Alkylation in gasoline manufacture: Which of the following statements about the isobutane–olefin alkylation process in petroleum refining is incorrect?

Introduction:
Alkylation in refining combines light olefins (e.g., propene, butenes) with isobutane to produce highly branched isoparaffins (alkylate) used as premium gasoline blendstock. The question asks you to identify the incorrect statement about operating principles and outcomes of this process.

Given Data / Assumptions:

• Feedstocks: isobutane and C3–C4 olefins.
• Catalysts: strong liquid acids in commercial practice.
• Output: high-octane, low-olefin, low-sulphur alkylate.

Concept / Approach:
Liquid-acid alkylation is a low-temperature process. Typical reactor temperatures are near ambient to moderately low (often 0–15°C for H2SO4 units and 25–40°C for HF units), nowhere near “very high” temperatures of 1000°C. Such extreme temperatures are associated with pyrolysis/steam cracking, not alkylation.

Step-by-Step Solution:

Verification / Alternative check:
Process descriptions for HF/H2SO4 alkylation specify low temperatures and moderate pressures to maximise selectivity and minimise acid consumption and side reactions.

Why Other Options Are Wrong:

• (a), (b), (d), (e) are correct statements about commercial alkylation and its product qualities.

Common Pitfalls:
Confusing alkylation with steam cracking/pyrolysis; assuming “reaction = high temperature.”

Final Answer:
All alkylation processes operate at very high temperatures (> 1000°C).