Performance Evaluation of a Medium Capacity Diesel Engine on Thumba Biodiesel and Diesel Blends

The world has witnessed industrial revolution in the past two centuries and faced serious problem of indiscriminate utilization of the energy resources. This has resulted in severe environmental degradation and very high dependence on fossil fuels. Researchers all over the world are experimenting on variety of renewable fuels for meeting future energy demands and biodiesel is fast becoming a potential alternative fuel for use in agriculture and transport sector. There are many varieties of feedstock which are used for biodiesel production worldwide; however, there is an urgent need to explore the potential of biodiesel from variety of locally available sources. Thumba is one such species found in Rajasthan State of India and this paper highlights the results of investigations carried out on assessing potential of biodiesel derived from Thumba oil and its blends with mineral diesel (B10, B20, B40, B60, B80, B100) in a medium capacity, single cylinder, direct injection, water-cooled diesel engine. The performance test was carried out at different loads and brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) were evaluated. The exhaust gas temperature and exhaust emissions (CO, CO₂, HC, NOₓ, and Smoke Opacity) were also recorded. The highest BTE was achieved in case of B10. As the concentration of biodiesel was increased in biodiesel-diesel blends, a reduction in BTE was observed. The exhaust gas temperature was found minimum in case of B10 and maximum for B100. The CO, HC and Smoke opacity were found lower for biodiesel based fuels than neat diesel. The CO₂ and NO ₓ emissions were found higher in case of biodiesel based fuels. The results suggest that Thumba biodiesel can be used as an extender to diesel fuel, which would results in better performance and improved emission characteristics.