Separation method of ammoniation dehydration product of caprolactam and synthesis method of hexamethylenediamine

A separation method, caprolactam technology, applied in the dehydration preparation of carboxylic acid amide, preparation of amino compounds, chemical instruments and methods, etc., can solve the problems of low separation yield and high energy consumption for separation, and achieve high separation efficiency and low energy consumption for separation , the effect of reducing production costs

Active Publication Date: 2020-08-25
JIANGSU YANGNONG CHEM GROUP +2
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  • Abstract
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  • Application Information

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Problems solved by technology

[0004] The main purpose of the present invention is to provide a kind of separation method of the ammoniation dehydration product of caprolactam and the synthetic method of hexamethylenediami

Method used

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Examples

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preparation example Construction

[0030] In another typical implementation of the present application, a synthesis method of hexamethylenediamine is provided, the synthesis method comprising: reducing 6-aminocapronitrile, hydrogen and a catalyst to obtain hexamethylenediamine, 6- Aminocapronitrile is the 6-aminocapronitrile fraction obtained by any of the aforementioned separation methods.

[0031] In this application, caprolactam is used as a raw material, and through ammoniation and dehydration reactions, a product system containing 6-aminocapronitrile, caprolactam and other components is obtained, and then the product system is subjected to the above-mentioned primary condensation treatment to obtain a caprolactam-containing fraction and a primary gas phase group. points, reduce the condensation temperature again, and carry out secondary condensation treatment to the primary gas phase components at a lower temperature to obtain 6-aminocapronitrile fractions and secondary gas phase components, wherein the 6-a...

Embodiment 1

[0037] Synthesis of 6-aminocapronitrile: mix fresh ammonia gas and recovered ammonia gas and preheat to 500°C, mix recovered caprolactam with fresh caprolactam, mix according to 34.2L / min of pure ammonia gas and 413.8g / h of pure caprolactam, enter In the column tube of the fixed-bed reactor filled with 100g of catalyst, the ammoniation dehydration reaction is carried out under the conditions of the reaction temperature of 400° C. and the pressure of 0.2 MPa to obtain the product system. Among them, the weight hourly space velocity of caprolactam is 4.14h -1 , The molar ratio of caprolactam to ammonia is 1:25, the single-pass conversion rate of caprolactam is 96.6%, and the selectivity of 6-aminocapronitrile is 95.6%.

[0038] Product separation: The product system undergoes the following heat exchange and condensation treatments respectively. The gauge pressure of the treatment process is 0.2MPa. After pretreatment in turn, the product system is cooled to 320°C to separate the...

Embodiment 2

[0040] The difference between Example 2 and Example 1 is that the synthesis of aminocapronitrile is carried out using fresh ammonia and fresh caprolactam.

[0041] Preheat fresh ammonia gas to 500°C, mix ammonia gas 34.2L / min with fresh caprolactam 413.8g / h, and enter the column tube of a fixed-bed reactor filled with 100g of catalyst, at a reaction temperature of 400°C and a pressure of 0.2MPa The hydrogenation dehydration reaction is carried out under the conditions to obtain the product system. Among them, the weight hourly space velocity of caprolactam is 4.14h -1 , The molar ratio of caprolactam to ammonia is 1:25, the single-pass conversion rate of caprolactam is 96.8%, and the selectivity of 6-aminocapronitrile is 95.8%.

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Abstract

The invention provides a separation method of an ammoniation dehydration product of caprolactam and a synthesis method of hexamethylenediamine. The separation method comprises the following steps: S1,carrying out ammoniation and dehydration reaction on caprolactam and ammonia gas to obtain a product system; S2, carrying out primary condensation treatment on the product system to obtain a caprolactam-containing fraction and a primary gas-phase component; and S3, carrying out secondary condensation treatment on the primary gas-phase component to obtain a 6-aminocapronitrile fraction and a secondary gas-phase component, wherein the temperature of the secondary condensation treatment is lower than that of the primary condensation treatment. According to the separation method, the product system obtained through the reaction is directly subjected to condensation treatment, secondary heating is not needed, continuous operation of the reaction and product separation can be achieved, waste heat can be fully utilized, the separation efficiency is high, the production intensity is high, the separation energy consumption is low, and therefore the whole process is more energy-saving.

Description

technical field [0001] The invention relates to the technical field of preparation of hexamethylenediamine, in particular to a method for separating an ammoniated dehydration product of caprolactam and a method for synthesizing hexamethylenediamine. Background technique [0002] Hexamethylenediamine (1,6-Hexanediamine), also known as 1,6-diaminohexane, referred to as HDA, is a colorless and transparent crystal, mainly used in the production of nylon 66 and nylon 610, and can also be used to synthesize 1, 6-Hexamethylene diisocyanate, of which more than 85% is used to produce nylon 66. According to different raw materials, the production methods of hexamethylene diamine are divided into adiponitrile method and caprolactam method, and the caprolactam method is: caprolactam is reacted with ammonia gas under the action of a catalyst. The reaction gives 6-aminocapronitrile, which is further hydrogenated and purified to obtain hexamethylenediamine. The process initially focused o...

Claims

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Application Information

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IPC IPC(8): C07C253/20C07C253/34C07C255/24C07C231/02C07C237/06C07C209/48C07C211/12
CPCC07C253/20C07C253/34C07C231/02C07C209/48C07C237/06C07C255/24C07C211/12
Inventor 王根林王铖徐林丁克鸿殷恒志刘鑫梅学赓王鑫宇郭博博
Owner JIANGSU YANGNONG CHEM GROUP
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