Modeling and simulation of simulated countercurrent moving bed chromatographic reactor for oxidative coupling of methane

Oxidative coupling of methane (OCM) is a reaction of industrial importance but per pass equilibrium conversion and product yield in a single reaction column is severely low. The simulated countercurrent moving bed chromatographic reactor (SCMCR) has been reported to significantly improve the methane conversion and C-2-product yield. This paper addresses the mathematical modeling of a five section SCMCR for OCM, which is particularly important for understanding the operation of this SCMCR system. In order to obtain the various process parameters, a realistic and rigorous kinetics was adopted in reactors for OCM and subsequently a kinetic model was developed which can best describe the associated kinetics of OCM in SCMCR. Adsorption isotherm parameters were then derived based on the experimental breakthrough curves acquired using single adsorption column. The proposed mathematical model demonstrated extremely good predictions of the experimental results. Finally, effects of operating parameters, such as switching time, methane/oxygen feed ratio, raffinate flow rate, eluent flow rate, etc., on the behavior of the SCMCR were studied systematically. (C) 2009 Published by Elsevier Ltd.