L22274 Exhaust Emissions from Piston and Gas Turbine Engines Used in Natural Gas Transmission

A baseline emissions survey was conducted on stationary gas turbines and reciprocating engines used in natural gas transmission. A total of 59 reciprocating engines and nine gas turbines were tested over a ten-month period at ten different sites. Details are provided on the test procedure used and its development.Emission rates for all tests were calculated. For piston engines, emission rates were determined at or near the rated speed and load, and comparisons were made. Comparisons were also made between two and four stroke engines, as wells as turbocharged and normally aspirated versions of the same engine. Emission trends for a number of piston engines were developed as a function of engine operating parameters, such as ignition timing, scavenging air pressure, engine speed, and load. Gas turbine NOx concentrations were compared to the level currently under discussion as a possible proposed Federal standard.