UPSC Prelims 2025 Q45: Coal Gasification Products — Explained

Consider the following substances:

I. Ethanol

II. Nitroglycerine

III. Urea

Coal gasification technology can be used in the production of how many of them?

  1. Only one
  2. Only two
  3. All the three
  4. None

Answer: (b) Only two

Statement-wise explanation

  • I: correct — Coal gasification turns coal into syngas, a mixture of carbon monoxide and hydrogen. Syngas can be converted into ethanol over catalysts, either directly or through methanol. India has a working example in the pipeline. Under the ₹8,500 crore coal gasification incentive scheme, the Ministry of Coal backed a coal-to-ethanol demonstration project at Chandrapur, Maharashtra, with an 18 KTPA ethanol capacity.
  • II: incorrect — Nitroglycerine (glycerol trinitrate) is made by nitrating glycerol with a mix of concentrated nitric and sulphuric acids. Glycerol comes from fats and oils, mostly as a by-product of soap and biodiesel making. It does not come from syngas. Coal gasification is not a recognised route to nitroglycerine. The coal-based explosive India is actually building is ammonium nitrate, which is a different compound.
  • III: correct — Syngas supplies hydrogen, which reacts with nitrogen to make ammonia (Haber–Bosch process). Ammonia then reacts with carbon dioxide to make urea. Talcher Fertilizers Ltd, a joint venture of GAIL, RCF, Coal India and FCIL, is building India's first coal-gasification-based urea plant at Talcher, Odisha. Its planned capacity is 12.7 lakh tonnes a year.

How to eliminate

You need to know the facts to solve this. Option logic does not help much. You can still narrow it down by asking what syngas (CO + H2) is a building block for. Syngas makes hydrogen, ammonia, methanol and other alcohols. Urea comes straight from ammonia, and Talcher's coal-to-urea plant has been in the news for years, so Statement III is very likely in. That rules out 'None'. Ethanol is a two-carbon alcohol, so a CO + H2 route to it is believable, and the Chandrapur coal-to-ethanol project confirms it. Nitroglycerine is the odd one out because its backbone is glycerol, a fat-derived chemical. The only link to coal is indirect: coal-based ammonia can be made into nitric acid, one of the reagents. The examiners counted only established production routes, so 'All the three' is out. Fact to remember: coal gasification feeds ammonia, urea, methanol, ethanol, ammonium nitrate, hydrogen and synthetic natural gas. It does not feed glycerol-based products.

Know more

Coal gasification reacts coal with controlled amounts of oxygen and steam at high temperature. The coal is not burnt. It is partly oxidised into syngas, mainly carbon monoxide (CO) and hydrogen (H2). Syngas is a chemical building block, so one gasifier can feed many value chains.

Syngas route Product Indian example
H2 + N2 → ammonia → + CO2 Urea (fertiliser) Talcher Fertilizers, Odisha
Ammonia → nitric acid → ammonium nitrate Explosives for mining Lakhanpur (Jharsuguda), Odisha; BHEL technology
CO + H2 over catalyst Methanol, ethanol Coal-to-ethanol demo, Chandrapur, Maharashtra
Methanation Synthetic natural gas (SNG) Proposed under the mission
Shift reaction Hydrogen Bhadravati (Chandrapur) project

Why India is pushing it

  • India has large coal reserves, but it imports much of its natural gas, ammonia, methanol and urea feedstock. Gasification replaces imported gas with domestic coal.
  • The National Coal Gasification Mission targets 100 million tonnes of coal gasified by 2030.
  • In January 2024 the Union Cabinet approved an ₹8,500 crore financial incentive scheme for coal and lignite gasification projects. Coal India, BHEL and private firms received awards under it.

Challenges

  • Indian coal has a high ash content, which suits most imported gasifier designs poorly. BHEL's indigenous fluidised-bed technology is designed for high-ash coal.
  • Gasification also needs a lot of capital and water, and it emits CO2 unless paired with carbon capture (CCUS).

Do not confuse

  • Coal-bed methane is natural gas already trapped in coal seams. It is extracted, not made.
  • Underground coal gasification happens in the seam itself. Surface gasification happens in a plant.
  • Green urea or green ammonia gets its hydrogen from electrolysis powered by renewable energy, not from coal.

In the news

In January 2024 the Cabinet approved the ₹8,500 crore coal gasification incentive scheme. Through late 2024 and early 2025 the Ministry of Coal issued Letters of Award to selected applicants, including a coal-to-ethanol project and coal-to-ammonium-nitrate projects. The Talcher coal-to-urea plant was also in the news, which made the products of coal gasification a likely topic for 2025.

NCERT Concepts to Revise

  • Coal gasification: The whole question depends on what syngas is and which chemicals can be built from it.
  • Coal-bed methane: Coal-bed methane is a different coal-linked gas and is often confused with syngas from gasification.
  • Fossil fuel: Coal is a fossil fuel. Gasification lets it replace imported natural gas as a chemical feedstock.

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