Carbon removal is a hot topic in sustainability, with many companies involved in direct air capture. But now, a Dublin company is turning surplus concrete into a low-cost, carbon removal tool via a process called 'enhanced weathering'.
Silicate is the first enhanced weathering company to leverage the massive carbon removal potential of surplus concrete. This is the first time concrete has ever been used in this way.
The company is the collective effort of Professor Frank McDermott, a low-temperature geochemist based at University College Dublin and the company's science lead, and founder Maurice Bryson, a Master in Carbon finance graduate with extensive farming experience in Ireland and Australia.
I spoke to Bryson to learn more.
The company's technology removes around 2 tonnes of CO2 per hectare a year. Once scaled, Silicate believes it could remove more than 100-250 megatons of CO2 per year.
What is enhanced weathering?
Weathering is the naturally occurring process of the breakdown of rocks and minerals at the Earth's surface.
Enhanced weathering means crushing calcium- and magnesium-rich rocks and minerals to give them a larger surface area before applying them to agricultural soils, where the concentration of carbon dioxide is up to 10 times higher than in the atmosphere.
Enhanced weathering materials with high concentrations of calcium or magnesium cations (Ca2+, Mg2+) have the highest carbon removal capacity.
By increasing the amount of these materials that are available to react with carbonic acid (rainfall), significant carbon removal can be achieved in decades as opposed to millennia.
Bryson explained that In the case of Silicate, the company grounds surplus concrete into fine dust and gives it to farmers to spread onto their fields, and this then removes carbon from the atmosphere.
It measures the level of CO2 removed from the atmosphere and sells carbon credits of that value to private companies like Klarna and Milkywire.
"Concrete is the most abundant material on the planet, after water. Currently, about 1-4% of the 20-30 billion tonnes of concrete made each year is returned unused to where it was produced due to, among other things, over-ordering."
Giving concrete a second life offers a huge boost to farmers.
"It can improve crop productivity by optimising soil pH, enhance plants' natural resistance to herbivory through the release of bioavailable silica, and it can provide vital nutrients to the soil."
Bryson explained that the company is currently at a "pilot commercial scale and is constantly adding material to fields and measuring what happens.
"Our focus has always been the sciences, and we hope that if we nail the science, we'll be able to grow this thing for real."
The company is currently participating in the 2050 incubator, which provides valuable access to farmers, land owners, and agricultural experts in the Irish government.
Earlier this year, the company won the THRIVE Shell Climate Smart Agriculture Challenge at SXSW, receiving $100,000 in grant funding.