- Hydrogen technology company Hydrox Holdings is progressing the development of its pioneer Divergent-Electrode-Flow-Through (DEFT) hydrogen technology.
- De Jager claims that the DEFT technology provides an “innovative solution” for using curtailed “free” or “wasted” energy.
Hydrogen technology company Hydrox Holdings is progressing the development of its pioneer Divergent-Electrode-Flow-Through (DEFT) hydrogen technology. This is a membrane-less electrolyser, with the company advocating this as a viable, cost-effective storage solution for curtailed energy.
Developing this patented technology is part of the company’s efforts to bring down the cost of hydrogen and make the hydrogen economy viable.
Hydrox CEO Corrie de Jager noted that Hydrox is building a prototype demonstration unit of the technology, which is expected to be completed within the next three to four months.
It will then scale up the solution, before conducting rigorous testing by running it for about 2,000 continuous hours and applying for the requisite certification. It anticipates completing these steps within a year, after which commercialisation will start.
Initial funding was provided by the chemicals company Shell; however, development of the technology was temporarily halted in 2022 owing to challenges in securing additional funding required for further work.
De Jager expresses frustration in obtaining development funding, noting that venture capital funds and even entities like the Industrial Development Corporation are “risk-averse” and require bankable projects with fixed returns on investments. This makes it difficult for the company, which is still in the development phase, to leverage these funding mechanisms.
However, he expects that more funding opportunities may arise once the demonstration model is complete.
De Jager claims that the DEFT technology provides an “innovative solution” for using curtailed “free” or “wasted” energy.
He points out that there is a proliferation of renewable energy globally, but the electricity transmission networks are congested and cannot accommodate this volume. Building new transmission lines will take time, while other storage solutions are costly and/or ineffective.
University of Johannesburg (UJ) Department of Mechanical Engineering and the Built Environment’s Professor Tien-Chien Jen, who also partook in the interview, says that this challenge is especially prevalent in the global south, which is less industrialised, leading to energy generated from burgeoning renewable-energy sources being wasted. Jen acclaims, therefore, that hydrogen can play a significant role in the region for energy storage and transport.
However, the cost of electrolysers is very high, with De Jager estimating costs for a high-quality proton exchange membrane (PEM) electrolyser at about $2-million for a 1 MW unit. Moreover, these PEM electrolysers also have “serious maintenance issues”, which compounds the costs.
He explains that PEMs are more energy efficient than alkaline electrolysers; however, the latter are more robust.
The DEFT technology uses an alkaline system but it is unique in that the company’s technology has eliminated the need for a membrane, a core component, which delivers costs savings and considerable potential, De Jager says.
Moreover, this technology requires less maintenance and removes the risk of the membrane being compromised and the plant coming to a standstill.
De Jager says the technology is most suitable for curtailed energy, as only one compact unit can operate at high current densities, delivering huge volumes of hydrogen, considerably reducing the capital cost.
He explains that the cost of hydrogen production in general is determined by two factors: the cost of electricity (about 75%) and the cost of an electrolyser, its maintenance and replacement (about 25%).
De Jager explains that the technology can be used for curtailed energy because the simplicity of the membrane-less system and its unique flow-through operation means that it is capable of handling extreme current densities.
He points out that other electrolysers are limited in their current densities because of the formation of bubbles and the brittleness of the membrane. “The more bubbles there are, the more activity on the two electrodes, and the more the membrane can be affected, potentially causing it to crack or erode.”
De Jager explains that the company’s high current density tests achieved 20 A/cm2, which is 30 times better than the current available alkaline electrolysers.