Tianjin University Develops Novel Membrane for Enhanced Carbon Capture

A research team at Tianjin University has developed a new type of all-organic mixed-matrix membrane, potentially offering a more efficient and scalable approach to carbon capture. The membrane combines high separation performance with long-term stability and large-scale processability.

The study, published in Nature Energy, addresses the growing interest in membrane separation for carbon capture due to its potential advantages in energy efficiency and environmental performance. However, separating CO2 from industrial flue gases remains challenging, requiring membranes that can facilitate rapid CO2 transport, effectively separate other gases, and maintain stable performance over time.

Traditional mixed-matrix membranes have faced limitations due to compatibility issues between polymers and porous fillers. The Tianjin University team, led by Professors Jiang Zhongyi and He Guangwei, introduced a strategy that balanced weak interactions. By utilizing single-crystalline covalent organic frameworks (COFs) as fillers, they achieved uniform incorporation within a polymer matrix. The resulting membrane retained the polymer's flexibility and processability, while the ordered pores of the COF crystals provided efficient pathways for CO2 transport.

Tests using simulated flue gases showed a tenfold increase in CO2 permeability, setting a new record. The membrane also demonstrated significant long-term stability under conditions including water vapor, sulfur oxides, and nitrogen oxides. Preliminary techno-economic analysis estimated the cost of carbon capture at approximately $38 USD per ton of CO2, based on the study's assumptions. This development could pave the way for new membrane separation technologies supporting future carbon capture applications in power generation and the cement and steel industries.