Cis,cis-1,2,4-Cyclohexanetricarboxylic Acid Crystallization via Aqueous Solvent

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Solution Overview

Problem

Existing methods for producing cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals face issues with solvent safety, efficiency, and purity, particularly due to the use of THF and multiple solvent replacement steps, which are not industrially favorable.

Innovation Solution

A method involving configuring the mass ratio of cis,cis-1,2,4-cyclohexanetricarboxylic acid to trans,trans-1,2,4-cyclohexanetetracarboxylic acid in an aqueous solution for crystal precipitation, achieving a specific cis/trans ratio and concentrating the solution to achieve high purity cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals with improved recovery rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If THF is used as a solvent for nuclear hydrogenation and crystal precipitation, then the crystal precipitation process can be carried out, but THF produces explosive peroxides when exposed to air or oxygen, creating safety hazards

Engineering Contradiction:

ImprovesafetyVSAvoidprocessability

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces THF with water as the solvent. Water is safer, non-flammable, and does not form explosive peroxides. Although water has different solubility characteristics, the process is adapted to work effectively with aqueous solutions, eliminating the safety hazard while maintaining process functionality.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the solvent system from organic (THF) to aqueous, fundamentally altering the chemical environment. This parameter change affects solubility, reaction conditions, and crystal formation, but enables safe industrial operation by eliminating peroxide formation while achieving the desired crystal precipitation.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If solvent replacement from nuclear hydrogenation solvent to crystal precipitation solvent is carried out, then crystal precipitation can be optimized, but the number of processes increases, reducing industrial efficiency

Engineering Contradiction:

ImprovepurityVSAvoidefficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines the nuclear hydrogenation reaction and crystal precipitation steps into a single continuous process using water as the common solvent. The hydrogenation reaction is performed in aqueous medium, and the resulting solution is directly concentrated and cooled for crystal precipitation without intermediate solvent replacement, thereby maintaining purity while improving efficiency.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Water serves multiple functions in the process: it acts as the reaction medium for nuclear hydrogenation, the solvent for the intermediate product, and the medium for crystal precipitation. This multi-functionality eliminates the need for solvent replacement and streamlines the overall process.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If a large amount of solvent is used during hydrogenation reaction and crystal precipitation, then the reaction can proceed smoothly, but the mass ratio of solvent to charged starting material is high, reducing process efficiency

Engineering Contradiction:

ImproveprocessabilityVSAvoidefficiency

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent optimizes the solvent-to-starting-material mass ratio by changing from THF to water as the solvent. Aqueous systems typically require different solvent amounts compared to organic systems. The process is designed to operate efficiently at optimized ratios specific to water as the solvent, improving overall process efficiency while maintaining smooth reaction progression.

Inventive Principle:

Principle #35Parameter changes

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 approach results in high purity cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals with enhanced recovery rates, addressing the inefficiencies and safety concerns of previous methods, and is more industrially viable.

Implementation Method 1

subjecting the aqueous starting material solution for crystal precipitation obtained in step 1 to crystal precipitation

Methodology Applied

Scientific EffectCrystal precipitation: Crystallisation

Data Source

PatentEP3604265B1Method for producing cis,cis-1,2,4-cyclohexane tricarboxylic acid crystal

Publication Date: 2021.10.20 MITSUBISHI GAS CHEM CO INC

AI summary

An object of the present invention is to provide a method for producing cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals, from which high purity cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals are obtained. The method for producing cis,cis-1,2,4-cyclohexanetricarboxylic acid crystals of the present invention comprises the following steps: Step 1: measuring a mass ratio (cis/trans ratio) of cis,cis-1,2,4-cyclohexanetricarboxylic acid to trans,trans-1,2,4-cyclohexanetricarboxylic acid in an aqueous starting material solution comprising the cis,cis-1,2,4-cyclohexanetricarboxylic acid to give an aqueous starting material solution for crystal precipitation having a cis/trans ratio of 10 or more; and Step 2: subjecting the aqueous starting material solution for crystal precipitation obtained in step 1 to crystal precipitation.