UPSC Previous Year Question | Prelims GS | 2019

In 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?

  1. 1 only
  2. 2 and 3 only
  3. 4 only
  4. 1, 2, 3 and 4

Answer

Correct Answer

2 and 3 only

Explanation

H-CNG (up to about 18-20% hydrogen by volume) reduces CO2 and hydrocarbon emissions, and it lowers - but does not eliminate - carbon monoxide emissions. Blending hydrogen makes the fuel more expensive than plain CNG. So only statements 2 and 3 are correct.

Topics: alternative fuels, energy and environment, hydrogen-enriched cng (h-cng), science and technology