The start-up PMR Tech, founded in 2019, produces electrolyzers for a very specific niche. The WSG ONE from the Bochum-based team is a mini-electrolyzer that generates hydrogen as a plug-and-play solution for industrial customers. Company founder Phillip Reisenberg explains in this interview how it works and what makes on-site electrolysis so economically attractive.
Metalverse: Mr. Reisenberg, what problem are you addressing with PMR Tech?
Phillip Reisenberg: We want to make industrial processes more economical and climate-friendly where electrification is not possible and no hydrogen network is within reach. Our customers use oxy-fuel technology in industrial manufacturing. They use fossil fuel gases such as natural gas, acetylene, or propane in combination with pure oxygen for soldering, glass processing, or steel cutting. Many want to reduce emissions and costs. Direct electrification is usually the best solution here. But where it’s not possible, our WSG One comes into play. It generates a highly combustible hydrogen-oxygen mixture directly at the customer’s site and replaces, for example, the propane cylinder on-site.
Metalverse: What technology do your electrolyzers use?
Reisenberg: We use a classic alkaline bipolar electrolysis process. What sets us apart from the crowd is the size. The trend in the industry is “bigger, faster, further” – many hardly start below 1 MW; numerous plants are already growing into the GW range. We, on the other hand, build smaller systems starting at 20 kW. This power corresponds to a standard 32-ampere three-phase socket. There are also 63- and 125-ampere three-phase sockets, for which we are developing 40 and 80-kilowatt systems.
Metalverse: So these are plug-and-play electrolyzers that you can connect like an oven?
Reisenberg: Sort of – we also talk about an “onsite, on-demand” solution: electrolyzer and power electronics are added, while safety technology, process engineering, and gas treatment remain identical. The second difference from many other solutions is that we don’t produce pure hydrogen, but rather a mixture of hydrogen and oxygen.
Metalverse: So your hydrogen cannot be used in a fuel cell then.
Reisenberg: Exactly. But due to the high oxygen content, the devices become interesting for many industrial processes. Users of oxy-fuel technology need oxygen anyway: it makes the flame hotter than with pure air. That’s why they currently purchase oxygen in addition to the fuel gas – our electrolyzer delivers both in one.
Metalverse: What mixing ratio?
Reisenberg: We always have a stoichiometric mixing ratio – two parts H₂ and one part O₂. This is also a strength: normally, users have to adjust their flame, meaning regulate the ratios of fuel gas and oxygen to obtain a neutral flame. With our solution, they automatically get a neutral flame that doesn’t need further adjustment. This also offers our process significant advantages in heat transfer.
Metalverse: Why exactly?
Reisenberg: Let’s say a natural gas-oxygen mixture that is mixed at the surface has a heat transfer of 1. If you premix the same natural gas-oxygen mixture, the heat transfer improves to about 2. Surface-mixed hydrogen then has about twice the heat transfer value. And when you premix hydrogen and oxygen, as we do, the heat transfer rate doubles again. This is particularly interesting for areas like glass processing because the better heat transfer accelerates the production process. This addresses another problem our customers face: they must work ever more economically and maximize their output.
Metalverse: Does the H₂-O₂ mixture replace the fossil fuel gas, or can it also be mixed with it?
Reisenberg: Both are possible. Often the gas mixture can be used directly. But there are also application scenarios where it’s combined with other fuel gases to achieve certain properties or optimize processes.
Metalverse: How mature is your technology?
Reisenberg: In the flame cutting area, we’ve already conducted extensive tests. Currently, we’re between TRL 6 and TRL 7 (Technology Readiness Level) there. We’re also in contact with several companies in soldering technology and have initial projects in the pipeline. In glass processing, we’re still looking for suitable partners.
Metalverse: What would be the ideal use case for your mini-electrolysis?
Reisenberg: Our ideal customer has a relatively continuous gas demand and uses the flame for as long as possible, ideally in an automated process. Concrete examples include the production of energy-saving lamps, where the glass tube needs to be heated to bend it, or the production of ampoules, syringes, and similar products in the medical field. Another example is automated soldering technology in white goods manufacturing. The economic viability of our solution doesn’t just come from the direct comparison of gas and electricity costs. The customer can also produce more in the same time and thereby becomes more economical.
