Experimental Evaluation of Performance and Emission Characteristics of a Diesel Engine Fuelled with Neem Methyl Ester

The dwindling fossil fuel resources and the environmental degradation have spurred research interest to find better renewable alternative energy sources. Biodiesel is one such viable promising alternative fuel, which can be extracted from various renewable vegetable oils. In the present study, biodiesel extracted from neem oil is characterized for engine performance and emission analysis is done at various compression ratios (CR) and fuel blends. The brake thermal efficiency (BTE) of the blend B20 is considerably higher than that of diesel at CR 18, 20, and 22. The specific fuel consumption (SFC) increases with diesel blends due to a higher calorific value of diesel in comparison with biodiesel. All the biodiesel blends had lower carbon monoxide (CO) emissions compared with diesel, which indicates better combustion due to the presence of inherent oxygen. At lower CRs, the in-cylinder temperature is lower, which in turn reduces the nitrogen oxide (NOx) emission. The overall engine performance is optimum at CR of 18 with the NB20 fuel blend