Correct Option
Statements 2 and 3 are correct.
- H-CNG as fuel contributes to a reduction in carbon dioxide (CO₂) and unburnt hydrocarbon emissions. The presence of hydrogen in the blend promotes more complete combustion, leading to these environmental benefits.
- Hydrogen can be blended with CNG for use as fuel in buses, with studies and pilot projects indicating that blending up to 18-20% by volume (approximately one-fifth) is feasible and effective. This proportion enhances combustion efficiency without necessitating major engine modifications.
Incorrect Options
- Statement 1 is incorrect. While H-CNG significantly reduces carbon monoxide (CO) emissions, often by a substantial percentage, it does not lead to the complete elimination of these emissions.
- Statement 4 is incorrect. H-CNG is generally more expensive than conventional CNG. The higher cost is primarily due to the energy-intensive process involved in blending hydrogen and the additional infrastructure required for hydrogen production, storage, and distribution.