Catalytic reforming – typical catalyst system Identify the commonly used catalyst for catalytic reforming of naphtha to improve octane number and produce aromatics/hydrogen.
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Aplatinum on alumina
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Bnickel
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Ciron
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Daluminium chloride
Answer
Correct Answer: platinum on alumina
Explanation
Introduction / Context:Catalytic reforming upgrades low-octane naphtha to high-octane reformate for gasoline blending and generates valuable hydrogen. The process relies on bifunctional catalysis to promote dehydrogenation, isomerization, and cyclization reactions.
Given Data / Assumptions:
- Naphtha range feed, presence of paraffins and naphthenes.
- Desired reactions: dehydrogenation to aromatics, isomerization, hydrocracking (controlled).
- Commercial continuous catalyst regeneration (CCR) or semi-regenerative units.
Concept / Approach:Platinum on chlorided alumina (Pt/Al2O3) is the classic reforming catalyst. Platinum provides dehydrogenation/hydrogenation sites, while acidic alumina (often promoted with chloride) provides isomerization/cyclization functionality. Other metals like rhenium may be added, but the base system is Pt/Al2O3.
Step-by-Step Solution:
Match process needs (bifunctional) with catalyst: metallic Pt + acidic alumina.Recognize industry-standard: Pt/Al2O3 (with promoters in some formulations).Select platinum on alumina as the correct answer.Verification / Alternative check:Licensors (e.g., UOP, Axens) specify Pt/Al2O3-based systems for reforming, corroborating the choice.
Why Other Options Are Wrong:
- Nickel/iron: Typical for hydrogenation or ammonia synthesis, not reforming selectivity.
- Aluminium chloride: Lewis acid used in alkylation/polymerization, not standard reforming catalyst.
Common Pitfalls:Confusing catalytic reforming with catalytic cracking; FCC uses acidic zeolites at low hydrogen partial pressure, not Pt on alumina.
Final Answer:platinum on alumina