n-BUTANE CHEMICALS

Like propane, n-butane is mainly obtained from natural gas liquids.

It is also a by-product from different refinery operations. Currently, the major use of n-butane is to control the vapor pressure of product gasoline. Due to new regulations restricting the vapor pressure of gasolines, this use is expected to be substantially reduced. Surplus n-butane could be isomerized to isobutane, which is currently in high demand for producing isobutene. Isobutene is a precursor for methyl and ethyl tertiary butyl ethers, which are important octane number boosters. Another alternative outlet for surplus n-butane is its oxidation to maleic anhydride. Almost all new maleic anhydride processes are based on butane oxidation. n-Butane has been the main feedstock for the production of butadiene. However, this process has been replaced by steam cracking hydrocarbons, which produce considerable amounts of by-product butadiene.

The chemistry of n-butane is more varied than that of propane, partly because n-butane has four secondary hydrogen atoms available for substitution and three carbon-carbon bonds that can be cracked at high temperatures:

Like propane, the noncatalytic oxidation of butane yields a variety of products including organic acids, alcohols, aldehydes, ketones, and olefins. Although the noncatalytic oxidation of butane produces mainly aldehydes and alcohols, the catalyzed oxidation yields predominantly acids.