Multiphase Membrane Reactors

One of the most potentially important applications of membranes is in multiphase reacting systems. The membrane segregates two fluid phases and acts as an interface between them. In this chapter, from the concept of membrane as an interface, the application as both (1) a membrane contactor to improve the mass transfer from one phase to another and (2) three-phase membrane reactor to efficiently carry out multiphase heterogeneous catalytic reactions are discussed.The basic aim of this chapter is to present to the readers some fundamentals, which might be useful for further and more demanding investigation on multiphase membrane reactors. Starting from the membrane contactor, a description of the mass transfer resistances involved in such systems is introduced. Then, three-phase membrane reactors, where a catalytic membrane catalyzes a reaction with an alternative contact mode to traditional three-phase reactors, are examined using some concepts and definitions typical of the engineering of chemical reactions. Finally, some considerations about mass balances on the entire membrane system are presented.