izobutanu

Izobutanu, also known as isobutane or methylpropane, is a branched aliphatic hydrocarbon with the chemical formula C4H10. It is one of the two structural isomers of butane, the other being n-butane. The typical structural representation is CH3-CH(CH3)-CH3, or equivalently (CH3)3CH, indicating a central carbon bonded to three methyl groups and one hydrogen.

Occurrence and production

Izobutanu occurs in small amounts in natural gas and crude oil streams and is recovered during refining. Industrially it is produced by isomerization of n-butane, and it can also be separated from refinery gas streams. As a component of light hydrocarbon mixtures, it is commonly separated by fractional distillation and stored under appropriate pressures or cooling.

Physical properties and uses

Izobutanu is a colorless, flammable gas at room temperature. It has a boiling point of about −11.7 °C and a relatively high vapor pressure, making it convenient to store as a compressed liquid. It is widely used as a refrigerant (often marketed as R600a) in domestic refrigerators and as a propellant in aerosol products. In petrochemical processing, izobutanu serves as a feedstock for the production of isobutylene and various alkylating compounds that improve gasoline octane.

Safety and handling

As a flammable hydrocarbon, izobutanu poses fire and explosion hazards if exposed to heat, sparks, or flames in poorly ventilated areas. It is denser than air and can accumulate in low-lying spaces. Proper ventilation, leak detection, and adherence to storage guidelines are essential to safe handling.