Static membrane reactor

Diffusion is an efficient means of materials transport in natural and artificial nanoscale systems and can be readily employed in the study of enzymatic reactions in fluid membrane reactors of static or of changing geometries and morphologies. Other means of transport, e.g. electrophoretic or tension-driven modes are also available. 

Degradation of Orange II on catalytic Fe/Nafion membranes. Static and reactor processes... 

The most important technique for perfusion culture methods is to separate the concentrated cells and conditioned medium from the suspended culture broth. As noted above, the separation methods chiefly used are filtration with tubular and flat membranes as well as ceramic macroporous filters. These membrane reactors can be employed for both anchorage-dependent and suspension growing cells. Static maintenance type systems are commercially available for disposable reactors, and small size unit reactors from 80 ml to 1 liter are used for continuous production of monoclonal antibodies with hybridoma cells. The maintainable cell densities are about 10 -10 cells/ ml which is essentially mouse ascites level. However, in these systems, the cell numbers cannot be counted directly because the cells adhere to membranes or hollow fibers. Therefore, the measurement of cell density must use indirect methods. Such indirect methods include the assaying of the quantities of glucose consumption and the accumulation of lactate. The parameters of scale-up have not yet been established for these static methods. 

Concentration polarization phenomena, which are the main drawbacks of the aforesaid enzyme membrane reactors, can nevertheless be used to form, either in dynamic or in static conditions, a gel layer of enzyme proteins on a membrane.27 1 It is even possible to establish more than one enzyme layer and no coupling agent is needed to carry out the immobilization. Due to high protein... 

The mesoporous nickelsilicate membranes obtained are active and very selective to benzaldehyde and condensation products in the oxidation of styrene with hydrogen peroxide. The variation of the synthesis parameters and the pretreatment of the supports affects the permeation (Table 2) and the conversion of styrene (Fig. 7). In comparison with the conventional static reactor with a control of the H2O2 feed, the conversion of hydrocarbon on membranes after 12 h reaction was lower, but the efficiency of the H2O2 and selectivity to benzaldehyde and condensation products are higher. A variation of the pressure in the feed room favors the control of the rate of the oxidation. 

Two categories of methods are commonly used for organic and hybrid membrane characterization. The first ones, named static characterizations, are aimed at the description of the structure and texture of membranes while the second ones named dynamic characterizations describe membranes at work, in other words the transfer of fluids and solutes through the membrane top-layer. Both static an dynamic characterization methods are important for a thorough understanding of single mass transport and even of the additional functions of the membranes (contactor, reactor...). 

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