Grant: Discovery Grants Program - Individual

In Canada, mines and agriculture account for ~6 and 67 million tonnes of CO2 emitted annually, and forests are net carbon sources. In addition to reducing these and other greenhouse gas (GHG) emissions, removing carbon dioxide (CO2) from the atmosphere is necessary to offset hard-to-abate emissions and mitigate climate change. Enhanced weathering and mineralization aim to accelerate Earth's natural ability to sequester atmospheric CO2 through chemical weathering and the formation of stable carbonate minerals that store CO2. These processes can be accelerated in mining environments using mine wastes, agricultural fields and forests using mineral amendments, and engineered systems using reactive oxide minerals. While these approaches offer enormous capacities to capture and securely store CO2, there are uncertainties relating to the rates of CO2 removal that can be achieved, verification and quantification of carbon storage, co-benefits, and environmental concerns. This research program comprises three main themes: (1) CO2 mineralization within mine wastes, (2) enhanced rock weathering, and (3) mineral oxide looping, which aim to address knowledge gaps by discovering and developing geochemical CO2 removal processes while aiding industries in deploying these negative emissions technologies. Certain mines produce millions of tonnes of mineral wastes suitable for CO2 removal that are accessible for deployment. A large-scale field pilot will be initiated at a mine to measure rates of CO2 removal and verify carbon storage under real-world conditions. While the field pilot will be deployed at an ultramafic mine (e.g., diamond or nickel with Mg-rich tailings), other deposit types (e.g., base metals) have largely been unexplored. A laboratory study will examine the potential for CO2 mineralization of other deposit types, including those mined for critical minerals needed for green technologies. Enhanced rock weathering field trials will be undertaken in agricultural and forested lands using wollastonite, a calcium silicate mineral that reacts quickly with CO2. These trials will evaluate CO2 removal, develop novel approaches for carbon verification, investigate soil-rock interactions, and assess potential co-benefits or negative impacts such as on plant growth (crops and trees) due to nutrient or metal release. CO2 mineralization can be greatly accelerated when using highly reactive oxides (e.g., MgO and CaO) produced from mining and calcining carbonate rocks. Research will determine the ideal conditions to maximize CO2 sequestration capacity and identify opportunities for acceleration for large-scale CO2 removal. Addressing the climate crisis requires developing and deploying negative emission technologies while drastically reducing GHG emissions. This research program advances the most promising technologies by developing new processes, addressing uncertainties, and demonstrating their effectiveness at large scales.