Method for recycling mother solid in PTA-refining wastewater

A technology for refining wastewater and recycling methods, applied in chemical instruments and methods, multi-stage water/sewage treatment, water/sludge/sewage treatment, etc. The effect of high recovery rate and avoiding waste of resources

Active Publication Date: 2011-01-12
FUZHOU UNIV
View PDF6 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If the PTA purified wastewater is directly treated with membrane, the membrane device will not be able to operate stably

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 recycling mother solid in PTA-refining wastewater
  • Method for recycling mother solid in PTA-refining wastewater
  • Method for recycling mother solid in PTA-refining wastewater

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Stream 1 PTA (PTA refined wastewater) and stream 2 (pure PX) respectively enter the mixing tank through the flow regulating valve for mixing cooling and primary extraction. The mass ratio of stream 1 to stream 3 in the mixing tank is 1:4. Control the flow of cooling water in the mixing tank coil so that the outlet temperature of the mixing tank is 40°C. After the mixed solution enters the clarifier, there will be TA solid precipitated and precipitated in the clarifier, and at the same time, the P-TOL and PTA in the PX extraction wastewater form an oil phase and water layer, which flows out from the upper layer of the clarifier (stream 5), and returns to Oxidation reaction system. The PTA wastewater (stream 4) from the clarification tank enters from the upper part of the extraction tower, while pure PX (stream 6) enters from the bottom of the extraction tower through a regulating valve, and the mass ratio of stream 6 to stream 4 is 1 :5. In the extraction tower, after...

Embodiment 2

[0027] Stream 1 PTA (PTA refined wastewater) and stream 2 (including pure PX and the extraction phase discharged from the top of the extraction tower in Example 1) respectively enter the mixing tank through the flow regulating valve for mixing cooling and primary extraction. The mass ratio of stream 1 to stream 3 in the mixing tank is 1:3. Control the flow of cooling water in the mixing tank coil so that the outlet temperature of the mixing tank is 41°C. After the mixed solution enters the clarifier, TA solids will precipitate and settle down in the clarifier, and at the same time, the P-TOL and PTA in the PX extraction wastewater form an oil phase and water layer, which flow out from the upper layer of the clarifier (stream 5), and return to Oxidation reaction system. The PTA wastewater (stream 4) from the clarification tank enters from the upper part of the extraction tower, while pure PX (stream 6) enters from the bottom of the extraction tower through a regulating valve, ...

Embodiment 3

[0031]Stream 1 PTA (PTA refined wastewater) and stream 2 (pure PX) respectively enter the mixing tank through the flow regulating valve for mixing cooling and primary extraction. The mass ratio of stream 1 to stream 3 in the mixing tank is 1:2. Control the flow of cooling water in the mixing tank coil so that the outlet temperature of the mixing tank is 40.5°C. After the mixed solution enters the clarifier, there will be TA solid precipitated and precipitated in the clarifier, and at the same time, the P-TOL and PTA in the PX extraction wastewater form an oil phase and water layer, which flows out from the upper layer of the clarifier (stream 5), and returns to Oxidation reaction system. The PTA wastewater (stream 4) from the clarification tank enters from the upper part of the extraction tower, while pure PX (stream 6) enters from the bottom of the extraction tower through a regulating valve, and the mass ratio of stream 6 to stream 4 is 1 :8. In the extraction tower, afte...

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 recycling mother solid in PTA-refining wastewater, comprises the following steps: mixing PTA-refining wastewater and paraxylene in a prepositioned mixing tank, carrying out single-stage extraction and cooling on the wastewater, dissolving and extracting the solid in mother liquor into a PX phase, returning the extract phase PX discharged from a clarification tank to an oxidizing reaction system, and delivering the wastewater to an extraction tower to be subject to multistage countercurrent extraction; delivering the wastewater discharged from the bottom ofthe extraction tower to be subject to further treatment; and returning the extraction phase discharged from the top of the extraction tower to serve as extract liquor for single-stage extraction. By adopting the method in the invention, most of organic matters, such as p-toluic acid, terephthalic acid and the like in the wastewater can be recycled, thus the purpose of recycling wastes is achieved, and wasting of resources is avoided; and the invention omits the conventional filtering unit, saves the filter cloth-replacing cost, ensures that the extraction tower can operate at appropriate operating temperature, and has the advantages of investment saving, low energy consumption, high resource recovery rate and the like.

Description

technical field [0001] The invention relates to a method for recovering valuable substances in industrial wastewater, in particular to a method for recovering solids from purified terephthalic acid wastewater. Background technique [0002] Purified terephthalic acid (PTA) is a very important organic chemical raw material, which is widely used in the production of polyester industry and other chemical industries. The PTA device uses p-xylene (PX) as raw material, acetic acid as solvent, and reacts with compressed air in the oxidation reactor to generate crude terephthalic acid (CTA) slurry. In the PTA refining section, the CTA from the oxidation process is mixed with process water to form a slurry, and the temperature and pressure are increased to completely dissolve terephthalic acid in water. The solution passes through a high-pressure hydrogenation device at 250~280°C and 4~5 MPa, and under the action of a palladium / carbon fixed bed catalyst, p-carboxybenzaldehyde (4-CBA)...

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): C07C51/42C07C63/04C07C63/26C02F9/08
Inventor 吴燕翔邱挺郑辉东黄智贤王碧玉
Owner FUZHOU UNIV
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