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Confined facilitated transport within covalent organic frameworks for propylene/propane membrane separation.
- Source :
-
Chemical Engineering Journal . Jul2022, Vol. 439, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- [Display omitted] • COF-based membranes are utilized for C 3 H 6 /C 3 H 8 separation for the first time. • Large-sized COF pores can achieve maximum contact between Ag+ and C 3 H 6 molecules. • High-density Ag+ facilitates C 3 H 6 confined transport along nanochannel surface. • Density differences result in asymmetric structure and directional transport. • Confined mechanism with asymmetric structure provide superior separation performance. Energy-efficient membrane technology is sought to replace or integrate with conventional energy- and cost-intensive distillation for precise propylene/propane separation. Covalent organic framework (COF)-based composite membranes (CMs) are promising candidates for the representative difficult propylene/propane separation system. However, the large-size pore of COFs cannot achieve an effective separation of gas pairs with sub-angstrom (0.2 Å) size differences. Here, we design confined facilitated transport nanochannels within COFs as productive fillers to construct CMs. The anchored high-density Ag+ carriers facilitate C 3 H 6 monomolecular high-speed transport along the nanochannel surface. Under this confined transport mechanism, the problem of over-sized COF pores can be partially circumvented, and high selectivity obtained. Moreover, the obtained asymmetric configuration of SCOF-Ag/PI CMs results in directional gas transport. As the first work of COF-based membranes for olefin/paraffin separation, SCOF-Ag/PI CMs demonstrate a high propylene permeability of 75.16 barrer and good propylene/propane selectivity of 35.45, out-performing most of the polymer-based membranes and approaching the performance of ZIF-8 membranes. Furthermore, SCOF-Ag/PI CMs exhibit over one-month durability. The excellent separation performance combined with operating stability provides a promising alternative approach toward efficient C 3 H 6 /C 3 H 8 separation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13858947
- Volume :
- 439
- Database :
- Academic Search Index
- Journal :
- Chemical Engineering Journal
- Publication Type :
- Academic Journal
- Accession number :
- 156229440
- Full Text :
- https://doi.org/10.1016/j.cej.2022.135657