Distillation method of oxime

A distillation method and distillation process technology, applied in oxime preparation, organic chemistry, etc., can solve the problems of large-scale production equipment, stable product quality, easy coking and carbonization, etc., and achieve improved separation efficiency and product quality, simple operation, The effect of reducing emissions

Active Publication Date: 2013-07-10
ZHEJIANG SAINON CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 1. The kettle-type reboiler cannot be large-scaled due to the limited heat exchange surface, and it is easy to coke and coke. Usually, it must be cleaned once every 3 to 7 days
[0006] 2. The heating and heat transfer effect of the outer tube of the U-shaped tube is better, but it cannot avoid the carbonization of the material on the layered coiled heating coil and the wall of the tower kettle. It takes 3 to 30 days to clean the outer tube
[0007] 3. Although the rotary thin film evaporator is better than the former two, it also needs to clean the evaporator once every 7~30 days
[0008] Therefore, so far, there is no distillation method for the rectification of oximes and oxime compounds that can make the tower kettle run for a long period without coking, with high distillation efficiency and stable product quality.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] According to the mass fraction ratio of the oxime in the solution: the high boiling point solvent is 1%: 0.02%, weigh 1.46 grams of glycerol with a purity of 99.6%, add it to 109 grams of acetone oxime content of 66.9% solution, and stir for 10 minutes with a stirrer After that, distillation is carried out, and the temperature of the bottom of the rectification tower is controlled at 50-60°C, the absolute pressure is 0.01MPa, the reflux ratio is 3, and the distillation is finished after about 30 minutes. Collected 70 grams of distillate, the oxime content was 99.8%, and the content of impurities in the distillate was low.

Embodiment 2

[0023] According to the mass fraction ratio of the oxime in the solution: the high boiling point solvent is 1%: 5%, weigh 364.6 grams of glycerol with a purity of 99.6%, add it to 109 grams of acetone oxime content of 66.9% solution, and stir for 8 minutes with a stirrer Afterwards, distillation is carried out, and the temperature of the bottom of the rectification tower is controlled at 110-120°C, the absolute pressure is 0.05MPa, the reflux ratio is 2.5, and the distillation is finished after about 50 minutes. The collected fraction is 71.3 g, the oxime content is 99.9%, and the impurity content in the fraction is low.

Embodiment 3

[0025] According to the mass fraction ratio of the oxime in the solution: the high boiling point solvent is 1%: 10%, weigh 729.2 grams of glycerol with a purity of 99.6%, add it to 109 grams of acetone oxime content of 66.9% solution, and stir for 5 minutes with a stirrer Afterwards, distillation is carried out, and the temperature of the bottom of the rectification tower is controlled at 150-160℃, the absolute pressure is 0.09MPa, the reflux ratio is 2, and the distillation is finished after about 60 minutes. The collected fraction is 72.5 grams, the oxime content is 99.86%, and the impurity content in the fraction is low.

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PUM

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Abstract

The present invention relates to a distillation method of oxime. Tower bottom materials are usually heated by still distillation, a U-shaped outer tube or a rotary film evaporator, long-term operation of the tower bottom is easy to coking, and the distillation efficiency is low. The invention is characterized in that: in the distillation and separation section of oxime, at least one high boiling point solvent is added in the distillation process, the content of the high boiling point solvent in the tower bottom is maintained in proportional to that of oxime, and finally oxime is effectively separated by distillation. Oxime is fed into a rectifying tower, and is distilled at an absolute pressure of 0-0.4 MPa and at 20-300 DEG C to collect fractions. The unevaporated liquid left in the tower bottom is subjected to the processes of removing water and impurities, and is recycled to the rectifying tower as a high boiling point solvent. The present invention can reduce total production costs, simplify operation processes, prevent the product from coking in the tower bottom or decomposing due to overheating, ensure product distillation to be efficient, continuous, safe and stable, and improve product quality.

Description

Technical field [0001] The invention relates to the technical field of separation and purification of organic chemistry, in particular to a distillation method of oxime. Background technique [0002] Oxime is a kind of fine chemical product with a wide range of applications. For example, methyl ethyl ketoxime is used as an anti-skinning agent in coatings, acetoxime is used as a deoxidizer in thermal boiler water deoxidation, acetaldoxime is used as an intermediate for the production of methomyl pesticides, and cyclohexanone oxime is used to produce nylon -6 monomer ε-caprolactam intermediate. [0003] Industrial separation and purification of oximes are mainly carried out through rectification towers. However, both the synthesis of oxime and the oxime recovery process in the application of oxime compounds have the problem of rectification of oxime. The rectification problem of oxime is because oxime is very easy to form carbon and block pipelines and equipment, which makes the r...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C249/14C07C251/38C07C251/44
Inventor 徐书群孙茂金何勇王艳霞刘勇严茗
Owner ZHEJIANG SAINON CHEM
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