Comparative Performance Analysis of Catalysts for Syngas Production from Biogas: A Simulation Study Using DWSIM

Abstract

This study explored how CH₄/CO₂ feed ratio, temperature, and pressure affect the conversion of carbon dioxide and methane and the H₂/CO ratio of syngas using simulations for six catalysts: Rh/La₂O₃, Rh/La₂O₃-SiO₂, Ru/La₂O₃, Ni-Co/Al-Mg-O, LaNiO₃, and Ce-La-Ni-O₂. Simulations with DWSIM^© were conducted at CH₄/CO₂ feed ratios of 1–2, pressures of 1–5 bar, and temperatures of 550–750 °C. The effects showed that increasing the temperature by as much as 750 °C boosted the H₂/CO ratio and improved CO₂ and CH₄ conversions because of the endothermic nature of the reactions. Higher pressure reduced conversion rates and H₂/CO ratios across all catalysts, with a notable similarity between 2 and 5 bar, indicating thermodynamic limits. A higher feed ratio of CH₄/CO₂ decreased CH₄ conversion while increasing the H₂/CO ratio at the expense of reduced H₂ yield. As the pressure decreases, the Ru/La₂O₃ and Rh/La₂O₃-SiO₂ catalysts exhibited higher activity because of the kinetic factor. The current research focuses on the possibility of using dry reforming of biogas to synthesize syngas with suitable H₂/CO ratios for different uses. The observations suggest that future studies should include techno-economic analysis to determine the least expensive catalysts that will ensure the dry reforming process yields the right composition of syngas.