Methane Oxidative Coupling: Synthesis of Membrane Reactor Networks

Abstract

In this work, the performance of the methane oxidative coupling process based on different alternative reactor structures including fixed-bed reactor, two different feeding-structures of porous packed bed membrane reactor, and different conceptual network combinations of them was analyzed in a comprehensive model-based study. In this context, a contour-based graphical visualizing method accompanied by multiscenario generation and examination approach was exploited so as to systematically screen out the high achievable process performances and the corresponding reactor network specifications. As performance indicators, several objective measures including the highest achievable values for yield, selectivity and methane conversion were applied over a high number of design scenarios. Thereby, several sets of structural and operating parameters were evaluated. The investigated parameters are temperature, membrane thicknesses, types of catalysts, amount of inert packing in the catalyst bed, the flow rate of oxygen-rich stream entering the reactor system (total methane to oxygen ratio), distribution of the oxygen rich stream through the reactor blocks (local methane to oxygen ratio), distribution of the total methane-rich feed stream into the reactor blocks, and the contact time represented by the reactor length. A high C2-yield of 31% and 88% C2-selectivity were observed at the same time, and thus, highlighting the performance potential of the reactor network. Moreover, the proposed method enables one to consider operating aspects such as hot spot formation during the analysis and screening procedure.