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Process for preparation of meta-benzene dimethanamine by continuous hydrogenation reaction

A technology for m-xylylenediamine and isophthalonitrile, which is applied in the field of preparation of m-xylylenediamine, can solve the problem that the catalytic activity of the catalyst decreases rapidly, the disassembly, assembly, activation and regeneration are inconvenient, and the catalyst is easily worn, broken and lost. and other problems, to achieve the effects of inhibiting the formation of by-products, high hydrogen utilization rate, and not easy to wear and tear.

Active Publication Date: 2009-01-07
江苏德纳化学股份有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In the above-mentioned method in the prior art, the preparation of m-xylylenediamine by the fixed-bed hydrogenation of isophthalonitrile has problems such as the rapid decline rate of the catalytic activity of the catalyst, the inconvenience of disassembly, activation and regeneration, and the traditional stirred tank batch method In the hydrogen process, each operation has to go through repeated frequent operation steps such as feeding, replacement, reaction, and discharging. Not only is the labor intensity high, the catalyst life is short, the catalyst is easy to wear, break and lose, and the utilization rate of the equipment is low, and the hydrogen gas is lost during the operation. Large amount, frequent switching operation of reaction equipment under high and low pressure conditions will increase the fatigue strength of the reactor, thereby reducing the life of the reactor, and it is difficult to realize automatic production

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  • Process for preparation of meta-benzene dimethanamine by continuous hydrogenation reaction
  • Process for preparation of meta-benzene dimethanamine by continuous hydrogenation reaction
  • Process for preparation of meta-benzene dimethanamine by continuous hydrogenation reaction

Examples

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Effect test

Embodiment 1

[0027] Example 1 Using the method of the present invention to prepare m-xylylenediamine by continuous hydrogenation of isophthalonitrile, the process flow is as follows figure 1 Shown.

[0028] Hydrogen, reaction raw materials (isophthalonitrile and solvent) and catalyst enter the slurry-bed reactor 2 from the bottom to perform continuous hydrogenation reaction of isophthalonitrile, and the reaction materials are separated in the head space of the reactor 2 to achieve gas-liquid separation. The tail gas discharged from the top of the reactor 2, that is, the unreacted hydrogen is pressurized by the compressor 1 and recycled; the liquid-solid mixture extracted from the upper part of the reactor 2 enters the liquid-solid separator 3 for liquid-solid separation, so that the solid catalyst and The reaction liquid is separated. The separated solid catalyst enters the stirred tank regenerator 4, adds an appropriate amount of solvent, and is washed and regenerated with the solvent in the...

Embodiment 2～5

[0032] In Examples 2 to 5, m-xylylenediamine was continuously prepared according to the process method of Example 1. The difference lies in the catalyst used in the hydrogenation reaction and the reaction temperature and pressure. When using Raney nickel catalyst, Raney nickel is a commercially available Raney nickel catalyst with a nickel content of 87.5% (weight); the weight ratio of Raney nickel catalyst to liquid is 0.08:1, and the hydrogen circulation volume is 120 standard cubic meters per hour. , The residence time of the material in the reactor is 2.25 hours. Raney nickel catalyst regeneration conditions are the same as in Example 1 except that the regeneration time is 3 hours.

[0033] The results of the reaction are shown in Table 1.

[0034] Table 1 Reaction results of continuous hydrogenation of isophthalonitrile to prepare metaxylylenediamine

[0035]

Embodiment 6

[0037] Example 6 The method described in the present invention was used to prepare m-xylylenediamine by continuous hydrogenation of isophthalonitrile. The catalyst regeneration adopts a slurry bed regenerator. The process flow is as follows figure 2 Shown.

[0038] Hydrogen, reaction raw materials (isophthalonitrile and solvent) and catalyst enter the slurry-bed reactor 2 from the bottom to perform continuous hydrogenation reaction of isophthalonitrile, and the reaction materials are separated in the head space of the reactor 2 to achieve gas-liquid separation. The tail gas discharged from the top of the reactor 2, that is, the unreacted hydrogen is pressurized by the compressor 1 and recycled; the liquid-solid mixture extracted from the upper part of the reactor 2 enters the liquid-solid separator 3 to separate the catalyst and the reaction liquid. The separated catalyst is added with a proper amount of solvent and enters the slurry bed regenerator 4, where it is washed and rege...

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Abstract

The invention discloses a method for preparing m-xylene diamine by continuous hydrogenation, which adopts m-phthalonitrile as the raw material and carries out multi-phase hydrogenation. The method is characterized in that the mixture of m-phthalonitrile and a solvent and hydrogen contact a granular solid catalyst in a slurry bed reactor to carry out continuous hydrogenation reaction; the reactive solution and the solid catalyst are continuously fed into a separator for liquid-solid separation; the separated reactive solution is separated to obtain the final product; and the separated catalyst can be recycled after regeneration and returned to the slurry bed reactor. The method can achieve continuous hydrogenation of m-phthalonitrile, and has the advantages of good conversion rate and selectivity, convenient operation, and high equipment utilization rate and hydrogenation efficiency, and the catalyst is not easy to abrade and crush and can be continuously regenerated and recycled.

Description

Technical field [0001] The invention relates to a method for preparing m-xylylenediamine, in particular to a method for preparing m-xylylenediamine by continuous hydrogenation of isophthalonitrile. Background technique [0002] M-Xylylenediamine (m-Xylylenediamine, abbreviation MXDA, CAS1477-55-0) is an aliphatic amine containing aromatic rings, which is widely used due to its excellent physical and chemical properties. Metaxylylenediamine is a low-toxic epoxy resin curing agent with excellent performance, excellent curing performance at room temperature, excellent heat resistance, water resistance and chemical corrosion resistance; it can be used to synthesize polyamide (MX nylon); it also It can be used to synthesize polyurethane raw material meta-xylene diisocyanate (XDI); it is also an important fine chemical raw material, which is effectively used in rubber crosslinking agents, stabilizers, plastic materials, fiber finishing agents, agrochemicals (pharmaceuticals) and Surfac...

Claims

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Application Information

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IPC IPC(8): C07C211/27C07C209/48
CPCY02P20/584
Inventor 秦怡生秦旭东朱德宝段启伟陈荣福蒋大智
Owner 江苏德纳化学股份有限公司
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