Process for producing adipic acid and hexanediamine by depolymerization of nylon-66

A technology of hexamethylenediamine and adipic acid, which is applied in the preparation of carboxylates, organic compounds, amino compounds, etc., can solve the problems of poor production safety, high operating costs, and poor operability, and achieve low pollution Effect

Inactive Publication Date: 2006-05-31
宁波敏特尼龙工业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 1. The large-scale industrial production of recycled nylon-66 monomer has poor operability and high operating costs;
[0006] 2. Serious secondary pollution;
[0007] 3. Nylon waste has many impurities;
[0008] 4. Poor production safety;
[0009] 5. The quality of the product is not good

Method used

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Examples

Experimental program
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Embodiment Construction

[0021] Below by embodiment the present invention is further described:

[0022] Embodiment: Add 1100kg of 98% sulfuric acid, 2000kg of water and 30kg of catalyst phosphoric acid in the reaction kettle, then add 1200kg of waste nylon-66 while heating, stir, and react for about 10 hours under the condition of maintaining the pressure at 0.1-0.6MPA, Make the reaction complete to obtain the acid solution; then filter the acid solution through a coarse filter and then freeze and crystallize it. Cool to crystallize and keep stirring while cooling. After the crystallization is completed, the crude adipic acid and hexamethylenediamine sulfate solution are separated by a box filter press. The crude adipic acid is decolorized, recrystallized, and dried to obtain refined adipic acid. When the adipic acid is decolorized, first heat the water in the decolorizing kettle to ≥90°C, and gradually add 50% by weight of water Crude adipic acid, after dissolving, add 4% activated carbon for deco...

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PUM

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Abstract

The present invention is a process for producing adipic acid and hexamethylenediamine by depolymerizing nylon-66. It consists of an acid hydrolysis section, a cooling crystallization section, a crude acid separation section, a recrystallization section, a neutralization section and a refining section. Adipic acid is decomposed to obtain adipic acid, and then alkali is added for neutralization reaction to obtain hexamethylenediamine. The acid used in the acid hydrolysis section is sulfuric acid, and the alkali used for neutralization is milk of lime. This process is suitable for large-scale industrial production and solves the problem of waste nylon-66 The problem of high operating costs in the industrial production of depolymerization to produce monomers can obtain adipic acid and hexamethylenediamine with high purity, and there is no new pollution, which has high economic and social benefits.

Description

technical field [0001] The invention relates to a process for producing adipic acid and hexamethylenediamine by depolymerization of nylon-66, in particular to a process for producing adipic acid and hexamethylenediamine by depolymerization of nylon-66, which is suitable for large-scale industrial production. Background technique [0002] The good functionality and practicability of polymer materials have brought a lot of convenience to human beings. Plastics are ubiquitous in people's lives today, and the amount of use is increasing year by year, but at the same time, it has also caused serious environmental problems. Discarded high molecular polymers are difficult to degrade in nature, and some will not last for hundreds of years. degradation. This has already attracted global attention, and many countries have enacted laws requiring recycling of waste polymers. [0003] At present, there are mainly the following methods for polymer recycling...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C55/14C07C51/00C07C211/12C07C209/62
Inventor 张振民
Owner 宁波敏特尼龙工业有限公司
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