An Eindhoven company wants to strip carbon dioxide from the air in a layer one atom thick

Carbyon received $1 million in prize money this past April. The startup idea from Eindhoven has been named as one of fifteen promising ideas to reduce CO2₂ to remove from the air. The prize was great for publicity, the XPrize Foundation’s global innovation competitions are prestigious, and tech billionaire Elon Musk funded this edition. But it was also uncomfortable.

The idea has not yet been proven. Far from it,” laughs Hans de Neve, inventor and founder of Carbyon. We’ve been trying to prove it for four years, and nothing works. It was nothing more than a good idea.”

A breakthrough followed two months later with the prize money. And now there has been a demonstration installation in Eindhoven for several weeks. De Neve now dares to say with confidence that his technique is ten times better than CO’s₂ From the outside air of current technologies to Live air capture (DAC). “I think this could form the basis for a whole new generation of DAC technologies.”

viewed with suspicion

co₂ Filtration from outside air is difficult. Of every million particles in the air, only 420 are carbon dioxide₂. It is captured by letting the air flow through filters where the carbon dioxide is₂Particles stick to it. When the filters are filled, they are heated, causing carbon dioxide₂ versions and can be removed. It takes a lot of energy to pass a lot of air and heat the filters – which is a reason many people view these types of technologies with suspicion.

For Elon Musk, it was the high energy consumption (and therefore the high price) that prompted the XPrize organization to organize a competition. Suppose there is a way to generate a lot of carbon dioxide with very little energy₂ In the air, the climate might be salvageable and a host of possibilities would open up. Make cheap green kerosene, for example.

Carbyon technology works almost as well as existing technologies, but faster. It’s in the filter. Carbyon’s adhesive layer is only one atom thick. As a result, it is saturated in a few minutes and discharged again in a few seconds. Other technologies have a thicker adhesive layer, which is carbon dioxide₂ You must penetrate and this takes time. Heating also costs less energy with the Carbyon. The thin layer heats up by activating the filter, while the other layer requires hot steam.

The idea for Thin Layer was born when De Neve was still working at TNO. “I am a semiconductor physicist. At TNO I worked on thin materials for solar panels. They are also applied in single-atom layers. I followed the field of CO₂Capturing has been intently for some time. At a certain point, we thought it might also be possible to filter the material for carbon dioxide₂Capture as thin as thin films on solar panels.”

as much space as possible

I started in 2018 with lab experiments at TNO. “We quickly thought we’d done it,” says de Neve. That’s why I dared to take the step in 2019 to leave TNO and start Carbyon. But when I asked TNO about the latest results after a while, my former colleagues said, ‘Sorry, Hans, the previous results turned out to be incorrect measurements. It doesn’t even work at all.’ Now. That was a difficult moment.”

The difficulty lies in the porous material, which turns out to be more complicated to put an extremely thin layer on than with flat solar panels.

“This porous material is essential because you want to have as large a surface area as possible, and then you can absorb as much carbon dioxide as possible₂ on getting lost. “Because the layer is so thin, it saturates quickly,” says De Neve. Activated carbon is a convenient carrier black powder that the layperson may know as norite. One gram of activated carbon covers an area of ​​3,000 square metres.

I think three quarters of these powders do absolutely nothing

Hans Deneve Carbon

The reactant layer, consisting of amines or potassium carbonate, is applied to the carbon using various processes. atomic layer deposition is the most important of these. “You expose the carrier to the gas and the atoms of that gas settle on the carrier,” says De Neve. “The chemical process is self-limiting, in principle the layer does not become thicker than one atom. This is where it differs from the classical vapor deposition technique.”

“But such a porous carrier material also has a drawback: the holes are only a nanometer wide,” says de Neve. “One nanometer, that’s a few atomic layers. Silt builds up pretty quickly, and that’s been happening all the time. Then the filter won’t work, because the air where the CO₂ in which he cannot pass.”

Four years of trying followed. With different forms of carrier, different adhesive layer materials and different layer application methods. Carbyon does not have an extensive laboratory, so De Neve sought collaborations with TNO and universities in Antwerp, Eindhoven and Twente.

nothing at all

“A lot of work is being done in universities Live air captureand more to CO₂ Capture in flue gases. The general picture is still that DAC is useless, and I was told that on all sides when I started this,” says Di Neve. So we mainly work with researchers in thin-film technology or a particular chemistry. We went to collect puzzle pieces from different universities.” .

