DMF recycling method

A recovery method and technology for recovering liquid, applied in the directions of organic chemistry, carboxylic acid amide separation/purification, etc., can solve the problems of environmental pollution, waste of production cost, etc., and achieve the effect of high recovery efficiency, reduction of production cost, and reduction of recovery cost.

Inactive Publication Date: 2010-06-30
石狮龙祥制革有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

A large amount of harmful chemical dissolved dimethylformamide (DMF) is used in the wet production process. These dimethylformamides are discharged as sewage without recycling. On the one hand, they pollute the environment and on the other hand, they cause huge production costs. waste

Method used

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Embodiment Construction

[0014] refer to figure 1 , the embodiment discloses a kind of DMF recycling method, comprises the steps:

[0015] 1), the dimethylformamide waste liquid (being DMF waste liquid) that produces in synthetic leather production process is uniformly transported to DMF waste liquid tank for storage, and described DMF waste liquid tank is the hollow structure with certain liquid volume, and tank The body is provided with a liquid inlet and a liquid outlet. When DMF is recovered, the DMF waste liquid is pumped from the waste liquid tank to the DMF cooler for preheating. The DMF cooler is a heat exchanger whose structure is similar to that of The known heat exchangers used for liquid heat exchange are similar. The temperature of the DMF waste liquid after preheating is 60±3°C. The heat medium used for preheating is the DMF recovery liquid after deacidification treatment in the subsequent recovery step. The DMF recovery The temperature of the liquid is between 120±5°C;

[0016] 2), pu...

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Abstract

The present invention provides a DMF recycling method with low recycling cost and high recycling rate. In the method, DMF is pumped to a DMF cooler from a waste liquid tank for preheating; then the preheated DMF waste liquid is pumped to a dewatering tower which is vacuumized by a vacuum motor to -0.078 plus or minus0.01 MPa to evaporate part of liquid water; the DMP waste liquid from the dewatering tower is pumped to a reboiler to be heated to 68 plus or minus3 DEG C and be further concentrated, thereby obtaining DMF waste liquid with the mass percentage concentration of 40-50%; next, the DMF waste liquid from the reboiler is pumped to a heater to be heated to 120 plus or minus5 DEG C; the waste liquid from the heater is pumped to a rectifying tower to evaporate and separate liquid water from the DMF recycling liquid; the DMF recycling liquid from the rectifying tower is deacidified in a deacidification tower; and then the deacidified DMF recycling liquid is inspected through a sampling can, if qualified, the DMF recycling liquid is delivered to a DMF tank of finished products.

Description

technical field [0001] The invention relates to a method for recovering DMF, which is used for recovering DMF in the waste liquid discharged in the production of synthetic leather. Background technique [0002] Synthetic leather (imitation leather) is more and more widely used in the fields of clothing, sports shoes, sofas and bags, which largely compensates for the impact of the scarcity of animal skin on related manufacturing industries. The production process steps generally include: production ingredients - wet production - drying and winding - intermediate inspection - dry production - finished product lamination - finished product inspection. In the wet production process, a large amount of harmful chemical dissolved dimethylformamide (ie DMF) is used. These dimethylformamides are discharged as sewage without recycling. On the one hand, they pollute the environment and on the other hand, they cause huge production costs. waste. Contents of the invention [0003] Th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C233/03C07C231/24
Inventor 蔡友凯
Owner 石狮龙祥制革有限公司
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