Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for recovering terephthalic acid based on parameter optimization

A technology of terephthalic acid and optimized parameters, which is applied in the field of recycling terephthalic acid in polyester alkali reduction waste residues, can solve the problems of poor process safety and reduced efficiency of recycling TPA, and achieves high purity, improved safety, and recovery rate. high effect

Inactive Publication Date: 2015-11-25
刘健
View PDF0 Cites 0 Cited by
  • 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

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for recovering terephthalic acid based on parameter optimization
  • Method for recovering terephthalic acid based on parameter optimization

Examples

Experimental program
Comparison scheme
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...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for recovering terephthalic acid based on parameter optimization. The method comprises the following steps: dissolving an alkali-decrement waste residue in a DMF / MEK mixed solvent; carrying out stirring, filtration, adjustment of the pH value, decoloration, separation, and recovery treatment to obtain terephthalic acid. Experiments show that the amount of recovered terephthalic acid is gradually increased with a gradual increase of the mass fraction of DMF in the mixed solvent; when DMF in the mixed solvent is surplus, the amount of recovered terephthalic acid tends to be stable; the mount of recovered terephthalic acid is gradually increased with an improvement on the mass ratio of the mixed solvent to the alkali-decrement waste residue; when the mass ratio of the mixed solvent to the alkali-decrement waste residue reaches an equilibrium value, the amount of recovered terephthalic acid reaches the highest level; when the mass ratio of the mixed solvent to the alkali-decrement waste residue is continued to be improved, the amount of recovered terephthalic acid tends to be decreased. The method has the advantages of being large in amount of recovered terephthalic acid, low in toxicity of the mixed solvent, and safe in process, and is mainly utilized for the application field of recovery of terephthalic acid in polyester alkali-decrement waste residues.

Description

technical field [0001] The invention relates to the field of methods for recovering terephthalic acid in polyester alkali weight reduction waste residue, in particular to a method for recovering terephthalic acid with optimized parameters. 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 substance, DMF is used alone as a solvent, and the safety of the p...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C07C63/26C07C51/42C07C51/47
CPCC07C51/42C07C51/47C07C63/26
Inventor 刘健
Owner 刘健