Large-scale preparation of multilayer composite membranes for post-combustion CO2 capture

Membrane technology is a promising strategy in flue gas CO2 capture. Recently, many high-performance multilayer composite membranes for CO2/N2 separation were successfully developed in the laboratory. However, the detailed scaling-up processes were rarely discussed due to the lack of mature technology and equipment that specially designed for the proven advanced membrane materials. This study investigated the large-scale production of the defect-free thin multilayer composite membrane for flue gas CO2 capture. A novel coating machine with double blades and surface cross-linking unit was designed, and the industrial scale multilayer composite membranes were prepared by running the coating machine twice. The coating solution stability of intermediate layer solution was prolonged to more than 72 h. The key technologic parameters including web speed and the concentration of cross-linking unit were analyzed. The continuously prepared multilayer composite membrane shows high and stable CO2/N2 performance and great potential in the application of flue gas CO2 capture.