Study Of Kinetics Of CO/CO₂ Hydrogenation Chemical Reaction

With the depletion of fossil energy and the gradual deterioration of the environment,the pursuit of new energy and the capture,conversion and utilization of greenhouse gases has attracted attention from all walks of life.Compared with traditional fossil fuels,methanol and methane are considered as clean fuels with high calorific value,high combustion efficiency and low emission.The synthesis of methanol and methane by CO/CO2 hydrogenation has achieved industrial applications.In order to optimize the reaction process,the development process and design Reactor,the study of reaction kinetics has important practical significance and application value.In this paper,the new MC17 methanol synthesis catalyst and the Mn-Ni series CO2 methanation catalyst developed by the cooperative enterprise are used as the research objects.The reaction kinetics of the two catalysts are studied respectively,and the kinetic parameters are obtained.Contribute to promotion.For the MC17 catalyst,the intrinsic kinetic experimental data of the catalyst were obtained under the conditions of reaction pressure of 3-6 MPa,reaction temperature of 200-260℃,and space velocity of 8000-12000 mL/(gcat·h).At the same time,hydrogenation to synthesize methanol is the mechanism,the LH type kinetic model is selected,and the kinetic parameters obtained by data simulation using the Marquardt method combined with the improved genetic algorithm are as follows:k1=12.7789×103exp(-9954/RgT);k2=0.2389×103 exp(-10054/RgT);KCO=exp(-2.8287-0.9954×104-(1/T-1/T));KCO2=exp(-3.1571-0.9959×102-(1/T-1/T));KH2=exp(-2.3222+0.9248×103-(1/T-1/T);which T=503.15 K,Through model checking,it is proved that the selected model is suitable.For the Mn-Ni series catalyst,the activity evaluation proves that the catalyst has good catalytic performance for CO2 methanation,and the crystal structure and pore size distribution of the catalyst are verified by XRD,N2 adsorption-desorption,H2-TPR,XRF,etc.,element composition.Then,under the reaction conditions of reaction pressure of 0.5-3 MPa,reaction temperature of 200-300℃,and mass space velocity of 8000-12000 mL/(gcat·h),the kinetic model represented by the pressure of each component was selected to obtain kinetic data.as follows:ki=1.416×1011exp(-16.91/RT)Ki=1842exp(-21.59/RT)At the same time,the influence of operating conditions on the synthesis of methanol and methane was investigated.The experimental results showed that the conversion rates of CO and CO2 in the two reactions were positively correlated with the reaction pressure,but the conversion rates decreased with the increase of space velocity;In the methanol synthesis reaction,the CO conversion rate first increased and then decreased with the increase of temperature within the experimental condition range,while for the CO2 methanation reaction,the CO2 conversion rate increased with the temperature increase in the experimental condition range.