Simulation membrane reactors

One-dimensional models have been extensively used in the literature to simulate membrane reactors and to compare the reactor performance with the conventional systems (without membranes). This comparison has been, so far, fair enough because thick membranes i.e. low flux membranes) were generally considered in those works. Even 40-100 pm thick self-supported membranes have been considered. At these conditions (unfortunately too far away to be... 

Basile, A.G. Chiappetta, S. Tosti, and V. Violante, Experimental and simulation of both Pd and Pd/Ag for a water gas shift membrane reactor, Sep. Purif. Technol., 25,549-571, 2001. 

S., Fiaty, K., and Dalmon, J.-A. (2000) Experimental smdy and numerical simulation of hydrogen/isobutane permeation and separation using MFI-zeolite membrane reactor. Catal. Today, 56 (1-3), 253-264. 

Simulations based on kinetic modelling of the reduction of acetophenone with propan-2-ol, using polymer-enlarged and the unmodified catalysts, revealed that comparable performance cannot be obtained by batch operation. Polymer enlargement allowed a continuous operation of transfer hydrogenation in a chemical membrane reactor.353... 

Chiral amines, here (R)-l-aminotetralin, were obtained from racemic amine and pyruvate in a 39 mL hollow-fiber membrane reactor with (SJ-cotransaminases (ft>TA) (Shin, 2001). The substrates were recirculated until the e.e. value exceeded 95%. Simulations suggested residence times should be short to minimize product inhibition. 

A simulative comparison of dense and microporous membrane reactors for the steam reforming of methane,... 

Brunetti, A., Caravella, C., Barbieri, G. and Drioli, E. (2007) Simulation study of water gas shift in a membrane reactor. Journal of Membrane Science, 306 (1—2), 329-340. 

Gallucci F., Paturzo L., Basile A. A simulation study of the steam reforming of methane in a dense tubular membrane reactor. Int.J. Hydrogen Energy 2004 29 611-617. 

Barbieri, G. DiMaio, F. Simulation of the Methane Steam reforming Process in a Catalytic Pd-Membrane Reactor Ind. Eng. Chem. Res. 36 (1997) 2121-2127. 

Fig. 10.6 Experimental (open circle) and simulated data (Line) in the enzymatic membrane reactor with HRT of 72 min. Initial Orange II concentration 91.1 mg/L H202 addition rate 15 pmol/(L min)...

Baker, J. O., Vinzant, T. B., Ehrman, C. I., Adney, W. S., and Himmel, M. E., Use of a new membrane-reactor saccharification assay to evaluate the performance of cellulases under simulated SSF conditions—Effect on enzyme quality of growing Trichoderma reesei in the presence of taigeted lignocellulosic substrate. Appl. Biochem. Biotechnol. 1997, 63-5, 585-595. 

Marin et al. (250) attempted to model a reactor similar to that used by Alonso and co workers. Their simulations were compared with simulations representing a fixed-bed reactor operated under similar conditions. They concluded that the membrane reactor (with the external fluidized bed) was a viable technology for n-butane oxidation, but that it offered only a modest increase in MA yields relative to those realized in a fixed-bed reactor. Nonetheless, the safer operating conditions which keep the O2 and hydrocarbon flows separate, particularly with the oxidation of butane to MA, are desirable. Presently, MA yields are chiefly governed by the explosive limits of butane in air (i.e., 1.8%). Increasing the butane concentration with an optimized membrane reactor may increase overall MA yields. 

Hwang, G.J. and Onuki, K., Simulation study ou the catalytic decomposition of hydrogen iodide in a membrane reactor with a silica membrane for the thermochemical water splitting IS process. Journal of Membrane Science, 194, 207, 2001. 

For ease of fabrication and modular construction, tubular reactors are widely used in continuous processes in the chemical processing industry. Therefore, shell-and-tube membrane reactors will be adopted as the basic model geometry in this chapter. In real production situations, however, more complex geometries and flow configurations are encountered which may require three-dimensional numerical simulation of the complicated physicochemical hydrodynamics. With the advent of more powerful computers and more efficient computational fluid dynamics (CFD) codes, the solution to these complicated problems starts to become feasible. This is particularly true in view of the ongoing intensified interest in parallel computing as applied to CFD. 

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. 

Thus, expectedly no rigorous mathematical models are available that can accurately describe the detailed flow behavior of the fluid streams in a membrane separation process or membrane reactor process. Recent advances in computational fluid dynamics (CFD), however, have made this type of problem amenable to detailed simulation studies which will assist in efficient design of optimal membrane filtration equipment and membrane reactors. 

