Three-phase hybrid facilitated transport hollow fiber membranes for enhanced CO2 separation

Saravanan Janakiram,Juan Luis Martín Espejo,Karen Karolina Høisæter,Arne Lindbråthen,Luca Ansaloni,Liyuan Deng

doi:10.1016/j.apmt.2020.100801

Saravanan Janakiram, Juan Luis Martín Espejo + Show 4 more

Open Access

https://doi.org/10.1016/j.apmt.2020.100801

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Abstract

The configuration of thin film composite (TFC) in the form of hollow fiber is desired for gas separation membranes to achieve better gas permeation and higher packing density. In this work, we developed and tested TFC hollow fiber membranes with a defect-free, ultrathin (200 nm) hybrid facilitated transport selective layer consisting of three phases, i.e., a host polymeric matrix with fixed-site carriers, a 2D inorganic filler, and, a CO2-philic mobile carrier. The effect of lateral size of graphene oxide (GO)-based fillers on CO2 permeation were studied in detail, and the modified size-optimized porous GO (pGO) fillers were found to enhance CO2 permeation at a very low loading of 0.2 wt%. The optimized hybrid materials were then combined with selected mobile carriers, which interact with CO2 reversibly to form carbonate/carbene-CO2 adduct to further enhance the CO2 permeation performance. The resulting hybrid facilitated transport membranes with mobile carriers showcase a CO2 permeance of up to 825 GPU with a CO2/N2 separation factor of 31 and a CO2/CH4 of 20. These membranes also exhibit increased resistance to carrier saturation phenomena typical of facilitated transport membranes, showing potential for CO2 separation applications also at elevated pressures.

Highlights

Membranes offer a potential solution for applications related to CO2 separation due to their high modularity, lower footprint, easier up-scaling, and lower environmental impact when compared to conventional amine-based absorption systems [1,2,3,4]
We report the first three-phase hybrid facilitated transport membranes (HFTMs) in thin film composite (TFC) hollow fiber configuration with outstanding separation performance
graphene oxide (GO)-based fillers were found to benefit HFTMs to increase the CO2 separation properties depending on their lateral dimensions and loading. porous GO (pGO) fillers derived from size-optimized GO nanosheets enhanced CO2 permeation effectively at a loading of 0.2 wt%

Summary

Introduction

Membranes offer a potential solution for applications related to CO2 separation due to their high modularity, lower footprint, easier up-scaling, and lower environmental impact when compared to conventional amine-based absorption systems [1,2,3,4]. In order to be competitive and industrially attractive for gas separation applications, membranes should be characterized with high permeability and selectivity. The successful development of membrane materials is benchmarked with improvements in transmembrane CO2 flux (permeance), which reduces the effective membrane area required to achieve targeted separation [12,13,14]. Such membranes are, in general, fabricated in the form of thin film composite (TFC) as flatsheet or hollow fiber membranes with a stable, selective layer typically with a thickness of a few hundred nanometers [15]

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