The Influence of Fuel Composition on Emissions of Carbon Monoxide and Oxides of Nitrogen

A theoretical and experimental investigation has been carried out in an attempt to determine the effect of fuel composition on the exhaust emission levels of carbon monoxide and nitric oxide from a reciprocating spark ignition engine. Fuels considered in the investigation were representative of the aromatic, paraffin, cycloparaffin, and olefin families.

Results show that both energy content and hydrogen/carbon ratio of the fuel are instrumental in predicting the carbon monoxide and nitric oxide concentrations present in the exhaust. In addition, it has been shown that a progressive change from paraffinicity to aromaticity is accompanied by an increase in nitric oxide and, to a lesser extent, an increase in carbon monoxide exhaust concentrations.