Combined method for preparation of methyl tert-butyl ether and isobutylene from tert-butyl alcohol and methanol

Abstract

The invention provides a combined method for preparation of methyl tert-butyl ether and isobutylene from tert-butyl alcohol and methanol. The method is carried out in a device including a catalytic rectification tower. The catalytic rectification tower comprises a catalytic reaction section located at the middle part, tert-butyl alcohol enters the catalytic rectification tower through the catalytic reaction section, and methanol and water enter the catalytic rectification tower from the tower top; in the catalytic reaction section, one part of tert-butyl alcohol dehydrates to generate isobutylene, and the other part of tert-butyl alcohol and the isobutylene respectively further react with methanol fed to the tower top to both generate methyl tert-butyl ether; wherein, the tert-butyl alcohol is pretreated, and the tert-butyl alcohol and methanol are in a feeding mole ratio of 10:1-10:9. The combined process provided by the invention combines reaction and separation, promotes the rightward reaction, enables preparation of isobutylene by tert-butyl alcohol dehydration and synthesis of MTBE in "one-pot process", greatly simplifies the operation procedure, lowers the process cost and enables easy implementation, and improves the raw material conversion rate overall.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a combined method for preparing methyl tert-butyl ether and isobutene from tert-butanol and methanol. Background technique [0002] Both methyl tert-butyl ether and isobutene are important C4 raw materials, which are mainly separated and reacted from the mixed C4 by-products of oil refining, cracking ethylene and coal-to-olefins. [0003] After the butadiene is extracted from the mixed carbon four, in the remaining mixture, the boiling point difference between isobutene and butene-1 is only 0.6°C, which is difficult to separate by rectification. Usually, methanol is added to make isobutene generate methyl tert-butyl The method of base ether separation. MTBE is a liquid at normal temperature and pressure, and is easy to transport. Most of it is used for oil adjustment, and a small part is cracked in situ to make isobutylene, which is used to synthesize buty...

AI Technical Summary

Problems solved by technology

However, an extraction tower and two extractant recovery towers are added in the process flow, the equipment is complex and the investment cost is large

[0008] In the disclosed technology, methyl tert-butyl ether is produced by the reaction of excess methanol and tert-butanol, which requires methanol to be recycled, and requires multiple reactors to consume excess methanol, thereby increasing energy consumption

Images