In addition to the Navier-Stokes equations, the convective diffusion or mass balance equations need to be considered. Filtration is included in the simulation by preventing convection or diffusion of the retained species. The porosity of the membrane is assumed to decrease exponentially with time as a result of fouling. Wai and Fumeaux [1990] modeled the filtration of a 0.2 pm membrane with a central transverse filtrate outlet across the membrane support. They performed transient calculations to predict the flux reduction as a function of time due to fouling. Different membrane or membrane reactor designs can be evaluated by CFD with an ever decreasing amount of computational time. 

Itoh [1990] simulated a Pd membrane reactor coupling the cyclohexane dehydrogenation reaction on the feed side with oxidation of hydrogen on the permeate side. Given in Figure 11.35 is the predicted conversion of the dehydrogenation reaction as a function of the total flow rate of the sweep gas with the Damkbhler number for the permeate side as a parameter... 

Basile, A., Paturzo, L., Lagana, F. (2001). The partial oxidation of methane to syngas in a palladium membrane reactor simulation and experimental studies. Catalysis Today 67,65-75. 

Assahumrungrat S, Kiatkittipong W, Praserthdam P, and Goto S. Simulation of pervaporation membrane reactors for liquid phase synthesis of ethyl rert-butyl ether from tert-butyl alcohol and ethanol. Catal Today 2003 79-80 249-257. 

Barbieri G, Marigliano G, Golemme G, and Drioli E. Simulation of CO2 hydrogenation with CH3OH removal in a zeolite membrane reactor. Chem Eng J 2002 85 53-59. 

Pagnanelli F, Beolchini F, Di Biase A, and Veglio F. Effect of equilibrium models in the simulation of heavy metal biosorption in single and two-stage UF/MF membrane reactor systems. Biochem Eng J, 2003 15(1) 27-35. 

Takeuchi et al. 7 reported a membrane reactor as a reaction system that provides higher productivity and lower separation cost in chemical reaction processes. In this paper, packed bed catalytic membrane reactor with palladium membrane for SMR reaction has been discussed. The numerical model consists of a full set of partial differential equations derived from conservation of mass, momentum, heat, and chemical species, respectively, with chemical kinetics and appropriate boundary conditions for the problem. The solution of this system was obtained by computational fluid dynamics (CFD). To perform CFD calculations, a commercial solver FLUENT has been used, and the selective permeation through the membrane has been modeled by user-defined functions. The CFD simulation results exhibited the flow distribution in the reactor by inserting a membrane protection tube, in addition to the temperature and concentration distribution in the axial and radial directions in the reactor, as reported in the membrane reactor numerical simulation. On the basis of the simulation results, effects of the flow distribution, concentration polarization, and mass transfer in the packed bed have been evaluated to design a membrane reactor system. 

Yu, W., Ohmori, T., Yamamoto, T., Endo, A., Nakaiwa, M., Hayakawa, T., and Itoh, N. Simulation of a porous ceramic membrane reactor for hydrogen production. International Journal of Hydrogen Energy, 2005, 30 (10), 1071. 

Takeuchi, T., Aihara, M., and Habuka, H. CFD-simulation of membrane reactor for methane steam reforming. AIChE Fall 2004 Meeting, Abstract 392e. 

C.-Y. Tsai, Y.H. Ma, W.R. Moser and A.G. Dixon, Simulation of nonisothermal catalytic membrane reactor for methane partial oxidation to syngas, in Y.H. Ma (Ed.), Proceedings of the 3rd International Conference on Inorganic Membranes, Worcester, 1994, pp. 271-280. 

Some recent models have also appeared discussing the operation of three phase catalytic membrane reactors by Torres et al. [82]. The models which represent extension of prior models by Akyurtlu et al. [79] and Cini and Harold [80] are numerically analyzed and appear to simulate well the experimental results of the nitrobenzene hydrogenation reaction in a three phase catalytic membrane reactor. 

M. Torres, J. Sanchez, J.-A. Dalmon, B. Bemauer and J. Lieto, Modeling and simulation of a three-phase membrane reactor for nitrobenzene hydrogenation. Ind. Eng. Chem. 

M. Tayakout, B. Bernauer, Y. Toure and J. Sanchez, Modeling and simulation of a catalytic membrane reactor. /. Simul. Pract. Theory, 2 (1995) 205. 

A.B. Bindjouli, Z. Dehouche, B. Bernauer and J. Lieto, Numerical simulation of catalytic inert membrane reactor. Computers Chem. Eng., 18 (Suppl.) (1994) 5337-5341. 

Kragl, U. VasicRacki, D. Wandrey, C. Continuous production of L-tert-leucine in series of two enzyme membrane reactors— modelling and computer simulation. Bioprocess Eng. 1996, 14 (6), 291-297. 

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