Phosgenation reactor and method for preparing isocyanate monomer by using phosgenation reactor

A reactor and phosgenation technology, applied in chemical instruments and methods, chemical/physical/physicochemical fixed reactors, preparation of organic compounds, etc., can solve the problems of reduced yield, internal leakage blockage, high overall energy consumption, etc. problems, to avoid incomplete amine reaction, reduce contact opportunities, and improve the quality of salt formation

Active Publication Date: 2018-05-29
WANHUA CHEM GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, amines with high melting points generally have poor solubility in the above solvents, resulting in lower reaction concentrations
In addition, some isocyanate polymers and chlorinated by-products will be produced during the reaction, which will not only reduce the yield of the product, but also increase the difficulty of product purification and increase production costs.
[0003] U.S. Patent US2015246873 (A1) provides a method for preparing isocyanate by liquid phase method. High melting point isocyanate is prepared by cold and hot phosgenation. It uses a dynamic mixer to mix amine and solvent to form a suspension and control the particle size. , strengthen the dispersion, thereby reducing the occurrence of side reactions and increasing the yield, but the rapid mixing of solid or liquid suspensions is more difficult, and the minimization of by-products cannot be guaranteed
[0004] Chinese patent CN101638372A uses salt-forming phosgenation to prepare p-phenylene diisocyanate, but its hydrochloric acid needs to be specially prepared, and when forming a salt, it is necessary to dissolve all the amine in a solvent and then pass in hydrogen chloride gas, which can easily cause the amine to be wrapped by hydrochloride , reducing the yield
However, in order to solve the clogging problem and enhance the mixing effect in the process of application, the process needs to be operated at an extremely low concentration of xylylenediamine hydrochloride, and the overall energy consumption is relatively high.
[0006] In the Chinese patent CN102070491A, a centrifugal device is used to concentrate the low-concentration hydrochlor

Method used

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  • Phosgenation reactor and method for preparing isocyanate monomer by using phosgenation reactor

Examples

Experimental program
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Example Embodiment

[0041] Example 1

[0042] The volume of the phosgenation reactor is 800L, and the discharger is perpendicular to the feed pipe. The ratio of the distance between the lower surface of the upper discharger and the upper surface of the lower discharger to the height of the reactor is 1:6, the upper and lower dischargers are of hollow cylindrical structure, and the lower surface of the upper discharger 10 The upper surface of the lower discharger 6 and the lower discharger 6 are evenly distributed with circular outlet holes, the opening rates are 60% and 70%, respectively, the discharger diameter is 70% of the reactor diameter, and the height of the discharger and the diameter of the discharger The ratio is 1:20, the height of the packing block 8 in the rotating zone and the distance between the lower surface of the upper discharger and the upper surface of the lower discharger is 1:1. The filler is a wire mesh filler filled in a regular manner. The inner diameter of the outer feed ...

Example Embodiment

[0044] Example 2

[0045] The volume of the phosgenation reactor is 800L, and the discharger is perpendicular to the feed pipe. The ratio of the distance between the lower surface of the upper discharger and the upper surface of the lower discharger to the height of the reactor is 1:7, the upper and lower dischargers are of hollow cylindrical structure, and the lower surface of the upper discharger 10 And the upper surface of the lower discharger 6 is evenly distributed with diamond-shaped outlet holes, the opening rates are 70% and 55%, respectively, the diameter of the discharger is 80% of the diameter of the reactor, and the ratio of the height of the discharger to the diameter of the discharger 1:35, the ratio of the height of the packing block 8 in the rotating zone to the distance between the lower surface of the upper discharger and the upper surface of the lower discharger is 3:4. The packing is a plate corrugated mesh packing filled in a regular manner. The inner diamet...

Example Embodiment

[0047] Example 3

[0048] The volume of the phosgenation reactor is 800L, and the discharger is perpendicular to the feed pipe. The ratio of the distance between the lower surface of the upper discharger and the upper surface of the lower discharger to the height of the reactor is 1:8, the upper and lower dischargers are of hollow cylindrical structure, and the lower surface of the upper discharger 10 And the upper surface of the lower discharger 6 is evenly distributed with triangular outlet small holes, the opening rate is 65%, the diameter of the discharger is 50% of the diameter of the reactor, and the ratio of the height of the discharger to the diameter of the discharger is 1: 40. The ratio between the height of the packing block 8 in the rotating zone and the distance between the lower surface of the upper discharger and the upper surface of the lower discharger is 1:2. The packing is a plate corrugated mesh packing filled in a regular manner, and the outer feeding pipe T...

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Abstract

The invention discloses a phosgenation reactor and a method for preparing an isocyanate monomer by using the phosgenation reactor. The phosgenation reactor comprises an inner material inlet pipe, an outer material inlet pipe, a mechanical stirring rotation shaft, a rotation area and a kettle body, wherein the rotation area comprises a support structure, a rotation area filler block, an upper material outlet device and a lower material outlet device, the inner material inlet pipe and the outer material inlet pipe are coaxially arranged from inside to outside, the upper material outlet device and the lower material outlet device are arranged in parallel, are connected through the support structure, and are respectively communicated to the outer material inlet pipe and the inner material inlet pipe, the rotation area filler block is filled between the upper material outlet device and the lower material outlet device, the upper material outlet device is connected to the mechanical stirringrotation shaft, and the kettle body is provided with a gas phase material outlet, a liquid phase material outlet, a gas phase material inlet and a liquid phase material inlet. According to the present invention, by pre-treating the hydrochloride solution in the reactor, the salt forming concentration and the quality of the hydrochloride solution are improved while the rapid removal of hydrogen chloride gas during the phosgenation is achieved, such that the generation of chlorination by-products is effectively reduced, and the product separation difficulty is reduced.

Description

technical field [0001] The invention relates to a phosgenation reactor and a method for preparing isocyanate using the reactor, more specifically, to a phosgenation reactor and using the reactor to prepare isocyanate monomers through high-temperature salt-forming phosgenation Methods. Background technique [0002] In the prior art, the phosgenation method of preparing isocyanates by reacting organic primary amines with phosgene in an inert solvent is well known. For existing methods, chlorobenzene or o-dichlorobenzene is usually used as a solvent, which is widely used because of its good inertness and solvency, and is very suitable for recovering excess phosgene and separating hydrogen chloride produced . However, amines with high melting points generally have poor solubility in the above solvents, resulting in lower reaction concentrations. In addition, some isocyanate polymers and chlorinated by-products will be produced during the reaction, which will not only reduce t...

Claims

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Application Information

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IPC IPC(8): B01J19/18B01J19/32B01J4/00C07C263/10C07C265/14
CPCB01J4/001B01J19/18B01J19/32C07C263/10C07C265/14
Inventor 韩金平孙中平尚永华李建峰史培猛李同和乔小飞华卫琦
Owner WANHUA CHEM GRP
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