From CO2 to Methane: A Thermodynamic Study of the Sabatier Reaction for Clean Energy Applications

This work presents a numerical analysis of the steady-state thermodynamic equilibrium of the CO2 methanation reaction, based on solving mass balance equations using equilibrium constants. It evaluates how temperature, pressure, and the H2/CO2 ratio affect methane yield and by-product formation. The results show that temperatures below 450 °C, high pressures, and a stoichiometric H2/CO2 ratio maximize methane production and CO2 conversion. For instance, at 400 °C and 10 bar, the equilibrium molar fractions are approximately 0.30 for CH4, 0.00021 for CO, and 0.020 for CO2. The process is particularly promising when renewable hydrogen is used, offering a viable pathway for CO2 valorization. The methane produced can be integrated into existing natural gas networks, supporting the energy transition and helping reduce greenhouse gas emissions.