PR-84-148-R01 Monitoring Engine Operation as a Substitute for Continuous Emission Monitoring

The NOx emissions versus engine operating parameter setting profile was established during performance/emissions mapping tests of a two-stroke turbocharged (Cooper-Bessemer GMVH-lOM) compressor station engine. Rased on this profile the operating envelope corresponding to NOx emissions below 700 ppm (corrected to 15 percent 02) for this engine was defined. Engine emissions and operations were then continuously monitored for a 4-week period in which the engine ran in response to station demands. Over this extended monitoring period, NOx emissions from the engine were always less than 700 ppm provided engine operation was in accordance with the defined operating envelope. This implies that monitoring appropriate engine operating parameters would be an acceptable substitute for continuous engine exhaust emissions monitoring for demonstrating continuous compliance with a regulated emission limit.