LAUSR

ABSTRACT Bio-alcohol has the potential to be used as an alternative to fossil fuels to reduce the total exhaust emissions from spark-ignition engines. This paper reviewed the most recent experimental studies on fundamental effects of performance, emissions and some combustion characteristics in SI engines. It also provides a guideline for suitable ethanol-gasoline and methanol-gasoline blend rates. Investigations were performed on different engines, operating conditions and rates of fuel blends with varying engine speeds. Most of the results showed that ethanol-gasoline has more benefits compared to methanol-gasoline in terms of exhaust emissions, engine power, and torque output, especially at low engine speed. The small differences in properties between ethanol-gasoline and methanol-gasoline blends are enough to create a significant change in the combustion system. These effects lead to behavioural mechanisms which are not easy to analyze or understand, sometimes make it difficult to identify the fundamentals of how ethanol or methanol affects emissions.