(462f) Electrified Fiber Sorbent for Energy-Efficient Direct Air Capture

Direct air capture (DAC) technology is one of the most prominent technologies for negative CO₂ emission, where either solid or liquid sorbents will allow selective removal of CO₂ even at extremely low concentrations from the air, which is then thermally desorbed for future utilization or sequestration. However, for a successful DAC deployment, critical milestones include reducing pressure drop, maximizing CO₂ sorption, optimizing regeneration, improving scalability, and reducing cost.

The reflection of the outlined objectives has driven the advancement of solid sorbents, capable of capturing CO₂ through chemical or physical interactions, in post-laboratory scale production, demonstrating the viability of this technology in addressing negative CO₂ emissions. Additionally, the platforms of utilization such as monoliths or fiber sorbents account for the treatment of large volumes of ambient air treatment and scalability of the system. However, although many of the aforementioned milestones has been achieved through the laboratory innovations, the two collating problems of the sorbent regeneration via energy efficient operations still a hurdle for the DAC.

Currently, one of the most commonly conceived methods of solid sorbent desorption is temperature swing adsorption (TSA), where CO₂-saturated sorbents are heated up to their respective desorption temperatures under atmospheric or vacuum pressure. However, the location of TSA cycle operations is limited to the source of heat for regeneration, which is heavily dependent on either superheated steam, or scavenged heat from point sources. The ubiquity of CO₂ in the atmosphere requires freedom from location-based installation constraints for a DAC module, necessitating the exploration of alternative methods for thermal energy input, unbounded by geographical limitations.

Herein, we intend to provide a next step for the DAC deployment via introducing electrified fiber sorbents. Through an efficient but effective implantation of a Joule heating copper wire in the center of the fibers parallel with the highly scalable dry-jet wet-quench spinning process, the fiber sorbent contactor is introduced to an additional functionality of in-situ conductive Joule heating using solely electricity as the intrinsic source of heat. The ease of fabrication, and the unique fiber sorbent formfactor enhances the direct and homogenous heating of with minimal heat loss independence from the heat source, even enabling renewable energy for sorbent regeneration.

Additionally, we demonstrate a bench scale module capable of capturing approximately 0.3 tpy of CO₂. This cutting-edge bench scale module with unique fiber sorbent contactor design verifies an additional option for plant-scale DAC deployment, which may easily be met with semi-continuous production of the electrically connected fiber sorbent bobbins. Assisted with the rigorous technoeconomic analysis modeling and systematic analysis based on the isotherm, breakthrough, and pressure drop data, we intend to expand this project from the status quo into a multi-metric-ton scale CO₂ plant for an additional step toward the “Negative Emission.”