SINGLE-CYLINDER ENGINE STUDY OF HYDROGEN-RICH FUELS.

Various proportions of hydrogen and gasoline were used to fuel a single-cylinder engine operated at constant compression ratio, speed and airflow, and at MBT spark timing. At these conditions, the equivalence ratio was varied from 0. 9 to 0. 4, and the fraction of fuel energy supplied by hydrogen (HEF) varied from 0 to 1. 0. At any given equivalence ratio, hydrogen enrichment reduced HC emission but increased NO//x emission. Consequently, hydrogen enrichment for reduced HC emission must be accompanied by leaning to hold NO//x constant. A hydrogen-rich fuel that does show potential for in-the-engine control of NO//x, HC, and CO is the product of an on-vehicle hydrogen generator. Gasoline is partially oxidized in the generator to a gaseous mixture of CO, H//2, CH//4, and various diluent gases.