Combustion Characteristics of the Mustard Methyl Esters

Abstract

Mustard Methyl Esters (further biodiesel) and regular diesel fuel were tested in direct injection diesel engine. Analysis of experimental data was supported by an analysis of fuel injection and combustion characteristics. Engine fuelled with biodiesel had increased brake specific fuel consumption, reduced nitrogen oxides emission and smoke opacity, moderate increase in carbon monoxide emission with essentially unchanged unburned hydrocarbons emission. Increase in fuel consumption was attributed to lesser heating value of biodiesel and partially to decreased fuel conversion efficiency. Analysis of combustion characteristics revealed earlier start of injection and shorter ignition delay period of biodiesel. Resulting decrease in maximum rate of heat release and cylinder pressure was the most probable reason for reduced emission of nitrogen oxides. Analysis of combustion characteristics also showed that cetane index determined by ASTM Method D976 is not a proper measure of ignition quality of biodiesel. Conclusion was made on applicability of mustard oil as a source for commercial production of biodiesel in Pakistan. Potentialities of on improving combustion and emissions characteristics of diesel engine by reformulating biodiesel were discussed.