A realistic analysis of hydrogen production based on flare gas considering life cycle assessment

•The serious environmental challenges of greenhouse gas emissions are disputable.•Flare gas can be used as a feedstock for hydrogen production.•The economic analysis is used to calculate the hydrogen production price.•The sensitivity analysis is performed to investigate the role of effective factors.•Well-to-pump life cycle assessment of hydrogen production has been considered. Among the different methods for flare gas recovery, the comprehensive evaluation of hydrogen production has yet to be studied. The techno-economic evaluation and life cycle assessment of using flare gas to produce hydrogen are performed in this study. The Aspen HYSYS software is used to simulate the different units of hydrogen production, and the economic assessment is performed to calculate the hydrogen production expenditures. The results illustrated that the mass flow rate and the capacity of the hydrogen production plant are 117600 kg/h and 4856.4 MW, respectively. The obtained results demonstrate that the hydrogen production costs can be considered reasonable using flare gas with a low price and large flow rate. In this regard, the breakeven price of hydrogen is US$ 0.27, and the share of Capital expenditure in hydrogen production cost is 55.4%, as well. Moreover, the life cycle assessment (LCA) of hydrogen production has been conducted to evaluate the environmental effects of hydrogen production. Thanks to the novel CO2 capturing process considered in this study, GHG and CO2 productions have been reduced, respectively, by 59 and 63 percent, demonstrating the necessity of using the CO2 capturing process.