Generally, this term is used for something that would be gaseous under normal ambient temperatures and pressures, but is currently in a liquid state (usually because it's highly compressed or has been cooled.).
because that's what it is?Liquefied Petroleum Gas = LPG
LPG: Liquefied Petroleum Gas CNG: Compressed Natural Gas
gas
by compressing it
NGL is not liquefied natural gas, which is condensed natural gas that is compact and therefore convenient for overseas shipping.
Helium.
You cool it down.
Yes.
That the gas has liquefied.
Carbon dioxide (CO2) can be liquefied under pressure at ordinary temperature.
lpg
sometimes