Distributor/contactor-type membrane

Distributor/contactor-type membrane reactors Applied to PCMRs and PIMRs. This type of reactor finds application whenever the reactants ... 

Espro et al. reported the oxidation of propane to the corresponding oxygenated products (n-propanol, isopropanol, propionic aldehyde and acetone) mediated by the Fe " -H202 Fenton system in a distributor/ contactor-type membrane reactor, under mild conditions. A composite Nafion/PEEKWC (a modified polyetheretherketone) catalytic membrane separates the gas (propane/helium) and liquid (Fe -H202) phases. The flat and hollow fibre multi-tubular membrane reactor configurations were compared, being the best performances achieved with the hollow fibre multi-tubular configuration. 

Key words catalytic/inert polymeric membranes, polymeric membranes preparation, membrane reactors, extractor-type, distributor/contactor-type, forced-flow-type, polymeric inert membrane reactors (PIMRs), polymeric catalytic membrane reactors (PCMRs), modelling. 

The use of polymeric catalytic membranes in distributor/contactor-type reactors for hydrogenation or oxidation reactions has been widely described in several former and recent reviews. Mixed-matrix membranes of PDMS hlled with Pd particles, composite membranes of ionic liquid-polymer gels filled with Pd/C, ° ionic liquids containing rhodium complexes and supported in polystyrene sheets in a corrugated configuration, have been used for the selective gas-phase hydrogenation of hydrocarbons in contactor-type membrane reactors. 

Catalyst placement in extractor, distributor and two contactor-type membrane reactors (A, B reactants P product) (Miachon and Dalmon, 2004). 

In the extractor-type reactor one of the reaction products is removed through the membrane from the reactor. The distributor type is used for reactant delivery along the catalyst bed. In the contactor type the flow either goes through the membrane and catalyst bed, or is introduced from both sides of the membrane to the catalyst bed. It is also worth noting that the amount of catalyst needs to be sufficient for the reactor type, and that both the membrane and the catalyst have an influence on the efficiency of... 

Membranes are used nowadays typically for the purification and separation of gases in several industrial processes. The role of catalysts in the development of membrane reactors (MRs) has in many cases been ignored in some levels, as the research has been concentrated on the membrane and development of new membranes. There is, however, a need for a catalyst in the MR to perform the desired reaction. The MRs containing a catalyst have been classified in three categories, namely extractor, distributor and contactor reactors (Miachon and Dalmon, 2004 van Dyk et ai, 2003). These reactor types are presented in Fig. 11.1. 

Catalysts in the MR can be placed in three different ways. The classifications of these types of membranes are extractor, distributor and contactor. The last one can be either interfacial or flow-through. Both the catalyst and membrane have an influence on the reaction. Depending on the MR, the catalyst is dispersed on the membrane, the membrane can be catalytically active, or the membrane exhibits some catalytic properties. In addition, how the catalyst pellets, extrudates, tables, fibres or foams are distributed inside the MR is a critical parameter. 

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