Definition of “gas-based” fertilizer plant:\nA fertilizer plant is classified as gas-based when it uses which gas as the primary hydrogen source for ammonia manufacture?

Introduction / Context:
Ammonia synthesis requires hydrogen, traditionally obtained by reforming hydrocarbons. Industry shorthand categorizes plants by the primary feedstock to the hydrogen unit. A “gas-based” plant refers specifically to facilities using natural gas—largely methane—as the principal hydrogen source via steam reforming or autothermal reforming.

Given Data / Assumptions:

• Hydrogen is produced upstream of the Haber–Bosch loop.
• Feedstock options include natural gas, naphtha, coal/coke oven gas, and others.
• Classification is based on main feedstock, not minor supplements.

Concept / Approach:
“Gas-based” denotes natural gas-based hydrogen production, which is common due to methane's high hydrogen-to-carbon ratio, established steam methane reforming technology, and widespread pipeline infrastructure. While coke oven or producer gases can contain hydrogen and be processed, plants using these are typically called “by-product gas-based” or classified under separate schemes, not the standard “gas-based” label in fertilizer sector reporting.

Step-by-Step Solution:

Verification / Alternative check:
National fertilizer statistics typically segregate capacity as gas-based (natural gas), naphtha-based, fuel oil/LSHS-based, or coal-based, confirming the accepted usage.

Why Other Options Are Wrong:

• Coke oven gas and producer gas can be hydrogen sources but are not the standard meaning of “gas-based” in this context.
• Coal gasification routes are categorized as “coal-based.”
• Refinery fuel gas varies and is not the canonical definition.

Common Pitfalls:
Assuming any gaseous feed qualifies; sector nomenclature specifically points to natural gas-based hydrogen generation.

Final Answer:
Natural gas (methane-rich).