Spark-ignition engine performance with ‘Powergas’ fuel (mixture of CO/H2): A comparison with gasoline and natural gas

Results are presented of tests from a variable compression ratio Ricardo E6 single-cylinder spark-ignition (SI) engine operating on ‘Powergas’—a synthetic fuel consisting mainly of carbon monoxide and hydrogen. The tests cover a range of air/fuel ratios from rich to the lean operating limit at different speeds and two different compression ratios. Measured results are given for brake torque, brake specific fuel consumption and the concentrations of carbon monoxide (CO), oxides of nitrogen (NOx) and total unburnt hydro-carbon (THC) emissions in the exhaust gases. Experimental results indicate that ‘Powergas’ produces about 20 and 30% lower engine power output than natural gas (NG) and gasoline fuelling respectively under similar operating conditions. For ‘Powergas’, concentrations of THC and CO in the exhaust were negligible, but carbon dioxide (CO2) and NOx were found to be higher compared to other fuels. The engine simulation program ISIS has been used to simulate some of the exhaust emissions and the results show agreement with the experimental values and help explain the experimental results.