Preparation method and application of catalyst for preparing isoamylene

Abstract

The invention discloses a multicomponent SO42- / POMs / NiO / Al2O3 catalyst for preparing high-purity isoamylene through cracking of tert-amyl methyl ester and a preparation method thereof. According to the preparation method of the multicomponent SO42- / POMs / NiO / Al2O3 catalyst, the multicomponent SO42- / POMs / NiO / Al2O3 catalyst is composed of, by weight percentage, 20-95% of Al2O3, 1-50% of NiO, 0.1-20% of POMs and 0.5-35% of SO42-. The multicomponent SO42- / POMs / NiO / Al2O3 catalyst is prepared through an impregnation method and is simple in operation and low in prices, and compared with existing similar catalysts, can achieve the reaction of preparing the isoamylene through cracking of the tert-amyl methyl ester under a lower temperature, thereby ensuring high selectivity of isoamylene and methanol and meanwhile approximately fully converting the tert-amyl methyl ester; the liquid space velocity ratio of the reaction can be increased by 2-10 times compared with that of reactions with similar industrial catalysts; meanwhile, without adding of halogen, cleanliness and environmental protection can be achieved.

Description

technical field [0001] The invention relates to a preparation method and application of a catalyst for preparing isopentene. Mainly involved in metal oxides, heteropolyacids and SO 4 2- Multicomponent SO and its salt supported on Al2O3 4 2- / POMs / NiO / Al 2 o 3 type catalyst. Background technique [0002] Isopentene is a mixture of 2-methyl-2-butene and 2-methyl-1-butene. It is an important raw material for fine chemical intermediates, mainly used in the production of isopentene, pinacolone, and tert-amyl alcohol. It can also be used as a protective agent for synthetic rubber, resin and organic synthesis, of which the production of pesticides and spices accounts for the vast majority. Due to the many downstream products of isopentene, the demand for isopentene in China is very large, especially with the domestic prohibition of phosphorus-containing pesticides, triazole fungicides and plant growth regulators synthesized with isopentene as basic raw materials Non-phospho...

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 generation of dimethyl ether also causes the product to be lost, and the generation of by-product tert-amyl alcohol 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.

The disadvantages of the fluoride system catalyst are that the conversion rate of TAME is relatively low, and the existence of halogen will continue to accumulate in the organism, affecting human health and destroying the ecological environment

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