Direct Air Capture (DAC) technology has emerged as a promising solution to remove carbon dioxide (CO₂) directly from the atmosphere, offering a way to fight against climate change. Among the various DAC approaches, solid sorbent-based technologies have gained significant traction in recent years due to their efficiency and potential for scalability. Unlike liquid sorbent-based DAC systems with integrated CO₂ sequestering process, current solid sorbent DAC technologies can only separate CO₂ for storage or reuse.
Solid sorbents are specially designed to capture CO₂ from ambient air. They coat the surface of a porous or monolithic-structured support material, resulting in a large area for efficient CO₂ adsorption. The sorbents for industrial DAC systems generally use amine-functionalized materials, inorganic salts, and zeolites. These DAC systems require lower regeneration temperatures and consume less water, making them more energy-efficient and cost-effective.
An alternative industrial DAC technology uses solid sorbent microparticles laid out as a thin layer onto a large area tray to capture CO₂. This DAC technology typically requires a high temperature and consumes more water to regenerate sorbents. While this approach can offer high adsorption capacities, the energy and water requirements can be significant drawbacks.
Here, we analyze industrial DAC technologies with solid sorbents based on our research of DAC companies. We categorize them based on the design of solid sorbent materials: sorbent coated on porous or monolithic support and sorbent microparticles.
(This article contains 6 diagrams and 1336 words.)