Exhaust Emission Characteristics of an Un-Modified Diesel Engine Operated on Bio-Diesel Fuels

Abstract

Among the biomass-based fuels, plant oil esters (bio-diesel) hold good promise as an alternate fuel for compression ignition (CI) engines, especially during periods of diesel shortage. A study on the use of bio-diesels in an unmodified diesel engine was carried out in the Deptt. of Farm Power and Machinery, Punjab Agricultural University, Ludhiana. A commercially available single cylinder 3.67 kW, direct-injection diesel engine was fuelled with bio-diesels made from five different feed stocks, namely, linseed, rice-bran, gobhi sarson (Brassica napur), sunflower and jatropha curcas. The exhaust emission characteristics of these fuels were studied. "Nucon" Multi Gas Analyzer (model MGA) was used to monitor the concentration of combustibles, carbonmonoxide (CO) and oxides of Nitrogen (NOx) in the exhaust gases. The combustible concentration was found to be in the range of 0.1 to 0.167 % for all the bio diesels studied. However, the oxides of Nitrogen (NOx) was found to be 0.2 to 26% higher as compared to petro-diesel. Among different feed stocks, the sunflower oil based bio-diesel had the highest NOx emissions (26% higher). Carbon monoxide emissions of all bio-diesels were observed to be 25 to 45% lower as compared to petro-diesel. The lowest CO emissions were observed for sunflower oil based bio-diesel. Similarly, the combustible emissions for all bio-diesels were observed to be lower as compared to petro-diesel.