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 forregenerationof sorbents during separation processes. In this work, we investigatedthe efficacy of magnetic sorbents comprising iron oxide and zeolite13X in ethylene/ethane separation via a magneticinduction process. The electromagnetic properties of the sorbentswere tuned by varying the iron oxide (Fe2O3)particle size (30 nm, 100 nm, 5 mu m) and iron oxide phase structure(FeO, Fe2O3, Fe3O4) at20 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 reducedby increasing the particle size of Fe2O3 from30 nm to 5 mu m. The results indicated that regardless of ironoxide particle size or phase structure, the C2H4/C2H6 selectivity ranges between 2.44 and 2.65for all the magnetic sorbents. The specific heat absorption rate (SAR) was increased by similar to 60% upon increasing the magneticfield intensity from 21.4 to 31.4 mT when the particle size increasedfrom 30 nm to 5 mu m. Fe3O4 was found tooutperform the other phases by exhibiting 91.3 and 93.3% higher SAR than Fe2O3 and FeO at 31.4 mT,respectively, owing to its unique lattice structure with dual ionstates (Fe2+ and Fe3+). Fe3O4/13X exhibited an ethylene desorption rate of 0.41 mmol/g center dot minat 21.4 mT, which was 58.5% faster than that under conventional thermalheating. Additionally, the sorbent was found to be highly durable,maintaining its adsorption and desorption capabilities over five consecutivecycles in the magnetic induction swing adsorption (MISA) process,conducted at 25 degrees C and 1 bar during adsorption and at 31.4 mTduring desorption. These results indicate the potential of Fe3O4/13X as an effective magnetic sorbent in theMISA process. This study builds on our previous proof-of-concept workon the potential of magnetic sorbents as stimuli-responsive materialsfor light olefin/paraffin separation. Fe3O4/13X-zeolite is designed as ahybrid magnetic sorbent to enhance sorbent regeneration in ethylene/ethaneseparation.