Alkaline Electrolyser with Cryogenic Distillation for Hydrogen Purity
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Solution Overview
Problem
Current hydrogen gas generation systems, particularly those based on PEM technology, face high capital and maintenance costs, low conversion efficiency, short system life expectancy, and reliability issues, making them expensive and wasteful, especially when scaling up for large-scale infrastructure projects like Hydrogen Highways.
Innovation Solution
The system employs multiple small alkaline electrolysis stacks mass-produced by molding, which are modular and scalable, using cryogenic distillation to separate and purify hydrogen from a stoichiometric mixture of hydrogen and oxygen, reducing costs and improving efficiency by using alternative drying methods like pressure swing adsorption or molecular sieves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PEM-based electrolysers are used for hydrogen generation, then hydrogen production capability is improved, but capital cost and maintenance cost increase significantly
Solution Approach 1:
The patent replaces expensive PEM electrolysers with cheaper alkaline electrolysers that can be mass-produced using molded plastic components. The electrolyser cells use inexpensive materials including plastic housings, rubber gaskets, and standard electrical components, making them significantly cheaper to manufacture while maintaining adequate service life for the application
2Productivity
If PEM-based electrolysers are used for hydrogen generation, then hydrogen production capability is improved, but system reliability deteriorates due to membrane failure and leakage
Solution Approach 1:
The patent uses simpler alkaline electrolyser technology with no fragile membranes, relying instead on robust plastic housings and rubber seals that are more reliable and easier to replace if needed
Solution Approach 2:
The patent changes the electrolyte from the membrane-based system to an aqueous potassium hydroxide solution, fundamentally altering the chemical environment to eliminate membrane-related failures while maintaining electrolysis functionality
3Manufacturing precision
If palladium filters and compressors are used for hydrogen purification and storage, then hydrogen purity is improved, but product gas loss increases due to purge requirements and seal leakage
Solution Approach 1:
The patent uses cryogenic distillation which exploits the different boiling points of oxygen and hydrogen at low temperatures to achieve separation without the gas losses associated with palladium filter purges and compressor seal leaks
Solution Approach 2:
The patent replaces mechanical compression and palladium filtration with a thermal separation process using cryogenic distillation, eliminating the seal leakage and purge losses inherent in mechanical systems
4Productivity
If PEM-based systems are scaled up for infrastructure projects, then hydrogen generation capacity is improved, but system complexity and maintenance requirements increase
Solution Approach 1:
The patent divides the system into modular electrolyser stacks that can be easily assembled and scaled, with each stack being a self-contained unit that simplifies installation and maintenance while allowing flexible capacity expansion
Solution Approach 2:
The patent adopts alkaline electrolysis technology with aqueous electrolyte and simple plastic-molded components, fundamentally changing the system architecture from complex membrane-based PEM technology to a simpler, more maintainable design suitable for large-scale deployment
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 approach significantly lowers capital and maintenance costs, achieves high hydrogen purity, and makes the system infinitely scalable, with costs comparable to or below hydrocarbon fuels, while maintaining reliability and reducing waste.
Implementation Method 1
an electrolysis reactor stack adapted to perform electrolysis on an electrolyte solution and generate a mixture of electrolyte solution and oxygen and hydrogen gas
Implementation Method 2
a drying system configured to receive the mixture of oxygen and hydrogen gas and remove water from the gaseous mixture
Implementation Method 3
the gas enters a cryogenic system wherein it is primarily dried by distillation of the molecular water
Implementation Method 4
a gas separation system configured to expose the dried gas mixture to cryogenic temperatures to distil the oxygen out of the mixture as non-gaseous oxygen to leave purified hydrogen gas
Implementation Method 5
exposing the dried gas mixture to cryogenic temperatures
Data Source
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AI summary
A hydrogen gas generator system comprises an electrolysis reactor stack adapted to perform electrolysis on an electrolyte solution and generate a mixture of electrolyte solution and oxygen and hydrogen gas, a separator configured to receive from the reactor stack the mixture of electrolyte solution and oxygen and hydrogen gas, and separate the oxygen and hydrogen gas mixture from the electrolyte solution, and a drying system configured to receive the mixture of oxygen and hydrogen gas and remove water and impurities contained within the water from the mixture of gasses. A gas separation system is configured to expose the at least partially dried gas mixture to cryogenic temperatures to distil the oxygen out of the mixture as non-gaseous oxygen to leave purified hydrogen gas, and a storage system is provided for storing the purified hydrogen as a gas or a liquid.