Bipolar Membrane Electrodialysis for On-Site Cleaning Solution Generation
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Solution Overview
Problem
Existing chemical cleaning solutions for filtration systems, such as hydrochloric acid, sodium hydroxide, and free chlorine, pose safety hazards and logistical challenges due to their concentrated form, making them unsuitable for decentralized water treatment systems in remote areas with strict environmental regulations.
Innovation Solution
A bipolar membrane electrodialysis device generates hydrochloric acid, alkali hydroxide, and free chlorine from benign starting solutions on-site, using a configuration of anode, cathode, and intermediate compartments with specific membranes, allowing ion transfer and electrolysis to produce these solutions without the need for transport or storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If concentrated cleaning solutions are produced and transported to user sites, then cleaning effectiveness is improved, but safety hazards and storage requirements increase
Solution Approach 1:
The patent applies preliminary action by pre-installing benign precursor solutions (such as sodium chloride solution) at the user site before cleaning is needed. These precursors remain harmless until activated on-demand by applying electricity through the electrodialysis device, which then generates the concentrated cleaning solutions (hydrochloric acid, sodium hydroxide, free chlorine) directly at the point of use, eliminating the need to transport and store dangerous concentrated chemicals while ensuring cleaning effectiveness is achieved when needed.
2Productivity
If concentrated cleaning solutions are stored on-site, then immediate cleaning capability is improved, but environmental permit requirements and storage infrastructure increase
Solution Approach 1:
The system applies self-service by enabling the user site to generate its own concentrated cleaning solutions on-demand from benign precursor solutions using the electrodialysis device. Instead of relying on external delivery of pre-made concentrated chemicals or maintaining complex storage infrastructure, the system produces the necessary cleaning agents (hydrochloric acid, sodium hydroxide, free chlorine) locally when needed by simply applying electricity, thus achieving immediate cleaning capability without storage infrastructure or environmental permit requirements.
3Ease of operation
If multiple cleaning solutions are produced in a single device, then handling requirements are reduced, but device complexity increases
Solution Approach 1:
The electrodialysis device applies universality by being designed to produce multiple different cleaning solutions (hydrochloric acid, sodium hydroxide, and free chlorine) simultaneously within a single integrated device structure. By using a stack of alternating cation-exchange and anion-exchange membranes with bipolar membranes that can be configured in different patterns, the device can generate various cleaning chemistries from the same benign precursor solutions, reducing handling requirements compared to multiple separate devices while the membrane configuration provides the necessary functional 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
The device is compact, lightweight, and flexible, enabling in-situ generation of cleaning solutions as needed, reducing safety risks and environmental discharge, and adhering to regulatory requirements by avoiding the handling and storage of concentrated chemicals.
Implementation Method 1
The stack of membranes comprises an outer cation-exchange membrane, and one or more repeating units respectively comprising a sequence of a bipolar membrane, an anion-exchange membrane, and a cation-exchange membrane
Implementation Method 2
The bipolar membrane electrodialysis device is configured to receive the chloride salt solution feed within the anode compartment and within the intermediate compartment between the anion-exchange membrane and the cation-exchange membrane
Implementation Method 3
The bipolar membrane electrodialysis device is configured to generate the hydrochloric acid solution, the alkali hydroxide solution, and the free chlorine from the chloride salt solution feed and the water feed
Implementation Method 4
The free chlorine generated by the bipolar membrane electrodialysis device refers to an active form of chlorine that is capable of disinfection such as, for example, chlorine gas, Cl2
Data Source
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AI summary
Example embodiments relate to a bipolar membrane electrodialysis device (100) for generating a hydrochloric acid solution (133), an alkali hydroxide solution (132, 134), and free chlorine (131) from a chloride salt solution feed (135, 138) and a water feed (136, 137, 139); the bipolar membrane electrodialysis device comprising an anode compartment (101) comprising an anode (106); a cathode compartment (105) comprising a cathode (107); and intermediate compartments (102 - 104) separated by a stack of membranes (110, 121, 122, 123) arranged in series between the anode compartment and the cathode compartment. The stack of membranes comprises an outer cation-exchange membrane (110), and one or more repeating units (120) respectively comprising a sequence of a bipolar membrane (121), an anion-exchange membrane (122), and a cation-exchange membrane (123); and wherein the bipolar membrane electrodialysis device is configured to: receive the chloride salt solution feed (135, 138) within the anode compartment (101) and within the intermediate compartment (104) between the anion-exchange membrane and the cation-exchange membrane of the one or more repeating units (120); and receive the water feed (136, 137, 139) within the other intermediate compartments (102, 103) and the cathode compartment (105).