Multiphase Membrane Reactor

Figure 4.21 Multiphase membrane reactor synthesis of ibuprofen from ibuprofen methoxyethyl ester applying a multiphase membrane reactor in batch mode followed by extraction and distillation for downstream processing...

Low solubility two-phase system multiphase membrane reactor... 

In a multiphase membrane reactor, the conversion of benzylpenicillin to 6-aminopenidllinic acid is performed. The type of microstructured reactor used is a fermentation reactor which contains the enzyme penicillin acylase immobilized on the wall of a hollow-fiber tube. The hollow-fiber tube extracts 6-aminopenicillinic acid at the same time selectively. Benzylpenicillin is converted at the outer wall of the hollow fiber into the desired product, which passes into the sweep stream inside the fiber where it can be purified, e.g. by ion exchange. The non-converted benzylpenicillin is recycled back through the reactor [84],... 

Figure 17.3 Schematic representation of multiphase membrane reactor.

S. L. Matson, Method and apparatus for catalyst containment in multiphase membrane reactor systems, PCT WO 87/02381, PCT US 86/02089,1987. 

Di Felice, R., Capannelli, G, Comite, A., 2010. Multiphase membrane reactors, in Comprehensive Membrane Science and Engineering. Elsevier, Amsterdam. 

A multiphase reactor design, very similar to the trickle-bed reactor, is the tubular multiphase hollow membrane wall reactor sketched in Eigure 13.2h. In a regular trickle-bed reactor, the liquid flows over a partially wetted pellet as a thin film and supplies the liquid phase reactant to the catalyst pores. This action, however, has the effect of hindering pore access to the gas, thus lowering the reaction rate. On the other hand, in the multiphase membrane reactor, the liquid-filled membrane is directly accessible to the gas flowing in the inside tube. Thus, mass transfer in this reactor is considerably more efficient than in the conventional trickle-bed reactor. 

Chemical species can transfer between phases, and this represents the coupling between the mass-balance equations. This geometry looks like a membrane reactor in which a permeable area A (dashed lines) separates the phases, but all multiphase reactors can be described by this notation. 

The quantity couples the two equations. For a membrane reactor this is simply the area of the membrane, but for other multiphase reactors the interfacial area may vary with conditions. 

In the membrane reactor a wall of area separates the phases, and this area is generally fixed by the geometry of the reactor using planar or cylindrical membranes. However, most multiphase reactors do not have fixed boundaries separating phases, but rather allow the boundary between phases to be the interfacial area between insoluble phases. This is commonly a variable-area boundary whose area wiU depend on flow conditions of the phases, as shown in Figure 12-7. 

Guha A K, Shanbhag P V. Sirkar K K, Vaccari D A, Trivedi D H (1995) Multiphase Ozonolysis of Organics in Wastewater by a Novel Membrane Reactor, American Institute of Chemical Engineers Journal 41 ... 

J.L. Lopez and S.L. Matson, A Multiphase/Extractive Enzyme Membrane Reactor for Production of Diltiazem Chiral Intermediate, J. Membr. Sci. 125, 189 (1997). 

S.L. Matson, Method for Resolution of Stereoisomers in Multiphase and Extractive Membrane Reactors, US Patent 4,800,162 (January, 1989). 

Additionally, membranes have the unique advantage of allowing the simultaneous contact with two different media, at each membrane side, creating compartments with different properties. Therefore, membranes offer the potential to promote the spatial organization of catalytic compartments and selective barriers. This feature is used with advantage in new concepts of membrane multiphasic (bio)reactors and membrane contactors. 

Membrane bioreactors have been reported for the production of diltiazem chiral intermediate with a multiphase/extractive enzyme membrane reactor [15, 16]. The reaction was carried out in a two-separate phase reactor. Here, the membrane had the double role of confining the enzyme and keeping the two phases in contact while maintaining them in two different compartments. This is the case of the multiphase/ extractive membrane reactor developed on a productive scale for the production of a chiral intermediate of diltiazem ((2R,3S)-methylmethoxyphenylglycidate), a drug used in the treatment of hypertension and angina [15]. The principle is illustrated in... 

