Investigation of the Phase Equilibria of CO2/CH3OH/H2O and CO2/CH3OH/H2O/H2 Mixtures

The storage of excess electricity from renewable energy sources is nowadays a crucial topic. One promising technology is the methanol (CH₃OH) synthesis from H₂/CO₂ mixtures. The achievable one‐pass conversion is limited within this exothermic equilibrium reaction. A possibility to overcome this limitation would be withdrawing CH₃OH and H₂O from the gas phase through in situ condensation under reaction conditions. In this work, the phase equilibrium for mixtures representative for different degrees of conversion was studied. A view cell was employed to determine systematically the single‐ and two‐phase regimes and obtain phase envelopes for mixtures of H₂, CO₂, CH₃OH, and H₂O from 66 to 305 °C and 61 to 233 bar. Furthermore, the densities in the single‐phase area were determined and quantified by an empirical model.