Amine Recovery via pH-Driven Phase Separation
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Solution Overview
Problem
Current methods for separating amines from aqueous mixtures are energy-intensive, expensive, and prone to amine degradation, especially in temperature-sensitive processes, and often result in high water and sodium concentrations, making them inefficient and costly.
Innovation Solution
Increasing the pH of the aqueous mixture above the highest pKa value for the amine to form an amine-rich layer, which can be separated from the aqueous layer, using strong bases like sodium or potassium hydroxide and inorganic salts to enhance density differences and facilitate extraction with organic solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If distillation is used to separate amines from aqueous mixtures, then separation efficiency is improved, but energy consumption increases and amine degradation occurs
Solution Approach 1:
The patent changes the pH parameter of the aqueous mixture to above the highest pKa value of the amine, transforming the amine from its protonated water-soluble form to its neutral form. This parameter change enables phase separation without requiring thermal energy input for distillation, thus resolving the contradiction between separation efficiency and energy consumption
Solution Approach 2:
The patent utilizes phase transition by adjusting pH to cause the amine to transition from a water-soluble ionic state to a neutral state that forms a separate organic phase. This phase separation achieves efficient amine recovery without the energy-intensive heating and vaporization required by distillation, eliminating both high energy consumption and thermal degradation risks
2Manufacturing precision
If distillation is used to separate amines from aqueous mixtures, then separation efficiency is improved, but amine degradation occurs due to high temperature exposure
Solution Approach 1:
The patent changes the pH parameter to above the highest pKa value, transforming the amine to its neutral form that can be extracted without thermal processing. This avoids high-temperature exposure entirely, preventing dimerization, trimerization, and other degradation reactions while maintaining effective separation
Solution Approach 2:
The patent employs phase separation through pH adjustment rather than thermal phase change. By transitioning the amine from ionic to neutral form via pH control, the amine partitions into an organic phase that can be separated at ambient or mild temperatures, completely avoiding the thermal degradation pathways present in distillation
3Quantity of substance
If conventional separation methods are used, then amines can be recovered, but water and sodium concentrations remain high in the product
Solution Approach 1:
The patent introduces an organic solvent as an intermediary phase that selectively extracts the neutral amine from the aqueous mixture. This intermediary extraction phase separates the amine from water and sodium ions, allowing recovery of high-purity amine while leaving impurities in the aqueous phase, thus resolving the contradiction between recovery quantity and product purity
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 allows for efficient, low-cost separation of amines with reduced salt concentrations, minimizing amine degradation and improving product yield, achieving high amine concentrations in the amine-rich layer while reducing salt-to-amine ratios significantly.
Implementation Method 1
increasing the pH of the aqueous mixture to above the highest pKa value for the amine
Implementation Method 2
forming an aqueous layer and an amine-rich layer, wherein the amine-rich layer comprises the at least one amine; and separating the amine-rich layer from the aqueous layer
Implementation Method 3
using strong bases like sodium or potassium hydroxide and inorganic salts to enhance density differences
Implementation Method 4
facilitate extraction with organic solvents
Data Source
AI summary
The present disclosure generally relates to methods for the recovery of amines from aqueous mixtures. In particular, the disclosure relates to methods for separating amines from amine-containing aqueous mixtures by adjusting the pH of the aqueous mixture relative to the highest pKa value for the amines.