CFD를 이용한 촉매 멤브레인 반응기 해석에 관한 연구

Abstract

CFD (Computational Fluid Dynamics) technique can be applied to the reactor simulation to solve the complex fluid dynamics problems of a reactor and to consider the optimal design of the reactor. Especially, the profiles of physical and chemical properties obtained from CFD simulations play an important role in enhancing the understanding of the reactor system: CFD simulations furnish more accurate results than 1,2 dimensional ODE-based simulations as the complexity of the systems increase. In this research, results of the analysis of a catalytic membrane reactor for the water gas shift (WGS) reaction are presented and discussed using CFD technique. Reaction kinetic expressions were researched, and Langmuir-Hinshelwood kinetic's expression has been selected to give the best result. The optimal operation temperature was found out to be 630K. A CFD module for the palladium (Pd) membrane, separating hydrogen, was also developed, simulated and compared to the references. The developed framework easily simulates the effects of the reaction temperature, pressure, sweep gas flow rate, sweep gas flow direction and palladium membrane thickness to the CO conversion of the catalytic membrane reactor. On the basis of these simulations, the optimal design parameters of a catalytic membrane reactor for WGS could be obtained. The optimal operating condition for the catalytic membrane reactor is as following. Time factor is 15,450[g-cat·min/gmole CO], reaction temperature is 630[K], operating pressure for Plumen is 3[atm], operating pressure for Psweep=1[atm], sweep gas flow direction is counter-current, sweep gas flow rate is 43.6[ml/min] and Pd-Ag palladium membrane foil thickness is 75[㎛]. As a result of the simulation, 92.06% CO conversion was obtained, which is 14.5% increase compared to the thermodynamic equilibrium conversion. Results of the analysis are very useful in the commercialization of the hydrogen-generation process, and the developed simulation framework is easily adaptable for further design and modification when more detailed profiles are necessary.