Coal-based fertilizer complexes at Ramagundam (Telangana) and Talcher (Odisha): which statement best describes how coal is utilized there?

Introduction / Context:
Ammonia—the building block for urea and many nitrogen fertilizers—requires hydrogen. While most modern plants derive hydrogen by steam reforming of natural gas (methane), coal-based complexes use coal gasification to make synthesis gas (CO and H2), which is then shifted and purified for ammonia synthesis.

Given Data / Assumptions:

• Locations: Ramagundam and Talcher in India are known for coal-based ammonia–urea projects.
• Coal is an alternative feedstock to natural gas for H2 production.
• The question asks about the principal chemical role of coal in such plants.

Concept / Approach:
Coal gasification converts coal into syngas. After water–gas shift (CO + H2O → CO2 + H2) and CO2 removal, the resulting hydrogen is combined with nitrogen (from air separation) in the Haber–Bosch loop to make ammonia, subsequently used to produce urea. Thus, coal is not a mere fuel or filler; it is a chemical feedstock for hydrogen generation.

Step-by-Step Solution:
Coal → Gasification → CO + H2.Shift reaction converts CO to additional H2 with CO2 by-product.Purified H2 + N2 → ammonia → downstream fertilizers such as urea.

Verification / Alternative check:
Process flow diagrams of coal-based ammonia plants show gasifiers, shift reactors, CO2 removal, and ammonia synthesis loops, confirming coal’s role as a hydrogen source.

Why Other Options Are Wrong:
Using coal solely as heat (A) misses the core chemistry; fillers/conditioners (C/D) are not standard; coal is not a potash source (E).

Common Pitfalls:
Assuming all ammonia plants are gas-based; coal and even heavy oil residues have also been used historically where natural gas is scarce.

Final Answer:
Coal is gasified to obtain hydrogen-rich synthesis gas (coal gas) for ammonia/urea