A comparison of gasoline, methanol and propane on S.I. Engine performances.

Abstract

Methanol has emerged as a near-term alternative to hydro-carbon fuel. On the one hand, in Japan, LPG fuel has been utilized for the Taxi as an alternate to gasoline in respect of economy. This paper reports a comparison of methanol and propane as LPG fuel to base gasoline on S. I. engine performance. The results obtained are as follows: (1) the compression ratio is as high as 12:1; the maximum methanol and propane engine output is higher by approximately 20% and 8% respectively than the base gasoline engine. (2) brake thermal efficiency of the methanol and propane engine is better than the base gasoline engine, but the difference becomes smaller as the engine output becomes lower. (3) engine out emission level of methanol fuel are lower than gasoline, especially for NOx and THC; but the NOx level of propane fuel is higher than that for gasoline.