High-octane gasoline production: Straight-run naphtha is upgraded to a high-octane petrol primarily by which catalytic process?

Introduction:
Raising the octane number of straight-run naphtha is central to gasoline production. Several catalytic processes exist, but only one directly transforms naphtha into an aromatic- and isoparaffin-rich high-octane stream.

Given Data / Assumptions:

• Feed: Straight-run naphtha.
• Objective: Increase octane number significantly.

Concept / Approach:
Catalytic reforming (often platinum-based) dehydrogenates naphthenes to aromatics and rearranges paraffins to isoparaffins, boosting research octane number (RON) and producing hydrogen as a valuable byproduct.

Step-by-Step Solution:

Verification / Alternative check:
Reforming units are standard in refineries to supply high-octane reformate for gasoline blending and hydrogen for hydrotreating.

Why Other Options Are Wrong:

• Cracking: Breaks large molecules to smaller; not the main route for naphtha to high octane.
• Polymerisation: Joins light olefins; not a naphtha upgrading step.
• Isomerisation: Raises octane of light naphtha (C5–C6) but not to the level of reformate.
• Alkylation: Combines isobutane with C3–C4 olefins; feed and objective differ.

Common Pitfalls:
Confusing isomerisation (C5–C6) improvements with the much larger octane boost from reforming.

Final Answer:
Reforming