Effect of Bentonite Binder on the Critical Properties of Zeolite Extrudates in Dehumidification in Confined Space

The shaping of zeolite powder is an essential process for enhancing zeolite utilization. It facilitates easier handling, improves fluid flow distribution, minimizes pressure drop during operation, and enhances mass transfer. Adding a bentonite binder is necessary for zeolite particle cohesion to create strong bonds between the zeolite crystals. The resulting quartz, anorthoclase, and metabentonite phases can enhance the mechanical stability of the zeolite extrudates. In addition, the bentonite binder modifies the pore size distribution of the extrudates by generating mesopores in the 7.5–24 nm range. In contrast, adding more bentonite (26.7:100 bentonite-to-zeolite weight ratio) can reduce the specific surface area and pore volume by 35.9% and 32%, respectively. NaX zeolite extrudates are effective dehumidifying adsorbents for moisture control in confined spaces. Incorporating a bentonite binder into the extrudate creates a highly suitable hierarchical structure (mesopore-to-micropore ratio). This structure facilitates the diffusion of water vapor into the active sites within the extrudate core, thereby enhancing adsorption performance. The linear driving force (LDF) model combined with the Freundlich equation is empirically fitted to the adsorption kinetics of the zeolite extrudates. The extrudates remain stable for at least four cycles of post-regeneration with no loss in efficiency. These results demonstrate that the prepared NaX extrudates are suitable for this application and can be effectively utilized in large-scale applications.