3D-Printed Zeolite Monoliths for CO₂ Removal from Enclosed Environments

Structured adsorbents, especially in the form of monolithic contactors, offer an excellent gas-solid contacting strategy for the development of practical and scalable CO₂ capture technologies. In this study, the fabrication of three-dimensional (3D)-printed 13X and 5A zeolite monoliths with novel structures and their use in CO₂ removal from air are reported. The physical and structural properties of these printed monoliths are evaluated and compared with their powder counterparts. Our results indicate that 3D-printed monoliths with zeolite loadings as high as 90 wt % exhibit adsorption uptake that is comparable to that of powder sorbents. The adsorption capacities of 5A and 13X monoliths were found to be 1.59 and 1.60 mmol/g, respectively, using 5000 ppm (0.5%) CO₂ in nitrogen at room temperature. The dynamic CO₂/N₂ breakthrough experiments show relatively fast dynamics for monolithic structures. In addition, the printed zeolite monoliths show reasonably good mechanical stability that can eventually prevent attrition and dusting issues commonly encountered in traditional pellets and beads packing systems. The 3D printing technique offers an alternative, cost-effective, and facile approach to fabricate structured adsorbents with tunable structural, chemical, and mechanical properties for use in gas separation processes.