Keywords: value added, bioconversion, Methanol
Summary:Different efforts have been done to mitigate CO2 emissions in the industry in the last decades that involve CO2 capture and storage and/or CO2 capture and utilization techniques. In fact, the advantage of CO2 utilization into value added products over CO2 storage is that it provides economic value to the capture process. Amongst the different CO2 utilization processes, CO2 hydrogenation to methanol is a promising large-scale process due to the maturity of similar methanol production processes from syngas in industry. Moreover, methanol demand in international markets is anticipated to expand due to the increase in demand in markets for using methanol as a feedstock for chemical processes to produce plastics, glues, or pharmaceutical products or as a cleaner fuel for powering vehicles and heating homes. Additionally, with the emergence of hydrogen as an energy carrier, hydrogen conversion to a liquid value-added methanol product is more commercially viable solution for transportation to distant markets which in turn supports the hydrogen economy. In this work, sustainable catalytic hydrogenation of CO2 to methanol using the commercial catalyst Cu/ZnO/Al2O3 is studied at a pressure of 50 bar. The CO2 feedstock of the process is pure CO2 produced from a biogas cryogenic upgrading process, whilst hydrogen is produced from water electrolysis using carbon-free electricity. The process consists of three main sections: feed preparation, reaction, and purification, designed and simulated using Aspen Plus software and yields a methanol product purity of 98% at 1 bar and 25 °C. Moreover, the influence of different reaction kinetics and process thermodynamics on the CO2 conversion rate and methanol yield were studied and analyzed.