Experimental investigation on a diesel engine fuelled with biodiesel produced from waste cooking oil

Petroleum product resources are limited and their consumption is increasing very fast with globalization and high technology development since last decade. Since the prices of these products are on the rise, so there is a need to search for an alternate source, which would fuel the Automobiles without any major engine modifications. Diesel engines are used for most of the engineering applications because they have low specific fuel consumption and higher thermal efficiency compared to petrol engines. However inspite of these advantages the oxides of nitrogen and smoke emission from the diesel engines cause serious environmental concerns. Waste cooking oil and other non-edible oil (Mahua oil, Karanja oil, Jatropha oil) pose some problems when subjected to prolong use in diesel engines. The problems are attributed to its high viscosity and low volatility. These problems can be minimized by transesterification process which is a reversible reaction between the triglycerides present in vegetable oil and alcohol in presence of a base catalyst to produce mono alkyl ester which is commonly known as biodiesel and glycerol. Molecular weight of biodiesel is one third of that diesel and therefore has a low viscosity. The fuel properties for biodiesel were evaluated and compared with that of diesel. These characteristics include specific gravity, density, viscosity, pour point, flash point, fire point etc. The biodiesel was then blended with diesel in various volume proportions to prepare a number of test fuels which were tested in a single cylinder diesel engine to study the various engine performance parameters and compare those with that of diesel. The results show highest brake thermal efficiency with B60 blend, highest brake specific fuel consumption and exhaust gas temperature with pure biodiesel.