Compressed Natural Gas
Also called: CNG · Topic: Environment and Sustainable Development · NCERT: Class 11, Ch 7 "Environment and Sustainable Development"
Meaning
Compressed Natural Gas (CNG) is natural gas squeezed under high pressure so it can be stored in a vehicle's tank and used as fuel. It burns much more cleanly than diesel or petrol, so it gives off far less smoke and soot. That matters in Indian cities, where vehicle exhaust is released at ground level, right where people breathe.
Example
In the M.C. Mehta case in 1998, the Supreme Court ordered Delhi's public transport to switch to CNG. Buses and autos changed over in the early 2000s. NCERT says Delhi's air "has become cleaner" as a result, and many other cities followed.
Don't confuse with
- LPG (liquefied petroleum gas): mainly a household cooking fuel that is stored as a liquid in cylinders. CNG is mainly used as a transport fuel.
- Compressed biogas: made from cattle dung and other organic waste. CNG is a fossil fuel.
Related concepts
- Non-conventional sources of energy
- Wind power
- Solar photovoltaic power
- Mini-hydel plants
- LPG as clean fuel
- Biogas
- Road space rationing
- Energy poverty