Difficulty: Medium
Correct Answer: The most ideal feedstock for thermal reforming is dearomatised kerosene.
Explanation:
Introduction / Context:
Gasoline reforming improves octane by rearranging and dehydrogenating hydrocarbons. Understanding correct vs. incorrect statements about octane trends, desired reactions, suitable feeds, and catalysts is essential in refining practice.
Given Data / Assumptions:
Concept / Approach:
Lower boiling (shorter chain) paraffins typically show higher octane than heavier normal paraffins; dehydrogenation of naphthenes to aromatics increases octane; Pt on silica-alumina (often chlorided alumina) is standard for catalytic reforming. "Dearomatised kerosene" is not an ideal thermal reforming feed; reforming targets naphtha—not kerosene—with significant naphthene content for octane uplift.
Step-by-Step Solution:
Verification / Alternative check:
Refining textbooks specify straight-run naphtha (naphthenic/paraffinic) as reforming feed; catalytic reforming replaced thermal reforming due to selectivity and octane gains.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing reforming with hydrocracking; reforming chiefly rearranges and dehydrogenates, not deep cracking of kerosene feeds.
Final Answer:
The most ideal feedstock for thermal reforming is dearomatised kerosene.
Discussion & Comments