Optimization of ignition delay and combustion efficiency in diesel-biodiesel-ethanol blends for compression ignition engine

The growing demand for sustainable energy solutions has intensified interest in renewable fuel alternatives to reduce environmental impact and reliance on fossil fuels. Diesel-biodiesel-ethanol blends, incorporating soybean-derived biodiesel, offer potential advantages in improving engine performance and reducing emissions but present challenges in maintaining efficiency and combustion stability. This study addresses these challenges by evaluating the performance and emission characteristics of these blends in compression ignition engines. The research aims to optimize fuel composition and injection timing to balance performance and environmental benefits. Using a four-cylinder engine, various fuel blends with ethanol contents ranging from 5 % to 20 % and biodiesel derived from soybean oil were tested across different operating conditions. Parameters such as thermal efficiency, specific fuel consumption, ignition delay, and emissions (CO, NOx, and particulate matter) were analyzed. The findings reveal that while ethanol-rich blends reduce CO and particulate emissions by up to 25 % and 30 %, respectively, they increase NOx emissions by approximately 15 %. The study also identifies extended ignition delays and reduced thermal efficiency with higher ethanol content, though optimized injection timing mitigates some efficiency losses. These results underscore the need for advanced injection strategies to maximize biofuel benefits. Future research should explore co-solvents and additives to enhance fuel blend stability and engine adaptability for renewable fuels.