Sorbent-coated carbon fibers for direct air capture using electrically driven temperature swing adsorption

Direct air capture (DAC) by electrically driven temperature swing adsorption (ETSA) is an emerging technology due to its simplicity and ease of pairing with renewable electricity energy sources. Herein, we describe the preparation of sorbent-coated carbon fibers via roll-to-roll process that exhibit 400 ppm CO2 adsorption of ∼1.2 mmol gfiber−1. The fibers exhibit Joule heating upon application of a potential, reaching CO2 regeneration temperatures within 1 min. DAC modules show fast electrothermal CO2 desorption with directly applied electric potential, releasing the adsorbed CO2 six times faster than externally driven thermal desorption. The simplicity and modularity of the sorbent-coated carbon fibers and their rapid adsorption/desorption cycling by ETSA have the potential to improve the productivity of DAC systems. A techno-economic analysis of a pilot-scale ETSA-DAC system projects an overall cost of about 160 $ tCO2−1, with convective energy losses to the ambient accounting for only 7% of the Joule heating input during desorption.