Modeling and Simulation of Combined CO₂ Capture and Hydrogenation to Methanol at Atmospheric Pressure and Low Temperature

Carbon capture and utilization play an important role by converting CO₂ emissions to high value fuels and chemicals such as methanol. This work reports the modelling and simulation of the CCU to methanol using a bifunctional catalyst with amine sites for CO₂ capture and Pt sites to catalyze the reduction of intermediates to methanol. The bifunctional material exhibited high CO₂ capture capacity under post-combustion conditions at 50°C–70°C and promising methanol formation under dynamic experiments of sequential CO₂ capture and hydrogenation steps. CO₂ sorption experiments using TGA were employed to extract kinetics for the CO₂ capture. Steady-state CO₂ hydrogenation over the bifunctional material was used for the development of the hydrogenation kinetic model. The validation of the kinetic models coupled with a transient reactor model under dynamic conditions showed that the model can predict the transient formation of methanol. A parametric investigation under varying operation conditions highlighted the advantage of isothermal cycles at high temperature with respect to experimental time efficiency and maximized methanol formation rate compromised by the lower capture capacity. Further investigations in material development focusing on the facilitation of the methanol desorption from the pores would significantly improve the combined process and allow more time-efficient screening protocols.