At Carbyon itself, there are two test setups for filter material testing. Both are one meter by one meter and two meters high. Behind a glass door, you can see all kinds of boxes connected to each other and to the mass spectrometer via tubes wrapped in plastids. A lot of wires go to the gauges. Air is supplied from the bottles to control composition, temperature and humidity. On a table beside him, two boxes filled with a jar of black powder, and all variants of filter material.

“Here we send air through the filter material and then use a mass spectrometer to see what happened to the air. How much CO₂ De Neve says. “I think three-quarters of these powders do absolutely nothing. There are only a few of them.”

Further filter to 100 percent of carbon dioxide₂ Others can do very well

Hans Deneve Carbon

If the filter material passes, the mass spectrometer displays an S-shaped graph. The air will be free of carbon dioxide for a short while₂ It should be, and when the filter is full, it fires back up. “But we’ve never seen it look like this,” says de Neve. “Keep trying, I kept saying. The day we saw exact demand was really cool, I still remember that phone call I got from the lab. We actually improved the score five times, but that first time was really a goosebumps moment.”

Now the demonstrative installation shines in another room. It was delivered at the beginning of April. The thick tubes work outside, but they work with outside air. Not yet operational, a colleague of De Neve’s is working abroad. The size of the reactor core is 30 x 30 x 30 cm. It takes from 1 to 3 kilograms of filter material. The block can be seen in the foreground with the energy source to heat the filter material after saturation to remove carbon dioxide₂ to take out.

This relatively small thing should be producing 2 tons of CO2 per year₂ It will be removed, with (sustainably generated) energy consumption of 2,500 to 3,000 kilowatt-hours per tonne. (Compare: A passenger car emits 3.3 tons of carbon dioxide₂ annually and ten solar panels generating about 3,000 kWh per year in the Netherlands). “If we can prove that this works, then we’ve completely proven the original idea from 2018,” says De Neve.

The gas that leaves the facility consists of 60 to 70 percent carbon dioxide₂The rest is water, nitrogen and oxygen. “Then we came from a concentration of 0.04 percent,” De Neve says. “This is really the hardest step. Keep filtering to 100 percent carbon monoxide₂ Others can do very well. We’re focused on getting it out of thin air.”

We are aiming for a cost price of $50 per ton of CO2₂

Hans Deneve Carbon

The final installation that De Neve has in mind is many times larger. “It consists of 20 of these types of units next to each other and on top of each other. A pole 2 or 3 meters in diameter and 5 or 6 meters high. We go for units like this and not one big reactor because everything has to go fast. If you make it big, The inertia of the mechanical parts will hinder the speed.”

In terms of collection capacity, such a large installation is close to other major players in the field Live air capture It is possible now. Swiss company Climeworks will commission an installation in Iceland in 2021 with a capacity of 4,000 tons per year. A new installation with a capacity of 36,000 tons per year is being prepared.

Cost is crucial

“If we built a facility of a similar size to Climeworks’ current installation, we could hold 40,000 tons,” says Di Neve. “The cost of installation will be about the same, so our cost is about 10 times lower. Ultimately, we are aiming for a cost price of $50 per ton of CO2.”₂. “

This cost is crucial. co₂ From the air it could serve as a raw material for sustainable kerosene, for example, but that only happens if it is available simply and inexpensively. The airline industry is very interested in this Live air capture. CO availability₂ It remains the bottleneck for making sustainable kerosene,” says De Neve. “As long as it’s $500 a ton, no one is going to make it from the fuel. If it can be done for $100, it can be done.”

If it was just yanked out of the air with great effort, it would happily fly back into the air. Why CO₂ Don’t store underground, as Climeworks does in Iceland? “Of course we’re doing it to save the climate, not to support the airline industry,” says de Neve. But the first step is to replace fossil fuels with circular ones. You can’t fly across the ocean with batteries, and people will keep flying. Once you replace fossil fuels, you can use carbon dioxide₂ Storage and hopefully the share of carbon dioxide₂ Back to the air. I always say: the tap must first be closed, and only then it makes sense to start wiping. “