Abstract
Polysulfone (PSF)-based mixed-matrix membranes (MMMs) were developed through incorporation by solvent casting of poly(ethylene glycol)-grafted carbon nanotubes (PEG-g-CNTs) into the polymer matrix. Single-gas permeability and the respective perm-selectivity values of the resulting MMMs for CO2, CH4, and N2 along with mixed-gas selectivities were determined at various temperatures and pressures. The performance was further analyzed by obtaining gravimetrically gas adsorption isotherms and interpreting the results to determine the solubility and diffusivity coefficients of the prepared membranes. Simultaneous improvement in CO2 permeability, selectivity, and mechanical robustness was achieved. Indicatively, an increase in CO2 permeability by 52.4% at 1.5 bar was discerned for the MMM containing 5 wt % PEG-g-CNTs along with enhancements of 81 and 74% in CO2/N2 and CO2/CH4 perm-selectivities, respectively, while an up to 43.4% increase in tensile modulus and a 12.5% increase in tensile strength were achieved as well. This performance, in conjunction with the stability of the fillers, and the low cost, structural stability, and commercial availability of the polymer make the PSF/PEG-g-CNT MMM a promising base case for developing industrially relevant CO2 separation membranes.
Highlights
Carbon capture, utilization, and storage (CCUS) is currently the most promising strategy to face the continuously increasing CO2 accumulation in the atmosphere and the associated environmental impact, caused mainly by anthropogenic sources such as fossil fuel combustion and other industrial emissions.[1−5] Membranes constitute a major share in the efforts for energy-efficient gas separation with particular focus on applications related to carbon dioxide removal, air purification, gas sweetening, post enhanced oil recovery separation, and more
A major peak attributed to stretching of the hydroxyl groups of poly(ethylene glycol) (PEG) was observed at 3426 cm−1
A peak corresponding to the C−O stretch of ester between PEG and carbon nanotubes (CNTs) was evidenced at 1133 cm−1
Summary
Utilization, and storage (CCUS) is currently the most promising strategy to face the continuously increasing CO2 accumulation in the atmosphere and the associated environmental impact, caused mainly by anthropogenic sources such as fossil fuel combustion and other industrial emissions.[1−5] Membranes constitute a major share in the efforts for energy-efficient gas separation with particular focus on applications related to carbon dioxide removal, air purification, gas sweetening, post enhanced oil recovery separation, and more. Various attempts have been made to introduce such surface functionalities on CNTs by chemical modifications involving hydrophilic groups, PEG, chitosan, β-cyclodextrin, amino acids, etc.[92] Fonseca et al.[93] reported Pebax-based MMMs loaded with amine-functionalized MWCNTs. Compared to pure polymers, the MMMs showed a 40% improvement in CO2 permeability. The resulting membrane with 3 wt % filler exhibited higher CO2 permeability and CO2/N2 selectivity for dry CO2/N2 mixtures.[107] Khan et al.[108] prepared PIM-1-based MMMs loaded with PEG-functionalized CNTs. Functionalization of the CNTs helped in improving their dispersion in the PIM-1 matrix. The resulting MMMs showed enhanced CO2 permeability with improved O2/N2 and CO2/N2 selectivity owing to the strong interfacial adhesion and absence of voids between the polymer matrix and filler. Single-gas and mixed-gas separation studies were performed at various pressures, temperatures, and feed compositions, while adsorption experiments and kinetics evaluation shed light on the solubility and diffusivity coefficients of the prepared membranes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
