Methanol formation from carbon dioxide hydrogenation using Cu/ZnO/Al2O3 catalyst

Abstract

Abstract Methanol synthesis was performed using a copper-based catalyst (Cu/ZnO/Al2O3) and the coprecipitation method in a fixed bed reactor. The experimental parameters, including gas hourly space velocity, coprecipitation temperature, and reaction temperature, were examined to obtain the optimal conditions for methanol synthesis. A lower precipitation temperature when preparing the catalyst is propitious for obtaining higher Cu dispersion, smaller Cu crystal size, and higher methanol synthesis activity. The optimal temperature range for methanol synthesis was 180–200°C. The most observable space–time yield was 9.33 g/kg-cat/h, which was obtained using a Cu/ZnO/Al2O3 (45/45/10 mol%) catalyst when the reaction temperature was 200°C, CO2 conversion equaled 13%, and methanol yield was 2.7% at 7 bar. The lifespan was more than 120 h. Characterization of the catalyst was performed with accelerated surface area and porosimetry, an X-ray diffractometer, and temperature program reduction.