The membrane reactor (MR) concept, combining in the same unit a conversion
effect (catalyst) and a separation effect (membrane), already showed variou
s potential benefits (increased reaction rate, selectivity and yield) for a
range of reactions involving the membrane as extractor, distributor or con
tactor. Due to the generally severe conditions of heterogeneous catalysis,
most MR applications use inorganic membranes, which can be dense or porous,
inert or catalytically active. After a rapid overview of the working conce
pts of MRs, the main types of porous ceramic membranes, which have been dev
eloped for MR applications, are reported and discussed (characteristics and
limitations). Starting from these general basis, our objective is to put r
ecent developments into focus, with a special emphasis on porous composite
infiltrated membranes and related synthesis methods. Some new ideas current
ly explored in our group, such as the 'chemical valve membrane' concept and
the interest of nanophase materials for oxygen transport, will be also dev
eloped. An attempt in addressing the future developments of porous membrane
s for MRs will be finally proposed. (C) 2001 Elsevier Science B.V. All righ
ts reserved.