PERFORMANCE AND EMISSION CHARACTERISTICS OF A MEDIUM CAPACITY COMPRESSION IGNITION ENGINE FUELLED WITH MAHUA BIODIESEL EMPLOYING COLD EGR

摘要

Oil provides energy for 95% of transportation and the demand of transport fuel continues to rise. According to the assessment of IPCC (International Panel on Climate Change) to climate change, global oil demand will rise by 60% from 75 Mb/d in 2000 to 120 Mb/d in 2030. All countries including India are grappling with the problem of meeting the ever increasing demand of transport fuel with the constraints of international commitments, legal requirements, environmental concerns, and limited resources. Hence, search for renewable fuels is becoming more and more prominent for ensuring energy security and environmental protection. This has renewed the interest of scientific community to look for alternative fuels of bio-origin which can provide a feasible environmental friendly solution with improved performance characteristics. Biodiesel is produced by a chemical process known as transesterification, by which the triglycerides are reacted with alcohols, in the presence of a catalyst, to produce fatty acid alkyl esters. For quite some time focus for production of biodiesel has shifted towards non-edible oil feedstock from the edible ones, mostly due to food security issues. One such non-edible oil, locally known as Mahua in Indian subcontinent, may be evaluated as a potential feed stock for biodiesel production. The fuel properties were found to be comparable with that of diesel fuel. In the present study, mineral diesel fuel along with 20% (v/v %) blend of Mahua oil methyl ester (MOME) was prepared for conducting experiments and the performance and emission characteristics was investigated at 5%, 10%, 15% and 20% exhaust gas recirculation (EGR) rates. Major observations drawn from the exhaustive experiments is that the brake thermal efficiency (BTE) for M20 increased in comparison to diesel baseline whereas on employing cold EGR, BTE abridged with the increase in EGR rate. Unburned Hydrocarbon and Carbon monoxide emissions as well as Smoke Opacity upsurge with increase in EGR percentage. However, a considerable decline in NO_x was obtained at higher EGR levels.