METHOD FOR PRODUCTION OF ISOPRENE FROM FORMALDEHYDE AND ISOBUTENE Russian patent published in 2001 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: acid-catalyzed liquid-phase process conducted in presence of water at elevated temperature comprises two consecutive chemical conversion stages, the first one largely consisting in synthesis of intermediates and the second in decomposition of the latter to form isoprene, which is taken away in vapor flow and further subjected to separation. Decomposition of intermediates is carried out within reaction system including at least one shell-and-tube reaction zone heated through tube space and one bubbling-reaction zone connected to the in-tube space of the former zone and having volume by at least 1,2 times, preferably 1.5-3 times, exceeding volume of shell-and-tube reaction zone. EFFECT: increased yield of product. 2 dwg, 4 ex