Vegetable oil and its esters (biodiesel) are the renewable alternative fuels that can be used as a substitute for diesel in the diesel engines. The vegetable oil fuelled diesel engine results in lower efficiency and higher smoke emission. Hence in this work, an attempt has been made to use inedible and under utilised mahua oil (MO) as a substitute for diesel by fumigating liquefied petroleum gas (LPG) along with the air. A single cylinder diesel engine was modified to work in dual fuel mode by suitable retrofitting. The MO was injected into the cylinder using a fuel pump and LPG was fumigated along with the air. In MO + LPG dual fuel mode, 9% increase in brake thermal efficiency and 35% reduction in smoke emission of the engine were observed as compared to the sole fuel mode with MO. Also, the engine performance characteristics in MO + LPG dual fuel mode are close to sole fuel mode with diesel. From this work, it is concluded that LPG can be fumigated along with the air to increase the performance of MO fuelled agricultural diesel engine.
Keywords: alternative fuels, mahua oil, liquefied petroleum gas, LPG, dual fuel mode, engine performance, emissions, biodiesel, vegetable oil, diesel engines, brake thermal efficiency, agricultural engines