An Experimental Study on Performance and Emission Characteristics of Vegetable Oil Blends with Diesel in a Direct Injection Variable Compression Ignition Engine

Abstract

In order to meet the energy requirements, there has been growing interest in alternative fuels like vegetable oils, biodiesels, biogas, LPG, CNG to provide a suitable diesel oil substitute for internal combustion engine. Vegetable oils, because of their agricultural origin, due to less carbon content compared to mineral diesel are producing less CO2 emissions to the atmosphere. It also reduces import of petroleum products. In the present paper an experimental study is carried out on an I.C. engine laboratory single cylinder, four-stroke VCR, direct injection diesel engine to analyze the performance and emission characteristics of pure diesel, Jatropha oil and Jatropha oil-diesel blended fuels with various blended rates. The measurements are recorded for the compression ratio of 16, 17 and 18 varying the load from idle to rated load of 3.7kW. Comparative results are given at constant engine speed, variable compression ratio and various engine loads for pure diesel, Jatropha oil and Jatropha oil-diesel blended fuels revealing the effect of diesel, Jatropha oil and Jatropha-diesel blended fuels combustion on engine performance and exhaust emissions. The results show that various parameters such as thermal efficiency, CO and NOX emissions are very close to mineral diesel for lower blend concentrations. But, it is observed that for higher blend concentrations, performance and emissions were much inferior compared to diesel.