A further improvement of the multiphase reactor concept using lipase for enantioselective transformation has been recently reported, that is, an emulsion enzyme membrane reactor. Here, the organic/water interface within the pores at the enzyme level is achieved by stable oil-in-water emulsion, prepared by membrane emulsification. In this way, each pore forms a microreactor containing immobilized... 

Lopez, J.L. and Matson, S.L. (1997) A multiphase/extractive enzyme membrane reactor for production of diltiazem chiral intermediate. Journal of Membrane Science, 125, 189. 

Prazeres DMF, Cabral JMS (2001) Enzymatic membrane reactors. In Cabral JMS, Mota M, Tramper J (eds) Multiphase bioreactor design. Taylor Francis, London... 

As a building block for simulating more complex and practical membrane reactors, various membrane reactor models with simple geometries available from the literature have been reviewed. Four types of shell-and-tube membrane reactor models are presented packed-bed catalytic membrane reactors (a special case of which is catalytic membrane reactors), fluidized-bed catalytic membrane reactors, catalytic non-permselecdve membrane reactors with an opposing reactants geometry and catalytic non-permselective membrane multiphase reactors. Both dense and porous inorganic membranes have been considered. 

Membranes have also been used in reactors where their permselective properties are not important. Instead their well-engineered porous matrix provides a well-controlled catalytic zone for those reactions requiring strict stoichiomeuic feed rates of reactants or a clear interface for multiphase reactions (e.g., a gas and a liquid reactant fed from opposing sides of the membrane). Functional models for these types of membrane reactors have also been developed. The conditions under which these reactors provide performance advantages have been identified. 

Vospemik M, Pintar A, Bercic G, Levee J, Wabnsley J, Raeder H, lojoiu EE, Miachon S, and Dalmon JA. Performance of catal3ftic membrane reactor in multiphase reactions. Chem Eng Sci 2004 59 5363-5372. 

Li, N., Giomo, L., and Drioli, E., Effect of immobihzation site and membrane materials on multiphasic enantiocatalytic enzyme membrane reactors, Ann. N.Y. Acad. Sci., 984, 436-452, 2003. 

In Chapter 2 we discussed a number of studies with three-phase catalytic membrane reactors. In these reactors the catalyst is impregnated within the membrane, which serves as a contactor between the gas phase (B) and liquid phase reactants (A), and the catalyst that resides within the membrane pores. When gas/liquid reactions occur in conventional (packed, -trickle or fluidized-bed) multiphase catalytic reactors the solid catalyst is wetted by a liquid film as a result, the gas, before reaching the catalyst particle surface or pore, has to diffuse through the liquid layer, which acts as an additional mass transfer resistance between the gas and the solid. In the case of a catalytic membrane reactor, as shown schematically in Fig. 5.16, the active membrane pores are filled simultaneously with the liquid and gas reactants, ensuring an effective contact between the three phases (gas/ liquid, and catalyst). One of the earliest studies of this type of reactor was reported by Akyurtlu et al [5.58], who developed a semi-analytical model coupling analytical results with a numerical solution for this type of reactor. Harold and coworkers (Harold and Ng... 

When producing high value biochemicals, the economic analysis is, generally, more favorable for the MBR systems, when compared with the more conventional units. Often selectivity rather than conversion may be the key, since higher selectivities typically result in the elimination of some of the purification steps which have a strong influence on the total production costs. The application of the multiphase/extractive enzyme membrane reactor for the production of a diltiazem chiral intermediate was reported in Chapter 4... 

M. Reif, Tubular inorganic catalytic membrane reactors Advantages and performance in multiphase hydrogenation reactions, Catal. Today 2003, 79-80, 139-149. 

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