Prelims 2019 · Q43
HardIn the context of proposals to the use of hydrogen-enriched CNG (H-CNG) as fuel for buses in public transport, consider the following statements:
- 1.The main advantage of the use of H-CNG is the elimination of carbon monoxide emissions.
- 2.H-CNG as fuel reduces carbon dioxide and hydrocarbon emissions.
- 3.Hydrogen up to one-fifth by volume can be blended with CNG as fuel for buses.
- 4.H-CNG makes the fuel less expensive than CNG.
Which of the statements given above is/are correct?
Answer & explanation
Answer: (b) 2 and 3 only
Statements 2 and 3 are correct. Blending hydrogen, which has no carbon, into CNG lowers carbon dioxide and hydrocarbon emissions, and India's trials and rules use a blend of about 18% hydrogen by volume, which is within one-fifth. H-CNG does not eliminate carbon monoxide and is not cheaper than plain CNG.
- ✗ 1. H-CNG is still mostly natural gas, a carbon fuel, so it can lower carbon monoxide but cannot eliminate it. Official pages describe the benefit as emissions reduction, not elimination.
- ✓ 2. Part of the fuel is carbon-free hydrogen, so less carbon is burnt per unit of energy and the blend gives lower carbon dioxide and hydrocarbon emissions; the Petroleum Ministry calls H-CNG an interim technology for emissions reduction.
- ✓ 3. The Road Transport Ministry allowed H-CNG with an 18% hydrogen mix in CNG engines, which is under one-fifth (20%) by volume; the Delhi bus trials also used 18%.
- ✗ 4. Making the blend is costly: the Petroleum Ministry notes that the high cost of producing and blending hydrogen offsets the fuel-economy savings over plain CNG, and its Secretary called commercial viability the main challenge.
- • Since then After the exam year, the Road Transport Ministry notified (GSR 585(E), 25 September 2020) H-CNG with an 18% hydrogen mix as an automotive fuel.
Remember · H-CNG is CNG blended with up to about 18% hydrogen by volume: it lowers emissions but does not remove them, and it is costlier than plain CNG.
Sources
- Notification allowing use of H-CNG issued, Ministry of Road Transport and Highways (PIB, 28 Sept 2020) ↗ “In a major step toward adopting alternative clean fuel for transportation, the Ministry of Road Transport and Highways has allowed use of H-CNG (18% mix of hydrogen) in CNG engines.”
- Shri Pradhan inaugurates H-CNG Plant and launches trials in Delhi, Ministry of Petroleum and Natural Gas (PIB, 20 Oct 2020) ↗ “Hydrogen-blended HCNG is emerging as an excellent interim technology for achieving emissions reduction and import substitution. … This process's high cost offsets the savings achieved from fuel economy gains compared to baseline CNG.”
Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·