A technology that can desalinate water , capture CO2, recover raw materials and even generate renewable energy. The Frisian scale-up REDstack came up with a revolutionary solution to major environmental problems and aims to be an essential link to a fully circular and carbon-neutral economy. And with a new investment from Pure Terra Ventures, the NOM and Easter Technology, the company will further scale up and accelerate its production in the coming year.
REDstack is a spin-off of knowledge institute Wetsus, the European knowledge center for sustainable water technology in Leeuwarden. It was there that the foundations were laid for the technology. RED stands for Reverse Electrodialysis, a technique in which salt and fresh water are mixed with special stacked membranes. Stacks, in other words. 'The last real breakthrough in this technique was 70 years ago, when the original ED stack was invented. The first concept of electrodialysis (ED) was applied in the 1950s and the first Electrodialysis Reversal (EDR) stack was invented in the 1970s,' said Paula Gonzalez, CEO of REDstack.
'And our team has provided another breakthrough in EDR stack technology 4.0,' Gonzalez continued. 'And that is to design and produce electromembrane stacks that can achieve 100% chemical recovery, consume three times less electricity, last much longer and are also completely leak-proof. And that allows this technology to now be very cost-effective for various applications.
World first
One of the first applications was to use the fresh and salt water to generate blue energy, which REDstack already had a world first in 2014 in the form of a pilot plant on the Afsluitdijk. "That plant runs for another two years, but we're not yet at a point with the technology where blue energy can be produced on the same scale as wind or solar energy," Gonzalez says. "So that's why we've also been looking at using our technology to solve other problems.
As an example, Gonzalez cites the growing shortage of drinking water. 'Because of climate change and rising sea levels, you get more and more salt intrusion from the sea into groundwater. And because of the heavy rainfall in recent years, rivers are also taking a lot of salts and minerals with them, such as high concentrations of nitrate and silica, which again end up in groundwater. The traditional way of desalinating water is quite expensive and energy-intensive, but we can use our technology to desalinate water in a very sustainable and much cheaper way.'
Solving big problems
'Also, more and more raw materials are running out, so we are relying more and more on secondary raw materials,' Gonzalez continues. 'That means we need to recover those raw materials from waste streams instead of extracting them from the ground. For example, from wastewater or communal wastewater, as we do with nitrogen and lithium. But that is very energy-intensive and a lot of additional chemicals have to be used to do that properly and you produce more greenhouse gases, such as nitrous oxide (N₂O). Nitrous oxide is a powerful greenhouse gas, much stronger than CO₂. By using bipolar membranes, we can not only desalinate water, but also split it into protons (H⁺) and hydroxide ions (OH-). That means we can also recover chemicals with our stacks. And we can also capture things with them, so carbon capture is also among the possibilities'.
For all such applications, REDstack works with Wetsus. 'They were of course already at the basis of what we do, but we still work together intensively and we make grateful use of their research,' Gonzalez says. 'And that has also allowed us to position ourselves much better as a company. We are experts in electrodialysis and produce "core" technology, just like Intel does for laptops, for example. And we thereby help companies that are looking for ways to capture CO2 or recover lithium, for example. Or companies that use a lot of water, for example, and want to use it more efficiently, such as a paper manufacturer or chemical company.
Lessons learned
That way of positioning is also one of the most important lessons they learned as a company, according to Gonzalez. REDstack initially started with a technology to generate blue energy, but we had yet to find a customer with an urgent problem who was willing to pay for our technology. Now we target existing urgent problems with a cost-effective technology that solves their problems. As a company, we want to make the world a better place, and this way we can do that much more effectively.'
Investment
To further scale up production, REDstack brought Pure Terra Ventures and Easter Technology on board. NOM also joined this investment round. 'We find it important to strengthen innovative companies that drive impactful transitions in sustainable and smart technologies,' said Sjouke Mulder, investment manager Green Chemistry.
'And given the technological advances, the updated proposition and the team behind it, it was also a great time for NOM to join this investment round.
'The progressive technology fits perfectly with NOM's mission,' Mulder continued. 'With their recent establishment in Heerenveen and the strong connection with Wetsus in Leeuwarden, they emphasize the importance of cooperation for sustainable growth in the Northern Netherlands.'
Scaling up
In the coming year, REDstack will work hard to increase production of the stacks in Heerenveen from 1 to 10 per week. 'We will do this by automating the production process, which will make it easy to scale up with the expected growth in sales,' Gonzalez says. 'We want to make at least 500 stacks a year with one shift. With automated production, you can easily decide to work in two or three shifts as needed. But also a modular product with one standard size makes it possible. Right now it's a lot of work to get everything just right, but we expect to be ready for large-scale production by March of next year. In any case, we expect demand to grow quickly and we are proud that we can contribute to a better world in this way. After all, it's all about purpose and technology coming together.'