All spark-ignited engines can be converted to CNG, but a specially designed conversion kit is required for the purpose. The kit consists of a cylinder to be fixed in the boot of the car and other equipment to allow gas flow into the engine.
Natural gas is mainly Methane-CH4 with a small percentage of other hydrocarbons. The ratio of carbon to hydrogen is least in methane and hence it burns almost completely making it the cleanest fuel. It is procured from the oil/gas wells and transported through a network of pipelines across the country.
PNG is not stored at one place but is continuously supplied through pipelines mainly Hazira-(B) Vijalpur-Jagdishpur (HBI) pipeline of GAIL.
Yes, the supply is absolutely regular. The pipeline distribution network is based on an on-line supply system that consists of safety valves and regulators that control and monitor the gas supply and pressure, and assist in identifying system leaks. Thus an un-interrupted supply at a constant pressure is assured.