Abstract

Magnetic induction has emerged as a viable method for regeneration of sorbents during separation processes. In this work, we investigated the efficacy of magnetic sorbents comprising 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 indicated that regardless of iron oxide particle size or phase structure, the C2H4/C2H6selectivity ranges between 2.44 and 2.65 for all the magnetic sorbents. The specific heat absorption rate (SAR) was increased by ∼60% upon increasing the magnetic field intensity from 21.4 to 31.4 mT when the particle size increased from 30 nm to 5 μm. Fe3O4 was found to outperform the other phases by exhibiting 91.3 and 93.3% higher SAR than Fe2O3and FeO at 31.4 mT, respectively, owing to its unique lattice structure with dual ion states (Fe2+and Fe3+). Fe3O4/13X exhibited an ethylene desorption rate of 0.41 mmol/g·min at 21.4 mT, which was 58.5% faster than that under conventional thermal heating. Additionally, the sorbent was found to be highly durable, maintaining its adsorption and desorption capabilities over five consecutive cycles in the magnetic induction swing adsorption (MISA) process, conducted at 25 °C and 1 bar during adsorption and at 31.4 mT during desorption. These results indicate the potential of Fe3O4/13X as an effective magnetic sorbent in the MISA process. This study builds on our previous proof-of-concept work on the potential of magnetic sorbents as stimuli-responsive materials for light olefin/paraffin separation.

Department(s)

Chemical and Biochemical Engineering

Comments

National Science Foundation, Grant CBET-2019350

Keywords and Phrases

13X; C H /C H separation 2 4 2 6; Fe O 3 4; induction heating; magnetic sorbent

International Standard Serial Number (ISSN)

2168-0485

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 American Chemical Society, All rights reserved.

Publication Date

12 Jun 2023

 
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