Unlocking the potential of novel ternary non-edible seed oil biodiesel: impact on diesel engine knock intensity, performance, combustion, and emissions

The escalating demand for sustainable energy sources amid dwindling fossil fuel reserves prompts an exploration into innovative biodiesel alternatives for automotive applications. This study investigates a unique ternary mixture comprising non-edible seed oils from Azadirachta indica (Neem), Argemone mexicana (Satyanashi), and Melia azedarach (Bakayan) for biodiesel production and its potential as an alternative to conventional diesel. The ternary blend, extracted using a mechanical oil press, achieved a raw oil yield of 32%. Optimising process parameters, including a 93% biodiesel yield, was attained with a methanol to oil molar ratio of 6:1, 0.6% NaOH by weight, and a temperature of 60°C for 60 min. Performance testing of blends in a computerised single-cylinder, 4-stroke CI engine revealed notable improvements in brake thermal efficiency, with the B80 blend demonstrating the most significant reduction in brake-specific fuel consumption by 8.5%. The B100 blend exhibited the highest brake thermal efficiency at 37.6%. Emission analyses demonstrated reductions in CO and CO2 emissions, with the NOx reduction percentages varying for different blends. Notably, all blends exhibited comparable in-cylinder pressure and ignition delays with diesel, indicating the potential of the ternary seed oil mixture biodiesel as a viable diesel fuel substitute in CI engines.