Specific Guidelines for Reactions using Catalysts

In commercial operation, the solid catalysts usually lose their effectiveness because of (i) poisons (such as sulfur, chloride), (ii) sintering, (iii) fouling by carbon and coke, and (iv) loss of the active species via volatilization. Purthermore, the life of the catalyst depends partly on the thermal stability of the support/carrier. Poisoning is minimized by the removal of poisons from the feed stream by upstream guard units. Sintering is minimized by operating at lower temperatures. Regeneration can be used to periodically remove the coke and carbon active species may be added. 

Enzyme catalysts deactivate especially for temperatures 50 °C and inadequate control of such conditions as pH. 

Type of reaction Example catalysts Products/ reactants Temperature, °C Catalyst life Cause of decay Max. temp., °C Comments about regeneration 

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