Metalverse: How is the water supply managed?
Reisenberg: There are three options. We have an internal water tank that lasts approximately one operating day. So you could also manually refill once a day, even during ongoing operation. Alternatively, you can install an external 500- or 1,000-liter tank next to the system. But thirdly, the system can also be connected to a normal water line if you install a reverse osmosis system in between. This demineralizes the water and automatically feeds it to the electrolyzer.
Metalverse: And where does the electricity come from?
Reisenberg: The power supply is relatively unproblematic due to the small size of our systems. We’re not in the MW or GW range where grid capacity becomes difficult. Ultimately, the customer can decide for themselves where they get their electricity from – whether they have a PV system on the roof, buy green electricity, or use conventional electricity from the grid. A switch from grid to green electricity is also possible at any time.
Metalverse: … and thus essentially “gradual decarbonization.”
Reisenberg: Right. The first step is to switch from fossil fuel gases to a hydrogen-based system. Complete “greening” can then occur in a second step when more renewable energies are available. This gradual approach is more realistic than trying to change everything at once.
Metalverse: When do you want to bring your electrolyzer to market?
Reisenberg: Our goal is to come to market this year. We’re currently conducting tests with pilot customers. We usually drive to them, connect the WSG One, and let it run for a day. We’ve already fulfilled a large part of the requirements for market readiness – operating instructions, risk analysis, technical documentation, pressure vessel testing, etc.
Metalverse: And until then, you’re optimizing the product?
Reisenberg: Yes. Unlike large electrolyzers, where every percentage point of efficiency improvement is crucial, in our use cases it’s more about on-site process optimization. And we learn something new with each test run. For example, one customer requested that the invisible hydrogen flame be more recognizable. We’re currently working on that – one option would be to add a minimal amount of propane or bio-ethanol vapor. At the same time, we’re discovering new application areas for the WSG One. We’re currently looking more closely at the industrial furnace sector.
Metalverse: In what way?
Reisenberg: About 70% of industrially used energy in Germany is burned in the form of natural gas in furnaces. We’ve already planned initial projects to investigate how adding our hydrogen-oxygen mixture to natural gas affects things. You can start with small steps and gradually increase the hydrogen content. However, numerous institutes, universities, and large corporations are already researching in this area. For PMR Tech, this is not currently our core area – we’re focusing on oxy-fuel technology, where we can quickly achieve market readiness.
Metalverse: Is it actually more important for your customers to save CO₂ or to work more energy-efficiently?
Reisenberg: Originally, I was convinced that marketing had to be purely economically argued. Meanwhile, however, I’ve found that many companies are willing to invest just for decarbonization alone. Some don’t even expect a green solution to be more economical than a fossil one! The sustainability aspect could become even more important due to rising prices for CO₂ certificates, but that’s more of a regulatory question.
Metalverse: How did the development of the WSG One come about?
Reisenberg: In a conversation with my brother, I learned that during World War II, water was injected into aircraft engines to briefly increase their performance through the cooling effect. This got me thinking: you need oxygen for any combustion, hydrogen burns – shouldn’t water be able to burn too? After a quick search, I knew that water electrolysis is the process by which we “make water burn.” I was so fascinated by this that I immediately went to the hardware store and tried to build a small electrolyzer – that was the beginning of the WSG One. Since then, the topic hasn’t let me go. Thanks to a scholarship and a funding commitment, the garage project became a company. At some point, we moved into the Energy Efficiency Center Bochum, and last December we were able to move into an even larger workshop.
Metalverse: What are your further plans?
Reisenberg: In 2025, we want to bring our product to market, and at the end of this year or the beginning of next year, we’re planning another financing round. The new coalition agreement and the prospect of increased investment in the hydrogen sector are currently creating a better environment for hydrogen technology again. Recent years have shown that this can also change quickly again. We’re therefore focusing above all on our customers and their needs.
