Abstract
Current sorbents investigated for light olefin/paraffin separation usually suffer from low selectivity. Besides, multicomponent analysis of this important separation is usually overlooked in the literature. To enhance the separation efficiency of zeolite 13X, we developed a series of Fe2O3/13X composite sorbents and assessed their separation performance using binary, ternary, and multicomponent gas mixtures of C2H4, C2H6, CH4, and H2. In these composites, nano- and micro Fe2O3 particles (NPs and MPs) with varied loadings were used, while Fe was also ion-exchanged into the 13X zeolite structure. The microporosity and surface area of the bare sorbent were reduced upon increasing Fex loading for all particle sizes. However, Fe1(NPs)/13X demonstrated a higher C2H4 adsorption capacity and C2H4/C2H6 selectivity despite its lower surface area, which was attributed to its higher surface electron transfer property that enhanced its adsorption performance via electrostatic interactions. Additionally, the incorporation of Fe1 into the 13X framework resulted in narrowing of the micropore channels, thereby promoting the molecular sieving effect and improving the selectivity toward C2H4. The dynamic adsorption results revealed the reduction in C2H4/(C2H6 + CH4 + H2) selectivity in the presence of impurity gases (CH4 and H2), from 4.10 to 3.84 and 3.20 for binary, ternary, and multicomponent gas mixtures, respectively. Nevertheless, the C2H4/C2H6 selectivity was found to be roughly constant at ∼4 across all feed conditions. Moreover, the affinity of Fe1(NPs)/13X toward different adsorbates from the most adsorbed to the least adsorbed component was in the order of C2H4 > C2H6 > CH4 > H2, while the rates of species transport were found to be primarily dependent on the rates of molecular diffusion within the pores of the 13X zeolite.
Recommended Citation
K. Baamran et al., "Kinetic Assessment Of Light Hydrocarbons Separation Over Fe-Doped 13X Composite Sorbents Under Multicomponent Feed Conditions," Industrial and Engineering Chemistry Research, American Chemical Society, Jan 2023.
The definitive version is available at https://doi.org/10.1021/acs.iecr.3c00620
Department(s)
Chemical and Biochemical Engineering
International Standard Serial Number (ISSN)
1520-5045; 0888-5885
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2023 American Chemical Society, All rights reserved.
Publication Date
01 Jan 2023
Comments
National Science Foundation, Grant CBET-2019350