Performance, combustion, and emission characteristics of DI diesel engine using mahua biodiesel

This chapter mainly focuses on the production of biodiesel from mahua oil and the study its performance, combustion, and emission characteristics as a fuel in a diesel engine. Response Surface Methodology (RSM) based on Central Composite Design is used to optimize the transesterification parameters. The maximum biodiesel yield of 95.4% was obtained at optimum conditions of 9:1 M ratio, 1.25% catalyst, 45°C temperature for 120 min and 800 rpm stirrer speed. For the engine study, the performance characteristics at a rated load revealed that the brake thermal efficiency (BTE) decreased with increasing the biodiesel concentration. BTE obtained for mahua biodiesel (B100) was 3.5% lesser compared to diesel due to its higher viscosity and lower calorific value. Brake specific energy consumption for mahua biodiesel (B100) was 36% higher than diesel. Ignition delay for the biodiesel was lower than diesel due to higher oxygen availability in biodiesel. Unburnt hydrocarbon (UBHC) and smoke (FSN) emission were decreased by 22% and 23% compared to diesel at rated load. Nitric oxide (NO) emission was increased with increasing biodiesel concentration. At rated load, NO emission for mahua biodiesel was 6% higher than diesel. Higher oxygen content and complete combustion will lead to lower unburnt hydrocarbon and smoke emission for biodiesel and its blends compared to diesel.