Aromatic Acid Recovery via Simultaneous Two-Phase Extraction

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Solution Overview

Problem

Current methods for recovering aromatic carboxylic acids and cobalt-manganese catalysts from the effluent of terephthalic acid production suffer from low yields and long cycle times, and are unable to effectively separate aromatic carboxylic acids, bromide, and acetic acid.

Innovation Solution

A process involving simultaneous extraction of the residue stream with two liquid phases, followed by filtration, to separate monocarboxylic, dicarboxylic, and tricarboxylic acid streams, allowing for the recovery of aromatic polycarboxylic acids, cobalt, manganese catalysts, and acetic acid with high yields and reduced cycle times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional sequential separation methods are used to recover aromatic carboxylic acids and catalysts, then the process is simpler to implement, but the cycle time increases and yields decrease

Engineering Contradiction:
Improverecovery yield and cycle timeVSAvoidseparation process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple separation operations into a single simultaneous two-phase extraction step. The residue stream is contacted with both water and organic solvent at the same time, allowing parallel separation of aromatic carboxylic acids into the organic phase and catalyst components into the aqueous phase in one operation, rather than through sequential extraction and filtration steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the mixed residue stream into distinct components through phase separation. By using two immiscible liquid phases (water and organic solvent), the process divides the complex mixture into separable phases: the organic phase containing aromatic carboxylic acids and the aqueous phase containing catalyst components, enabling efficient recovery of each component.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If conventional extraction methods are used, then the separation process is simpler, but the ability to separate aromatic carboxylic acids, bromide, and acetic acid effectively is reduced

Engineering Contradiction:
Improveseparation efficiencyVSAvoidextraction process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses an organic solvent as an intermediary substance to facilitate the separation of aromatic carboxylic acids from the residue stream. The organic solvent selectively extracts aromatic carboxylic acids from the mixture, while catalyst components and inorganic salts remain in the aqueous phase, achieving effective separation of multiple components simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the purge stream is incinerated or disposed of, then the treatment process is simpler and faster, but environmental contamination occurs and valuable chemicals are lost

Engineering Contradiction:
Improvechemical recovery yieldVSAvoiddisposal process simplicity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies the discarding and recovering principle by extracting and recovering valuable aromatic carboxylic acids and catalyst components from the purge stream that would otherwise be discarded through incineration or landfill. The simultaneous two-phase extraction process captures these valuable chemicals, converting waste into recoverable products while eliminating the need for destructive disposal methods.

Inventive Principle:
Principle #34Discarding and recovering

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This process enables efficient separation and recovery of valuable components, reducing waste and environmental contamination by achieving high yields and shorter processing times.

Implementation Method 1

separating the residue stream into a dicarboxylic acid rich stream, a catalyst and tricarboxylic acid rich stream, and a monocarboxylic acid rich stream, wherein the separation comprises simultaneous extraction of the residue stream with two liquid phases

Methodology Applied
Scientific EffectLiquid-liquid extraction: Liquid-Liquid Extraction

Data Source

PatentEP2560941B1Recovery of aromatic carboxylic acids and oxidation catalyst
Publication Date: 2020.01.01 INVISTA TEXTILES (U K) LTD
  • EP2560941B1 patent drawingFigure 1

AI summary

The present invention relates to a process for recovery of catalyst, aromatic polycarboxylic acids and aromatic monocarboxylic acids from a residue stream from manufacture of an aromatic polycarboxylic acid.