A Study on Emissions and Catalytic Conversion Efficiency Characteristics of an Electronic Control Engine Using Ethanol Blended Gasoline as Fuels

Abstract

In this paper, the effects of ethanol blended gasoline on emissions and their catalytic conversion efficiency characteristics were investigated in a multiple-point EFI gasoline engine. The results show that with the increase of ethanol concentration in the blended fuels, THC emissions were drastically reduced by up to thirty percent. And brake specific fuel consumption was increased, but brake specific energy consumption could be improved. However, unburned ethanol and acetaldehyde emissions increased. Pt/Rh based three-way catalysts were effective to reduce acetaldehyde emissions, but had low catalytic conversion efficiency for unburned ethanol. The effect of ethanol on CO and NOx emissions and their catalytic conversion efficiency had close relation to the engine's speed, load and air/fuel ratio. Furthermore fuels blended with thirty percent ethanol by volume could dramatically reduced THC CO and NOx emissions at idle speed.