📘 IAS Prelims 2025 — GS-I Q.45 | Classroom Explanation

(Environment & Ecology | Energy & Industrial Processes)

📌 Question

Q.45) Consider the following substances:

I. Ethanol
II. Nitro-glycerine
III. Urea

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

(a) Only one
(b) Only two
(c) All the three
(d) None

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✅ Correct Answer: (b) Only two

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🧑‍🏫 Classroom Explanation

This question tests understanding of coal gasification as a feedstock technology, not as a final product process. UPSC expects clarity on syngas pathways.

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🔍 Core Concept: Coal Gasification

• Coal gasification converts coal into syngas
• Syngas = Carbon Monoxide (CO) + Hydrogen (H₂)
• Syngas is a platform feedstock for fuels, fertilizers, and chemicals

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🔍 Statement-wise Analysis

✅ I. Ethanol — Correct

• Syngas can be converted into:

• Methanol
• Ethanol

• Modern routes include:

• Biological fermentation of syngas using anaerobic microbes
• Thermo-chemical conversion

• Used in:

• Synthetic fuels
• Bio-refinery models
• Low-carbon fuel pathways

➡️ Hence, ethanol can be produced using coal gasification.

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❌ II. Nitro-glycerine — Incorrect

• Nitro-glycerine is:

• An organic nitrate compound
• Synthesised from glycerol + nitric acid

• Used as:

• Explosive (dynamite)
• Vasodilator drug (angina)

• No role of syngas or coal gasification in its production pathway.

➡️ Hence, nitro-glycerine is NOT produced using coal gasification.

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✅ III. Urea — Correct

• Coal gasification → Syngas → Hydrogen
• Hydrogen used to produce Ammonia (NH₃) via Haber process
• Ammonia + CO₂ → Urea

📍 India Example (Very UPSC-relevant):
• Talcher Fertilizer Project, Odisha

• Coal gasification-based urea plant
• Uses high-ash Indian coal
• Capacity: ~1.27 MMTPA Neem-coated urea

➡️ Hence, urea is produced using coal gasification.

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🧮 UPSC-Style Count Logic

Substance	Coal Gasification Used?
Ethanol	✅
Nitro-glycerine	❌
Urea	✅

➡️ Total correct = 2

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🎯 Final Answer

✅ Correct Answer: (b) Only two

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📦 High-Value Prelims Add-Ons (Info Box)

🧠 One-Line Memory Hook

Coal gasification feeds fuels and fertilizers — not explosives.

📌 India Linkage (High Yield)

• Coal gasification is promoted under:

• Atmanirbhar Bharat
• Fertilizer import substitution
  • Reduces dependence on natural gas imports

⚠️ UPSC Trap Alert

• Don’t confuse chemical synthesis with feedstock origin
• Syngas helps make:

• Fuels
• Fertilizers
  • Not specialty explosives or pharmaceuticals

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