//next Best Things

Silicate: "We are removing CO2 from the air and locking it away"

It's getting warmer on our planet. Sustainable Start-ups have dedicated themselves to pulling CO2 and other greenhouse gases out of the air to slow down this trend. After Reverse Carbon and Treeconomy, we now present Silicate as the third part of our new article series: This Irish start-up uses "enhanced weathering" to capture CO2. An innovative approach that //next columnist Markus Sekulla wanted to know more about from co-founder Maurice Bryson.

Professor Frank McDermott (University College Dublin, left) and Maurice Bryson, founder of Silicate

Markus: Hello Maurice! Who are you, what does Silicate do, how many people work for you, and where are your people based?

Maurice: Hi Markus, thank you for having us. We are an enhanced weathering company based in Ireland. We take returned concrete, this is concrete that has gone to a building site and was surplus to requirements because they've over ordered, or there's just too much concrete in the truck, and turn it into a carbon removal solution through processing the material and working with farmers to apply it to their fields. You're looking at anywhere between 2 and 5% of all concrete produced is returned. 

This material is amazing for removing carbon and this is what we do. We process this material, work with farmers to apply it to their fields, and monitor the fields to see how much carbon we are permanently removing from the atmosphere. On the scale of durability for carbon removal, enhanced weathering is at the very top, because once the chemical reaction happens between carbonic acid in the soil and our material, it forms bicarbonate, which makes its way to the aquifers below the fields and eventually to the ocean where it precipitates as limestone. It is carbon storage for 100,000 years! 

Silicate works with University College Dublin, where, with grant support from iCRAG, the Science Foundation Ireland Research Centre in Applied Geosciences, we have been engaged in a series of laboratory and field trials and have been able to work with postdoctoral researchers to expand our knowledge of the material and its carbon removal capabilities. All of our larger field trials are happening in the south of Ireland. All very exciting, and I love all the science we are undertaking. New things coming out every week, which are shaping where we steer the company.

Just planting trees is not enough

Markus: Could you describe the moment when you knew that the idea is that great that you need to become an entrepreneur / found a company?

Maurice: That is a hard one. What I will say is that I never set out with the express idea of starting a company. I just read a paper in the scientific journal “Nature“ about enhanced weathering, and the potential basalt, olivine and some alkaline materials have to durably remove CO2 from the atmosphere. The concept really resonated with me because I had worked on large farms in Australia and the UK and was at that time working in sustainable finance. So I approached Professor Frank McDermott of University College Dublin, who had written some papers on basalt weathering in Ireland and suggested we undertake some trials with concrete. Everything that's happened since then has been just like a snowball. But was there a moment where I said I must start a business? Not honestly, it just kind of was a natural progression.

 Which specific problem are you solving and how?

Maurice: The planet is warming. This is because there is a lot of CO2 in the atmosphere. This gas captures heat and holds on to it. And that has a big impact on the climate, and for how we're living on Earth. Even if we stopped burning fossil fuels today, we still have emitted far too much CO2 into the atmosphere, and so the world is going to keep warming. To have a livable planet as we know it, we have to decarbonise everything and we must remove CO2. 

What we do at Silicate is remove CO2 and lock it away permanently. Normally, when it comes to carbon removal, people would think of trees. Trees work, of course, but there are potential impacts on land use - land use change – that come with planting them. The surface albedo effect can also come into play because trees are darker, and in certain areas, they attract more heat because they are darker than if the ground was left bare. They also can be a fairly impermanent store of carbon, as they could be felled or burnt. It’s more complicated than simply planting trees to solve climate change. Ideally, we need more permanent solutions to take CO2 out of the atmosphere.

The Intergovernmental Panel on Climate Change, estimates that we need to remove billions of tonnes of CO2 from the atmosphere between now and the end of the century if we are to avoid the worst effects of climate change. These carbon removal solutions have to be permanent. We need to take the CO2 that we have put in the atmosphere and lock it away somewhere safely for a long time.

The best way to do that is by tapping into a natural process, which is the weathering of rocks. Every year, basalt, olivine and other mafic and ultramafic rocks naturally weather and remove CO2 from the atmosphere. As they decay, their chemistry means that they react with carbonic acid to form bicarbonate and calcite. A natural process that removes CO2 from the atmosphere and turns it into rock. Our material can play the exact same role, but it can do it in about 1/20th the time of basalt. It’s a Ferrari in enhanced weathering terms – a terrible analogy …

The amount of CO2 in the atmosphere has to go down

Markus: Do you think it's possible that in the future, we could capture enough greenhouse gases to offset the amount that we produce?

Maurice: We have to stop producing them. We're in the high-quality carbon removal space, which means you're storing carbon for more than 1,000 years. But this whole new industry of permanent carbon removal is not a substitute for emissions reductions. We have to stop burning fossil fuels. We have to find replacements or electrify everything that we're doing.

