Carbon capture, utilization and storage (CCUS) technology has received increasing attention in order to cope with environmentalproblems such as global warming. CO2 hydrogenation to methanol is an important CCUS technology, realizing both CO2 resource utilizationand chemical storage of renewable energy. In order to explore and optimize the process of CO2 hydrogenation to methanol, the catalytic performance of commercial Cu - ZnO/ Al2 O3 catalyst in the process of CO2 hydrogenation to methanol was tested in a fixed bed reactor.The catalytic effects of the catalyst at 448.15-543.15 K, 1-3 MPa, and 3-9 molar ratio of H2 and CO2 were investigated. The resultsshow that the CO2 conversion rate increases with the increase of reaction temperature. Methanol selectivity is mainly affected by temperature and hydrogen/ carbon molar ratio: the higher the temperature is, the lower the methanol selectivity is, and the higher thehydrogen/ carbon molar ratio is, the higher the methanol selectivity is. Both CO2 conversion and methanol selectivity are enhanced by increasing pressure. Taking formate hydrogenation step as the rate control step of the reaction, the reaction kinetic model of the catalyst usedin the process of CO2 hydrogenation to methanol was derived and established on the basis of LHHW kinetic theory. The model optimizationfunction was constructed in MATLAB to solve the model parameters, and the reaction kinetic equation was obtained. The activation energies of the two reactions are 42.4 and 122.1 kJ/ mol, respectively. The recycling process of CO2 hydrogenation to methanol was establishedin Aspen Plus software, and the energy consumption of the recycling process was optimized by increasing the heat transfer betweenstreams. The heat of the reactor outlet gas was recovered by a shell and tube heat exchanger for the preheating of the feedstock gas, whichreduced the energy consumption of the preheating process by 86.2%. At the same time, the sensitivity analysis of flash separation temperature and raw material gas preheating temperature was carried out, and the final choice of flash separation temperature was 323.15K,raw material gas preheating temperature was 498.15K. The process product is refined methanol with molar purity above 99.5% and methanol recovery >99%. The optimal methanol production energy consumption is 4.84 GJ/ t.

邱浩书(1998—),男,四川乐山人,硕士研究生。E-mail:1575563053@qq.com

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QIU Haoshu,SONG Lei,YANG Qiulin,et al.Kinetics and process flow simulation and optimization of CO2 hydrogenationto methanol[J].Clean Coal Technology,2024,30(4):102-110.