Based in Sligo, Silicate has found a novel way to sequester carbon using returned concrete. It is now building on that idea.
The time is ripe for setting up a carbon removal business in Europe. Other than the fact that the world can do with any company taking steps to fight the climate crisis, the EU has set targets to reduce greenhouse gas emissions by 55pc by the end of this decade.
“Our industry, carbon dioxide removal, will inevitably play a part in meeting this target,” said Maurice Bryson, founder of climate-tech start-up Silicate, tells SiliconRepublic.com.
Having worked on some of the world’s largest farms in the UK and Australia, as well as working in sustainable finance in London, Bryson started carbon removal company Silicate in 2021.
Silicate has a unique business proposition. It has developed technology to remove excess carbon dioxide from the atmosphere through the weathering of silicate and hydroxide minerals.
What’s more, it uses returned concrete as a weathering agent – which is processed and spread on agricultural land to sequester carbon at scale.
“Silicate is the first company in the world to utilise this material to sequester carbon at scale, and we have developed robust in-situ measurement and modelling capabilities to verify the rates of carbon removal we enable,” Bryson said.
Unlike previous work on enhanced weathering for carbon dioxide removal that has largely focused on crushed basalt, olivine or volcanic glass, Silicate uses more reactive and abundant waste materials to durably remove excess carbon dioxide from the atmosphere.
“The idea of using crushed returned concrete instead of volcanic material is entirely novel, and the technology is potentially disruptive,” he went on.
“Simultaneously [it addresses] the need to remove CO2 from the atmosphere while utilising a highly alkaline low-value construction waste product that is frequently landfilled or used for low-value filler applications.”
This material has a significantly higher dissolution rate than the more commonly used basalt and olivine. It also does not contain any potentially toxic heavy metals such as nickel and chromium, which makes it usable in arable, food-producing soils.
“About 2bn tonnes of concrete are created through demolishing buildings. We take these abundant waste streams from the construction sector and process the material to better harness its carbon removal properties, and then work with farmers to apply it to their fields.”
Bryson, who studied carbon finance and marine biology, runs the company with Prof Frank McDermott of UCD School of Earth Sciences, who is Silicate’s science lead. McDermott has more than 30 years’ experience in high and low temperature geochemistry and igneous petrology.
One of a handful of companies to have sold more than $250,000 in carbon removal credits on a pre-purchase basis, Silicate counts among its customers Swedish ‘buy now, pay later’ fintech Klarna, climate-tech platform Milkywire and carbon removal tracing platform CarbonFuture.
“For a company of our scale, we are performing extremely well,” Bryson added, noting that he has his eyes on a pre-seed round worth $5m to $6m by the end of the first quarter of this year. This round, he hopes, will help Silicate enter new markets.
Globally, Silicate estimates that between 2pc to 5pc of all ready-mix concrete made is returned concrete. Bryson believes that there is adequate supply of usable material to durably sequester megatonnes and even gigatonnes of carbon dioxide.
“As we expand operations to other countries, we anticipate that we will be able to remove megatonnes of CO2 safely from the atmosphere by 2034, scaling to potentially gigatonnes by 2040,” he said.
“To achieve these larger scales, we would also employ demolished concrete as an additional material in our supply chain.”
Currently taking part in the AgTechUCD accelerator programme until the end of this month, Sligo-based Silicate plans to move base to Dublin’s NovaUCD in March.
“Carbon removal is a new industry that is gaining serious momentum in the US, but is only beginning to be understood in Europe now,” Bryson added.
“I expect this will change in time, as new initiatives, such as the EU’s recently launched framework for carbon removal certification come into law.”
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