(412a) Magnetic Induced Swing Adsorption over Iron Oxide/13X: Effects of Particle Size and Oxide Phase on Sorbent Regeneration in Ethylene/Ethane Separation

Magnetic induction has emerged as a viable method for regenerating sorbents during separation processes. In this work, we investigated the efficacy of magnetic sorbents comprising of iron oxide and zeolite 13X in ethylene/ethane separation via a magnetic induction process. The electromagnetic properties of the sorbents were tuned by varying the iron oxide (Fe₂O₃) particle size (30 nm, 100 nm, 5 µm) and iron oxide phase structure (FeO, Fe₂O₃, Fe₃O₄) at 20 wt% loading. The effects of these parameters on adsorption capacity, selectivity, and desorption rates were systematically investigated. The microporosity and surface area of magnetic sorbents were reduced by increasing the particle size of Fe₂O₃ from 30 nm to 5 µm. The results also indicated that regardless of iron oxide particle size or phase structure, the C₂H₄/C₂H₆ selectivity ranges between 2.63-2.85 for all the magnetic sorbents. The specific heat absorption rate (SAR) was increased by ~ 60% upon increasing the magnetic field intensity from 12.6 to 31.4 mT when the particle size increased from 30 nm to 5 µm. The Fe₃O₄ was found to outperform the other phases by exhibiting 91.3% and 93.3% higher SAR than Fe₂O₃ and FeO at 31.4 mT, respectively, on the basis of its unique lattice structure. The Fe₃O₄/13X exhibited an ethylene desorption rate of 0.41 mmol/g.min at 12.6 mT, which was 58.53% faster than that under conventional heating. Fe₃O₄/13X was then formulated into a monolithic structure using 3D-printing, and the desorption performance was assessed under a hybrid induction vacuum swing adsorption process (IVSA). The findings revealed that the ethylene desorption rate was notably improved when induction heating and vacuum were utilized simultaneously as the means of stimulating sorbent regeneration. This work builds on our previous proof-of-concept work on the potential of magnetic sorbents as stimuli-responsive sorbents for olefin/paraffin separation.