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R Incorporated Providing Environmental Technical Support Since 1989

1 MEMORANDUM

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 Rentz2 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.3 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.