Butanol-gasoline blends impact on performance and exhaust emissions of a four stroke spark ignition engine

This study examined the possibility of finding an alternative fuel to replace the Iraqi-origin gasoline. Iraqi gasoline has high levels of lead and sulfur compounds, so the pollutants emitted from it are very dangerous to human health and the environment. In the current study, butanol was added to gasoline with volume fractions of 25%-75% gasoline (G75B25) and 50% butanol to 50% gasoline (G50B50). The influence of these two alcohol ratios of blending on the performance and exhaust emissions of engine were compared. This study aims to provide a clean and healthy fuel as an alternative to gasoline of Iraq with low combustion emission content.The results revealed that mixing gasoline with butanol led to better engine performance and lower exhaust emissions compared to the case of gasoline fuel alone. When comparing gasoline with G75B25 blend, it shows a relative decrease in the specific brake consumption (bsfc) of about 2% while (bsfc) was increased by 2.38% when G50B50 was used compared to gasoline. The CO emissions were reduced by 27.79% and 39.11%. Also, HC levels were reduced by 15.93% and 28%, respectively, compared to gasoline. The studied blends reduced noise levels by 1.64% and 3.93%. The obtained results confirm the possibility of adopting any of the two studied blends as a suitable alternative to gasoline and friendly to the Iraqi environment.