Cryogenic electrolyzers
With their ability to produce emissions-free hydrogen, electrolyzers are hailed as the future of green energy, but there are still some high costs and risk associated with the catalytic and membrane elements used in traditional electrolyzer configurations. A new cryogenic electrolyzer developed by Clean Power Hydrogen Group Ltd. (CPH2; Doncaster, U.K.; www.cph2.com) has eliminated the need for catalysts and membranes in the production of hydrogen. The CPH2 system starts with a mixed gas stream that is cryogenically separated. “We make use of a highly efficient heat exchanger to recover the cold energy invested in the distillation of the oxygen from the mixed gas stream, and it is this process that renders the separation highly efficient,” explains Nigel Williamson, CPH2 technology director. He also notes that CPH2’s system adds safety benefits when compared to membrane-based systems, since membrane failure can lead to undetected mixing of gases, potentially resulting in catastrophic ignition. CPH2 has designed its systems for two hydrogen-purity output standards: 99.5% H 2 for standard applications; and 99.999% H 2 for fuel-cell applications. “Our gas leaves the system at 34 bars pressure, or, alternatively, may go on further down the Kelvin scale for liquefaction of the hydrogen. This makes our system highly cost-effective and efficient in such cryogenic storage and transportation applications,” says Williamson.
So far, CPH2 has built small-scale proof-of-concept systems, but the company is currently manufacturing its first commercial-scale units for its joint venture with B9 Energy, which will implement green-hydrogen projects in Northern Ireland. “The technology is designed specifically for scalability and simplicity of construction. We are discussing the establishment of manufacturing plants in Australia, South Africa, Northern Ireland and Scotland, with a view to address the significant growth required to meet demand for the future,” adds Williamson. The company is currently developing robotic-assembly capacity to improve manufacturing scaleup, while also working to further improve system efficiency and reduce costs.