Electrodeionization Apparatus for Acid Stream Purification
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Solution Overview
Problem
Current separation methods, such as distillation and electrodialysis, are costly and unsuitable for separating components in acidic environments, particularly for separating organic acids like propionic acid from acetic acid.
Innovation Solution
An electrodeionization apparatus with a configuration of an anode, spaced apart cathode, and three membranes (a first cation exchange membrane, a first anion exchange membrane, and a second cation exchange membrane) along with propionate-selective ion exchange resin wafers, which facilitate the separation of propionic acid from acetic acid by applying an electric potential across the electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If distillation or conventional electrodialysis is used to separate organic acids, then separation can be achieved, but the process becomes very expensive and requires phase change
Solution Approach 1:
The patent changes the operating parameters by using electrodeionization with selective ion exchange membranes and resins, allowing separation without phase change. The system uses controlled ion transport through membranes under electrical potential, avoiding the expensive phase change requirements of distillation while achieving high separation efficiency for organic acids in acidic environments
Solution Approach 2:
The patent replaces the mechanical/thermal system of distillation with an electrochemical system. Instead of using heat to drive phase change and separation, the system applies electrical potential to drive ion transport through selective membranes, achieving separation more cost-effectively without requiring phase transition
2Manufacturing precision
If conventional separation methods are used in acidic environments, then separation can be performed, but they are largely unsuitable and particularly poorly suited for separating organic acids
Solution Approach 1:
The patent introduces selective ion exchange membranes and ion exchange resin wafers as intermediary components that are specifically suited for acidic environments. These intermediaries enable the separation process to function reliably in acidic conditions by providing selective ion transport pathways that maintain stability and effectiveness in the acidic medium
Solution Approach 2:
The patent employs composite materials including ion exchange membranes and ion exchange resin wafers that are specifically designed for acidic environment stability. The combination of these materials provides both the necessary chemical stability in acid and the selective separation capability, making the system reliable for separating organic acids in acidic conditions
3Manufacturing precision
If propionate-selective ion exchange resin wafers are added to the electrodeionization system, then propionic acid separation is enhanced, but device complexity increases
Solution Approach 1:
The patent segments the separation function by adding discrete propionate-selective ion exchange resin wafers into specific compartments of the electrodeionization system. This segmentation allows the system to target specific ions (propionate) for enhanced removal while maintaining the overall structure of the existing electrodeionization apparatus, thus improving separation precision without excessive complexity
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
Effectively separates propionic acid from acetic acid, producing a purified acetic acid stream with reduced propionic acid concentration, while being stable in acidic conditions and cost-effective compared to existing methods.
Implementation Method 1
at least one propionate-selective ion exchange resin wafer located transverse to the fluid flow within the feed stream passage
Implementation Method 2
three spaced apart membranes located between the anode and the cathode and comprising a first cation exchange membrane, a first anion exchange membrane, and a second cation exchange membrane
Implementation Method 3
electrodeionization of liquid streams
Implementation Method 4
providing an electric potential across the anode and the cathode
Data Source
AI summary
Electrodeionization apparatuses, systems including a reactor system and an electrodeionization system, and methods of purifying acetic acid are provided herein. In some embodiments, the electrodeionization apparatus includes an anode, and three spaced apart membranes located between the anode and the cathode: a first cation exchange membrane, a first anion exchange membrane, a second cation exchange membrane, defining: a first electrode rinse passage between the anode and the first cation exchange membrane, a first concentrate passage between the first cation exchange membrane and the first anion exchange membrane, a feed stream passage located between the first anion exchange membrane and the second cation exchange membrane, and a second electrode rinse passage between the second cation exchange membrane and the cathode. In some embodiments, the electrodeionization apparatus also includes at least one propionate-selective ion exchange resin wafer within the feed stream passage.