Assessment of CO ₂ methanation integration in a power to gas system

Abstract

Abstract E-methane production represents a sustainable approach to valorising CO 2 captured from energy-intensive industries. In this context, the methanation process is assessed with respect to energy efficiency by utilizing locally produced green hydrogen and captured CO 2 , supporting the transition to low-carbon energy systems while addressing the intermittency of renewable energy sources. This study evaluates the transition from laboratory-scale experiments to an industrial-scale e-methane production plant, leveraging surplus renewable energy, which is inherently subject to fluctuations. The studied plant operates with a methane output of 300 kg/h, achieving a CO 2 conversion rate of 88 % at 550 °C and 30 bar. Various plant configurations, reactor designs, and performance scenarios were assessed based on available bibliographic data. CO 2 methanation was carried out using a 0.5 wt% Ru/γ-Al 2 O 3 catalyst in a plug flow reactor. A modified LHHW kinetic model was found to provide the best fit to the experimental data. A sensitivity analysis was conducted to quantify the influence of key parameters, including temperature, pressure, catalyst mass, and reactant feed ratio, on reactor efficiency. The results provide valuable insights into process optimization, evaluating the potential of this approach for future industrial-scale development.