Methane Aromatization Upgraded by Oxygen-Permeable Membrane Reactor

Recently the CAS Qingdao Institute of Bioenergy and Processes in collaboration with the Leibniz Universit?t Hannover, Forschungszentrum Jülich and Bayer AG has made attempts to carry out methane aromatization reaction in an oxygen-permeable membrane reactor to yield benzene and its derivatives.

Methane aromatization is one of the effective routes to directly convert methane into liquid products, which has great significance in the area of catalytic science and commercial application. The early research was concentrated at development of catalysts with high activity and stability. The Mo/ZSM-5 catalyst is among those that are extensively studied and applied at present. However this type of catalyst is prone to deactivation due to coke deposition coupled with low methane conversion rate. The research workers have been trying to introduce in the reaction system a definite amount of oxygen or mild oxidizing agent to achieve selective catalytic conversion of methane.

The research team has conducted methane aromatization reaction in an oxygen-permeable membrane reactor. The reactor is made of perovskite type oxygen-permeable membranes, through which oxygen can diffuse from the air side into the other side of the membrane to react upon hydrogen, which is generated during methane aromatization reaction, to form water in order to break up the chemical equilibrium so that the methane conversion can be increased. Furthermore, application of this oxygen-permeable membrane can retain nitrogen in the air side to prevent it from entering the methanearomatics system. Meanwhile, the researchers have found out that the existence of oxygen and steam can apparently delay the coke deposition and deactivation of Mo/ZSM-5 catalyst, resulting in an extended service life of the catalyst.