ISOPRENE PRODUCTION PROCESS Russian patent published in 2003 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: invention provides process consisting in liquid-phase reaction of formaldehyde and optionally formaldehyde precursor(s) with tert-butanol and optionally isobutene in isoprene-synthesis reaction zone in presence of strong acid catalyst and water at elevated temperature and molar excess of tert-butanol supplied relative to summary amount of formaldehyde fed into indicated reaction zone and possibly that released by indicated formaldehyde precursor(s), in which process synthesized isoprene and isobutene and a part of water are continuously distilled off the reaction zone, after which isoprene and isobutene are isolated. Vertical isoprene-synthesis reaction zone, with its height at least fourfold exceeding its diameter, connected from below to boiler, is operated at pressure maintained at a level preventing condensation of isoprene whereas larger part of water and formaldehyde and considerable part of tert-butanol are in liquid phase. Vapors and liquid in reaction zone move predominantly in bottom-up direction. From the top part of reaction zone, one or two liquid streams are withdrawn with boiling temperatures higher than that of isoprene. At least part of recovered isobutene is subjected to reaction with water and resulting tert-butanol is reused in isoprene synthesis. EFFECT: simplified technology. 11 cl, 3 dwg, 4 tbl, 11 ex