Emission Characteristics of Methanol Fueled Vehicles Using Feedback Carburetion and Three Way Catalysts

Alcohols (both ethanol and methanol) have been recognized as alternative fuels to replace dwindling gasoline supplies. In previous studies, the alcohols have shown a potential for lowering the emissions of regulated species (hydrocarbons, carbon monoxide, oxides of nitrogen.) In order to assess three-way catalyst performance on alcohol fuels, three 1978 Ford Pintos have been retrofitted to run on neat methanol, fuel.

Over 30,000 vehicle miles have been assumulated during an 18-month period. Driveability, fuel economy and emission histories (CVS-78) have been obtained. Regulated emissions levels of all vehicles were below 1983 United States Federal standards throughout 10,000 miles of operation on each vehicle. Aldehyde emissions were a factor of three higher for methanol operation than gasoline. The energy economies for highway and urban driving cycles on the two fuels were comparable.

Catalytic system efficiency for both fuels were evaluated. Conversion efficiency for the regulated pollutants were similar. Aldehyde conversion efficiencies were found to be of the order of 90%.