The Research Of Carbon Dioxide Hydrogenation To Methanol

The potential utilization of CO₂-as a raw material in place of CO in methanol synthesis reaction has become an important area of research, Which is a effective way to solution greenhouse effect ,and it have excellent prospects in the chemical industry and environmental field.In this paper, methanol synthesis from carbon dioxide hydrogenation over Cu-based catalysts have been study detailted.First, the industrial catalyst was researched in different reaction conditions on carbon dioxide hydrogenation to methanol in fixed-bed plug flow reactor. The result showed temperature, weight hourly space velocity, pressure , the ratio of hydrogen and carbon on the reaction have a major impact. The optimal experimental conditions is 240℃, weight hourly space velocity 3600h^-1, H₂/CO₂=3.In the experiment, CuO-ZnO-Al₂O₃ catalysts were prepared by co-precipitation method in carbon dioxide hydrogenation to methanol , and the catalysts were investigated by XRD and the performance of catalytic reaction . The result showed precipitant and solvent have a obvious impact by reaction . calcination temperature was 400℃and the radio of Cu/Zn was 1 , the catalytic properties of catalysts was optimization.In the experiment, metal oxide were doped CuO-ZnO-Al₂O₃ catalysts, including ZrO₂ as promoters, Ag₂O, La₂O₃, MnO, CeO₂, Fe₂O₃ six promoters. The catalytic performance of the CuO-ZnO-Al₂O₃ catalyst were studied for methanol synthesis from CO₂ hydrogenation by BET, XRD and H₂-TPR characterization, it is found that ZrO₂-doped and Ag₂O-doped CuO-ZnO-Al₂O₃ catalysts have enhanced CO₂ conversion by about 2 percentage points, methanol selectivity by about 4 percentage points , methanol yield by about 1 percentage point.correspondingly, Under 240℃2.0 MPa WHSV=3 600 h^-1 and H₂/CO₂ =3 reaction conditions. When ZrO₂ and Ag₂O additive was 2 and 3 mol, CO₂ conversion and methanol selectivity, the yield of methanol is maximum. It showed the ZrO₂-doped CuO-ZnO-Al₂O3 catalyst enhanced surface area of catalysts, which led to high copper dispersion on catalysts surface, or the Ag₂O-doped CuO-ZnO-Al₂O₃ catalysts produced Ag⁺ active sites.