Techno-Economic, Energy, Exergy, and Environmental Comparison of Hydrogen Production from Natural gas, Biogas, and their Combination as Feedstock

Despite the fact that fossil fuel resources can produce a substantial amount of hydrogen, their pollution level is concerning, and their reserves are depleting. Consequently, the use of renewable resources like biogas in the production of chemicals could benefit from the high potential of these sources alone or in combination with fossil fuels. Both carbon dioxide and methane are present in biogas, making it an excellent renewable energy source. In this study, three models of hydrogen production from fossil sources (natural gas), renewable energy sources (biogas), and a combination of fossil and renewable sources were evaluated using a multicriteria decision-making technique. The calculated and compared parameters included the net energy efficiency of the process, the total carbon dioxide emission flow rate, the carbon dioxide emission intensity, the hydrogen production intensity, and the annual total cost. According to the results, the production of hydrogen from natural gas results in the highest amount of carbon dioxide emissions (8.76 \(\frac{{\dot{\mathrm{ m}}}_{\mathrm{CO}2 }}{{\dot{\mathrm{m}}}_{\mathrm{H}2}}\)) for (3.31 \(\frac{{\mathrm{t}}_{\mathrm{H}2}}{{\mathrm{t}}_{\mathrm{feed}}}\)) of hydrogen production. Biogas combination with natural gas (combined feedstock) has the highest exergy (80.84%) and energy (81.62%) efficiency compared to the other two methods. In addition, the TAC for the combined process is the lowest of the three scenarios (TAC = $31.35 M). Due to the limitation of fossil fuel resources, combining renewable energy sources with fossil fuels enhances the thermodynamic performance of the system while reducing the required capital.