Shaping technique of catalysts

6 Preparation Technique of Spherical Catalysts 4.6.1 Shaping technique of catalysts 

Therefore, the prepared catalyst should possess the given chemical composition and physical structure and shape, which can meet the requirements of engineering. The geometrical shape and particle size of catalyst are determined by the requirements in industrial process, including the type of the reactor, the operation pressure, flow velocity, permitted pressure drop of the bed, the reaction kinetics, the physicochemical properties of the catalyst, shaping properties and economic factors. 

The shape of particles in the catalyst commonly used in industries includes cylindrical, spherical, flake, mesh, powder-like, irregular-shaped and strip and so on (Fig. 4.22). During the recent years, there are also many special shapes of catalysts, such as the bowl, three leaf-like, the wheel-shaped, honeycomb and membranous etc. 

Theoretically, all sohds can be squashed in three directions imder large enough external force. In fact, it is performed on pelletizer which is made up of steel nails and dies. Therefore, the pressiue must be lower than the limits that can cause the 

4 23 Relation between the elastic module of inorganic solid emd their melting 

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See also in sourсe #XX -- [ ]

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