Study on the synthesis of methanol by low pressure hydrogenation of carbon dioxide over CuO-ZnO-Al_2O_3 catalyst

CuO-ZnO-Al2O3 catalysts were prepared by co-precipitation methods,and the effects of the ways of co-precipitation on catalyst performances were studied.Parallel flow coprecipitation was found to be the best way to prepare the catalyst.The effects of reaction temperature,pressure and feed gas space velocity on the catalytic performances of the catalysts for the synthesis of methanol by carbon dioxide hydrogenation were investigated.For the feed gas with a H2/CO2 volume ratio of 2.6,the optimum reaction parameters were determined as follows:temperature of 240℃,pressure of 1.0MPa,and feed gas space velocity of 2400h-1.Under the optimized conditions,the conversion of carbon dioxide and the selectivity to methanol were 9.0% and 14.1%,respectively.