Performance and Emission Characteristics of Vateria Indica Oil as Alternative Fuel for Petrodiesel in CI Engine

Abstract

Vateria Indica Linn seeds contain nearly 19% oil/fat which can be converted into biodiesel by normal method of esterification followed by transesterification generally adopted for high FFA oils. Biodiesel is a promising alternative fuel for CI engines. In the present work, study of the combustion, performance and emission characteristics of a CI engine fuelled with Vateria Indica biodiesel blends at 180 bar, 200 bar and 220 bar injection pressures (IP) and injection timings at 19obTDC, 23obTDC and 27obTDC (before TDC) is carried out. Blending is done in volumetric ratios of 10%, 15%, 20%, 25% of biodiesel with diesel which are called as B10, B15, B20, B25. Increasing fuel injection pressure promotes atomization, and full penetration into the combustion chamber leading to better combustion. Blend B25 showed better thermal efficiency of the order of 33.03% and minimum NOX emission of 1047ppm at 220 bar injection pressure and 75% Load. Advancing the injection is proved to be advantageous because of longer residence time and complete combustion with thermal efficiency of the order of 37%, but it also causes higher NOX and soot emissions. Blend is restricted to 25% due to low cetane number of biodiesel which causes severe knocking problem at higher blends. Due to high NOX emission with the blend (B25), NOX mitigation technique like hot EGR is adopted to the extents of 5% and 10%.Finally, it is concluded that blending up to25% can be adopted with 10% EGR at 220 bar injection pressure with 27obTDCinjection timing for better performance, combustion and emission characteristics.