Electrolysis Device Catholyte Circuit Hydrogen Separation

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Solution Overview

Problem

Existing devices for electrolysis of aqueous alkali metal chloride solutions face issues with the formation of secondary components like chloride ions and chlorates, which reduce the quality of the disinfectant solution, and instability due to fluctuations in mineral content and chemical composition, leading to reduced sporicidal activity and increased maintenance needs.

Innovation Solution

The device incorporates a catholyte circuit with a circulation pump and overflow device, a cooled moisture separator, and a specific arrangement of components to enhance circulation and separation of hydrogen, reducing the concentration of sodium ions and chlorates, and includes a system for quick stabilization of operating parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If continuous liquid conversion of starting materials is used in the electrolysis process, then the production of disinfectant solution is maintained, but secondary components like sodium chloride and chlorates accumulate reducing product quality

Engineering Contradiction:
Improveproduction of disinfectant solutionVSAvoidquality of disinfectant solution
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent extracts and removes secondary components (sodium chloride, chlorates) from the electrolysis process by implementing separate circulation circuits for anolyte and catholyte, with the catholyte circuit selectively removing cations through ion-exchange resins, thereby preventing their accumulation in the final disinfectant product

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The electrolysis system is segmented into separate anolyte and catholyte circulation circuits with independent control mechanisms. The catholyte circuit includes ion-exchange columns that selectively remove specific ions, allowing precise control over product composition while maintaining continuous production

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a shared catholyte circulation vessel is used for main and auxiliary electrolysis units, then system complexity is reduced, but operating parameters become unstable due to spontaneous changes in mineral content

Engineering Contradiction:
Improvecatholyte circulation systemVSAvoidoperating parameters stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The catholyte circulation system is divided into separate circuits for main and auxiliary electrolysis units, each with its own ion-exchange columns and control mechanisms. This segmentation allows independent stabilization of operating parameters for each unit, preventing the instability that would arise from a shared vessel

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements feedback control through pH sensors and flow meters that continuously monitor operating parameters and automatically adjust the circulation rates and ion-exchange processes to maintain stable conditions despite variations in mineral content

Inventive Principle:
Principle #23Feedback

3Productivity

If divalent metal cations migrate from cathode to anode compartments, then the electrolysis process continues, but the sporicidal activity of the disinfectant is reduced

Engineering Contradiction:
Improveelectrolysis process continuityVSAvoidsporicidal activity of disinfectant
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent removes divalent metal cations from the system by implementing cation-exchange columns in the catholyte circuit that selectively capture these ions before they can migrate to the anode compartment, thereby preserving the sporicidal activity of the produced disinfectant while maintaining continuous electrolysis operation

Inventive Principle:
Principle #2Taking out (Extraction)

4Quantity of substance

If cation hydroxides are deposited in diaphragm pores due to reciprocal transmembrane interaction, then ion exchange occurs, but the system requires periodic cleaning increasing maintenance needs

Engineering Contradiction:
Improveion exchange efficiencyVSAvoidmaintenance requirements
Core Design Contradiction:
Quantity of substanceVSEase of repair

Solution Approach 1:

The patent prevents cation hydroxide deposition in diaphragm pores by extracting cations through ion-exchange columns in the catholyte circuit before they can participate in reciprocal transmembrane interaction, thereby maintaining ion exchange efficiency without requiring periodic cleaning operations

Inventive Principle:
Principle #2Taking out (Extraction)

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 improves the performance and quality of the disinfectant solution by reducing secondary components, stabilizing the system, and increasing the permissible current load, resulting in a more efficient production of oxidizing agents with improved pH control and reduced maintenance requirements.

Implementation Method 1

The catholyte circuit includes a circulation pump with an overflow device for the return of the pumped fluid, which ensures the forced circulation of the catholyte

Methodology Applied
Scientific EffectCirculation: Pump

Implementation Method 2

a heat exchanger for cooling the circulating catholyte

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a capacitive (volume) separator for separating the hydrogen from the catholyte

Methodology Applied
Scientific EffectPhase separation: Phase Change

Implementation Method 4

in the line for the discharge of the hydrogen from the capacitive (volume) separator for the separation of the hydrogen from the catholyte, a cooled moisture separator is arranged

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

Device for the electrolysis of aqueous alkali metal chloride solutions to produce chlorine, chlorine compounds, oxygen, ozone and hydroperoxide compounds

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 6

the differential pressure across the ceramic ultrafiltration diaphragm creates a pressure gradient within the diaphragm's pore space. This gradient ensures ion-selective (ion-sensitive) charge transfer by cations (sodium ions) from the anode compartment to the cathode compartment

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 7

a circulation pump with an overflow device for the return of the pumped fluid

Methodology Applied
Scientific EffectGravity flow: Gravitation

Data Source

PatentEP3673098B1Device for the recovery of products of the electrolysis of an alkali metal chloride solution
Publication Date: 2023.12.06 BLUE SAFETY GMBH
  • EP3673098B1 patent drawingFigure 1
  • EP3673098B1 patent drawingFigure 2

AI summary

The invention relates to a device for the recovery of products of the electrolysis of an alkali metal chloride solution, said device containing an electrochemical reactor that is represented by one or a plurality of modular electrochemical elements (cells) which are hydraulically connected in parallel, wherein the anode chamber and the cathode chamber of the reactor are divided by a porous, tubular, ceramic diaphragm that is arranged coaxially between the electrodes of the modular electrochemical elements (cells), wherein the inlet of the anode chamber is connected to the device for the supply of saline solution under pressure, the outlet being connected to the device for stabilizing the predetermined overpressure in the anode chamber, which is connected to the mixing device for gaseous products of the anodic electrochemical reaction with fresh water current. The cathode chamber of the electrochemical reactor is an integral part of the catholyte circuit which likewise contains a capacitive (volume) separator for the separation of hydrogen from the catholyte, a device for discharging the excess catholyte from the receiving container of the separator and a heat exchanger for cooling the circulating catholyte. According to the invention, the device contains a metering apparatus for the addition of catholyte to the oxidation agent solution for the purpose of regulating the pH value. It is provided according to the invention that a circulating pump with an overflow device for the return flow of the pump liquid is incorporated in the cathode circuit, said circulating pump ensuring the forced circulation of the catholyte continuously via the heat exchanger, the cathode chamber and the capacitive (volume) separator for separating the hydrogen from the catholyte. The receiving container of the separator, which is connected to the pump inlet, is situated lower than the electrochemical reactor, namely in such a way that the level of the catholyte in the receiving container of the separator, which is intended for the discharge of the excess catholyte from the circuit by the position of the connecting piece (extension tube), is located below the inlet connecting piece (the inlet connecting pieces) in the cathode chamber of the electrochemical reactor and that a cooled moisture separator is installed in the discharge of the hydrogen from the capacitive (volume) separator for separating the hydrogen from the catholyte, the condensate collecting container of said moisture separator being connected to the supply line of the fresh water to the mixing device of the fresh water stream with the gaseous oxidation agent mixture via a metering pump.