SILICATE CARBON

XPRIZE TRACK
ROCKS

CDR PATHWAY(S)
Rocks - Ex-situ mineralization of mined rocks
Rocks - Mineralization of mine or industrial waste
Rocks - Other

PHYSICAL PRODUCTS
None

FOUNDED
2021

GET IN TOUCH

Silicate Carbon Ltd.
Dublin, Ireland
www.silicatecarbon.com

Maurice Bryson
[email protected]

COMPANY DESCRIPTION

Harnessing a natural geochemical process, Silicate Carbon permanently removes carbon dioxide from the atmosphere via the acceleration of mineral weathering. Silicate Carbon applies fast weathering carbonate minerals to agricultural land to amend soil pH, boost crop productivity, and – most importantly - permanently remove excess carbon dioxide from the atmosphere.

CORE INNOVATION

Silicate Carbon’s climate solution lets the rocks do the work. The chemical weathering of minerals is a natural sink for carbon capturing around one billion tonnes of carbon dioxide each year. Silicate Carbon accelerates and enhances this natural process, so that it can be added to the toolkit of climate change mitigation solutions. Their process tackles three problems in one: (i) increase the resilience of farmland to climate change, (ii) improve soil pH for optimised plant growth and (iii) durably sequester carbon dioxide.

CO2 CAPTURE

The team is focused on enhancing the chemical weathering of calcite and milled returned concrete (MRC). Silicate Carbon applies these carbonate-bearing materials to agricultural land following its science-led amendment protocol, and then measures soil waters, soils and greenhouse gas fluxes to measure carbon removal. The weathering reaction takes carbon from the atmosphere and stores it as soluble bicarbonate ions (HCO3-). This is a natural reaction that occurs every day. By spreading milled material, the surface area available for weathering is increased and CO2 capture is accelerated.

CO2 SEQUESTRATION

The bicarbonate ions flow to the ocean via surface and ground waters. The residence time of bicarbonate in the oceans is ~80,000 years (Berner and Berner, 1987). It is this ocean residence time that ensures that the carbon dioxide is durably sequestered well beyond a 100-year timescale. After ~80,000 years, negatively charged bicarbonate ions bond with positively charged calcium ions, forming CaCO3 (limestone).

CO-BENEFITS OR PRODUCTS

Because of its rapid weathering kinetics, calcite and MRC can be used to amend soil pH in farmland, which not only can unlock crop productivity gains, but the adjustment of pH can reduce N2O fluxes. The addition of silica to soil from the MRC also strengthens crop roots and can increase the resistance of plants to herbivory (Ahmed et al., 2023). Another widely discussed co-benefit of EW is that once the dissolved bicarbonate makes its way to the ocean, it can facilitate the remediation of ocean acidification.