Emission Benefits from the Use of Castor Oil in a Compression Ignition Engine Fuelled with Diesel-Ethanol Blends

Abstract

Castor oil which is produced from non-food crop and contains high proportion of ricinoleic acid was added to ethanol-diesel blend, forming the ternary blend. The extremely high viscosity and good lubricating properties of castor oil were expected to restore the substantial reduction in such fuel properties due to the presence of ethanol in the blend. The basic physical and chemical properties of the test fuels were measured according to ASTM standards and the engine test was conducted on a four-cylinder direct injection diesel engine with naturally aspirated and water-cooled system. The experimental results showed that the high viscosity, density, flash point of castor oil can help to improve the properties of the fuel blend due to some poor properties of ethanol leading to keep the fuel properties of the ternary blend under the limit of diesel fuel specifications. The emission benefits of the reduction in CO, NOx and smoke emissions were obtained by the combustion of the ternary blend without the significant increase in THC emissions at high engine operating loads, compared to diesel fuel combustion. It is evident that the incorporation of castor oil and ethanol as blend components to reduce the use of diesel fuel for compression ignition engines is a feasible alternative for next generation fuels. 