Isobutane, also known as 2-methylpropane, is an organic compound with the formula C4H10 and is a colorless flammable gas at room temperature and pressure. Slightly soluble in water, soluble in ethanol, ether, etc., form an explosive mixture with air, mainly in natural gas, refinery gas and cracking gas, obtained by physical separation, mainly used for alkylation with isobutene to produce isoctane, as an improver of gasoline octane number, and can also be used as a refrigerant.