Unregulated Emission Characteristics of EFI Gasoline Engine Fueled with Butanol-Gasoline Blends

In a EFI gasoline engine,unregulated emission characteristics of the engine fueled with conventional gasoline,pure butanol,and 10%,15%,20%,50%,85%(in volume ratio)butanol-gasoline blends were measured respectively.The engine was not any modified.Test results show that engine power,SO2and greenhouse gas emissions decrease with butanol ratio increasing,but SFC and aldehyde emissions increase,and their varying magnitudes increase with the butanol ratio in the blends increasing.As the butanol ratio lowers below 20%,alcohol emissions decrease,and as it exceeds 20%,alcohol emissions increase.It is concluded that addition of butanol in fuel benefits to reducing its sulfur content,therefore reducing sulphuric oxides and greenhouse gas of the engine.