Sub project II explores and compares three technical approaches to capture CO2 from the ambient air and their scale-up. Three different technology paths are investigated. Exploration of the adsorbent path (1) includes system-level simulations, materials synthesis, and characterization, as well as system design and demonstration in a mini-plant. The approach membrane adsorbent path (2) studies the application of highly porous material containing functional groups working as adsorption sites. The electro swing approach (3) investigates the use of electrochemistry for the sorbent regeneration step. This approach requires only electrical energy for the regeneration step, without the need for a heat source.