Experimental investigation on the performance and emissions of extracted biodiesels from mixed Jatropha-Castor seeds: Comprehensive assessment

In pursuit of alternative fuels to reduce fossil fuel dependence and achieve carbon neutrality, this study explores biodiesel from mixed Castor-Jatropha seeds. Combining Jatropha's lower viscosity and higher heating values with Castor's higher yield, various biodiesel blends were obtained and tested in a single-cylinder, four-stroke diesel engine: pure Castor, 75% Castor-25% Jatropha, 50% Castor-50% Jatropha, 25% Castor-75% Jatropha, and pure Jatropha. The study examines the engine performance, emissions, and sustainability of these blends. The results demonstrated that the mixed biodiesels have similar physical and chemical properties to diesel fuel, allowing their application in conventional engines without modifications. The high flash point and cetane number as well as the oxygen content of these biodiesel blends, enhanced combustion stability. Mixed biodiesels exhibited lower HC, CO2, and smoke emissions, but higher BSFC, EGT, and NOx than diesel. The 75% Jatropha and 25% Castor blend exhibited superior performance and lower emissions through Self-Organizing Map analysis (SOM). This blend demonstrates a higher ηth and equivalent fuel consumption to diesel, particularly at high engine loads. Meanwhile, the 75% Jatropha and 25% Castor blend exhibited a reduction in NOx emissions due to its balanced oxygen content. At higher engine loads, the 75% Jatropha-25% Castor biodiesel blend (B60) resulted in a reduction in CO2 emissions by 75% compared to that of pure diesel. Overall, biodiesel from mixed Castor and Jatropha seeds emerges as a viable substitute for conventional fuel in diesel engines, indicating potential advancements in fuel technology in the foreseeable future.