Non-permselective Catalytically Active Membranes

As discussed in Chapter 2, in a number of membrane reactor applications the membrane is non-permselective, and it simply acts as a contactor device (when it is catalytic), or simply as a means to distribute one of the reactants in a more uniform manner (when it is inert). In modeling such reactors one must take into consideration, in addition to Knudsen diffusion, the presence of molecular diffusion and convective transport. The Dusty Gas Model 

Veldsink et al [5.50] also studied the influence of the dimensionless transmembrane pressure ATT, defined as 

In their study the model is taken to represent the oxidation of ethylene (B) by molecular oxygen (A) in order to produce acetaldehyde (R), an intermediate product for this reaction, which can further react under these conditions towards the products of total oxidation CO2 (X) and H2O (Y). Some of the simulation results are presented in the bottom part of the Fig. 5.15. In this figure the yield of R (in terms of moles of R formed per mole of B 

More recently Neomagus et al [5.56] utilized a similar model to study methane combustion in a CMR utilizing a catalytic porous alumina membrane activated with platinum. As in the previous studies the oxidant and the hydrocarbon were fed in different compartments separated by the porous, catalytically active membrane. In their study Neomagus et al 

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