Enhancing Desorption Performance of a Compressible Hybrid Structured Adsorbent via Localized Magnetic Induction Heating

Structured adsorbents have gained significant importance in gas separation applications due to their ability to fine-tune mass and heat transfer and lower pressure drop across the bed. This study presents a ferromagnetic compressible hybrid structured adsorbent, allowing regeneration via magnetic induction heating. A compressible melamine sponge is coated with the CO₂-selective Ni-MOF-74 adsorbent and Fe₃O₄ as a ferromagnetic susceptor, capable of dissipating heat instantaneously in an alternating electromagnetic field. Taking advantage of these properties, the potential of rapid CO₂ capture and thermal regeneration via magnetic induction swing adsorption is investigated. The successful incorporation of both ingredients on the melamine sponge is confirmed via SEM-EDX and XRD analysis. Breakthrough experiments with a CO₂/CH₄-mixture are performed. The selective property of Ni-MOF-74 toward CO₂ is retained, with the composite showing a capacity of 1.89 mmol CO₂/g. The compressible nature of the melamine sponge allowed for an improvement of 79% in the volumetric capacity of the adsorbent bed and a higher heating rate. In regard to regeneration, within 1 min of subjecting the structured composite to the alternating magnetic field, an efficient desorption (>90%) of CO₂ is achieved. Overall, a ferromagnetic compressible hybrid structured adsorbent is presented for fast cyclic gas-phase separation processes.