An Irish cleantech start-up is testing the use of concrete dust in agricultural settings to address climate change.

Silicate, based in Sligo, has created an innovative method known as “enhanced weathering technology” to permanently remove large amounts of carbon dioxide from the atmosphere. The company’s initial trial will take place in the United States, where hundreds of tons of crushed waste concrete will be spread over farmland.

The process of enhanced weathering involves the breakdown of the concrete in the soil, creating bicarbonate and sequestering carbon dioxide. This bicarbonate is then washed into rivers and the sea, where it is either stored in its dissolved form or trapped in the seabed.

By opting for concrete dust instead of rocks, Silicate is repurposing a substantial waste product. The company obtains leftover concrete from construction sites, pulverizes it, and applies it to farmland without charging any fees.

Workers measure the amount of carbon sequestered. Then, Silicate sells carbon removal credits to major corporations to generate additional income.

The start-up believes that its approach of using returned concrete to increase carbon sequestration can be revolutionary due to its low cost and safety. Moreover, concrete is abundant and readily available.

According to Euro News, the initial trial aims to permanently sequester around 100 tons of CO2. This CO2 would remain locked in the oceans for thousands of years.

The trial will test the effectiveness of the material in the American Midwest, where soil conditions differ from those in Ireland. Encouraging results have already been observed from trials conducted in Ireland.

Silicate has secured funding for the pilot project through prize money awarded by the THRIVE/Shell Climate-Smart Agriculture Challenge.

If the findings from the trial in the United States are positive, Silicate plans to expand the initiative to cover Illinois and the wider Midwest region.

The company predicts that its concrete dust could remove anywhere from 50 to 100 million tons of carbon dioxide per year in the American Midwest alone. This is equivalent to removing approximately 16 gasoline cars from the road every year.

Silicate is not the only start-up using enhanced weathering to sequester CO2.

In 2021, Heirloom Carbon Technologies received seed funding from a Bill Gates-backed climate fund. Heirloom uses limestone that’s undergone enhanced weathering to remove CO2 from the atmosphere. Heirloom sold over $20 million worth of carbon dioxide removal to Microsoft in September.

Image Source: The Rundown Tech,