Performance analysis and comparison of the spark ignition engine fuelled with industrial by-product hydrogen and gasoline

The global push for carbon neutrality in internal combustion engines has driven research into low-carbon or zerocarbon fuels for the transportation sector. Hydrogen, as a carbon-free, high-density, and secondary energy source, can be obtained on large scales during the petroleum refining process as industrial by-product hydrogen (IPH). In this work, the IPH is firstly used and tested in the spark ignition (SI) engine. In, addition, the impacts of operating and controlling parameters on the performances of the SI engine fuelled with IPH are investigated and compared with the engine fuelled with gasoline. The experimental results indicate that the CA 10 and CA50 locations of the SI engine fuelled with IPH initially advance and then retard with increasing load. Meanwhile, its brake specific gas consumption decreases, while the brake thermal efficiency (BTE) increases. The results demonstrate that NOx emissions of the test SI engine fuelled with IPH increase, while the CO and HC emissions reduce with increasing the load and remain relatively low under medium load conditions. The optimum spark timing of the SI engine fuelled with IPH achieves a balance between the BTE and emissions. In addition, the combustion phasing of the SI engine fuelled with IPH advances and its combustion duration shortens compared to the test gasoline engine. Additionally, the SI engine fuelled with IPH outperforms the gasoline engine in terms of fuel economy, and its BTE increases by 15.39% and 11.58% under loads of 2.5 bar and 5 bar, respectively. Compared to the gasoline engine, the NOx emissions of the test SI engine fuelled with IPH slightly increase while its CO and HC emissions are reduced by more than 90%.