Performance Analysis and Multi-objective Optimization of Microchannel Reactor for Oxidative Dehydrogenation Propane to Propylene using Response Surface Method

By using petroleum products in the petrochemical industry and performing series of chemical processes, various and value-added products can be obtained. Propylene is one of these very important and basic products that can be used to produce various materials. Therefore, in the present study, a two-dimensional steady state model of the process of oxidative dehydrogenation of propane to propylene in a micro-channel reactor was performed in the COMSOL simulator. Then, a multi-objective optimization with the purpose of increasing propylene (increasing production) and decreasing CO (preventing coke formation) was performed, for the first time. Comparison of the simulation results with laboratory data shows an error of about 7%, which is acceptable based on the model assumptions. In order to analyze the process, effect of temperature, feed flow rate, feed composition and heat transfer coefficient on the amount of propylene and CO production was investigated. To optimize the performance of the reactor and due to computational cost of the COMSOL model and optimization process, an alternative model for the micro-channel reactor was presented based on the design of experimental (DOE) method. Finally, the multi-objective optimization of the process was performed based on the prepared model by the response surface method (D-optimal), and the optimal pareto front was obtained. According to optimization results increasing propylene leads to an increase in CO production, which it shows a trade-off between objectives. After optimization, the results of one of the optimal points of the Pareto front were presented. The optimum temperature and velocity at this point is 513°C and 0.103 m/s, and in these conditions, the maximum concentration of propylene and the minimum amount of CO are set equal to 0.195 and 0.088 mol/m3, respectively.