Platforming (catalytic reforming) feed selection: pick the most suitable refinery stream for reforming to make high-octane reformate and hydrogen under typical Pt-based catalysts.

Introduction / Context:
Catalytic reforming (platforming) upgrades naphtha-range hydrocarbons to a high-octane gasoline blendstock (reformate) and produces hydrogen for hydrotreaters. Correct feed selection is essential for desired reactions: dehydrogenation of naphthenes, isomerization of paraffins, and limited hydrocracking/aromatization.

Given Data / Assumptions:

• Candidate feeds: naphtha, C3–C4 olefins, fuel oil, atmospheric residue.
• Catalysts: platinum or platinum–rhenium on chlorided alumina.
• Objective: octane uplift and H2 generation.

Concept / Approach:
Reforming targets the naphtha boiling range (roughly 70–180°C, depending on refinery practice). In this window, paraffinic and naphthenic hydrocarbons can be isomerized and dehydrogenated to aromatics, sharply increasing RON. Heavier streams (fuel oil, residue) are far outside the process envelope; light olefins are routed to alkylation or polymerization rather than reforming.

Step-by-Step Solution:

Verification / Alternative check:
Refinery block flow diagrams universally route hydrotreated naphtha to reformers; other listed streams go to different units.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing reforming (octane via aromatics) with FCC or hydrocracking that handle heavier feeds.

Final Answer:
Naphtha