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A kind of compound catalyst and method for preparing styrene

A styrene and catalyst technology, which is applied in the field of compound catalysts for the preparation of styrene, can solve the problems of reactor corrosion, high reaction temperature, intensified side reactions of heavy components, etc. effect of time reduction

Active Publication Date: 2022-08-05
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] At the same time, the acidic catalyst with a large molecular weight is easy to polymerize with styrene, resulting in a large amount of catalyst used, and the side reaction of generating heavy components is intensified
In addition, the traditional tank reactor has a large volume and high reaction temperature, which leads to serious corrosion of the reactor
[0008] In order to solve the above problems, one of the current methods for synthesizing styrene is to use 1-phenylethanol to carry out reactive distillation dehydration under high temperature and reduced pressure conditions, but the reaction and separation are carried out in the same equipment, the dehydration effect is poor, and the reaction residence time is long , the reaction product and catalyst cannot be separated from the heavy component in time, and styrene and the heavy component are further polymerized, which cannot fundamentally avoid the reduction of the overall yield caused by the polymerization of styrene
[0009] At the same time, liquid-phase dehydration uses a catalyst of p-toluenesulfonic acid macromolecule. In order to ensure a high conversion rate of 1-phenylethanol in a traditional reactor, a large amount of catalyst needs to be added, and these catalysts will also participate in the polymerization of styrene, resulting in catalyst and benzene double loss of ethylene

Method used

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  • A kind of compound catalyst and method for preparing styrene
  • A kind of compound catalyst and method for preparing styrene
  • A kind of compound catalyst and method for preparing styrene

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Experimental program
Comparison scheme
Effect test

Embodiment 1～11

[0056] The pressure of the control flash tank is 50kPa, the pressure at the top of the separation tower is 30kPa, the temperature of the dehydration reactor is 200 ° C, the pressure is 50kPa, based on the freshly added 1-phenylethanol raw material weight, methanesulfonic acid and p-phenol formic acid. The compounded catalyst is added according to the compounding ratio n, and the circulation ratio (the weight ratio of the heavy components of the circulating reaction medium to the feed mass ratio of the freshly added 1-phenylethanol) is 10:1 to 32:1. The obtained styrene-containing material is adsorbed and deacidified by D301 basic resin, and the resin adsorption bed space velocity is 0.5BV. The results are shown in Table 1 below.

[0057] Table 1

[0058]

[0059]

Embodiment 12～18

[0061] Recycle ratio 15, residence time 60s, based on the freshly added 1-phenylethanol raw material weight, methanesulfonic acid and p-phenol formic acid catalyst are compounded according to 1:1, compounded catalyst addition 100ppm, flash tank pressure P 1 kPa, separation tower top pressure P 2 kPa, where the dehydration reactor pressure is the same as the flash tank pressure and is P 1 kPa. The obtained styrene-containing material is adsorbed and deacidified by D301 basic resin, and the resin adsorption bed space velocity is 0.5BV. The reaction results are shown in Table 2.

[0062] Table 2

[0063]

[0064]

[0065] The results show that by controlling the temperature of the dehydration reactor R-1 and adjusting the circulation ratio, the conversion rate of 1-phenethyl alcohol can reach more than 98%, and the selectivity can reach more than 98.5%.

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Abstract

The invention discloses a method for preparing styrene. 1-phenethyl alcohol is dehydrated in the presence of a compound catalyst formed by compounding one or two of methanesulfonic acid, p-methoxyphenol and p-phenol formic acid inhibitor Styrene is produced. The composite catalyst and the styrene preparation method of the present invention can realize the separate circulation of the dehydration catalyst and the side reaction inhibitor, the total consumption of the composite catalyst is low, the occurrence of by-products is reduced, the conversion rate is improved, and the styrene selectivity can be improved. reached more than 98.5%.

Description

technical field [0001] The invention relates to a composite catalyst and a method for preparing styrene, in particular to a method for preparing styrene from raw materials containing 1-phenethyl alcohol through external circulation reaction and rectification. Background technique [0002] Styrene is an important basic organic chemical raw material, mainly used in the production of polystyrene resin (PS), acrylonitrile-butadiene-styrene terpolymer (ABS), styrene-acrylonitrile copolymer (SAN) )Wait. In addition, it can also be used in pharmaceuticals, dyes, pesticides and mineral processing industries, and has a wide range of uses. [0003] There are two main methods known for the preparation of styrene: (1) the preparation of styrene by catalytic direct thermal dehydrogenation of ethylbenzene; (2) the use of a method for the joint preparation of styrene and propylene oxide, commonly referred to as For the POSM process, a patent describing the process is U.S. No. 3,351,635. ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C1/24C07C15/46B01J31/04B01J31/02
CPCC07C1/24C07C15/46B01J31/04B01J31/0225B01J31/0204
Inventor 冷炳文董岩峰叶建初虞根海刘洋洋胡亚东张宏科
Owner WANHUA CHEM GRP CO LTD