Repurposing surplus concrete to help save the planet

Crushed concrete boosts crop productivity and removes carbon dioxide from the atmosphere, turning it into a stable bicarbonate ion

Maurice Bryson is one of a growing group of socially conscious young entrepreneurs developing novel solutions to tackle some of the big problems facing the world today. In Bryson’s case he founded Silicate, a carbon removal company which is harnessing the power of geochemistry to remove carbon dioxide permanently from the atmosphere.

Silicate is using the natural process of mineral weathering to achieve its objectives but with an innovative twist. Basalt, olivine and other alkaline materials are known to have the potential to remove carbon dioxide from the atmosphere. However, Silicate has gone in a completely different direction by putting the spotlight on the absorbent properties of waste concrete.

“We are the first company in the world to utilise this material to sequester carbon at scale,” says Bryson who adds that concrete is superior to other materials because it weathers quickly. In the company’s field trials, it had weathered almost completely within a year and its concentration of toxic heavy metals was much lower.

The carbon we remove from the atmosphere is safely locked away for more than 80,000 years

—  Maurice Bryson, founder of Silicate

“Concrete is the most abundant man-made material on earth and the building industry generates billions of tonnes of waste concrete each year,” Bryson says. “Crushed concrete is an ideal material for enhanced mineral weathering. By milling it, we create a fine dust that can be safely applied to agricultural land where it will boost crop productivity through soil pH amendment.


“This is good news for the farmer but the other huge benefit is that, as the material breaks down, it removes carbon dioxide from the atmosphere turning it into a stable bicarbonate ion. The carbon we remove from the atmosphere is safely locked away for more than 80,000 years.”

Silicate buys the returned concrete from producers, processes it, and then supplies and spreads it on agricultural land free of charge. While participating farmers reap the benefits of improved soil and yields, Silicate rigorously measures how much carbon has been sequestered and then sells premium carbon removal credits based on the amount to large corporates to help them manage their environmental footprint.

Most people will be familiar with the use of forests as carbon offsets. However, serious questions have been raised about their veracity and efficacy in mitigating global warming. This prompted Bryson, a marine biology graduate with an MSc in carbon finance and a background in sustainable finance with S&P in London, to look at alternatives.

“I was aware of enhanced weathering and its potential to remove CO2 from the atmosphere and I had also read papers by Prof Frank McDermott from UCD about basalt weathering in Ireland. I approached him and suggested we undertake some trials with concrete. This was the genesis of Silicate, and Frank is now our science lead,” says Bryson who heads a team of five.

“Our potential customers are global,” he adds. “At the moment, Stripe, Klarna, Microsoft, Shopify, Mitsubishi and JP Morgan are all leading purchasers of carbon removal credits and many more companies are set to join them. The EU Green Deal will require all residual emissions to be durably removed after 2050 meaning companies will be obliged to purchase carbon removal credits.

“Carbon removal is not a replacement for economy-wide greenhouse gas emissions reductions, but it is an important component in limiting the impacts of climate change.”

Silicate has been funded primarily through grant aid of about €300,000 which has come from various sources including Science Foundation Ireland, Enterprise Ireland, Sligo Local Enterprise Office, Munich Re, EIT Climate-KIC. The company also won $100,000 (€91,337) in the international Thrive Shell climate smart agriculture competition. Last year, it sold research credits to online payments company, Klarna, which will help fund its continuing development work.

“We are currently midway through our first commercial scale trial on the O’Connor family farm in Co Wexford and we expect to be fully market ready by 2026,” says Bryson, whose company is a recent graduate of AgTechUCD’s accelerator programme.