A catalytic combustor was designed and tested for a small recuperated gas turbine engine for use in a hybrid electric vehicle (HEV). Combustor rig and engine tests were performed with DF-2 diesel fuel, kerosene, and automotive gasoline. Rig test steady-state emissions were measured over the full engine operating range. Nitrogen oxides (NOx) emissions were insensitive to operating condition, and were almost strictly a function of fuel nitrogen content. For low-nitrogen kerosene, NOx emissions less than 1 ppm(vol) (at 15 percent O2) were demonstrated. Startup emissions were measured for conditions modeling engine spoolup from ignition to full speed.
Laboratory engine tests on DF-2 over a range of speeds and loads demonstrated tailpipe emissions less than 10 ppm(vol) NOx and less than 1 ppm(vol) unburned hydrocarbons (HC). NOx, HC, and carbon monoxide (CO) emissions were less than the California State Ultra-Low Emissions Vehicle (ULEV) standards for steady-state operation, corrected for assumed vehicle load and fuel consumption rate.