Electrochemical Cell Stack Cover Isolates Cathode
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Solution Overview
Problem
Existing electrochemical cell stacks immersed in reactor tanks face issues with cathode poisoning and secondary pollution due to intermediary reagents formed during wastewater treatment, which can reverse the oxidation process and cause piping corrosion from residual sodium chloride.
Innovation Solution
The implementation of a stack of electrochemical cells with a cover that isolates either the anode or cathode from the bulk solution in the reactor tank, using a non-conductive material for the cover and employing a solid polymer electrolyte membrane with open pore meshes and compression frames to maintain effective pollutant removal while preventing cathode poisoning and corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If both anode and cathode are exposed to wastewater in the reactor tank, then the system structure is simple, but the cathode catalyst gets poisoned by intermediary reagents and the oxidation process is reversed
Solution Approach 1:
The reactor is segmented into two distinct chambers: an anode chamber exposed to wastewater and a cathode chamber isolated from wastewater. This segmentation prevents cathode catalyst poisoning while maintaining system functionality through separate treatment zones.
Solution Approach 2:
An intermediary membrane structure with ion-exchange properties is introduced between the anode and cathode chambers. This membrane allows selective ion transport while physically isolating the cathode from harmful intermediary reagents in the wastewater, preventing catalyst deactivation.
2Ease of operation
If both anode and cathode are exposed to wastewater, then the system is simple to operate, but residual sodium chloride causes piping corrosion
Solution Approach 1:
The system is divided into separate anode and cathode chambers, allowing independent management of chemical environments. This enables controlled removal of sodium chloride in the cathode chamber without exposing corrosion-sensitive piping to high concentrations.
Solution Approach 2:
The ion-exchange membrane acts as an intermediary that selectively transports ions while blocking the passage of harmful intermediary reagents and controlling sodium chloride distribution, thereby protecting downstream piping from corrosion.
3Device complexity
If intermediary reagents are allowed to contact the cathode, then the oxidation process can be reversed, but the system structure remains simple
Solution Approach 1:
The reactor is divided into separate anode and cathode chambers to prevent intermediary reagents from reaching the cathode. This segmentation maintains high pollutant removal rates by preventing reverse reduction reactions while keeping the overall system structure manageable.
Solution Approach 2:
The membrane structure serves as an intermediary barrier that selectively permits ion transport necessary for electrochemical reactions while blocking harmful intermediary reagents, thereby maintaining high productivity without requiring complex multi-component systems.
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 configuration enhances pollutant removal rates, reduces operational costs, and minimizes the risk of cathode poisoning and piping corrosion, allowing for efficient and sustainable wastewater treatment with improved system performance.
Implementation Method 1
an electrochemical cell comprising a solid polymer electrolyte membrane, an anode catalyst layer adjacent to a first side of the solid polymer electrolyte membrane and a cathode catalyst layer adjacent to a second side of the solid polymer electrolyte membrane
Implementation Method 2
Electrochemical oxidation is efficient in eliminating a wide range of pollutants such as persistent organic pollutants, dioxins, nitrogen species (e.g. ammonia), pharmaceuticals, pathogens, microorganisms and a majority of priority pollutants and pesticides
Implementation Method 3
The system comprises an electrolytic cell comprising a cathode with a cathode gas diffusion layer and a cathode catalyst layer, an anode with an anode diffusion layer and an anode catalyst layer
Data Source
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AI summary
A stack of electrochemical cells for wastewater treatment is disclosed comprising at least one electrochemical cell having a solid polymer membrane, an anode catalyst layer and a cathode catalyst layer adjacent to each side of the membrane, an open pore mesh placed next to each of the catalyst layers and a compression frame placed next to each open pore mesh. A cover is placed between the compression frames of two neighbouring electrochemical cells in the stack thereby forming an enclosure which spans the distance between the two neighbouring electrochemical cells thereby isolating the cathode catalyst layer or the anode catalyst layer from the solution in the reactor tank in which the stack is immersed.