Method for preventing discoloration and degradation of N-methyl-2-pyrrolidone (NMP) and product thereof

A technology of methylpyrrolidone and deterioration, which is applied to a method for preventing discoloration and deterioration of N-methylpyrrolidone and its products, which can solve problems such as increasing difficulty, yellowing of products, and deeper discoloration, and improve user satisfaction , prevent the product from turning yellow, and widely promote the effect of value

Inactive Publication Date: 2020-09-18
金为环保科技(常州)有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] A large amount of NMP waste liquid will be produced in the production process of lithium batteries. In order to reduce costs, the NMP waste liquid can be recycled and purified for reuse. However, a common problem in the industry is that the recycled NMP product turns yellow after long-term storage. , and the degree of discoloration gradually deepens as time goes on, which seriously affects customer satisfaction, and the substance that causes the product to turn yellow cannot be known through common analysis and detection methods, which increases the difficulty for technicians in the field to solve this problem

Method used

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  • Method for preventing discoloration and degradation of N-methyl-2-pyrrolidone (NMP) and product thereof
  • Method for preventing discoloration and degradation of N-methyl-2-pyrrolidone (NMP) and product thereof
  • Method for preventing discoloration and degradation of N-methyl-2-pyrrolidone (NMP) and product thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0059] Embodiment 1 provides a kind of method that prevents N-methylpyrrolidone from changing color and deteriorating, comprising the following steps:

[0060] a. Pretreatment: Use a NaOH solution with a concentration of 30 wt% to adjust the pH of the NMP raw material to 10.5;

[0061] b. rectification: the material obtained in step a is taken to rectify in three towers; the three towers include No. 1 tower still, No. 2 tower still, and No. 3 tower still; The kettle temperature is 170°C, and the tower top temperature is 100°C; the No. 2 tower kettle is a negative pressure tower, the tower kettle pressure is -80~-90kPa, the tower kettle temperature is 130℃, and the tower top pressure is -90~-98kPa , the tower top temperature is 100°C; the No. 3 tower kettle is a negative pressure tower, the tower kettle pressure is -80~-90kPa, the tower kettle temperature is 130℃, the tower top pressure is -84~-96kPa, and the tower top temperature is 110°C.

[0062] This example also provides...

Embodiment 2

[0064] Embodiment 2 provides a kind of method that prevents N-methylpyrrolidone from changing color and deteriorating, comprising the following steps:

[0065] a. pretreatment: using a concentration of 30wt% NaOH solution to adjust the pH of the NMP raw material to be 10;

[0066] b. rectification: the material obtained in step a is taken to rectify in three towers; the three towers include No. 1 tower still, No. 2 tower still, and No. 3 tower still; The kettle temperature is 170°C, and the tower top temperature is 100°C; the No. 2 tower kettle is a negative pressure tower, the tower kettle pressure is -80~-90kPa, the tower kettle temperature is 130℃, and the tower top pressure is -90~-98kPa , the tower top temperature is 100°C; the No. 3 tower kettle is a negative pressure tower, the tower kettle pressure is -80~-90kPa, the tower kettle temperature is 130℃, the tower top pressure is -84~-96kPa, and the tower top temperature is 110°C.

[0067] This example also provides a pr...

Embodiment 3

[0069] Embodiment 3 provides a kind of method that prevents N-methylpyrrolidone from changing color and deteriorating, comprising the following steps:

[0070] a. Pretreatment: using a NaOH solution with a concentration of 30wt% to adjust the pH of the NMP raw material to 11;

[0071] b. rectification: take three tower rectification to the material obtained in step a; Described three towers comprise No. 1 tower still, No. 2 tower still, No. 3 tower still; Described No. 1 tower still is atmospheric tower, tower The kettle temperature is 170°C, and the tower top temperature is 100°C; the No. 2 tower kettle is a negative pressure tower, the tower kettle pressure is -80~-90kPa, the tower kettle temperature is 130℃, and the tower top pressure is -90~-98kPa , the tower top temperature is 100°C; the No. 3 tower kettle is a negative pressure tower, the tower kettle pressure is -80~-90kPa, the tower kettle temperature is 130℃, the tower top pressure is -84~-96kPa, and the tower top tem...

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Abstract

The invention discloses a method for preventing discoloration and degradation of NMP. According to the method, recovered NMP raw materials are pretreated, and process parameters are accurately controlled, so product yellowing caused by original impurities in the recovered materials can be prevented, and new unmeasurable impurities generated in the rectification process can be inhibited. Although ahigh-concentration alkaline condition is used in the method, high yield and product purity are still ensured, the product does not change color under the conditions of room temperature and high temperature, customer satisfaction is improved, and the product has wide promotion value in the market.

Description

technical field [0001] The invention relates to the technical field of lithium battery solvent recovery, in particular to a method for preventing discoloration and deterioration of N-methylpyrrolidone and a product thereof. Background technique [0002] N-methylpyrrolidone, also known as N-methyl-2-pyrrolidone, abbreviated as NMP in English, CAS No. 872-50-4, the appearance is a colorless transparent oily liquid with a slight amine smell, low volatility, heat It has excellent stability and chemical stability, can dissolve most organic and inorganic compounds, and is widely used in lithium batteries, electronic components and other fields. [0003] A large amount of NMP waste liquid will be produced in the production process of lithium batteries. In order to reduce costs, the NMP waste liquid can be recycled and purified for reuse. However, a common problem in the industry is that the recycled NMP product turns yellow after long-term storage. , and the degree of discoloratio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D207/267
CPCC07D207/267
Inventor 许林俊王其合吕远陆建清
Owner 金为环保科技(常州)有限公司
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