Method for purifying and recovering solvent NMMO (N-methylmorpholine oxide) in lyocell fiber production process

A production process and fiber technology, which is applied in the field of solvent NMMO purification and recovery, can solve the problems of cumbersome process steps, accelerate solvent degradation, increase production costs, etc., achieve the effects of simple equipment and process flow, improved cycle life, and easy operation

Inactive Publication Date: 2020-02-07
SHANDONG YINGLI IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The existing purification and recovery method of solvent NMMO is generally to process the recovered solvent NMMO through coarse filtration, deep flocculation, sedimentation, filtration, and then carry out anion and cation exchange purification. This method has a low recovery rate of NMMO and a lot of waste liquid. The addition of flocculant is easy to introduce impurities into NMMO, affecting its removal rate, the process steps are more cumbersome, the treatment cost is higher, and it is difficult to remove the residual chains produced by the degradation of cellulose in solvent NMMO
After the recovered solvent NMMO is purified, it needs to be concentrated and then reused. If the concentration of cellulose residual chains in the solvent NMMO reaches a certain range, a chain reaction will occur, which will accelerate the degradation of the solvent, resulting in the solubility of cellulose It is greatly reduced, which in turn affects the preparation of chemical fibers. Similarly, the degradation of solvent NMMO will affect the cycle life of NMMO, thereby increasing the production cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] A method for purifying and recovering solvent NMMO in a lyocell fiber production process, comprising the steps of:

[0037] First of all, the solid suspended matter in the NMMO solvent should be removed. The first process uses a filter to filter, and the filter is divided into three parts. The first part is 100 mesh stainless steel sintered mesh, which mainly intercepts solid impurities larger than 150 μm. The second part It is a 200 mesh stainless steel sintered mesh, which mainly intercepts solid impurities of 75 μm to 150 μm, and the third part is a 300 mesh stainless steel sintered mesh, which mainly intercepts solid impurities of 48 μm to 75 μm.

[0038] The stainless steel sintered mesh is easy to change, and the retained impurities are easy to remove. The impurities in the mesh can be removed by high-temperature roasting. Since the solid impurities are mainly fibers, they will be converted into carbon dioxide and water after high-temperature roasting. There is no ...

Embodiment 2

[0045] A method for purifying and recovering solvent NMMO in a lyocell fiber production process, comprising the steps of:

[0046] First of all, the solid suspended matter in the NMMO solvent should be removed. The first process uses a filter to filter, and the filter is divided into three parts. The first part is 100 mesh stainless steel sintered mesh, which mainly intercepts solid impurities larger than 150 μm. The second part It is a 200 mesh stainless steel sintered mesh, which mainly intercepts solid impurities of 75 μm to 150 μm, and the third part is a 300 mesh stainless steel sintered mesh, which mainly intercepts solid impurities of 48 μm to 75 μm.

[0047] The stainless steel sintered mesh is easy to change, and the retained impurities are easy to remove. The impurities in the mesh can be removed by high-temperature roasting. Since the solid impurities are mainly fibers, they will be converted into carbon dioxide and water after high-temperature roasting. There is no ...

Embodiment 3

[0054] A method for purifying and recovering solvent NMMO in a lyocell fiber production process, comprising the steps of:

[0055] First of all, the solid suspended matter in the NMMO solvent should be removed. The first process uses a filter to filter, and the filter is divided into three parts. The first part is 100 mesh stainless steel sintered mesh, which mainly intercepts solid impurities larger than 150 μm. The second part It is a 200 mesh stainless steel sintered mesh, which mainly intercepts solid impurities of 75 μm to 150 μm, and the third part is a 300 mesh stainless steel sintered mesh, which mainly intercepts solid impurities of 48 μm to 75 μm.

[0056] The stainless steel sintered mesh is easy to change, and the retained impurities are easy to remove. The impurities in the mesh can be removed by high-temperature roasting. Since the solid impurities are mainly fibers, they will be converted into carbon dioxide and water after high-temperature roasting. There is no ...

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Abstract

The invention discloses a method for purifying and recovering a solvent NMMO in a lyocell fiber production process, which comprises the steps: firstly, carrying out coarse filtering with a filter screen to remove solid impurities in NMMO; secondly, performing micro-filtration treatment with a hydrophobic polymer membrane to remove small particular solid impurities, bacteria and macromolecular colloid; thirdly, treating the NMMO with a micelle enhanced ultrafiltration method again to remove degraded residual chains in the NMMO, and carrying out micelle enhanced adsorption on metal ions in the NMMO; and fourthly, carrying out nanofiltration treatment to remove other impurities in the NMMO. The method of the invention is simple, no flocculants are needed, and the impurity removal rate and recovery rate of NMMO can be obviously increased.

Description

technical field [0001] The invention belongs to the field of solvent NMMO purification and recovery, in particular to a method for solvent NMMO purification and recovery in the production process of lyocell fibers. Background technique [0002] The information disclosed in this background section is only intended to increase the understanding of the general background of the present invention, and is not necessarily taken as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. [0003] The advent of chemical fibers has greatly satisfied people's needs for clothing, decoration and industrial textiles, but with the reduction of world oil reserves, the development of synthetic fibers with oil as the main raw material will also be limited. The shortage of non-renewable textile raw materials has forced people to turn their attention to renewable textile raw materials, and with people's concern for en...

Claims

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Application Information

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IPC IPC(8): D01F13/02
CPCD01F13/02Y02P70/62
Inventor 郑世睿李永威韩荣桓张昕玥高建李景盛
Owner SHANDONG YINGLI IND
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