Chapter 11. Flow Chemistry Systems Based on Membranes

Abstract

In flow chemistry systems based on membranes, a dense or porous membrane is activated with a catalyst or a biocatalyst in order to couple reaction and separation in the same unit, resulting in an intensified process called catalytic membrane reactor (CMR). In this chapter the basic principles and concepts of CMRs are defined and the different configurations: CMRs for selective product removal, CMRs for the selective additions of reactants, flow-through membrane reactors (FTMRs) and enzymatic membrane reactors (EMRs) are described. Furthermore, a short account of some representative works of the peer reviewed literature and monographs works is given. CMRs have been successfully applied at laboratory scale to enhance the conversion of reactions which are limited by the thermodynamic equilibrium through selective product removal, in oxidation and hydrogenation reactions and improving the contact between the catalyst and substrates while decreasing mass transfer limitations. CMRs have already proven economic and strategic value in bio-transformations for the high-added value chemicals production. Such processes which take place at low temperature allow the use of polymer membranes which are commercially available materials. Further advances are expected on the development inorganic membranes for high temperature applications to be applied in high temperature reactions.