Multi–objective optimization approach to enhance ethylbenzene dehydrogenation in the multi-stage spherical reactors

This paper focuses on modeling and optimization of multi-stage spherical reactors to produce styrene through ethylbenzene dehydrogenation. A steady state heterogeneous mathematical model is developed based on the mass and energy conservation laws to predict the performance of the proposed configuration. For proving the accuracy of the considered model, simulation results are compared with available plant data. In optimization stage, the optimal feed temperature is calculated to maximize styrene production and minimize toluene and benzene production based on the multi-objective model and Pareto frontier curve. To achieve a single optimal point, the multi-objective model is converted to a single objective problem by weighted sum method. The simulation results show that styrene production is improved about 60000 kmole per year compared to conventional configuration. It is proved that lower pressure drop is one of main advantages of the proposed configuration