ISOBUTANE CHEMICALS

Isobutane is mainly used as an alkylating agent to produce different compounds (alkylates) with a high octane number to supplement the gasoline pool. Isobutane is in high demand as an isobutene precursor for producing oxygenates such as methyl and ethyl tertiary butyl ethers (MTBE and ETBE).

  Accordingly, greater amounts of isobutane are produced from n-butane through isomerization followed by dehydrogenation to isobutene. The Catofin process is currently used to dehydrogenate isobutane to isobutene. Alternatively, isobutane could be thermally cracked to yield predominantly isobutene plus propane. Other by-products are fuel gas and C₅ + liquid. The steam cracking process is made of three sections: a cracking furnace, a vapor recovery section, and a product fractionation section. The Coastal isobutene cracking process is reviewed by Soudek and Lacatena.