are hydrocarbons extracted from natural gas: primarily LPG (propane or butane) and natural gasoline, the latter being commonly blended with crude-derived gasoline to improve volatility. Natural gas liquids can be separated from the lighter hydrocarbons of natural gas by compression (the gas is compressed and cooled until the heavier hydrocarbons liquefy) or by absorption (the gas is mixed with a petroleum distillate, such as kerosene, which absorbs, or dissolves, the heavier hydrocarbons).