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Method for recovering TPA (terephthalic acid) from polyester alkali deweighting waste residues with limitation on rare earth materials

A technology of terephthalic acid and rare earth materials, applied in the separation/purification of carboxylic acid compounds, organic chemistry, etc., can solve the problems of poor process safety and reduced TPA recovery efficiency, and achieve high purity, improved safety, and recovery rate. high effect

Inactive Publication Date: 2015-11-25
刘健
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, as a toxic substance, DMF is used alone as a solvent, and the safety of the process is poor; in addition, when activated carbon is used as a decolorizing agent, when heavy metal ions are adsorbed, it will adsorb part of the active components of TPA, resulting in a reduction in the recovery of TPA efficiency.

Method used

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  • Method for recovering TPA (terephthalic acid) from polyester alkali deweighting waste residues with limitation on rare earth materials
  • Method for recovering TPA (terephthalic acid) from polyester alkali deweighting waste residues with limitation on rare earth materials

Examples

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Effect test

Embodiment 1

[0012] Prepare 50 g of DMF / MEK mixed solvents with a mass ratio of DMF and MEK of 1:1, 3:2, 7:3, 4:1, and 9:1, and weigh 3 g of alkali weight reduction waste residue to add to the mixed solvent , at 25°C, after fully stirring for 60 minutes, filter, add 2g of yttrium nitrate to the filtered filtrate, after the reaction is complete, pass through secondary filtration, precipitation and recovery treatment to obtain the product.

[0013] Depend on figure 1 As shown, with the gradual increase of the mass fraction of DMF, the recovery rate of TPA increases gradually, when the mass fraction of DMF is 80%. The recovery rate of TPA reached 89.21%, further increasing the mass fraction of DMF, the recovery rate of TPA tended to be stable. This is because DMF is a strong solvent. With the increase of the mass fraction of DMF in the mixed solvent, the degree of TPA dissolution is greater. When the mass fraction of DMF reaches a certain value, TPA is fully dissolved. Continue to increase t...

Embodiment 2

[0015] Prepare 50g of DMF / MEK mixed solvent with a mass ratio of DMF and MEK of 4:1, weigh 1g, 2g, 3g, 5g, and 10g of alkali weight reduction waste residue respectively, add them to the mixed solvent, and stir fully at 25°C After 60 minutes, filter, add 2g of yttrium nitrate to the filtered filtrate, after the reaction is complete, pass through secondary filtration, precipitation and recovery treatment to obtain the product.

[0016] Depend on figure 2 As shown, with the increase of the addition of alkali reduction waste residue, the recovery rate of TPA does not change significantly, and the recovery rate of TPA is 88.62-89.19%. When the addition amount of alkali reduction waste residue exceeds 3g, further increase the addition amount of alkali reduction waste residue , the recovery rate of TPA gradually decreased. This is because when the dissolved amount of TPA does not reach saturation, the recovery rate of TPA is constant; when the dissolved amount of TPA reaches satura...

Embodiment 3

[0018] Prepare 50 g of DMF / MEK mixed solvent with a mass ratio of DMF and MEK of 4:1, weigh 3 g of alkali weight reduction waste residue and add it to the mixed solvent. After fully stirring for 60 min at 25° C., filter, and the filtered 3g of yttrium nitrate and 3g of activated carbon were respectively added to the filtrate. After the reaction was complete, the product was obtained through secondary filtration, precipitation and recovery treatment. By calculation, after being treated with yttrium nitrate, the recovery rate of TPA in the product is 89.21%, and after being treated with activated carbon, the recovery rate of TPA in the product is 79.16%.

[0019] Reasons for analysis: When activated carbon is used as a decolorizing agent, when heavy metal ions are adsorbed, part of the active ingredients of TPA will be adsorbed, resulting in a decrease in the recovery of TPA. When heavy metal ions are electrostatically adsorbed by yttrium oxide, the effective components of TPA w...

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Abstract

The invention discloses a method for recovering TPA (terephthalic acid) from polyester alkali deweighting waste residues with limitation on rare earth materials. The method comprises steps as follows: the alkali deweighting waste residues are dissolved in a DMF / MEK (dimethyl formamide / methyl ethyl ketone) mixed solvent, stirring, filtration, pH value adjustment, decolorization, precipitation and recovery treatment are performed, and a product is obtained. Experiments prove that with the gradual increase of the mass fraction of the DMF in the mixed solvent, the amount of the recovered TPA is gradually increased, and when the DMF in the mixed solvent is excessive, the amount of the recovered TPA tends to stability; with the increase of the mass ratio of the mixed solvent to the alkali deweighting waste residues, the amount of the recovered TPA is gradually increased, when the mass ratio of the mixed solvent to the alkali deweighting waste residues reaches a balance value, the amount of the recovered TPA is maximum, and when the mass ratio of the mixed solvent to the alkali deweighting waste residues is continuously increased, the amount of the recovered TPA has a trend of decrease. The method has the advantages that the amount of the recovered TPA is high, the toxicity of the solvent is low, the technology is safe, and the like and is mainly applied to the application field of recovery of the TPA in the polyester alkali deweighting waste residues.

Description

technical field [0001] The invention relates to the field of methods for recovering terephthalic acid from polyester alkali weight reduction waste residues, in particular to a method for recovering terephthalic acid from polyester alkali weight reduction waste residues with limited rare earth materials. Background technique [0002] At present, the research on the recovery of terephthalic acid (TPA) in alkali reduction wastewater mainly uses neutralization method, ion exchange method and ultrafiltration neutralization method, etc., and the purity of TPA recovered by these methods needs to be improved. [0003] "He Yonglin; Journal of Textile Science [J]; The influence of organic solvents on the recovery of terephthalic acid in polyester alkali reduction waste residue; 2013 No. 12; 12-15" In the article, DMF was used as the solvent and activated carbon was used as the decolorizing agent. The TPA recovered by the crystallization method has higher purity. However, as a toxic s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/42C07C51/47C07C63/26
CPCC07C51/42C07C51/47C07C63/26
Inventor 刘健
Owner 刘健