Membrane reactor system

The inhibition analyses were examined differently for free lipase in a batch and immobilised lipase in membrane reactor system. Figure 5.14 shows the kinetics plot for substrate inhibition of the free lipase in the batch system, where [5] is the concentration of (S)-ibuprofen ester in isooctane, and v0 is the initial reaction rate for (S)-ester conversion. The data for immobilised lipase are shown in Figure 5.15 that is, the kinetics plot for substrate inhibition for immobilised lipase in the EMR system. The Hanes-Woolf plots in both systems show similar trends for substrate inhibition. The graphical presentation of rate curves for immobilised lipase shows higher values compared with free enzymes. The value for the... 

A residence time is defined as the time needed to fully replace the reaction volume of the continuous operating, membrane reactor system. 

Membrane Reactor System React icm/Cataly St Results Reference Remarks... 

Jeon, Y. J. and Kim, S. K. (2002). Antitumor activity of chitosan oligosaccharides produced in an ultra filtration membrane reactor system. J. Microbiol. Biotechnol. 12,503-507. 

Membrane reactor systems in which the enzyme is recovered by ultrafiltration of the reaction mixture after hydrolysis is complete have been developed. These systems have been pilot tested in Australia but have not been commercialized (Zadow 1984). 

P.N. Dyer, C.M. Chen, Engineering development of ceramic membrane reactor system for converting natural gas to H2 and syngas for liquid transportation fuel, Proceedings of the 2000 Hydrogen Program Review, DOE, 2000... 

A variety of processes have been developed in an enzyme membrane reactor system. Table 19.2 lists a selection of such developments ... 

Table 19.2 Selection of processes developed in an enzyme membrane reactor system.

Several important refinery and chemical feedstock reactions appear to be good candidates for membrane reactor systems some such reactions are listed in Table 13.4. Because of the high temperatures involved, developing the appropriate... 

Figure 9.6 Three-stage membrane reactor system in the HMR concept, after [27],...

Development of Ceramic Membrane Reactor Systems for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels, Proceedings of the 2002 U.S. DOE Hydrogen Program Review, NREL/CP-610-32405, Washington, D.C., 2002. 

Adds, A. Lim, C. Grace, J. The Fluidized Bed Membrane Reactor System A Pilot-Scale Experimental Study Chemical Engineering Science 49, No. 24B (1994) 5833-5843. 

Enzymatic synthesis of E-tm-leucine is another example of the use of isolated enzymes (Bommarius et al, 1995). An NADH-dependent leucine dehydrogenase was used as a catalyst for the reductive amination of the corresponding keto acid together with formate dehydrogenase (FDH) and formate as a cofactor regenerator (Fig. 19.5b Shaked and Whitesides, 1980 Wichmann et al, 1981). Furthermore, a unique membrane reactor system involving FDH and PEG-modihed-NAD for continuous NADH regeneration... 

The use of a membrane reactor for shifting equilibrium controlled dehydrogenation reactions results in increased conversion, lower reaction temperatures and fewer byproducts. Results will be presented on a palladium membrane reactor system for dehydrogenation of 1-butene to butadiene, with oxidation of permeating hydrogen to water on the permeation side. The heat released by the exothermic oxidation reaction is utilized for the endothermic dehydrogenation reaction. 

Table I Basic Equations Developed for the Membrane Reactor System...

The implications of being able to increase the conversion of an equilibrium reaction by using a permselective membrane are several. First, a given reaction conversion may be attained at a lower operating temperature or with a lower mean residence time in a membrane reactor. This could also prolong the service life of the reactor system materials or catalysts. Second, a thermodynamically unfavorable reaction could be driven closer to completion. Thus, the consumption of the feedstock can be reduced. A further potential advantage is that, by being able to conduct the reaction at a lower temperature due to the use of a membrane reactor system, some temperature-sensitive catalysts may find new applications [Matsuda et al., 1993]. 

While inorganic membrane reactors perform more efficiemly than conventional reactors in most cases, there are situations calling for the combined usage of these two types of reactors for reasons to be discussed. The conventional reactors in these special cases serve as either the pre-processing or post-processing step for the inorganic membrane reactor system to derive a maximum overall reaction conversion. These hybrid types of reactors consist of conventional reactors at the front end or tail end or both of the membrane reactor. 

FIGURE 13.17 Schematic flow diagram of the integrated membrane reactor system. (From Gan, Q., Allen, S.J., and Taylor, G., Biochem. Eng. J., 12, 223, 2002. With permission.)... 

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. 

The present study also investigate the catalytic reduction of CO2 into carbon with CH4 applying for membrane reactor system. 

In the case of membrane reactor system, double tubular type reactor where Pd-Ag tube was used as inner tube of hydrogen permeable film, was used for the reactor of CH4 decomposition. Ar gas was fed to the inside of Pd-Ag tube at an atmospheric pressure for sweeping the permeated hydrogen. Gaseous mixture of CO2, H2, and N2 (CO2 H2 Nj = 1 4 3) was fed to the catalyst bed at W/F = 50g-cat-h/mol, where W and F stand for catalyst weight and flow rate, respectively. 

Figure 2 shows the comparison of the conversion of COj into C with conventional reactor with that of membrane reactor. It is clearly shown that the conversion into C drastically increased with the apphcation of membrane reactor to CH4 decomposition. Although the conversion into C was as low as 10% at 500°C in the conventional fixed bed reactor, it attained 72% on the membrane reactor. The conversion into C was further increased with increasing the flow rate of sweep Ar, since the permeation rate of Hj was increased. Figure 3 shows the effects of flow rate of sweep Ar of membrane reactor system on the catalytic reduction of COj. Although the conversion of CO2 was independent on the flow rate of sweep Ar and attained a value as high as 32% at 400°C, which is available temperature for CO2 fixation in a practical apphcation. 

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. 

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