Performance and Emission Characteristics of Compression Ignition Engines Fuelled with Rubber Seed Oil Biodiesel Blended with Ethanol and Diethyl Ether

Abstract

The increasing global demand for sustainable energy and environmental concerns have necessitated the exploration of renewable alternatives to fossil fuels. Biodiesel, derived from vegetable oils and animal fats, presents a viable substitute for petroleum diesel, offering reduced emissions and improved biodegradability. This study investigates the performance and emission characteristics of compression ignition (CI) engines fuelled with rubber seed oil biodiesel blends, incorporating ethanol and diethyl ether as additives. Biodiesel was synthesized via transesterification and blended with petroleum diesel in varying proportions (B20–B100), with 5% ethanol (B20E5–B100E5) and 5% diethyl ether (B20EE5–B100EE5) to enhance fuel properties. The chemo-physical properties of the fuel samples were analysed following ASTM standards, and engine performance tests were conducted under varying loads and speeds. Results indicate that the addition of diethyl ether improved brake thermal efficiency (BTE) and reduced brake-specific fuel consumption (BSFC), while ethanol-blended biodiesel exhibited lower carbon monoxide (CO) and hydrocarbon (HC) emissions. The B80EE5 and B60EE5 blends demonstrated the most favourable performance, balancing efficiency and emissions. The study highlights the potential of rubber seed oil biodiesel with oxygenated additives as an alternative fuel for sustainable CI engine operation.