What we're doing isn't a way to offset our current emissions. Our company's purpose is to remove emissions that have already been put into the atmosphere. What I’d like to see is is the current amount of CO2 in the atmosphere which is around 420 parts per million (measured in Hawaii) begin to stabilize and then go down. To be at a safe level, it should be at 280ppm. I have a figure on my desktop from a presentation Dr James Rae from the University of St Andrews gave in 2020 that shows that the last time we had concentrations of CO2 this high in our atmosphere was 20 million years ago. 150 years of burning fossil fuels has perturbed a system that was fairly stable for >20 million years. Insane.

A vegan diet has the lowest impact on our climate

Markus: For someone who works in the climate crisis solution field, what do you think can we as individuals and communities do to save the planet and what future challenges do we need to tackle now?

Maurice: We all can have an impact. It may seem difficult to imagine, because we're part of society and there are planes flying and there are power plants producing electricity, but as an individual you can have an impact. The biggest way of having impact is through diet. And you can change your diet very easily. Way easier than changing how you heat your home, which can be quite a difficult thing to do, or how you travel. There's a seminal paper in “Science“ that talks about how the biggest impact individuals can have is through their diet. This means removing any animal products, essentially. 

A vegan diet has the lowest impact. One of the most potent greenhouse gas is methane. It is coming from dairy and beef production. Methane is about 28 times more warming than an equivalent amount of CO2, over a 100-year timeline. Cut that out of your diet, and you are already having a big impact on the climate.

We need to lock billions of tonnes of CO2 underground 

Markus: What is the biggest problem start-ups in the field of Sustainable Tech are facing?

Maurice: In the start-up scene, everyone talks about financing to get enough money for their own solution. In my eyes, this works well in Europe and the US, because there is a lot of interest from investors in supporting sustainable companies. People have realized that we need to solve these problems urgently. So, money is not the biggest issue. 

The biggest problem is the sheer size of the task. You have to keep that in mind: We need to remove billions of tonnes of CO2 and lock it underground very quickly. There are different ways to do this. We have our enhanced weathering approach, putting rocks on fields and letting them decay and capturing carbon that way. There's direct air capture, which, through different systems, can strip CO2 from ambient air (no mean feat at 420ppm!), condense it and then put it underground. With all these solutions, new systems have to be developed to transport the CO2 or put it underground. All of this is uncharted territory. 

If we had time, if we had 30 years to solve this problem, then it would be fine. But we don't. We are trying to get it done quickly and effectively. There is little room to go down the wrong path, we have to be sure of our approach and then implement it quickly and at a large scale.

The ship has left port, but we can still change its course

Markus: Maybe you can give us a little hope. Do you think they think this task is still doable? Or has the ship already sailed? 

Maurice: The ship has left port. I don't think it necessarily has to share the fate of the Titanic, just yet. But we've seen this summer how far climate change has gone. The flooding in Pakistan, the droughts in many parts of the world should be another wake-up call for all of us. What is needed is fundamental change. 

But I wouldn't be doing this if I didn't think we had a chance. Change is always hard. There's an inertia in the way we live that we have to overcome. But once we get enough weight behind us, we can almost certainly set the ship on a different course. 

Carbon removal has also become really topical in the last two years. There is more and more interest from all sides. We are pleased to have the support of Ergo and Munich Re, and there are accelerators for carbon removal in Europe and abroad. Those are a lot of promising steps, and more are coming. Still, it will take a lot of energy to really change the way we live.


Markus: What is your most important milestone in 2023

Maurice: We did a lot of field trials in 2021. That gave us the confidence that this material works extremely well to remove carbon. In 2022, we scaled it up. We went from one-hectare-in-size in field trials and small lab trials to 125 hectares in just a year. 

Next year, we want to repeat that. That means working with more farmers, getting more material, and also increasing the size of the team.

We learn a lot every time we put material on the ground. We can be more efficient the next occasion and be able to remove more carbon per amount of material we’re putting on the ground. Increase the bang to buck ratio, that is our goal with each iteration of our field and lab work.

More material on the ground next year, more data and more knowledge. That is what 2023 looks like for us. We are really looking forward to seeing how far we can grow our understanding and carbon removal capacities in the next 12 months. If the last 12 are anything to go by, I expect we will achieve a lot during 2023. 

Our Green Tech series here on //next

As part of the Climate-KIC accelerator, Munich Re and ERGO are currently supporting five start-ups active in the field of carbon removal, where they are making an important contribution to combating global warming. In a series of interviews with //next columnist Markus Sekulla, we will be presenting the five young companies with big ambitions in the coming weeks: NeoCarbon, Reverse Carbon, Silicate, Treeconomy and Ucaneo Biotech.

If you want to take a look at the companies already - here is the link to their websites:






You will find further information on ClimAccelerator here:


The German version of this article you will find here: Silicate: „Wir entfernen CO2 aus der Luft und schließen es weg“