Abstract
Processes, such as biogas upgrading and natural gas sweetening, make CO2/CH4 separation an environmentally relevant and current topic. One way to overcome this separation issue is the application of membranes. An increase in separation efficiency can be achieved by applying mixed-matrix membranes, in which filler materials are introduced into polymer matrices. In this work, we report the covalent triazine framework CTF-biphenyl as filler material in a matrix of the glassy polyimide Matrimid®. MMMs with 8, 16, and 24 wt% of the filler material are applied for CO2/CH4 mixed-gas separation measurements. With a CTF-biphenyl loading of only 16 wt%, the CO2 permeability is more than doubled compared to the pure polymer membrane, while maintaining the high CO2/CH4 selectivity of Matrimid®.
Highlights
Due to the high solubility of CO2 in ionic liquid (IL) [24,25,26] and noted positive effects of ILs on membrane performance [27,28,29], we investigated the incorporation of the IL 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, [BMIm][NTf2 ] in the covalent triazine frameworks (CTFs)/Matrimid® matrix membranes (MMMs)
CTF-biphenyl was synthesized via Friedel–Crafts-alkylation from cyanuric chloride and biphenyl to be applied as porous filler material in Matrimid® matrices
CO2 /CH4 mixed-gas measurements of the prepared CTF/Matrimid® MMMs resulted in an increase in CO2 permeability, while maintaining constant selectivity
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Since the first large-scale application of a hydrogen-separating membrane in the
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
