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Method for preparing m-phenylene dimethylamine

A technology of m-xylylenediamine and isophthalonitrile, which is applied in the field of preparation of m-xylylenediamine, can solve the problems of easy wear and tear of the catalyst, reduction of catalytic activity of the catalyst, increase of the fatigue strength of the reactor, etc. Effects of by-product formation, long catalyst life, and high hydrogen utilization

Active Publication Date: 2013-01-02
江苏德纳化学股份有限公司 +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] In the above-mentioned method in the prior art, the preparation of m-xylylenediamine by isophthalonitrile fixed-bed hydrogenation has problems such as reduced catalytic activity of the catalyst, inconvenient disassembly and activation, and the traditional stirred tank batch method hydrogenation process, each time The operation must 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 and tear, and the catalyst is easy to wear and tear, and the utilization rate of the equipment is low, and the loss of hydrogen gas during the operation is large. Frequent switching between high and low pressure 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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  • Method for preparing m-phenylene dimethylamine

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Effect test

Embodiment 1

[0027] Embodiment 1 adopts the method described in the present invention to prepare m-xylylenediamine by the continuous hydrogenation of isophthalonitrile, and its technological process is as follows figure 1 shown.

[0028] Hydrogen enters from the bottom of the regeneration zone of the reaction / regeneration coupling reactor 2, and the reaction raw materials (isophthalonitrile and solvent) and fresh catalyst enter from the middle of the reaction / regeneration coupling reactor 2 (bottom of the reaction zone), and the isophthalonitrile Continuous hydrogenation reaction of formonitrile, the reaction material realizes gas-liquid separation in the head space of coupling reactor 2. The tail gas discharged from the top of the reactor 2, that is, the unreacted hydrogen is recycled after being pressurized by the compressor 1; the liquid-solid mixture extracted from the top of the reactor 2 enters the liquid-solid separator 3 for liquid-solid separation, so that the solid catalyst and ...

Embodiment 2～6

[0032] Examples 2-6 According to the process method of Example 1, m-xylylenediamine was continuously prepared. The difference lies in the catalyst used in the hydrogenation reaction, the reaction temperature and pressure, and the regeneration temperature and pressure. When a Raney nickel catalyst is used, the Raney nickel is a commercially available Raney nickel catalyst with a nickel content of 87.5% by weight.

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

[0034] The reaction result of preparing m-xylylenediamine by continuous hydrogenation of isophthalonitrile in table 1

[0035]

Embodiment 7

[0037] Embodiment 7 adopts the method described in the present invention to prepare m-xylylenediamine by the continuous hydrogenation of isophthalonitrile, and its technological process is as follows figure 2 shown.

[0038] Hydrogen enters from the bottom of the regeneration zone of the reaction / regeneration coupling reactor 2, and the reaction raw materials (isophthalonitrile and solvent) and fresh catalyst enter from the middle of the reaction / regeneration coupling reactor 2 (bottom of the reaction zone), and the isophthalonitrile Continuous hydrogenation reaction of formonitrile, the reaction material realizes gas-liquid separation in the head space of reactor 2. The tail gas discharged from the top of the reactor 2, that is, the unreacted hydrogen is recycled after being pressurized by the compressor 1; the liquid-solid mixture extracted from the top of the reactor 2 enters the liquid-solid separator 3 for liquid-solid separation, so that the solid catalyst and The reac...

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Abstract

The invention discloses a method for preparing m-phenylene dimethylamine, which takes m-phthalonitrile as the raw material for multiphase hydrogenation. The method for preparing m-phenylene dimethylamine is characterized in that continuous hydrogenation is carried out in a slurry reactor or a catalyst regeneration coupling reactor; the lower part of the catalyst regeneration coupling reactor serves as a catalyst regeneration section, and the upper part serves as a hydrogenation reaction section; the mixture of the m-phthalonitrile and solvent and hydrogen contact with catalyst in a reaction zone for continuous hydrogenation reaction, and reaction solution is separated to obtain a target product; and after the liquid-solid separation, the catalyst returns to a catalyst regeneration zone and is continuously rinsed with the solvent for regeneration under the condition with the hydrogen. The method for preparing m-phenylene dimethylamine realizes the continuous hydrogenation of the m-phthalonitrile, has simple process and high equipment utilization ratio, is easy to operate, ensures that the catalyst is not prone to breakage and can be regenerated continuously and reused.

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 (MXDA for short, CAS1477-55-0) is an aliphatic amine containing an aromatic ring, which is widely used because of its excellent physical and chemical properties. m-xylylenediamine 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 is also It can be used for the synthesis of polyurethane raw material m-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, agricultural chemicals (drugs) and Surfactants ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C211/51C07C209/48B01J23/755C08K5/18
CPCY02P20/584
Inventor 秦怡生秦旭东陈荣福宋洪强张益军朱红伟张学君向珏贻朱德宝段启伟蒋大智
Owner 江苏德纳化学股份有限公司
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