Multicriteria Decision-Making Technique for Choosing the Optimal Ammonia Energy Share in an Ammonia-Biodiesel-Fueled...

Low-temperature combustion paired with the use of carbon-free ammonia and carbon-neutral biofuels is a novel approach for improving performance, reducing greenhouse gases, and reducing regulated emissions. Reactivity-controlled compression ignition (RCCI), a low-temperature combustion technology, dramatically reduces NOx and smoke emissions compared to traditional engines. Ammonia can be projected as a good transit fuel in the journey toward achieving net zero emissions and cleaner energy. This study examines the impact of ammonia energy premixing fraction (AEPF) (20, 30, 40, and 50%) as a low-reactive fuel (LRF) and algal biodiesel as a high-reactive fuel on the performance and emission characteristics of a single-cylinder, water-cooled 3.5 kW CI engine at a constant speed of 1500 rpm under various loading conditions. The research results indicate that the 40% ammonia share RCCI mode exhibited a reduction in carbon dioxide (CO₂) by 14.16%, nitrogen oxide (NOx) by 22.6%, and smoke by 42.1%, with an 11.5% improvement in thermal efficiency compared to the neat biodiesel-fueled conventional engine. Furthermore, the analytical hierarchy process (AHP) will be used in conjunction with the technique for order of preference by similarity to ideal solution (TOPSIS) of multiple criteria decision-making techniques to determine the optimal energy share in the RCCI combustion with the goal of achieving superior thermal efficiency and lower emissions. According to the AHP-TOPSIS study findings, AEPF40 is the best choice for all engine loads.