Consider the following substances : I. Ethanol II. Nitroglycerine III. Urea Coal gasification technology can be used in the production of how many of them?
- (a) Only one
- (b) Only two ✓ UPSC's answer
- (c) All the three
- (d) None
Why the answer is (b)
• Coal gasification reacts coal with steam and oxygen at high temperature to produce syngas — a mixture of carbon monoxide and hydrogen — which is a feedstock for many chemicals.
• Syngas is the route to ammonia (via hydrogen), and ammonia with carbon dioxide gives urea; India's Talcher fertiliser plant is a coal-gasification-to-urea project — III is correct.
• Syngas can also be converted to ethanol, either catalytically or by fermenting it with microbes (as in some 'second-generation' ethanol processes) — I is correct.
• Nitroglycerine is made by nitrating glycerol with a nitric–sulphuric acid mixture; it is not derived from syngas or coal gasification — II is not correct.
• Hence two of the three, option (b).
Why the other options are wrong
- (a) Only one
- Both ethanol and urea can be produced from gasification-derived syngas.
- (c) All the three
- Nitroglycerine is made by nitrating glycerol, not from syngas.
- (d) None
- Urea and ethanol are both syngas-derived products.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2025, held on 25 May 2025. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.