Methanol Fumigation of a Light Duty Automotive Diesel Engine

An Oldsmobile 5.7 ℓ V-8 Diesel engine was fumigated with methanol in amounts up to 40% of the fuel energy. The primary objectives of this study were to determine the effect of methanol fumigation on fuel efficiency, smoke, nitric oxide emission, and the occurrence of severe knock. An assessment of the biological activity for samples of the raw exhaust particulate and its soluable organic extract was also made using both the Ames Salmonella typhimurium test and the Bacillus subtilis Comptest.

Results are presented for a test matrix consisting of twelve steady state operating conditions chosen to reflect over-the-road operation of a Diesel engine powered automobile. Generally methanol fumigation was found to decrease NO emission for all conditions, to have a slight effect on smoke opacity, and to have a beneficial effect on fuel efficiency at higher loads. Also at higher loads the methanol was found to induce what was defined as “knock limited” operation. While the biological activity of the raw particulate was generally found to be lower than that of the soluble organic fraction, the fumigation of methanol appears to enhance this activity in both cases.