(462a) Development of Porous Electrospun Fibers Embedded with a High Loading of Coated Adsorbents for the Direct Air Capture of CO2

Since the industrial revolution, the concentration of CO₂ in the atmosphere has been continuously rising, resulting in a considerable increase in the global mean temperature on earth. Due to continuous increase in CO₂ emissions, the target of restricting “global warming to 1.5^oC” by the Intergovernmental Panel on Climate Change (IPCC) can only be met by negative CO₂ emissions techniques, such as the direct air capture (DAC) of CO₂. Therefore, significant research has been focused on capturing CO₂ from air. Most of the researchers in this area have focused solely on improving the CO₂ capacity of adsorbent materials while there is a deficit of options for scaling up the DAC process. Traditional packed beds composed of pellets less than 1 mm in diameter are unfavorable due to the rapid increase of bed pressure and issues with assembly as a result of the small particle size. In this work, porous electrospun fibers (PEF) embedded with a high loading of sorbent particles in a continuous thin polymer fiber were prepared, providing a promising solution to improve adsorption kinetics as well as heat and mass transfer efficiency without the problems of assembly and bed pressure issues. To maintain a high loading of sorbent particles in PEF, a core-shell structure of PEF with embedded sorbent particles is prepared by coaxial electrospinning. Two syringe pumps are used to control the feed of two different solutions through a core-shell spinneret. The coated sorbent particles are loaded in the core phase, while a thin coating layer of a selected polymer serves as a shell phase, in which the porous structure allows for the maximum exposure of sorbent particles. This coaxial electrospinning has been used previously for nanofiber fabrication, and core-shell spinnerets are commercially available for electrospinning, demonstrating the viability for the process to be scaled up.