As an alternative route for aromatics and hydrogen production, methane dehydroaromatization (MDA) is of significant academic and industrial interest due to the abundance of natural gas resources and the intensive demand for aromatics and COx-free hydrogen. In the present work, a simulation study on MDA in membrane reactors (MRs) was performed with the aim of co-producing aromatics and COx-free hydrogen with a highly improved efficiency. The effects of various parameters, including catalytic activity, membrane flux and selectivity, as well as the operating conditions on the MR performance were discussed with respect to methane conversion, hydrogen yield, and hydrogen purity. The results show that catalytic activity and membrane flux and selectivity have significant impacts on CH4 conversion and H2 yield, whereas H2 purity is mainly dominated by membrane selectivity. A highly improved MDA is confirmed to be feasible at a relatively low temperature and a high feed pressure because of the hydrogen extraction effect. To further improve MDA in MRs by intensifying H2 extraction, a simple configuration combining a fixed-bed reactor (FBR) and an MR together is proposed for MDA, which demonstrates good potential for the high-efficiency co-production of aromatics and COx-free hydrogen.
Keywords: COx-free hydrogen; aromatics; hydrogen separation; membrane reactor; methane dehydroaromatization.