Mixed matrix membranes for CO2 separations by incorporating microporous polymer framework fillers with amine-rich nanochannels

Membrane-based separation processes can improve separation efficiency and reduce the environmental hazards and energy costs of traditional separation processes. Mixed matrix membranes (MMMs) with broad development prospects are frequently restricted by interfacial incompatibility and the blockage of gas transport channels in the filler matrix. Here, we report a new type of high-valence metal-induced microporous polymer (HMMP-1) filler, with a high density of free amine groups, and having excellent alkaline stability. The HMMP-1 nanoparticles were incorporated into polyvinylamine (PVAm) to prepare facilitated transport mixed matrix membranes (MMMs). The resulting HMMP-1 based MMMs maintain their pore aperture structure, which is mainly due to the excellent compatibility between the polymer component in the HMMP-1 and PVAm. Amine-rich nanochannels with appropriate pore size allow rapid CO2 transport through the filler pores by preferential adsorption monomolecular surface diffusion, leading to high CO2 permeance and excellent separation performance for CO2/CH4, CO2/N-2 and CO2/H-2 compared with many other reported membranes. A techno-economic evaluation suggests that the MMM is feasible for carbon capture from post-combustion flue gas.

Automated summary

The introduction of the high-valence metal-induced microporous polymer (HMMP-1) filler into mixed matrix membranes (MMMs) enhances separation efficiency, with excellent alkaline stability and pore structure maintenance. The compatibility between HMMP-1 and PVAm improves the CO2 transport rate, leading to higher CO2 permeance and superior separation performance for CO2/CH4, CO2/N2, and CO2/H2 compared to other membranes.