The term direct air capture comes up again and again in discussions about measures against climate change. But what is actually behind the technology?
One term keeps coming up in debates about climate protection: Direct Air Capture (DAC). But what is that actually? DAC represents a mature technology that aims to remove carbon dioxide (CO2) directly from the air. This method can help combat climate change by reducing the amount of greenhouse gases in the atmosphere.
But how does direct air capture actually work? DAC uses chemical solutions or insoluble materials that can absorb and hold liquids (called sorbents) to absorb CO2 from the air. Manufacturers differentiate between two main methods when developing their systems.
Was ist Direct Air Capture?
With wet absorption, DAC systems use a liquid solution to absorb CO2. Dry absorption, on the other hand, is based on solid materials. Regardless of the method, the systems then extract the CO2 from these materials. It can then either be stored or reused for industrial purposes.
DAC research aims to optimize the efficiency and cost-effectiveness of these systems. The high energy requirements of the technology continue to be a major point of criticism. Researchers and companies are therefore working intensively on developing energy-efficient materials and processes to reduce costs and increase scalability.
Other measures in the fight against climate change are usually more effective
Some pilot projects, such as Carbon Engineering's facility in British Columbia (Canada), are already demonstrating the technical feasibility of DAC. The system can remove up to one ton of CO2 from the air per day. There are similar projects in the USA and Europe. However, high costs and a lack of efficiency have so far represented an obstacle to scaling.
This is also shown by a comparison with other CO2 reduction methods, which are often significantly cheaper – such as renewable energies or increasing energy efficiency. There is also the challenge of storing large amounts of CO2 safely and permanently.
Despite many open questions, many experts see DAC as an important part of a strategy to combat climate change. Nevertheless, Direct Air Capture remains just one page in a large catalog to protect the climate and the environment.
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Source: https://www.basicthinking.de/blog/2024/05/18/direct-air-capture/