Influence of Varying the Compression Ratios on the Emission and Performance Parameters of Pumpkin Seed Biodiesel Blend Fueled Diesel Engine

Depletion of fossil fuel reserves has led the researchers to work on identifying the substitute to be used as a fuel in internal combustion engines. Blending up to 20% biodiesel with mineral diesel is widely accepted among the research community. But, the lack of study on the effect of varying the compression ratios on the performance and emission behaviour of the blended biodiesel fuel led to this present study. This study was carried out on a variable compression ratio direct injection compression ignition engine using pumpkin seed biodiesel as fuel, which was blended at different compositions (20% pumpkin seed biodiesel-diesel and 50% pumpkin seed biodiesel-diesel) and tested at various compression ratios (viz., 17:1, 17.5:1, 18:1). D80PSB20 fuel blend produced higher brake thermal efficiency along with lower brake specific energy consumption. HC, CO, and smoke emissions were lower compared to the mineral diesel. But, oxides of nitrogen was higher due to attainment of higher cylinder temperature. Among all tested fuel blends, D80PSB20 was found to be the best fuel composition and the compression ratio of 18:1 was found to be the best to produce better performance with reduced emissions characteristics.