Sustainable waste to energy approach using waste derived biodiesel diesel and ethanol blends in a CRDI diesel engine

Automobile emissions have significantly intensified environmental degradation, contributing to climate change. Extensive research is underway to identify alternative fuels that can be renewable and enhance engine efficiency while minimising emissions. This study evaluates the performance and emission characteristics of a diesel engine powered by novel ternary blends of diesel, biodiesel derived from waste cooking oil (WCO), waste plastic oil (WPO), and ethanol (DBE blend). The blends were tested at varying load conditions and cold Exhaust Gas Recirculation (EGR) rates of 7% and 14% on a single-cylinder, 4-stroke, and 3.2 kW power CRDI (Common rail direct injection) diesel engine. Biodiesel was synthesised via a two-step esterification process, meeting ASTM standards. Key findings include improved BTE and reduced emissions with increased ethanol content. The D40CB10E10 blend demonstrates the highest BTE among the biodiesel blends. EGT decreases with rising ethanol content compared to diesel. The D60CB20E20 blend exhibited the lowest NOx emissions (9.98% lower than diesel) and the lowest smoke density. Ethanol's oxygenation and heat of vaporisation improved combustion, reducing EGT and CO emissions. However, HC emissions increased with ethanol. These results demonstrate that DBE blends can enhance engine efficiency and reduce emissions, offering a sustainable alternative to conventional diesel.