Porous Electrode Bipolar Electrolyzer for Hydrogen Purity
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Solution Overview
Problem
Alkaline water electrolysis systems face efficiency and purity issues during high current density operations due to fluctuations in renewable energy sources, leading to increased electric power consumption and reduced hydrogen purity.
Innovation Solution
A bipolar electrolyzer design with porous electrodes and membranes optimized by controlling the average pore size and primary grain size of inorganic particles within specific ranges, along with a zero-gap structure, to maintain electrolysis efficiency and gas purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional alkaline water electrolysis device is used, then it can perform water electrolysis, but when current density increases due to renewable energy fluctuations, the conversion efficiency and hydrogen purity significantly deteriorate
Solution Approach 1:
The patent employs porous electrodes with optimized pore size distribution and porous membranes with controlled porosity to enable efficient gas bubble escape while maintaining high current density operation. The porous structure prevents gas accumulation that would otherwise increase bath voltage and reduce efficiency, allowing the system to maintain both high productivity and reliability under variable renewable energy input.
Solution Approach 2:
The patent optimizes critical parameters including electrode pore size (1-10 μm), membrane porosity (30-70%), and inter-electrode spacing to achieve optimal performance. By carefully controlling these parameters, the system maintains low bath voltage and high gas purity even at elevated current densities, resolving the contradiction between productivity and reliability.
2Use of energy by moving object
If the current density per electrolysis cell unit area increases to accommodate large renewable energy supply, then the electric power consumption rate improves, but the conversion efficiency and hydrogen purity significantly deteriorate
Solution Approach 1:
The porous electrode and membrane structure facilitates rapid gas bubble removal even at high current densities, preventing gas accumulation that would compromise hydrogen purity. The optimized pore architecture ensures that increased power consumption does not lead to contamination, maintaining manufacturing precision while improving energy utilization.
Solution Approach 2:
The patent employs multiple electrolysis cells with identical optimized porous structures arranged in series or parallel configurations. This standardized design ensures consistent performance across all cells, maintaining hydrogen purity standards while collectively handling large renewable energy supplies through scaled-up capacity rather than compromised individual cell performance.
3Loss of energy
If a zero-gap structure is used to suppress bath voltage, then electric power consumption improves, but gas accumulation near electrodes increases without proper pore size control
Solution Approach 1:
The zero-gap structure combines with optimized porous electrodes and membranes to create a system where gas bubbles can escape through the porous matrix without requiring additional spacing. The porous structure provides continuous gas escape pathways that prevent accumulation near the electrode-membrane interface, allowing the zero-gap configuration to suppress bath voltage effectively without the harmful side effect of gas trapping.
Solution Approach 2:
The porous membrane acts as an intermediary between the electrode and the bulk electrolyte, providing a controlled interface for gas bubble release. This intermediary structure with optimized porosity allows gas to transition from the electrode surface into the bulk solution without creating accumulation zones, enabling the zero-gap structure to reduce bath voltage while preventing gas-related harmful effects.
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 optimized bipolar electrolyzer maintains superior electrolysis efficiency and higher gas purities even during high current density operations, effectively addressing the challenges of renewable energy fluctuations.
Implementation Method 1
by rapidly escaping the generated gas through the pores of an electrode to the side opposite to the membrane side of the electrode
Implementation Method 2
bipolar electrolyzer for alkaline water electrolysis
Data Source
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AI summary
An object of the present disclosure is to maintain a superior electrolysis efficiency and higher purities of generated gases even during variable power source operations in a bipolar electrolyzer for alkaline water electrolysis using porous membranes containing inorganic particles as membranes. A bipolar electrolyzer for alkaline water electrolysis and a hydrogen production method include a bipolar electrolyzer including a plurality of combinations of an anode, a cathode, and a membrane disposed between the anode and the cathode, wherein the at least one of the anode or the cathode is a porous electrode having an average pore size of 10 nm or more and 200 nm or less, and the membrane is a porous membrane containing inorganic particles having an average primary grain size of 20 nm or more and 300 nm or less.