Effects of Different Biodiesel on Diesel-Engine Performance and Emissions

In this paper, the emissions characteristics and performance of a direct four-stroke diesel engine fueled by three different kinds of biodiesel oils and normal diesel oil (DF) has been experimentally investigated. Biodiesel fuels of Palm, Coconut and Sunflower have been separately used as an alternative fuel and the results obtained have been compared with that results obtained using DF at the same operating conditions. The results indicated that a higher Brake Thermal Efficiency (BTE) has been obtained when using the Coconut fuel. For moderate engine speed, the use of biodiesel produces high Brake Specific Fuel Consumption (BSFC) up to 22% in comparison with that obtained using normal DF. The BSFC of sunflower fuel at the maximum torque has been observed to be 10% higher than when using normal diesel oil. For moderate engine speed, the measured amount of carbon monoxide (CO) emissions when using either Sunflower, Palm or Coconut as a biodiesel fuel have been found to be lower than that obtained by using the DF. For low engine speed, the emissions of NOx for all three kinds of biodiesel fuels is lower than when using normal DF. Most importantly, the results indicated that the biodiesel fuels have significant impact on the emissions characteristics and performance of engine and hence biodiesel fuel can be directly used for normal engine system. Therefore, adequate care must be taken while selecting such a biodiesel fuel in order to meet the process requirement of the environment.