A kind of method for synthesizing cyclohexylbenzene by liquid-phase alkylation of benzene and cyclohexene

Abstract

A method of liquid-phase alkylation of benzene and cyclohexene to form cyclohexylbenzene is disclosed. The method includes a process I of performing contact reactions of benzene, cyclohexene and cyclohexane under the existence of a catalyst containing an MWW structure molecular sieve to obtain cyclohexylbenzene, a process II of performing a contact reaction of the benzene and multi-cyclohexyl benzene to further obtain cyclohexylbenzene, and a process of separation, wherein benzene containing the cyclohexane, methylcyclopentylbenzene, cyclohexylbenzene and multi-cyclohexyl benzene cam be at least obtained from products of the process I and the process II after the process of separation; the benzene obtained from the process of separation is cycled and reused to the process I and / or the process II; and the multi-cyclohexyl benzene in the process II is obtained from the process of separation. The yield of the cyclohexylbenzene of the method is higher than 92%. The service lifetime of the catalyst can be prolonged by 50-100%.

Description

technical field [0001] The invention relates to a method for synthesizing cyclohexylbenzene by liquid-phase alkylation of benzene and cyclohexene, in particular to a method for synthesizing cyclohexylbenzene by liquid-phase alkylation of benzene and cyclohexene which can prolong the catalyst life method. Background technique [0002] Cyclohexylbenzene is an important chemical intermediate, which has a high boiling point (240°C) and a low freezing point (7°C), and has special physical and chemical properties. Cyclohexylbenzene can be oxidized to produce cyclohexylbenzene hydroperoxide, and cyclohexylbenzene hydroperoxide can be decomposed to produce phenol and cyclohexanone. Phenol is a chemical raw material in great demand, while cyclohexanone is an intermediate in the production of caprolactam and nylon. Cyclohexylbenzene can also be used as an additive for the electrolyte of lithium-ion secondary batteries, which can improve the cycleability of lithium-ion batteries, has...

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Problems solved by technology

[0004] U.S. Patent US3760018 and US3760019 have reported a kind of adopting supported type catalyst (M / SiO 2 -Al 2 o 3 , M is metal rhenium, cobalt and nickel, etc.) Catalyzed benzene hydroalkylation method to prepare cyclohexylbenzene, this method is actually the hydrogenation of benzene to synthesize cyclohexene and the alkylation of benzene and cyclohexene to synthesize cyclohexyl The two-step reaction of benzene is combined into one, and the selectivity of cyclohexylbenzene is less than 60%; U.S. Patent No. 4,268,699 provides a kind of improved method that uses ruthenium and nickel bimetallic supported catalyst, although the selectivity of this method cyclohexylbenzene improves , but still unsatisfactory (the selectivity of cyclohexylbenzene is lower than 80.6%); U.S. Patents US20100179351, US20100197971 and US7910779 disclose a metal-supported catalyst (wherein the metal is selected from palladium, ruthenium, nickel, zinc, cobalt and tin One, the carrier is any combination of MCM-22 molecular sieves), catalyzes the hydrogenation reaction of benzene, the conversion rate of benzene is improved, but it is still lower than 60%, and the selectivity of cyclohexylbenzene is lower than 88%

[0005] AppliedCatalysisA:General143(1996)271-281 reported that benzene and cyclohexene in SiO 2 grafted A1C1 3 The method of carrying out liquid phase reaction under the action of a catalyst, the conversion rate of cyclohexene in this method is 97.9%, and the selectivity of cyclohexylbenzene reaches 97%, but this method has the problems of catalyst polluting the environment, product recovery and purification complexity, and poor reusability question

[0006] CN1982263A and CN1982264A have reported respectively the method for preparing cyclohexylbenzene by reacting benzene with cyclohexanol or halocyclohexane, but the common defect that they exist is that used cyclohexanol or halocyclohexane are expensive and the corrosiveness of catalyst used larger

CN101811924A has reported the method that benzene and cyclohexene are catalyzed and prepared cyclohexylbenzene in pyridine type ionic liquid as catalyst, but the production process of ionic liquid is very complicated, causes its price to be generally more expensive, and ionic liquid is particularly sensitive to water, after meeting water Partial hydrolysis is easy to inactivate, and it will fail after being used many times, which affects the efficiency of recycling. These are the big problems that restrict its development and are not conducive to industrial applications.

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