Formulation and Evaluation of ISO Stoichiometric Gasoline Alcohol Blends in an SI Engine

Abstract

Alcohols, such as ethanol, have been widely used as an alternate fuel in SI engines by blending with gasoline to alleviate the negative effects of climate change and also to achieve energy security for any country. But extensive usage of ethanol blending with gasoline is limited due to biomass limit set by each country due to its impact on food chain sector. On the other hand, methanol, which can be produced from various non-food bio-resources, has the potential to extend the availability of alcohols in transportation sector. To limit the usage of ethanol, a model of ternary blends of Gasoline, Ethanol and Methanol (GEM) has been formulated equivalent to binary blend of gasoline and ethanol, in which reduced volume of ethanol is replaced by relative volumes of methanol and gasoline. The prepared ternary GEM blends have identical stoichiometric Air-Fuel ratio, density, lower heating value and Octane number as conventional binary gasoline-ethanol blend. In the present work, engine tests were carried out to investigate the performance, emissions and combustion parameters of single cylinder four strokes, port fuel injection SI engine fuelled withE10, E20, E30, E40 and E50 binary gasoline-ethanol blends and their equivalent iso-stoichiometric GEM blends. The engine tests were conducted at constant load of 5 kg and vary the speed from 1700 to 3300 RPM by controlling the throttle position. The performance, emission and combustion results were experimentally measured and compared with pure gasoline. The test results showed that formulated iso- stoichiometric GEM blends show similar performance, emission and combustion characteristics as conventional binary gasoline-ethanol blends due to similarity in fuel properties. Artificial Neural Network (ANN) has been used to predict the performance and emission characteristics of engine.