ingersoll-Rand engines in the
range of 1,500-2,000 horsepower (HP) used for compression would need
manifold work and new ignition systems for the oxidation catalyst to
operate properly.  Exterran believes even with these modifications, 90
percent reduction of HAP is not guaranteed.  Exterran also stated that
many of these compressor systems are integrated units (e.g.,
engine/compressor) and therefore, would in many cases need to replace
the whole unit.  Exterran added that older engines are not fuel injected
and the combustion system would need to be upgraded before an oxidation
catalyst could be retrofitted.

Another issue raised by Exterran was whether 90 percent HAP reduction
could be achieved using an oxidation catalyst.  Exterran believes that
2SLB engines have insufficient exhaust temperatures to oxidize 90
percent of the HAP in the exhaust stream.  Exterran stated that exhaust
temperatures of 600-650 degrees Fahrenheit (°F) are needed for
effective operation of the oxidation catalyst, and a 360 HP Ajax 2SLB
engine has an exhaust temperature of 350-400 °F.  In addition, Exterran
noted that the oxidation catalysts create backpressure in the engine
exhaust.  EPA responded that the information that it has reviewed shows
that an oxidation catalyst can be effective at exhaust temperatures as
low as 450 °F.  Exterran stated that it would like to receive the data
that shows the catalyst in operation.  Exterran noted that has not seen
any data that shows that oxidation catalyst will achieve effective HAP
reductions from stationary 2SLB engines.

The Exterran group asked EPA if they have received any information on
the proposed extension for SI engines.  EPA responded that they have not
received any new information regarding the extension for SI engines.

E C/R Incorporated	Providing Environmental Technical Support Since 1989



	

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