Abdellatif et al. (2025): Amine free direct air capture integrated with buildings’ cooling systems in humid environments
Yasser M. Abdellatif, Riham Surkatti, Raeesh Muhammad, Ahmed Sodiq, Nashaat Nassar, Tareq Al-Ansari, Abdulkarem I. Amhamed, IN: Energy Conversion and Management, https://doi.org/10.1016/j.enconman.2025.120544
Direct air capture, among the negative emission technologies, is well positioned to reach climate goals. However, adsorption-based direct air capture system faces significant challenges in humid environments due to water-CO₂ co-adsorption, which substantially increases thermal regeneration energy requirements and negatively impacts overall efficiency. To overcome this problem, this study presents novel direct air capture systems integrated with air handling units incorporating a silica gel wheel to dehumidify air before the adsorption process. Dehumidification of air by integrated silica gel wheel enhances the performance of physisorbents and chemisorbents such as NbOFFIVE, Zeolite-13X, SBA-15 functionalized with tetraethylenepentamine, SBA-15 functionalized with L-PEI, and Lewatit by reducing moisture, thereby improving CO₂ capture efficiency in humid environments. After capture, saturated part of silica gel wheel meet the moisture-free airstream and regenerate the water without heating and raising the stream humidity approaching the desired indoor humidity levels.