In catalytic reforming, reformate is a high-octane gasoline component. For unleaded reformed gasoline, select the typical upper-end research octane number (RON) value achievable.
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A60
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B70
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C80
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D90
Answer
Correct Answer: 90
Explanation
Introduction / Context:Catalytic reforming upgrades naphtha by dehydrogenation and aromatization, creating high-octane reformate used in gasoline blending. Understanding typical octane ranges helps in product slate optimization and compliance with gasoline specs.Given Data / Assumptions:
- Unleaded reformate (no TEL/lead additives).
- RON basis considered for comparison.
- Modern Pt/bi-metal catalysts under standard severity.
Concept / Approach:Reforming boosts octane substantially, with reformates commonly in the upper 80s to 90+ RON depending on feed severity and constraints (hydrogen balance, coke formation, aromatics limits). For a general upper-end typical value in an exam context, 90 is a reasonable benchmark for unleaded reformate blending quality.Step-by-Step Solution:
1) Recall that straight-run naphtha has modest octane.2) Reforming increases aromatics/isoparaffins, elevating RON markedly.3) Choose 90 as a representative upper-end value for unleaded reformate.Verification / Alternative check:Plant data often show reformate pools at ~88–95 RON; precise values depend on severity and feed quality.
Why Other Options Are Wrong:
60/70/80: too low for typical reformate outputs under normal severity.Common Pitfalls:Confusing motor octane number (MON) with RON; RON values are higher.
Final Answer:90