PRODUCTION OF METHYL TERTIARY BUTYL ETHER FROM ISOBUTYLENE

摘要

A C4 hydrocarbon mixture (A) containing isobutylene (e.g., by-product from an ethylene plant) is mixed with methanol (B) and recovered methanol from stream (F) in molar ratio 1:0.9 to 1.6, and the mixture is fed to a vessel (2) containing an acidic ion exchange resin as catalyst, to react to form methyl tert-butyl ether (MTBE). The reaction mixture is fed to a distillation column (3) and distilled to separate from the bottom the MTBE (C) and from the top a stream of unreacted hydrocarbons and methanol, which is fed to a second extraction column (4) containing water which is fed through stream (E) where it is washed and the methanol is removed in a stream (F) of water; this stream is fed to the first extraction column (1), where it is contacted with the feed hydrocarbon mixture (A) and part of the methanol is extracted and transferred to that feed; water (G) is recirculated to the second extraction column (4) and the hydrocarbon mixture and extracted methanol, with make-up methanol (B) if necessary, is fed to the reaction vessel (2). …Suitable distillation apparatus is:… (3) a distillation column having 24 theoretical plates;… (4) an extraction column having 4 theoretical plates;… (1) an extraction column having 10 theoretical plates. …The temperatures in the extraction steps can be 20-70 DEG C under a pressure that column contents are liquid.