Experimental study on combustion, exergy and emission analyses in a dual-fuel compression ignition engine using hydrogen and biodiesel

Hydrogen is a promising energy source for internal combustion engines because of its reliability, production from renewable energy sources, and clean combustion products. Hydrogen could be used in the diesel engine in dual-fuel mode with significant engine modifications. In this research work, combustion and exergy analyses were carried out to investigate the performance of the dual-fuel engine employing diesel and frying oil methyl ester (biodiesel) as a pilot fuel. In the compression ignition engine, the hydrogen is fumigated with the intake air stream at different volume flow rates of 3, 6, and 9 litres per minute, biodiesel as a pilot fuel. A diesel engine is modified and operated as a dual-fuel engine with biodiesel as a pilot fuel. The maximum brake thermal efficiency of the dual-fuel engine with biodiesel (B100) is 34.10%, 32.04%, 30.79%, and 29.82% corresponding to different hydrogen energy shares of 9.89%, 6.19%, 2.97%, and 0% is observed at the rated load condition. The maximum exergy efficiency of 46.34% is achieved with dual fuel engine using hydrogen fumigation at the engine rated load. The unburnt HC, CO, and smoke emissions are observed to be decreased with an increase in the hydrogen flow rate. [Received: May 21, 2025; Accepted: October 6, 2025]