Cross flow, monolithic reactor

Figure 8.7 Figures 1 (A) and 3 (B) from U.S. Patent 5 356 728 [22] showing a cross flow monolithic reactor (10 and 30) from Amoco consisting of membrane cores (A, 17) or a monolithic block (B, 19). The manifold...

All of these applications demand high surface area per unit reactor volume. Such a geometric requirement is best satisfied by cross flow monolithic elements this paper provides the first mathematical analysis of solid-state electrocatalytic reactors with such geometry. 

Cross-flow monoliths have been explored by Degnan and Wei (11-12) as cocurrent and countercurrent reactor-heat exchangers. Four cross-flow monoliths in series were employed the individual blocks were analyzed by a one-dimensional approximation. They found good agreement between theory and experiment. 

Roy and Gidaspow (13-14) developed two-dimensional continuum models to describe cross-flow monolithic heat exchangers and catalytic reactors. 

The modelling of single-cell, solid-state electrocatlytic reactors was recently discussed by Debenedetti and Vayenas (15) this paper s objective is to develop an analysis for cross-flow monolithic designs. 

A schematic diagram of a cross-flow monolith fuel cell reactor is given in Figure 1. The reactor consists of two sets of channels in the x and y direction, respectively. 

Oxygen Ion Transfer Area per Unit Reactor Volume. As discussed above, the prime attraction of the cross-flow monolith configuration is its potentially high oxygen ion transfer area per unit reactor volume. From our unit cell (Figure 2), this volume-specific area computes as... 

Consideration of diffusional and kinetic limitations, when justified by physical reality, may yield additional information on the behaviour of cross flow monolithic electrochemical reactors. A balance between added numerical complexity and a more complete description of electrode kinetics, should, of course, be kept in mind. 

Activation energy, stability in trickle-bed reactors, 76 Activation overpotential, cross-flow monolith fuel cell reactor, 182 Activity balance, deactivation of non-adiabatic packed-bed reactors, 394 Adiabatic reactors stability, 337-58 trickle-bed, safe operation, 61-81 Adsorption equilibrium, countercurrent moving-bed catalytic reactor, 273 Adsorption isotherms, countercurrent moving-bed catalytic reactor, 278,279f... 

Figure 8 A reactor consisting of four cross-flow monoliths in a steel manifold, (a) Reactor before assembly (b) top view of reactor. (From Ref. 36.)...

The catalytic plates are not completely accessible in the monolithic cross-flow structure, since a certain part of the plates is lost by contact with the corrugated interstitial planes of this structure. Moreover, the successful development in the preparation of thin, porous plates for electrochemical purposes created the idea that this preparation technique should also be used to produce permeable catalyst plates for cross-flow catalyst reactors. Instead of using these plates for the complicated cross-flow structure, the whole step was taken to using them in an electrochemical cell-like design of the reactor. The catalytic plates were thus mounted in a special rack like a filter press (Fig. 13), giving the so-called cell reactor [26]. 

The scale-up of the traditional cross-flow reactor with corrugated interstitial planes has been solved by Degnan and Wei [35,36], who showed that, for example, four cross-flow monoliths can be positioned in a clever way inside a steel manifold (Fig. 8). This technique is not limited to only four monoliths but may be scaled-up to a much larger... 

A novel reactor, consisting of a series of cross-flow monoliths for a coolant stream and a reactant stream, has been designed and run with a highly exothermic first order reaction. This reactor-heat exchanger is versatile and can be run in five modes ... 

Optimum performance of the monolith reactor requires uniform and stable distribution of gas and liquid over the cross section of the monolith. Because the monolith consists of many small channels, it may be difficult to obtain a good distribution of the gas and liquid flows within the monolith. This is very important for the monolith reactor, since an uneven inlet distribution would be propagated throughout the reactor. On the other hand, if the inlet distribution is appropriate, no nonuniformity will occur along the reactor. 

Catalytic cross-flow reactor Calcium aluminum silicate H2 diffusion in liquid-filled pores Hydrogenation of p-nitrobcnzoic acid Pd-coated monolith wall 60 ... 

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