Preparation method and application of a catalyst for preparing olefins

Abstract

The invention discloses a multi-component NiO / SiO2 / F<-> / SO4<2-> / Al2O3 catalyst for preparing high-purity olefins by ether cracking and a preparation method thereof. According to the method, the catalyst comprises the following components in percentage by weight: 20-95% of Al2O3, 1-50% of NiO, 0.1-20% of SiO2, 0.1-10% of F<-> and 0.5-35% of SO4<2->. The catalyst is prepared by using an impregnation method, the operation is simple, the price is low, the catalyst can be used for preparing olefins by ether cracking at a lower temperature over present congeneric catalysts, the ether cracking is close to complete conversion while high olefin and methanol selectivity is guaranteed, and the air speed ratio of the reaction liquid is improved by 2-10 times over congeneric industrial catalysts.

Description

technical field [0001] The invention relates to the preparation and application of a catalyst for preparing olefins by cracking ether. It mainly involves multi-component NiO / SiO supported on aluminum oxide by metal oxide, silicon oxide, halogen and sulfate 2 / F - / SO 4 2- / Al 2 o 3 type catalyst. Background technique [0002] Isoamyl is a mixture of 2-methyl-2-butene and 2-methyl-1-butene, and 2-methyl-2-butene is the active ingredient in most reactions, so 2-methyl-2 - The higher the butene content, the higher the value contained. As an important chemical raw material, isobutene is widely used in the production of isoprene, pinacolone, tert-amyl alcohol, spices and pesticides, of which the production of pesticides and spices accounts for the vast majority. Especially with the prohibition of phosphorus-containing pesticides in China, isopentene has been widely used as a basic raw material for the synthesis of triazole fungicides, plant growth regulators and herbicid...

AI Technical Summary

Problems solved by technology

However, when the cracking temperature is high, the side reactions increase, such as the oligomerization of isopentene leads to the loss of isopentene; the dehydration of methanol obtained by cracking produces dimethyl ether, and the production of dimethyl ether will reduce the recovery rate of methanol, resulting in the need to add a large amount methanol into the initial etherification reaction system; the hydration of water and isopentene produced during the formation of dimethyl ether also causes the product to be lost, and the generation of by-products increases the cost of separation and purification of the product, etc.

The disadvantage of ion exchange resin catalysts is poor high temperature resistance. When the reaction temperature is too high, the active components in it are easy to decompose and fall off. Due to the limitation of the reaction temperature, the conversion rate of the reaction is low.

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