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Technique and installation for preparing guaiacol by continuously hydrolyzing diazonium salt of o-amino pheylmethyl ether

A technology of o-anisole and guaiacol, applied in the preparation of organic compounds, chemical instruments and methods, organic chemistry, etc., can solve the problems of enlarged pipeline and material flow, low production efficiency, catalyst change, etc. Efficient mass transfer and heat transfer efficiency, short start and stop time, and reduce the effect of material back-mixing

Active Publication Date: 2010-07-14
ZHONGBEI UNIV
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  • Summary
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AI Technical Summary

Problems solved by technology

[0018] The hydrolysis reaction can only achieve the optimal selectivity of the main reaction in a certain hydrolyzate ratio, but with the evaporation of water, the continuous addition of non-volatile components in the diazonium salt solution and the generation of sulfuric acid in the hydrolysis reaction, It will lead to changes in the initial optimal composition of the hydrolyzate, and the content of the catalyst in the hydrolyzate will change, resulting in a decrease in the selectivity of the main product and an increase in by-products
At the same time, it can be seen from the colligative property of the solution that the boiling point of the hydrolyzed solution will continue to rise, thereby increasing the energy consumption required for evaporation.
[0019] (3), the evaporation of the product is limited
Due to the large volume of the reactor in the industry, coupled with the increase in production efficiency, the volume of the reactor is required to increase, resulting in a decrease in the surface area per unit volume, and the evaporation of the product is limited.
[0021] (4), product quality is not stable
[0022] Since the process is a batch operation, the conditions for producing each batch of products, such as the addition rate of the diazonium salt solution, the composition of the hydrolyzate, and the temperature control, are not exactly the same, which will change the selectivity of the main product, resulting in uneven quality of the product
[0023] In order to increase the yield of guaiacol by hydrolysis of diazonium salt and reduce by-products, Weng Liyong (Zhejiang Chemical Industry, 1992, 23(2): 57-59), Kong Huangkuan (CN02137265.9), Zhang Xiaoxi (CN 97118908.0) , Chen Minheng (CN 03141536.9), etc. have improved the traditional hydrolysis process, mainly optimizing the proportion of the hydrolyzate, improving the hydrolysis equipment, adding a phase transfer catalyst, etc., although the yield of guaiacol has been improved to a certain extent, but still The problems of low production efficiency and high energy consumption in the traditional method have not been completely solved
Yang Yuanyuan (dissertation: Zhejiang University, 2005, 3) prepared guaiacol by hydrolysis of diazonium salt in a pipeline. The inner diameter of the pipeline is 0.004m, the length is 23m, and the material flow rate is 8×10 -5 m 3 / h, under this condition, it can achieve rapid temperature rise, avoid back mixing and maintain the ratio of hydrolyzate, and the product yield has been improved to a certain extent, but with the increase of production capacity, the enlarged pipeline and material flow limit the rapid temperature rise. Thereby affecting the yield of the main product, industrial scale-up is difficult

Method used

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  • Technique and installation for preparing guaiacol by continuously hydrolyzing diazonium salt of o-amino pheylmethyl ether
  • Technique and installation for preparing guaiacol by continuously hydrolyzing diazonium salt of o-amino pheylmethyl ether
  • Technique and installation for preparing guaiacol by continuously hydrolyzing diazonium salt of o-amino pheylmethyl ether

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] The diazonium salt solution of anthranilic acid is sent into the diazonium salt solution head tank 9 with pump III8 from the diazonium salt solution storage tank 7, and the hydrolyzate is sent into the head tank with the pump I2 from the hydrolyzate storage tank 1 3, the extractant is sent into the extractant head tank 6 with the pump II 5 from the extractant storage tank 4; the hydrolysis reactor 14 is started, and the rotating speed of the rotary packed bed is adjusted to be 600r / min; to the preheater 11, the rotary packed bed The heating medium is passed into the jacket 2.5 and the sleeve heat exchanger 3.6 respectively; the agitator 15 and the condenser 16 are turned on; Liquid inlet II 2.9, the flow rate of diazonium salt solution is adjusted to 0.5m 3 / h, at the same time, the hydrolyzate in the hydrolyzate head tank 3 and the extractant in the extractant head tank 6 pass through the liquid flow meters 13 and 12 respectively, mix first, and then pass through the p...

Embodiment 2

[0048] Under the operation of Example 1, the rotating speed of the rotating packed bed is adjusted to be 600r / min; the flow rate of the diazonium salt solution is adjusted to 1.0m 3 / h, the flow rate of the hydrolyzate is adjusted to 0.5m 3 / h, the flow of toluene is adjusted to 0.2m 3 / h; the mixture of hydrolyzate and toluene is heated to 100°C, and the temperature of the liquid at the outlet of the impinging flow rotating packed bed is heated to 105°C; the total residence time of the reactants flowing through the hydrolysis reactor is adjusted to 7.0min. The yield of guaiacol was 87.5%.

Embodiment 3

[0050] Under the operation of Example 1, the rotating speed of the rotating packed bed is adjusted to be 1200r / min; the flow rate of the diazonium salt solution is adjusted to 1.5m 3 / h, the flow rate of the hydrolyzate is adjusted to 0.8m 3 / h, the flow of toluene is adjusted to 0.4m 3 / h; the total residence time of the reactant flow through the hydrolysis reactor is adjusted to 6.2min. The yield of guaiacol was 90.0%.

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Abstract

The invention belongs to the technical field of guaiacol preparation, in particular to a technique and an installation for preparing guaiacol by continuously hydrolyzing diazonium salt of o-amino pheylmethyl ether, which solves the problems of the prior guaiacol production method, including low efficiency, high energy consumption, severe pollution and difficult continuous production. The installation comprises a hydrolysis reactor which consists of a rotating packed bed and a coil, the coil is axially vertically arranged under the rotating packed bed, a liquid outlet of the rotating packed bed is connected with a coil inlet, and a coil outlet is sequentially connected with a stirrer, a condenser and an output liquid storage tank. The method includes the following steps that: hydrolysate and extractant are mixed and preheated, and are then sent into the hydrolysis reactor along with the diazonium salt solution of o-amino pheylmethyl ether at the same time and heated to the hydrolysis temperature, so that the guaiacol is produced. The invention has the following advantages that: the production of by-products can be reduced, the yield is increased to more than 90 percent, the emission of the three wastes is reduced, the production cost is reduced, moreover, the equipment size is small, the startup / shutdown time is short, and mounting, operation and maintenance are convenient.

Description

technical field [0001] The invention belongs to the technical field of guaiacol preparation, and specifically relates to a process and a device for preparing guaiacol by continuous hydrolysis of a diazonium salt of anthranil. Background technique [0002] Guaiacol, scientific name o-hydroxyanisole, colorless or light yellow crystal or colorless to light yellow transparent oily liquid, flammable, has a special aromatic smell, exposed to air or sunlight gradually becomes dark, slightly soluble in water And benzene, easily soluble in glycerin, miscible with ethanol, ether, chloroform, etc. Guaiacol is an important chemical raw material widely used in the synthesis of medicines, spices and dyes. [0003] According to the raw materials, the preparation of guaiacol is divided into: catechol method and anthranil method. The catechol method is to prepare guaiacol by reacting catechol with methylating reagents such as methanol and monohalomethane under the action of a catalyst. Thi...

Claims

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Application Information

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IPC IPC(8): C07C43/23C07C41/26
Inventor 刘有智祁贵生李光明焦纬洲
Owner ZHONGBEI UNIV
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