Irish climate tech startup, Silicate, is poised to conduct the inaugural trial of its cutting-edge enhanced weathering technology.
Irish climate tech startup, Silicate, is poised to conduct the inaugural trial of its cutting-edge enhanced weathering technology. This groundbreaking method aims to permanently extract CO2 from the atmosphere and sequester it in the world’s oceans for tens of thousands of years.
The trial involves the distribution of 500 tonnes of crushed waste concrete over 50 hectares of farmland near Chicago, equivalent to an area the size of 120 football fields. Over the course of a year, the milled concrete will undergo a process known as enhanced weathering.
As a quick refresher from high school geography class, chemical weathering is a natural process that slowly breaks down rocks over millions of years by dissolving them into bicarbonate. This form of carbon is then carried into rivers and eventually the sea, where it is either stored in dissolved form or sequestered in the seabed.
Enhanced weathering expedites this process by pulverizing silicate rocks into powder, increasing their reactive surface area, and then spreading the dust on farmland. In a unique twist, Silicate employs recycled concrete — the world’s largest single waste stream — for their process.
The Irish climate tech startup procures returned concrete from producers, processes it, and then supplies and distributes it onto agricultural land, free of charge. Silicate meticulously measures the amount of carbon sequestered and subsequently sells carbon removal credits to large corporations seeking to reduce their carbon footprint.
Maurice Bryson, CEO and co-founder of Silicate, stated, “We believe our approach of using returned concrete to improve both the productivity and the carbon removal potential of farmland could be game-changing, as it is low-cost, it is safe to apply to agricultural land, and it uses an abundant material that is easy to source.”
The trial is anticipated to permanently remove up to 100 tonnes of carbon dioxide from the atmosphere. Additionally, using this material as a soil pH amendment offers supplementary benefits including enhanced soil health and increased crop productivity.
Funding for the trial has been provided through prize money awarded to Silicate as part of the THRIVE/Shell Climate-Smart Agriculture Challenge. Shell is also contributing €475,000 worth of LI-COR soil gas flux measurement devices, which will monitor the fields throughout the one-year testing period.
The primary objective of the pilot is to evaluate how the material functions as an enhanced weathering feedstock in the American Midwest, where soil conditions differ from those in Silicate’s native Ireland. Preliminary tests in Ireland have already shown “huge promise,” according to the startup.
Pending the outcomes of the US trial, Silicate is poised to expand operations across Illinois and the Midwest in time for the next liming season in autumn each year. The technology has the potential to remove between 50-100 million tonnes of CO2 annually in the American Midwest alone, offering a significant contribution to carbon reduction efforts.
For comparison, a typical passenger vehicle emits about 4.6 tonnes of CO2 annually.