Continuous Quaternary Salt Production via Liquid Phase Segregation

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Solution Overview

Problem

Existing methods for producing quaternized N,N-dialkylaminoethyl (meth)acrylates (DMAEA.MCQ) are inefficient and costly, often requiring batch processes or multiple reactors, which are cumbersome and expensive, and do not allow for continuous removal of the product, leading to impurities and operational challenges.

Innovation Solution

A continuous method involving a continuously stirred tank reactor (CSTR) where reactants, including a tertiary amine substrate and an alkylating agent, form two distinct liquid phases, with the denser phase comprising over 80% quaternary amine product and less than 20% water, allowing continuous removal of the denser phase, which is then further processed to minimize impurities and enhance product purity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple CSTRs are connected in series to continuously produce DMAEA.MCQ, then continuous production is achieved, but the equipment becomes cumbersome and expensive

Engineering Contradiction:
Improvecontinuous production capabilityVSAvoidnumber of reactors
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The reaction system is segmented into two distinct liquid phases (aqueous phase and organic phase) that coexist and separate within a single CSTR. This phase segmentation allows different reaction conditions and product concentrations in each phase, enabling continuous production while simplifying equipment to one reactor instead of multiple series-connected reactors.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A solvent system acting as an intermediary medium is introduced to facilitate the quaternization reaction and enable phase separation. The solvent system mediates between the reactants and allows the dense quaternary ammonium salt product to form a separate phase that can be continuously removed, achieving continuous production in a single reactor.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If thin film evaporator reactor is used for synthesis, then reaction efficiency is improved, but operating costs increase

Engineering Contradiction:
Improvereaction efficiencyVSAvoidoperating costs
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The invention utilizes liquid-liquid phase separation instead of vaporization for product separation. The quaternary ammonium salt product forms a dense liquid phase that separates from the reaction mixture, allowing continuous removal without the high energy input required by evaporator reactors. This phase transition approach maintains reaction efficiency while significantly reducing operating costs.

Inventive Principle:
Principle #36Phase transitions

3Stability of the object's composition

If rotating disc agitated column design is used, then mixing is improved, but residence time becomes unduly long

Engineering Contradiction:
Improvemixing efficiencyVSAvoidresidence time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The invention changes the physical parameters of the reaction system by introducing a solvent system that creates distinct liquid phases with different densities. This parameter change enables rapid phase separation and continuous product removal, reducing the residence time required in the reactor while maintaining effective mixing through the phase interface.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If water is added to isolate quaternization product by forming two phases, then product separation is achieved, but the process becomes batchwise rather than continuous

Engineering Contradiction:
Improveproduct separation purityVSAvoidprocess continuity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention maintains continuous operation by continuously adding the solvent system and reactants to the CSTR, allowing the quaternization reaction and phase separation to occur continuously. The dense quaternary ammonium salt phase separates and can be continuously removed, eliminating the batchwise operation required in previous methods while maintaining high product separation purity.

Inventive Principle:
Principle #20Continuity of useful action

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 method enables the efficient and continuous production of high-purity DMAEA.MCQ with reduced impurities and operational costs, maintaining a stable two-phase separation that minimizes unwanted side reactions and facilitates easy product removal, resulting in a high-quality quaternary amine product.

Implementation Method 1

maintaining conditions in the CSTR such that two substantially distinct liquid phases form, a first phase and a second phase, the second phase being denser than the first phase, the second phase comprising more than 80% QAP and less than 20% water

Methodology Applied
Scientific EffectDensity difference: Density Gradient

Data Source

PatentEP2526083B1Continuous production of quaternary salts
Publication Date: 2016.03.23 NALCO CO
  • EP2526083B1 patent drawingFigure 1
  • EP2526083B1 patent drawingFigure 2
  • EP2526083B1 patent drawing

AI summary

The invention provides a method of continuously producing high quality quaternized N,N-dialkylaminoethyl (meth)acrylates (DMAEA-MCQ) that has a long shelf life and which is stable in water. The method involves placing starting marterials into a continuously stirred tank reactor in the presence of less than 6% water. This low amount of water causes two liquid phases to form and prevents unwanted side reactions. The denser liquid phase contains DMAEA-MCQ and the lighter phase containse the starting materials. Liquid from the denser phase is removed from a position where little of the lighter phase has been mixed in. The removed liquid then has any last traces of the starting materials reacted into DMAEA-MCQ and stips away any starting materials with a gas flow. The resulting liquid is high purity DMAEA-MCQ. Water can then safely be added to ease in the transport and use of the produced DMAEA-MCQ.