Performance, combustion, and emission characteristics of on a diesel engine fuelled with hydrogen compressed natural gas and Kusum seed biodiesel

Renewable fuels have many advantages over fossil fuels because they are biodegradable and sustainable, and help mitigate social and environmental problems. The objective of the present study is to evaluate the performance, combustion, and emission characteristics of a compression–ignition engine using hydrogen compressed natural gas (HCNG)-enriched Kusum seed biodiesel blend (KSOBD20). The flow rate of HCNG was set at 5 L/min, 10 L/min, and 15 L/min, and the injection pressure was varied in the range of 180 bar to 240 bar. Brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) were improved when HCNG was added to the KSOBD20. Combustion characteristics, namely, cylinder pressure (CP) and net heat release rate (NHRR), were also improved. Emissions of carbon monoxide (CO), hydrocarbons (HC), and smoke were also reduced, with the exception of nitrogen oxides (NO_x). The higher injection pressure (240 bar) had a positive effect on the operating characteristics. At an injection pressure of 240 bar, for KSOB20 + 15 L/min HCNG, the highest BTE and the lowest BSFC were found to be 32.09% and 0.227 kg/kWh, respectively. Also, the CP and NHRR were 69.34 bar and 66.04 J/°. CO, HC, and smoke levels were finally reduced to 0.013%, 47 × 10⁻⁶ and 9%, respectively, with NO_x levels at 1623 × 10⁻⁶. For optimum results in terms of engine characteristics, the fuel combination KSOBD20 + 15 L/min HCNG at FIP 240 bar is recommended.