Rapid Adsorption−Desorption in Direct Air Capture Using 3D-Printed Amine Adsorbents with Electromagnetic Induction Heating

Abstract Direct air capture (DAC) is a promising strategy to address climate change and achieve carbon neutrality goals. The development of an adsorbent material with a high capacity, low pressure drop, and short regeneration period is necessary for high-performance DAC. Here, we incorporated direct ink writing (DIW) for tetraethylenepentamine (TEPA)-loaded silica gel adsorbent preparation and induction heating techniques to enable a fast CO2 adsorption/desorption cycle for efficient CO2 capture. Fe3O4 and TEPA loadings and the drying methods were evaluated for adsorption/desorption performance. Under 430 ppm of CO2, the CO2 adsorption capacities reached 1.57 and 1.11 mmol/g for powdered silica gel and monolithic silica gel, respectively. The desorption process can be completed in ca. 25.5 min at 85 °C in magnetic induction swing adsorption (MISA), affording a saving of ca. 70% reduction of desorption time when compared to conventional heating. The addition of methyl cellulose was beneficial for adsorbent stability and structure strength enhancement. This work offers insights into high-throughput CO2 capture and demonstrates the feasibility of the MISA system for use with amine-loaded adsorbents for DAC.