UPSC Prelims 2023 Q99: Environment & Ecology – Renewable Energy & Green Technologies
- (a) Only one
- (b) Only two
- (c) All three
- (d) None
Answer: (c) All three
Explanation
Green Hydrogen for Heavy Industry Decarbonisation
| Industry | How Green Hydrogen Helps | Decarbonisation Role |
|---|---|---|
| Fertilizer plants | Ammonia (NH₃) = primary feedstock for nitrogen fertilizers. Ammonia synthesis currently uses grey hydrogen (from natural gas). Green hydrogen replaces grey hydrogen in the Haber-Bosch process — producing green ammonia and green fertilizers. | Replaces fossil-derived hydrogen in ammonia production → green ammonia |
| Oil refineries | Refineries use large amounts of hydrogen for hydrocracking and hydrotreating (removing sulphur from fuel). Green hydrogen can replace fossil-derived hydrogen in these processes. | Decarbonises hydroprocessing operations |
| Steel plants | Traditional steelmaking uses coking coal (carbon). Direct Reduced Iron (DRI) using hydrogen replaces coal — producing green steel with water as the only by-product (Fe₂O₃ + 3H₂ → 2Fe + 3H₂O). | Replaces coking coal via hydrogen-DRI route |
All three industries can be significantly decarbonised using green hydrogen → All three.
Answer: (c) All three.
Why each option is right or wrong
- (a) Incorrect. 'Only one' — all three heavy industries have documented pathways for green hydrogen adoption.
- (b) Incorrect. 'Only two' — fertilizer plants are one of the most advanced green hydrogen application areas (green ammonia).
- (c) CORRECT. Green hydrogen can decarbonise all three: fertilizers (green ammonia), oil refineries (hydroprocessing), and steel plants (hydrogen-DRI). All three are part of India's National Green Hydrogen Mission targets.
- (d) Incorrect. 'None' — all three industries currently use significant quantities of fossil-derived hydrogen or carbon and are prime green hydrogen candidates.
Key point
Green hydrogen decarbonises: Fertilizers (green ammonia via Haber-Bosch) + Refineries (hydroprocessing) + Steel (H-DRI replacing coking coal). All three are heavy emitters that green hydrogen can clean up. India's NGHM targets all three sectors.
Remember
Green hydrogen is expected to play a significant role in decarbonising all three industries: fertilizer plants (green ammonia production), oil refineries (hydroprocessing), and steel plants (hydrogen-based direct reduced iron). All three statements are correct.
Common mistakes
- Thinking steel plants don't use hydrogen — DRI technology uses hydrogen as a reductant; this is already commercial and rapidly scaling.
- Underestimating refinery hydrogen demand — refineries are the second-largest hydrogen consumers globally after ammonia production.
- Not knowing the fertilizer-hydrogen link — ammonia synthesis (Haber-Bosch) is the world's largest industrial hydrogen consumer.
Exam tip
Green hydrogen priority sectors: Fertilizers (green NH₃) > Refineries (hydroprocessing) > Steel (H-DRI) > Shipping > Aviation. India's National Green Hydrogen Mission (2023) targets all three plus mobility. All three = correct answer.
Sources
- Ministry of New and Renewable Energy — National Green Hydrogen Mission
- IEA — Hydrogen in Industry: Decarbonisation Pathways