Permeation, sorption, and diffusion of CO2-CH4 mixtures in polymers of intrinsic microporosity: The effect of intrachain rigidity on plasticization resistance

Genduso, Giuseppe; Wang, Yingge; Ghanem, Bader; Pinnau, Ingo

Permeation, sorption, and diffusion of CO2-CH4 mixtures in polymers of intrinsic microporosity: The effect of intrachain rigidity on plasticization resistance

Type

Article

Authors

Genduso, Giuseppe
Wang, Yingge
Ghanem, Bader
Pinnau, Ingo

KAUST Department

Advanced Membranes and Porous Materials Research Center
Physical Science and Engineering (PSE) Division
Chemical Engineering Program

KAUST Grant Number

BAS/1/1323-01-01

Date

2019

Abstract

CO2-CH4 mixed-gas sorption and permeation properties of a ladder polymer (PIM-Trip-TB)were measured experimentally at 35 °C to interpret nonideal transport behavior of polymers of intrinsic microporosity (PIMs). Both CH4 and CO2 mixed-gas solubilities were lower than those in the pure-gas environment mainly due to competitive sorption. In the range of pressures tested, the CO2/CH4 mixed-gas solubility selectivity of PIM-Trip-TB coincided on average with the value at infinite dilution, and at all pressures, it was higher than the pure-gas solubility selectivity. Because CO2 diffusion coefficient was found insensitive to mixture effects, we inferred that the increased diffusion coefficient of CH4 and the consequent loss of CO2/CH4 permselectivity in mixture environment were correlated to CO2-induced alteration of the selective diffusion domains of PIM-Trip-TB. Similar effects were also found for PIM-1 by an analysis of pure- and mixed-gas experimental permeation and sorption data. The increase of CH4 mixed-gas diffusion coefficients from the pure-gas values was more pronounced for both PIMs (PIM-Trip-TB and PIM-1)than for a conventional low-free volume polymer 6FDA-mPDA polyimide reported previously; this indicates that the high intrachain rigidity in PIMs cannot restrain unfavorable mixture effects on CO2/CH4 diffusion and permeability selectivity.

Citation

Genduso, G., Wang, Y., Ghanem, B. S., & Pinnau, I. (2019). Permeation, sorption, and diffusion of CO2-CH4 mixtures in polymers of intrinsic microporosity: The effect of intrachain rigidity on plasticization resistance. Journal of Membrane Science, 584, 100–109. doi:10.1016/j.memsci.2019.05.014

Acknowledgements

This work was supported by funding (BAS/1/1323-01-01)from King Abdullah University of Science and Technology (KAUST).