Purified Dicarboxylic Acid Recovery via Fractional Melt Crystallization

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Solution Overview

Problem

Current processes for obtaining high-purity dicarboxylic acids from triglycerides with multiple acid functional groups are complex and require multiple purification steps, leading to inefficient separation operations and low product recovery yields.

Innovation Solution

A process involving hydrolysis of triglycerides in the presence of water, followed by separation of an aqueous phase, evaporation/distillation, and fractional melt crystallization of dicarboxylic acids to achieve high-purity dicarboxylic acids, allowing for efficient recovery and reuse of crystallization mother liquors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple evaporation and distillation operations are used to separate monocarboxylic acids from dicarboxylic acids, then the purity of dicarboxylic acids is improved, but the process complexity and number of purification steps increase

Engineering Contradiction:
Improvepurity of dicarboxylic acidsVSAvoidnumber of purification steps
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts monocarboxylic acids from the reaction mixture through selective evaporation and distillation operations, separating them from dicarboxylic acids. This extraction approach allows purification of dicarboxylic acids by removing interfering monocarboxylic acid components through controlled volatility differences

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs parameter changes by controlling temperature, pressure, and heating rates during evaporation and distillation operations to selectively separate monocarboxylic acids from dicarboxylic acids. By adjusting these parameters, the process achieves high purity dicarboxylic acids while managing the complexity of multiple purification steps

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple purification operations are performed to obtain high-purity dicarboxylic acids, then the product purity is improved, but the product recovery yield decreases

Engineering Contradiction:
Improvepurity of dicarboxylic acidsVSAvoidproduct recovery yield
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent performs preliminary hydrolysis of triglycerides to convert them into free fatty acids before separation operations. This preliminary action simplifies subsequent purification steps and improves recovery yield by preventing loss of dicarboxylic acids during complex multi-stage purifications

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical separation systems with chemical transformation approaches. By hydrolyzing triglycerides in advance and using controlled evaporation/distillation based on volatility differences, the process achieves high purity with better recovery yields compared to purely mechanical separation methods

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If conventional separation processes are used to obtain high-purity dicarboxylic acids, then the purity requirement is met, but the process efficiency and separation performance are reduced

Engineering Contradiction:
Improvepurity of dicarboxylic acidsVSAvoidseparation efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent implements continuous hydrolysis and separation operations where triglycerides are continuously converted to free fatty acids and immediately separated based on volatility. This continuous process maintains high separation efficiency and productivity while achieving the required purity levels for dicarboxylic acids

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent utilizes parameter changes in temperature and pressure during evaporation and distillation to optimize separation efficiency. By dynamically adjusting these parameters, the process achieves both high purity dicarboxylic acids and high productivity without the inefficiencies of conventional batch purification methods

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 process enables the production of high-purity dicarboxylic acids with reduced purification steps, improving separation efficiency and product recovery yields, and allows for the recycling of mother liquors, thus enhancing the overall process efficiency.

Implementation Method 1

hydrolysing the said mixture containing triglycerides in the presence of water, obtaining a reaction product comprising dicarboxylic acids and glycerine

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

evaporating and/or distilling the organic phase obtained from step b), separating out a residue

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

evaporating and/or distilling the organic phase obtained from step b), separating out a residue

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 4

recovering at least a part of the dicarboxylic acids from the organic phase evaporated and/or distilled in step c) by means of at least one crystallisation operation, the said step comprising at least one melt crystallization of the said dicarboxylic acids carried out in fractional suspension

Methodology Applied
Scientific EffectCrystallisation: Crystallisation

Data Source

PatentEP3865470B1Process for the preparation of purified dicarboxylic acids
Publication Date: 2024.08.21 NOVAMONT SPA

AI summary

This invention relates to a process for the purification of dicarboxylic acids obtained from the hydrolysis of carboxylic acid triglycerides having more than one acid functional group. The process comprises in particular the separation of at least some of the glycerine from the hydrolysis product in an aqueous phase, evaporating and/or distilling the resultant organic phase and recovering at least some of the evaporated and/or distilled dicarboxylic acids through at least one crystallisation operation.