Direct Air Capture (DAC): Technologies and Costs for Capturing Carbon Dioxide from the Air

Climate change is one of the most pressing issues of our time, and reducing greenhouse gas emissions is essential to mitigate its impact. However, it is becoming increasingly clear that simply reducing emissions is not enough. We also need to remove carbon dioxide from the atmosphere to limit global warming to below 1.5 degrees Celsius. This is where direct air capture (DAC) technology comes in.

DAC technology involves removing carbon dioxide directly from the air and storing it or using it for industrial purposes. The process involves capturing CO2 using a variety of sorbents or solvents, which are then regenerated for further use. While DAC technology is still in its early stages of development, it is rapidly gaining traction as a promising tool for mitigating climate change.

Technologies for Direct Air Capture

DAC technology involves the use of sorbents or solvents to capture CO2 from the air. These sorbents and solvents vary in their effectiveness, cost, and scalability. Some of the most promising sorbents and solvents currently being developed for DAC include:

Solid sorbents: Solid sorbents are materials that adsorb CO2 molecules onto their surface. These sorbents can be regenerated by heating them to release the CO2. Solid sorbents include zeolites, metal-organic frameworks (MOFs), and activated carbon.

Liquid solvents: Liquid solvents are liquids that dissolve CO2 from the air. They can then be regenerated by heating them to release the CO2. Liquid solvents include amines, which are currently used in large-scale industrial processes for CO2 capture.

Ionic liquids: Ionic liquids are salts that are liquid at room temperature. They have the potential to be highly selective for CO2 capture, but they are currently more expensive than other solvents and require more research and development.

Cost of Direct Air Capture

The cost of DAC technology is a major barrier to its widespread adoption. Currently, DAC is more expensive than other methods of carbon capture, such as capture from industrial sources like power plants. However, the cost of DAC is expected to decrease in the coming years as the technology improves and economies of scale are achieved.

The cost of DAC can be broken down into several components, including the cost of the sorbent or solvent, the cost of energy required to capture and release CO2, and the cost of the equipment and infrastructure required for the process. The cost of the sorbent or solvent is the most significant component, accounting for up to 70% of the total cost.

The cost of DAC varies depending on the specific technology used and the scale of the operation. Currently, the cost of DAC ranges from $100 to $600 per ton of CO2 captured. This is significantly higher than the current cost of carbon credits, which are trading at around $50 per ton. However, as the technology improves and the scale of operations increases, the cost of DAC is expected to decrease to around $50 to $100 per ton of CO2 captured.

Direct air capture technology has the potential to play a significant role in mitigating climate change by removing carbon dioxide from the atmosphere. While the technology is still in its early stages of development, it is rapidly advancing and becoming more promising. The cost of DAC is currently a major barrier to its widespread adoption, but as the technology improves and economies of scale are achieved, the cost is expected to decrease significantly. With continued investment and research, direct air capture has the potential to become a critical tool in the fight against climate change.