Unleaded gasoline-azeotropic ethanol blends as fuels for spark ignition engines

Among the search for fuel alternatives for spark ignition engines special attention is directed recently towards the evaluation of ethanol and ethanol-gasoline blends as it was once again popular in the past. In this study, the use of unleaded gasoline containing 10% by volume azeotropic ethanol (containing 4.4 % water by weight and having a boiling point of 78.15°C) as a fuel alternative was investigated. Experimental procedure consisted of several steps as solving the stability problem of the ethanol-gasoline blends by (a) introducing fusel oil as the new blending agent; (b) determining the ASTM fuel properties of the homogenous - stable blend fuel thus prepared and (c) comparing the engine performance characteristics and exhaust emission values of the fuel alternative candidate with those given for gasoline. Both the fuel property tests and engine performance tests of the blend fuel gave very promising results.