The formation of activated carbon-based moisture-swing adsorbents and their CO₂ direct air capture performance

Currently, most research on moisture-swing adsorbents for CO₂ direct air capture (DAC) technology focuses on solid powder materials, which hinder large-scale engineering applications. By compositing activated carbon (AC) with binders such as methylcellulose and bentonite, and further loaded with K₂CO₃, a K₂CO₃/AC shaped adsorbent for direct air capture of CO₂ was prepared. Its practical performance was evaluated through characterization tests and CO₂ adsorption performance tests. Experimental results indicate that the shaped adsorbent exhibits good compressive strength and CO₂ adsorption performance under DAC circumstances. As the AC content in the shaped adsorbent increases, the adsorption capacity for DAC shows an upward trend. The K₂CO₃/AC-60 shaped adsorbent with an AC mass fraction of 60% has the optimal compressive strength and its adsorption capacity can reach 0.319 mmol/g. This study provides a scientific basis for the formation and industrial application of powder moisture-swing adsorbents, and holds great significance for the development of practical DAC adsorbents.