Process of recycling terephthalic acid to produce DOTP (dioctyl terephthalate) by using polyester alkaline to reduce wastewater

A technology of alkali reduction wastewater and terephthalic acid, applied in the field of plasticizers, can solve the problems of different purity and color, waste, uneven process level, etc., to shorten the process flow, reduce energy consumption and waste water generation volume effect

Inactive Publication Date: 2014-12-24
上海蓓奕化工有限公司 +1
View PDF4 Cites 16 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] However, although there are literatures in recent years on how to improve the purity of terephthalic acid separated from alkali reduction waste water, because the waste water treatment methods used by polyester textile enterprises are all different, and the process level is also uneven, the actual recovered Terephthalic acid also has a large difference in purity and color, and low purity (generally, the content of purified terephthalic acid (PTA) is 99.99%, and the content of crude terephthalic acid (CTA) is 94-95%. %, if it is less than 90-92%, it belongs to low-purity terephthalic acid (TA)), and the recycled terephthalic acid with color can only be incinerated to utilize its calorific value, causing great waste
At present, there is no record of a process that can uniformly and comprehensively utilize the terephthalic acid recovered from the alkali reduction wastewater of various fabrics to produce high-quality DOTP

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Put TA recycled material of white embryo polyester fabric with terephthalic acid content of 92% into the reaction kettle, put isooctyl alcohol in a mass ratio of 1:2.6, start stirring and raise the temperature to 160°C, when the water output is significantly reduced, add the following The catalyst of tetraisopropyl titanate and tetrabutyl titanate mixed in a ratio of 4:1 is added in an amount of 5‰ of the mass of TA recycled material, and at the same time, activated carbon with a mass of TA recycled material of 5‰ is added, and the temperature is controlled continuously by stirring and heating. At 200°C, keep water and iso-octanol reflux during the period. When the acidity reaches ≤0.05%, the reaction is considered to be over. Turn on the vacuum to -0.09MPa and use the remaining temperature to remove the excess iso-octanol. The still was heated to 285°C for 2.5 hours under reduced pressure, and the vacuum was maintained at -0.1MPa to obtain the crude ester. After the vac...

Embodiment 2

[0023] Put TA recycled fabric containing colored fiber with terephthalic acid content of 84.7% in the reaction kettle, put in isooctyl alcohol 2.2 times its weight, start stirring and raise the temperature to 120°C, add TA recycled material when the water output is significantly reduced 3‰ of the weight of tetraisopropyl titanate and tetrabutyl titanate catalyst mixed in a ratio of 3.5:1, and add activated carbon with 1% of the mass of TA recycled material, keep stirring and heating up, and control the temperature at 190°C. Keep the iso-octanol reflux and continuously drain the reaction water. When the acidity reaches ≤0.05%, the reaction is considered to be over. Turn on the vacuum to -0.08MPa and use the remaining temperature to remove the remaining iso-octanol. The still was heated up to 275°C for 4 hours under reduced pressure, and the vacuum was maintained at -0.1MPa under reduced pressure to obtain the crude ester. Turn off the vacuum, and then add 50% H 2 o 2 And use t...

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

PropertyMeasurementUnit
densityaaaaaaaaaa
flash pointaaaaaaaaaa
relative humidityaaaaaaaaaa
Login to view more

Abstract

The invention discloses a process of recycling terephthalic acid to produce DOTP (dioctyl terephthalate) by using polyester alkaline to reduce wastewater. The process comprises the following process steps: adding terephthalic acid reclaimed materials and isooctyl alcohol into a reaction kettle in a certain proportion, stirring and heating, adding a catalyst and activated carbon when water yield is obviously reduced, continuously stirring and heating the mixture, controlling the temperature of the mixture to 190-230 DEG C, carrying out dealcoholization in vacuum after reaction is ended, heating to 265-285 DEG C and distilling under reduced pressure under -0.09MPa to -0.1MPa to obtain raw ester, adding H2O2 in a certain proportion to discolor; and finally, absorbing impurities by use of activated carbon and kaolin and carrying out filter-pressing to obtain a nearly colorless DOTP finished product. According to the process, the raw materials can adopt untreated alkaline which is low in purity and chromaticity to reduce wastewater to recycle the terephthalic acid, so that a complex pretreatment process is avoided, the terephthalic acid reclaimed materials are utilized to the greatest extent, and the high ester content and the low colour and luster of the DOTP product are guaranteed while the efficiency is high and the energy consumption is low.

Description

technical field [0001] The invention relates to a production method of a plasticizer, in particular to a new high-efficiency and high-quality production process for producing terephthalic acid and octanol obtained from polyester alkali reduction wastewater as raw materials. Diisooctyl dicarboxylate. Background technique [0002] Diisooctyl terephthalate (DOTP) is a main plastic plasticizer with excellent performance. Except that the plasticizing performance is slightly lower than that of dioctyl phthalate (DOP), it has good performance in terms of volatility, volume resistivity, Compatibility with PVC and temperature and weather resistance are superior, and the toxicity is much lower than DOP. DOTP is mainly used for cable materials with a temperature resistance of 70°C. Because of its low volatility, the use of a certain amount of DOTP can fully meet the temperature resistance grade requirements of wire and cable materials and meet the standards of the International Electr...

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
Patent Type & Authority Applications(China)
IPC IPC(8): C07C69/82C07C67/08
CPCC07C67/08C07C51/02C07C67/54C07C67/56C07C67/60
Inventor 韩冬
Owner 上海蓓奕化工有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap