Hydrogen production membrane microreactors

Wan et al. [39] investigated the selective oxidation of aniline by hydrogen peroxide to azoxybenzene in a multi-channel MMR, with or without water removal, employing TS-1 nanozeolite as catalyst. The reaction was conducted at different residence times and temperatures. A hydrophilic ZSM-5 membrane was used to remove water selectively from the reaction mixture by membrane pervaporation. The results indicate that catalyst deactivation was reduced during the reaction. An improvement in the product yield and selectivity toward azoxybenzene was also observed. Increasing temperature was beneficial for both yield and selectivity, but beyond 340 K, microreactor operation was ineffective due to bubble formation and hydrogen peroxide decomposition. 

Nanofibrous membrane-supported Ti02 was used as a catalyst for the oxidation of benzene to phenol in a microreactor at ambient conditions through in situ production of hydroxyl radicals as oxidant [99]. Reaction conditions were optimized and the performance of the microreactor was compared with the conventional laboratory scale reaction, in which hydrogen peroxide was used as oxidant. The microreactor gave a better yield of 14% for phenol compared to 0.14% in the conventional laboratory scale reaction. Reaction conditions such as reaction time, reaction pH, and applied potential were optimized. With optimized reaction conditions, selectivity of >37% and >88% conversion of benzene were obtained. 

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