In the steam reforming section for producing synthesis gas from naphtha (fertilizer industry), which industrial catalyst is typically employed?

Introduction / Context:
Steam reforming converts light hydrocarbons such as natural gas or naphtha into synthesis gas (H2, CO, CO2), which is then processed to produce hydrogen for ammonia synthesis. The catalyst choice is critical to activity, selectivity, and resistance to coking and sulfur poisoning. Most fertilizer complexes rely on nickel-based catalysts in the primary reformer tubes due to their proven performance for C–H bond activation with steam.

Given Data / Assumptions:

• Feed: naphtha (paraffinic/light naphthenic cut) with desulfurization upstream.
• Reactions: steam reforming and water–gas shift downstream.
• Operating: high temperature, tubular fired reformer.

Concept / Approach:
Nickel provides strong activity for dehydrogenation/reforming while alumina support offers thermal stability and surface area. Commercial catalysts are often nickel oxide (as supplied) reduced in situ to metallic nickel on alumina, sometimes with promoters (e.g., calcium aluminate) to manage sintering and sulfur tolerance. Alternatives like cobalt or chromium are not standard for primary steam reforming of light hydrocarbons in fertilizer plants.

Step-by-Step Solution:
Identify desired function: break C–H and C–C bonds with steam to form H2/CO.Match catalyst to function: Ni/Al2O3 is industry standard.Exclude nonstandard options: bauxite (ore), cobalt (not typical here), chromium (used as alloy element, not principal reforming catalyst).Select “nickel oxide supported on alumina.”

Verification / Alternative check:
Commercial catalyst vendors (Topsoe, Johnson Matthey, Clariant) all supply Ni/Al2O3 primary reforming catalysts; unit operating manuals prescribe in situ reduction of NiO to Ni prior to feed introduction.

Why Other Options Are Wrong:
Bauxite: not a reforming catalyst; used historically in other processes.Cobalt: used for Fischer–Tropsch, not primary steam reformer in fertilizer context.Chromium: not the active phase for hydrocarbon steam reforming.

Common Pitfalls:
Confusing shift catalysts (e.g., Fe–Cr, Cu–Zn) with reforming catalysts; assuming any transition metal works in high-temperature reforming.

Final Answer:
Nickel oxide supported on alumina