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Method for preparing naphthalene sulphonic acid by sulfonating sulfur trioxide in microreactor

A technology of micro-reactor and sulfur trioxide, which is applied in the fields of sulfonic acid preparation, chemical instruments and methods, chemical/physical/physicochemical processes, etc., can solve the problems of waste acid polluting the environment, achieve strong heat transfer capacity, and avoid side effects Responsive, small footprint effect

Inactive Publication Date: 2009-12-23
SPECIAL CHEM CO LTD DALIAN FIRSTAR
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a method for preparing naphthalene-based sulfonic acid by sulfur trioxide sulfonation in a microreactor, so as to solve the problem of serious environmental pollution caused by a large amount of waste acid produced by the traditional sulfonation process

Method used

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  • Method for preparing naphthalene sulphonic acid by sulfonating sulfur trioxide in microreactor
  • Method for preparing naphthalene sulphonic acid by sulfonating sulfur trioxide in microreactor
  • Method for preparing naphthalene sulphonic acid by sulfonating sulfur trioxide in microreactor

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Embodiment 1

[0020] Dichloromethane, naphthalene and liquid sulfur trioxide are formulated into sulfur trioxide-dichloromethane solution and naphthalene-dichloromethane solution in molar ratio of 31:1:1 respectively, and the prepared sulfur trioxide-dichloromethane solution is and naphthalene-dichloromethane solution are sent to the corresponding reaction material inlet of the microreactor with a diameter of 10 micron channels at a flow rate of 1 ml / min through a calibrated constant flow pump. The extension channel volume is 1ml. The sulfonation reaction takes place in microreactors and extension channels placed in a constant temperature bath. The reaction temperature was controlled at -17°C. The reaction material at the outlet of the extension channel is passed into water to terminate the reaction. Take the water phase and add 20% sodium chloride for salting out, and the precipitated by-product sodium salt can be filtered off. The filtrate containing free α-naphthalenesulfonic acid is ...

Embodiment 2

[0022] Prepare sulfur trioxide-1,1,2,2-tetrachloroethane solution and naphthalene by mixing 1,1,2,2-tetrachloroethane, naphthalene and liquid sulfur trioxide in a molar ratio of 19:1:1 -1,1,2,2-tetrachloroethane solution, the prepared sulfur trioxide-1,1,2,2-tetrachloroethane solution and naphthalene-1,1,2,2-tetrachloroethane The alkane solution is sent to the corresponding reaction material inlet of the microreactor with a diameter of 200 micron channels at a flow rate of 4ml / min through a calibrated constant flow pump. The extension channel volume is 5ml. The sulfonation reaction takes place in microreactors and extension channels placed in a constant temperature bath. The reaction temperature was controlled at 20°C. The reaction material at the outlet of the extension channel is passed into water to terminate the reaction. Take the water phase and add 20% sodium chloride for salting out, and the precipitated by-product sodium salt can be filtered off. The filtrate conta...

Embodiment 3

[0024] Prepare 1,2-dichloroethane, 2-naphthol and liquid sulfur trioxide in a molar ratio of 50:1:3 to prepare sulfur trioxide-1,2-dichloroethane solution and 2-naphthol-1 , 2-dichloroethane solution, the prepared sulfur trioxide-1,2-dichloroethane solution and 2-naphthol-1,2-dichloroethane solution were calibrated with a constant flow pump at 7ml / The min flow rate is sent to the corresponding reaction material inlet of the microreactor with a channel diameter of 350 microns. The extension channel volume is 8ml. The sulfonation reaction takes place in microreactors and extension channels placed in a constant temperature bath. The reaction temperature was controlled at 50°C. The reaction material at the outlet of the extension channel is passed into water to terminate the reaction. Take the aqueous phase and add 20% potassium chloride for salting out, concentrate, cool, crystallize, filter, wash with water, and dry to obtain an off-white solid product. The product is detec...

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Abstract

The invention relates to a method for preparing naphthalene sulphonic acid by sulfonating sulfur trioxide in a microreactor, belonging to methods for preparing dye intermediates in the field of fine chemical engineering. The method comprises the following steps: taking alkyl halide and nitromethane as an organic solvent, naphthalene and derivative thereof as the raw material and organic solution of liquid sulfur trioxide as a sulfonating agent, preparing a solution according to the mol ratio of the organic solvent, the raw material and the sulfonating agent of 19-74:1:1-3 in the microreactor of with channel with the diameter of 10-50 microns, and sulfonating the reaction solution to prepare the naphthalene sulphonic acid by controlling the sulfonation reaction temperature to be between 17DEG C below zero and90 DEG C. The method adopts a continuous flow reactor, solves the problem of impossible transient mixing in the conventional reactor, prevents secondary reaction caused by local excess, and is especially suitable for strong exothermic reaction, fast reaction and flammable and explosive reaction. Compared with the preparation technology in the traditional batch reactor, the invention has the advantages of no generation of waste water and waste acid, clean and environment-friendly technology, consumption of sulphonic acid close to the theoretical quantity, fast reaction speed, low sulfonation temperature, high product yield, good repeatability, high labor productivity and low equipment cost.

Description

technical field [0001] The invention relates to a method for preparing naphthalene-based sulfonic acid by sulfur trioxide sulfonation in a microreactor, which belongs to the preparation method of dye intermediates in the field of fine chemical industry. Background technique [0002] The reaction of introducing sulfonic acid groups (-SO3H) into organic molecules is called sulfonation. Naphthalene sulfonic acid is an important intermediate in the dye industry, mainly used for the preparation of reactive dyes, acid dyes, direct dyes and dispersant NNO, dispersant MF. Traditional sulfonation process uses concentrated sulfuric acid or oleum as sulfonating agent. [0003] In 1860, sulfuric acid was the only sulfonating agent, and later added fuming sulfuric acid as a sulfonating agent. Today, it is still the most widely used sulfonating agent because of its low price and easy availability. Using sulfuric acid as sulfonating agent, 1 mol of sulfonated product will generate 1 mol ...

Claims

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Application Information

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IPC IPC(8): C07C303/06C07C309/35C07C309/43B01J19/00
Inventor 彭孝军孙大新樊江莉孙世国
Owner SPECIAL CHEM CO LTD DALIAN FIRSTAR
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