Performance Analysis of a Diesel Engine Fuelled with Soybean Seed Biodiesel-Diesel Blends

Abstract

In this investigation, the biodiesel produced from soybean crude oil was prepared by transesterification using potassium hydroxide as catalyst and was used in four stroke, single cylinder variable compression ratio type diesel engine. It has been observed that using straight vegetable oils cause operational and durability problems when subjected to long term combustion in C.I engines. These problems are mainly due to high viscosity, low volatility and polyunsaturated character of vegetable oils. The process of transesterification is found to be an effective method of reducing vegetable oil viscosity and eliminating operational and durability problems. The important properties of methyl ester of soybean oil (SBD) were compared with those of diesel. Diesel and biodiesel were used as fuels in the compression ignition engine, and its performance, emissions and combustion characteristics of the engine were analyzed. The results showed that biodiesel exhibited the similar combustion stages to that of diesel. Tests were carried out at a rated speed of 1500 rpm at different loads. The engine performance was analyzed with different blends of biodiesel and was compared with petroleum diesel. The brake specific fuel consumption was higher for biodiesel due to its lower heating value. Biodiesel provided significant reduction in CO, HC, NO_x and smoke under speed characteristic at full engine load. The results proved that the use of biodiesel in compression ignition engine is a viable alternative to diesel.

Keywords: Soybean Biodiesel, Diesel Engine, Emission Parameters, Brake Thermal Efficiency, Hydrocarbon, CO, No_x.