Single and multicomponent adsorption of hexane isomers in the microporous ZIF-8

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Patrícia A. P. Mendes (Author) FEUP; Alírio E. Rodrigues (Author) FEUP; Patricia Horcajada (Author) Other; Christian Serre (Author) Other; José A. C. Silva (Author) Other

Journal

Title: Microporous and Mesoporous Materials

Vol. 194

Pages: 146-156

ISSN: 1387-1811

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 1 Citation

Associated Projects

LA 20 - PROJECTO ESTRATÉGICO - LA 20 - 2013-2014

Other information

Authenticus ID: P-009-9YJ

DOI: 10.1016/j.micromeso.2014.04.009

Abstract (EN): Single, binary and ternary breakthrough experiments of hexane (C-6) isomers n-hexane (nHEX), 3-methylpentane (3MP), and 2,2-dimethylbutane (22DMB) were performed in the microporous zinc methyl-imidazolate metal-organic framework ZIF-8, covering the temperature range between 313 and 423 K and partial pressures up to 20 kPa. Adsorption equilibrium isotherms for nHEX were collected from single component breakthrough experiments who show that the sorption behavior of linear nHEX is totally different than the one observed for the branched isomers. Indeed, while nHEX is retained in the bed the branched paraffins spontaneously breakthrough leading to an efficient separation with a remarkable working capacity (25 wt%) for nHEX at 313 K and partial pressure 10 kPa. Langmuir isotherm is found to reasonably describe the adsorption equilibrium data of nHEX while the heat of sorption reaches 32.8 kJ/mol with Langmuir equilibrium affinity constants ranging from 1.73 to 0.0624 kPa(-1) between 313 and 423 K, respectively. The ternary experiments (nHEX/3MP/22DMB) show a complete separation between nHEX and the branched isomers together with an adsorbed amount of nHEX similar to the one found in single component experiments. In the binary experiments (3MP/22DMB) the separation and sorption capacity is negligible. A fixed bed adsorption dynamic model is used to demonstrate that the complete separation of nHEX from the branched paraffins is due to a spontaneous breakthrough of the branched paraffins due to its lower diffusivity values when compared with nHEX.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11