Shape Formation of the Catalyst Particles

Precipitated catalysts and supports for impregnation need to be formed into suitably sized particles for use in the reactor. The size and shape of catalyst particles depend on 

Catalysts are formed by a variety of methods depending on the rheology of the materials. The products of different processes have been compared in general terms in Table 3.2. The choice of the method depends on the size, shape and density of the catalyst particle required, on the strength required and on the properties of the starting material. The three main processes used in catalyst manufacture to make conveniently sized particles from powders are pelletizing, extrusion and granulation. 

Cross-sectional shapes with a higher external surface per unit particle volume than cylinders (e.g. a clover leaf) can give even larger external specific areas on extruded catalyst these have been used in some hydrodesulfurization catalysts. 

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