Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?
Even though CNG is termed as a clean fuel, when CNG is burnt, it produces some carbon dioxide which causes air pollution.
Incomplete combustion of CNG can lead to the production of carbon monoxide, which is a really harmful gas.
On the other hand, when hydrogen is burnt, it produces water vapour.
Water vapour does not contribute to any kind of pollution.
Hence, hydrogen is a better fuel than CNG.