Direct Air Capture
Direct air capture (DAC) is a technological method that uses chemical reactions to capture carbon dioxide (CO2) from the atmosphere. When air moves over these chemicals, they selectively react with and remove CO2, allowing the other components of air to pass through. These chemicals can take the form of either liquid solvents or solid sorbents, which make up the two types of DAC systems in use today.
Once the carbon dioxide is captured from the atmosphere, heat is typically applied to release it from the solvent or sorbent. Doing so regenerates the solvent or sorbent for another cycle of capture.
The captured CO2 can be injected underground for permanent storage in certain geologic formations or used in various products and applications. Permanent storage will result in the biggest climate benefit.
Resources:
An inter-model assessment of the role of direct air capture in deep mitigation pathways.
Direct Air Capture of CO2 by Physisorbent Materials.
Techno-economic assessment of CO2 direct air capture plants.Direct Air Capture.
Resource Considerations and Costs for Carbon Removal.