Which factors govern the deactivation of a porous catalyst pellet?
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Answer: D. All A., B. and C.
Explanation
Decay reactions degrade active catalytic sites over prolonged operating time periods. Pore diffusion limitations restrict reactant access to internal catalyst surface areas effectively. Surface attacks by chemical poisons permanently block active sites, causing rapid catalyst deactivation. Porous catalysts rely on internal pore networks to provide massive surface areas for reactions. Catalyst deactivation leads to loss of catalytic activity and reduced industrial chemical production. Poisoning, coking, and thermal sintering represent primary mechanisms of industrial catalyst degradation.
Petroleum refining relies on frequent catalyst regeneration cycles to counteract deactivation phenomena. Reactor design must incorporate provisions for catalyst replacement and poisoning mitigation strategies. Understanding deactivation mechanisms extends operational lifespans of expensive industrial catalytic systems. Option A neglects pore diffusion and surface poisoning which are equally vital deactivation causes. Option B ignores thermal decay and chemical poisoning mechanisms occurring inside catalyst pellets. Option C fails to include internal pore diffusion resistances and thermal decay reactions.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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