The effect of using an ethanol blended fuel on emissions in an SI engine

Abstract

The economic impact of limited fossil fuel resources plus the mandatory limit for carbon dioxide (CO2) emissions become important factors to developing alternative fuels for internal combustion engines. Ethanol (CH3CH2OH) blends are considered as alternative fuels due to their ability to reduce the greenhouse exhaust emissions. This study highlights the effects of unleaded gasoline (E0) and ethanol-unleaded gasoline blend E30 (with 30% volume of ethanol) on engine performance and exhaust emissions experimentally using a 1.4 litre four cylinder four stroke SI engine with a compression ratio of 9:1, for a variety of load and engine speed conditions.. The results indicate that the blend E30 slightly increases the engine’s torque and power after mid-engine speeds together with fuel consumption. However, exhaust emissions at 25% open throttle sees a reduction of carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbons (HC) whilst nitrogen oxide (NOX) emissions increase at the lower speeds. At full throttle, E30 reduces the CO considerably whilst CO2 and NOX increase. Similar quantities of HC are produced.