Thermodynamic Analysis of Membrane Separation-Enhanced Co-Hydrogenation of CO2/CO to Ethanol

Abstract

Co-hydrogenation of CO2/CO to produce ethanol presents an important way to utilize carbon-neutralized biomass resources through gasification. By applying a water-permselective membrane reactor, water, the byproduct of CO2/CO hydrogenation to ethanol, can be removed. Thus, ethanol formation can be promoted thermodynamically. Accordingly, herein, the thermodynamics of ethanol synthesis by CO2, CO, CO2/CO hydrogenation was investigated, as well as the promoting effects of water removal under various temperatures and pressures by Aspen Plus. It is found that, at medium reaction temperature (e.g., 250 °C), medium pressure (e.g., 10–50 bar), and medium CO fraction (e.g., 0.1–0.5) together with 1-stage water removal, a CO2/CO equilibrium conversion higher than 80 % can be obtained.