Catalyst for producing isobutene by cracking methyl tert-butyl ether

Abstract

The composition of solid acid catalyst for preparing isobutylene by cracking reaction of methyl tert-butyl ether contains (wt%) 20-95% of aluminium oxide, 0.1-20% of titanium dioxide, 0-5% of other oxide and 0.5-50% of loaded SO4, and its preparation method includes the following steps: adding aluminium oxide into the aqueous solution containing Ti(SO4)2 and other soluble metal salt, filtering, soaking filter cake in ammonia water, filtering, washing, drying, soaking in sulfuric acid solution, filtering, drying and baking so as to obtain the invented SO4/M-TiO2/Al2O3 type low-temp. catalyst.

Description

technical field [0001] The present invention relates to a catalyst for producing isobutene by cracking reaction of methyl tert-butyl ether, as well as its preparation method and application, in particular to a catalyst for producing isobutylene by cracking reaction of methyl tert-butyl ether, in which the active component is loaded on an alumina carrier solid acid catalyst. Background technique [0002] Isobutene is an important organic chemical raw material. In recent decades, its social demand has been growing rapidly. It can not only be used in the manufacture of gasoline and lubricating oil additives, but also can be used as an important auxiliary agent and raw material for other chemical products to prepare a variety of chemicals. main ingreadient. Therefore, the research on the industrial production method of isobutene has been very active in recent decades. There are many ways to prepare isobutene, mainly including sulfuric acid extraction method, direct hydration...

AI Technical Summary

Problems solved by technology

[0004] The thermal stability of methyl tert-butyl ether is better, and the cracking needs to be carried out at a higher temperature, but increasing the reaction temperature is beneficial to the improvement of the cracking conversion rate of methyl tert-butyl ether, and it is also conducive to the occurrence of side reactions , such as the dimerization of isobutene leads to the loss of product isobutene; the generation of dimethyl ether will reduce the recovery rate of methanol, resulting in the need to add a large amount of methanol to the initial etherification reaction system; the water produced when dimethyl ether is generated is hydrated with isobutene It also makes the product suffer losses, and the generation of by-product tert-butanol increases the cost for the separation and purification of the product, etc.

The higher reaction temperature also brings difficulties to the operation and increases energy consumption

The above-mentioned catalyst has a high conversion rate to the cracking of methyl tert-butyl ether, but a large amount of water vapor and other inert substances need to be added during the reaction, and the recovery rate and equipment utilization rate of methanol and isobutylene are greatly reduced, making the process complicated. and result in expensive additional costs

The disadvantage of the ion exchange resin catalyst is that the high temperature resistance is poor. When the reaction temperature is too high, the sulfonic acid group in it is easy to fall off. Due to the limitation of the reaction temperature, the conversion rate of the reaction is low.

The Achilles' heel of the sulfate system catalyst is that under the reaction conditions, the sulfate will gradually decompose, which will cause corrosion of equipment and decrease of catalyst activity.