Thermodynamic Equilibrium Analysis of CO2 Methanation through Equilibrium Constants: A Comparative Simulation Study

In this study, a steady-state thermodynamic equilibrium evaluation of CO2 methanation was conducted. Calculations were performed by solving the material balance equations using the equilibrium constants of CO2 methanation and reverse water–gas shift reactions. Results obtained from an analytical method developed with the aid of the Microsoft Excel platform were compared to simulations conducted using the commercially available free software COCO and DWSIM. The effects of temperature, pressure, and H2/CO2 ratio on CH4 yield, carbon oxide formation, and heat balance were investigated. The results indicate that the methanation process is highly favored by low temperatures and higher pressures with a stoichiometric H2/CO2 ratio. Under these conditions, CH4 output increases, and carbon formation is reduced, resulting in better performance. Simulations from all three models are in agreement, with minor differences noted in the DWSIM software.