Microporous inert membrane packed-bed reactor for propylene epoxidation with hydrogen and oxygen: Modelling and simulation

Abstract

United mathematical models for four reactors, two microporous inert membrane reactors as O2 (MR-O) or H2 (MR-H) distributor and two traditional reactors (i.e., three-stage reactor (TSR) and packed-bed reactor (PBR)) with different feeding strategies, are developed to describe direct propylene epoxidation with H2 and O2 to produce propylene oxide (PO). Effects of the feeding strategies on reactor performances (i.e., C3H6 conversion, PO selectivity, PO yield and H2 efficiency) are studied under both isothermal and non-isothermal conditions by using gPROMS. Significantly different reactor performances along the catalyst length are observed and then explained by the reactants and products concentration profiles and/or the temperature distributions. Then, effects of the catalyst lengths of the four reactors are further investigated. It is found that the MR-O gives rise to the outlet C3H6 conversion of 11.3%, which exceeds the previously estimated value (i.e., 10%) with a commercial potential. Finally, an attempt is made to probe whether increasing the H2 and C3H6 feed concentrations in the MR-O without the explosion risk further improves the reactor performance. All the results indicate the potential of the MR-O for the commercial production of PO by direct propylene epoxidation with H2 and O2.