Performance and Emission Optimization of a Diesel Engine using Karanja Biodiesel–Hydrogen Dual-Fuel with Azadirachta indica Antioxidant

Renewable fuels are critically required for internal combustion engines because of environmental degradation and the exhaustion of fossil fuels. Hydrogen, possessing a higher auto-ignition temperature and zero emissions has recently surfaced as a feasible alternative to biodiesel and other renewable fuels. Integrating hydrogen with an alternative liquid fuel and operating the engine in dual-fuel mode reduces the self-ignition temperature of the compression ignition engine. This study aims to investigate the impact of including a natural antioxidant on the performance of a diesel engine operating on biodiesel with an elevated hydrogen concentration. During the testing method, hydrogen is injected into the system by the intake manifold, while a B15 mixture of Karanja biodiesel is delivered into the combustion chamber. The experimental fuel samples comprised Diesel, B15, and B15 augmented with hydrogen at flow rates of 6, 9, 12, 15, and 18 lpm. The combination of B15 with hydrogen results in an enhancement of brake thermal efficiency (BTE). Blends of B15 with 15 liters of gasoline and B15 with 18 liters of gasoline demonstrated superior performance compared to the traditional engine at full load CO, achieving BTE improvements of 28.60% and 27.62%, respectively. HC emissions from B15 at 15 lpm and B15 at 18 lpm are reduced in comparison to other mixtures, however NOx emissions from diesel are elevated by 25 and 27 %, respectively. The combination of B15 + 15 lpm with 1000 ppm of Azadirachta indica (AI), a natural antioxidant, diminished NOx emissions to 1074 ppm, reflecting a reduction of 21.9% relative to B15 + 15 lpm without AI. The outcome was a 2.17% enhancement in BTE relative to B15 + 15 lpm without AI. Consequently, numerous test mixes are inferior than B15 + 15lpm with additive