Membrane reactors are mainly used to carry out the reactions limited by the equilibrium
conversion such as water gas shift and so on. In fact, in a MR the separation capability of a
membrane is utilized to improve the performance of a catalytic system. Usually, there are two
main generic approaches: selective product separation (Extractor) and selective reactant addition
(Distributor), as shown in Figure 11 (Julbe 2001a). The first MR type facilitates the in–situ
removal of one of the products (Figure 11.a)