Method for preparing isoprene by means of reaction and distillation

• Main Authors: ZHU PEIHONG, REN WEIJIANG, XIAO YUANSEN, FENG QIU, FAN NENGQUAN, WEN JINHU
• Format: Patent
• Language: English
• Published: 09.12.2015
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

The invention relates to a method for preparing isoprene by means of reaction and distillation. The method for preparing the isoprene by means of the reaction and distillation is characterized by comprising the following steps that tertiary butanol, an acid water catalyst and a formaldehyde solution are added into a tubular reactor for pre-reaction, and the tertiary butanol is reacted with partial formaldehyde to generate mixed liquor containing 4,4-dimethyl-1,3-dioxane under the action of the acid water catalyst; the mixed liquor enters a rectifying tower, under the action of gravity, most of the 4,4-dimethyl-1,3-dioxane, the acid water catalyst and partial water enter into the stripping section of the rectifying tower, isobutene, most of the tertiary butanol, and the formaldehyde and rest of the water enter into the rectifying section of the rectifying tower; an oil-water mixture obtained at the top of the reaction rectifying tower is sent to a phase-separation tank, and an oil-phase mixture containing light components with the number of carbon atoms smaller than five, the isoprene and other byproducts is obtained at the top of the phase-separation tank; the oil-phase mixture passes through a knockout tower, tower kettle materials are sent to an isoprene evaporating tower, and the isoprene product is obtained.