Hydrogen sourcing for nitrogenous fertilisers: Which routes are commercially used to produce H2 feed for ammonia/urea plants?
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ASteam reforming of naphtha and cracking of natural gas
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BElectrolysis of water
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CCryogenic separation of hydrogen from coke-oven gas
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DAll of the above
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ECoal gasification only, no other method
Answer
Correct Answer: All of the above
Explanation
Introduction / Context:Ammonia synthesis (Haber–Bosch) requires a reliable hydrogen source. Fertiliser complexes therefore adopt hydrogen-generation technologies suited to local feedstock availability, energy economics, and scale. This question asks which listed routes are used commercially to supply hydrogen to nitrogenous fertiliser plants.
Given Data / Assumptions:
- We consider proven industrial routes, not laboratory curiosities.
- Plants may be integrated with refineries, steelworks, or stand-alone utilities.
- Regional economics decide which option dominates in a country.
Concept / Approach:Steam reforming of light hydrocarbons (natural gas, naphtha) is the global workhorse, yielding syngas (H2 + CO/CO2) followed by shift and CO2 removal. Electrolysis of water is also used, particularly where low-cost power is available or for small/remote units. Coke-oven and other off-gases can be cryogenically or chemically separated to recover hydrogen. Hence, all three listed routes are used commercially in various contexts.
Step-by-Step Solution:
Identify mainstream method: steam reforming of NG/naphtha.Recognize alternative but commercial routes: water electrolysis; H2 recovery from coke-oven gas.Because each is practiced, select the inclusive option.Therefore, “All of the above” is correct.Verification / Alternative check:Plant surveys show dominant adoption of steam reforming, with electrolyzers used in power-rich regions and H2 recovery units in integrated steel–chemicals sites.
Why Other Options Are Wrong:
- Each single-route answer omits other commercially used routes.
- “Coal gasification only” ignores widespread reforming and electrolysis deployments.
Common Pitfalls:Assuming there is only one “right” technology globally; in practice, feedstock economics and emissions policy drive diverse choices.
Final Answer:All of the above