Fig. 1: Working principle of vapor promoted desorption for DAC.

a Calculated R values of conventional TVSA processes at various desorption temperatures and pressures, with fixed adsorption conditions of 25 °C and 400 ppm CO₂. b Working capacities of vapor promoted desorption (W_c,VPD) and TVSA (W_c,TVSA) processes calculated from the CO₂ adsorption isobar of a benchmark solid amine sorbent. P and T represent CO₂ partial pressure and desorption temperature, respectively. Assuming that adsorption is carried out at 25 °C with a CO₂ partial pressure of 0.04 kPa, while regeneration is conducted at 100 °C. Vapor promoted desorption, conducted without the use of vacuum conditions, results in a significant reduction in CO₂ partial pressure (around 2 kPa) due to the in situ purging effect of the generated water vapors. c Four-step DAC process including an adsorption step at ambient conditions, a preheating step for increasing temperatures, a desorption step for product collection, and a cooling step. d Schematic diagram of a solar-thermal desorption process based on in situ vapor purge. It is understood that the packing of the adsorbents in the column can be optimized for example into honeycomb structures to reduce the pressure drops; however, we emphasize the purpose of this study is to develop efficient regeneration methods and the configuration of adsorbents is not our focus. Source data are provided as a Source Data file.