Effect of hydrogen‐enriched biogas induction on combustion, performance, and emission characteristics of dual‐fuel compression ignition engine

Gaseous fuel induction in a compression ignition (CI) engine has picked up much attention over the most recent few years, particularly when it is produced by using renewable sources. In this study, hydrogen‐enriched biogas (HEB) was used as a gaseous fuel and co‐combusted in dual‐fuel CI engine. Experimentation was carried out on a 3.5‐kW CI engine test rig in the brake mean effective pressure range between 0 and 3.5 bar, as well as, HEB between 0.1 and 0.5 kg/hr. HEB induction effects on various engine characteristics (combustion, performance, and emission) were studied at rated engine speed (1,500 rpm). Results revealed that the peak cylinder pressure and ignition delay period increased with increasing HEB proportion (0.1 to 0.5 kg/hr) as compared with diesel mode. The calorific value of HEB (57.0 MJ/kg) is higher than diesel (42.0 MJ/kg), which led to improved BTE in dual‐fuel mode. The emission results showed that with an increase of HEB rates, the NOx emission mildly decreases, but smoke opacity and hydrocarbon emissions majorly reduce. Thus, the HEB induction has great potential to be a feasible technological solution to overcome low BTE and high hydrocarbon emissions in biogas operated CI engines.