Study of performance and emission characteristics of a direct injection diesel engine using rice bran oil ethanol and petrol blends

In this study, influence on the engine performance and exhaust emissions of a naturally aspirated, single cylinder direct injection diesel engine has been experimentally investigated using pure rice bran oil (RBO), and its 2.5%, 5% and 7.5% blends with ethanol (ERBO) and petrol (PRBO). The influence on the viscosity of the RBO with the addition of the ethanol and petrol from 200C to 700C has also been studied. The tests conducted from no load to full load of the engine with an increment of 20%of the load. The experimental test results showed that the kinematic viscosity reduced maximum by 28.3% and 31.7% with addition of ethanol and petrol respectively. The maximum brake thermal efficiency of 26.83% with ERBO2.5 and 27% with PRBO7.5 was obtained. Among the ethanol blends the minimum brake specific fuel consumption of 0.312 is observed with ERBO7.5 and among the petrol blends the minimum brake specific fuel consumption of 0.299 is observed with PRBO2.5 at full load of the engine. Lower CO emissions of 0.021 with ERBO2.5 and higher CO emissions of 0.032 observed with ERBO7.5. The CO emissions of petrol blends observed between the values of ethanol blends. The unburnt hydrocarbons increased with load in both the ethanol and petrol blends. The lower NOx emissions of 920 with ERBO2.5 and higher NOx emissions of 1045 measured with PRBO7.5. The CO2 increased to 3.72 with PRBO7.5 and reduced to 2.45 with ERBO7.5. The unused O2 increased 17.2%with ethanol blends and reduced to 13.1% with petrol blends. The smoke reduced with both the blends and lower value of 34.0% observed with PRBO7.5.