Compressed natural gas Compressed natural gas Compressed natural gas (CNG) (methane stored at high pressure) is a fuel which can be used in place of gasoline, diesel fuel and propane/LPG. CNG combustion produces fewer undesirable gases than the fuels mentioned above. It is safer than other fuels in the event of a spill, because natural gas is lighter than air and disperses quickly when released. Biomethane – cleaned-up biogas from anaerobic digestion or landfills – can be used. CNG is made by compressing natural gas, (which is mainly composed of methane, CH), to less than 1 percent of the volume it occupies at
Natural-gas processing of three types of wells: crude oil wells, gas wells, and condensate wells. Natural gas that comes from crude oil wells is typically called "associated gas". This gas can have existed as a gas cap above the crude oil in the underground formation, or could have been dissolved in the crude oil. Natural gas from gas wells and from condensate wells, in which there is little or no crude oil, is called "non-associated gas". Gas wells typically produce only raw natural gas, while condensate wells produce raw natural gas along with other low molecular weight hydrocarbons. Those that are liquid