Experimental study of a clean burning vehicle fuel

Preliminary research into the advantages of hydrogen-enriched compressed natural gas (CNG) as a motor fuel has been conducted. The objective of this research was to determine if the lean limit of CNG could be extended by the introduction of hydrogen. The hypothesis, based on previous research, was that the leaner the engine could be run without going into lean misfire, the lower the NOx would be while only incurring moderate increases in the hydrocarbons. The result of the tests demonstrated that extremely low levels of NOx are possible with acceptably moderate increases in unburned hydrocarbons using 28 and 36% hydrogen supplementation.