Effects of industrial catalyst structure and operating conditions on CO2 hydrogenation to methanol:A simulation study

LIN Zhenli; XIE Qinqin; XIE Nannan; WENG Junqi; YANG Daoming; SHU Zhongming; YE Guanghua; ZHOU Xinggui

doi:10.13226/j.issn.1006-6772.GPF25012601

Abstract：CO2 hydrogenation to methanol is an effective carbon reduction technology,the key of which is developing high-performance industrial catalysts.Based on particle-resolved computational fluid dynamics,a dual-scale model for CO2 hydrogenation to methanol is established,spanning from industrial catalyst particle to fixed-bed reactor.Utilizing this model,the impact of industrial catalyst particle structure and operating conditions on the performance of methanol synthesis is investigated.First,the accuracy of the particle-resolved computational fluid dynamics model was verified by comparing the experimentally measured pressure drop across the catalyst bed.The simulated pressure drop differed from the experimental value by less than 10%.Next,the effects of catalyst particle pore size,porosity,and particle diameter on methanol synthesis were investigated.It was found that when the catalyst particle pore size was 50 nm and the porosity was 0.4,a high CO2 conversion rate was achieved along with high methanol selectivity.Additionally,when the particle diameter was 8 mm,the bed pressure drop was reduced while maintaining high CO2 conversion and methanol selectivity.Finally,the influences of flow velocity,pressure,temperature,and CO2 concentration on the reaction were examined.The results showed that increasing the flow velocity not only rapidly decreased CO2 conversion but also raised the bed pressure drop.Higher pressure increased the reactant concentration in the reactor,which improved both CO2 conversion and methanol selectivity.When the inlet temperature was around 515 K,both CO2 conversion and methanol selectivity were relatively high.Below 515 K,the reaction was kinetically limited,hindering CO2 conversion,while above 515 K,the methanol synthesis reaction was thermodynamically constrained,leading to a slight decline in CO2 conversion.Increasing the inlet CO2 concentration reduced both CO2 conversion and methanol selectivity.This work can provide a reference for the development of industrial catalysts and fixed-bed reactors used in CO2 hydrogenation to methanol.