非晶質フッ素樹脂の気体透過性および分離特性

Abstract

The membrane gas separation process is the best method of all separation methods from the viewpoint of energy saving. The process is expected to be beneficial for O2 enrichment, CO2 capture and Helium separation from natural gas. Although organic materials for membrane separation are inferior in chemical resistance, fluoropolymers have excellent chemical resistance. Permeability and selectivity of membranes of four amorphous fluoropolymers, which are different in structure and formation, are measured in this report. Permeability relates with the kinetic diameter of a gas. The smaller the gases kinetic diameter is, the larger the permeability becomes except for Helium. On the other hand, the density of polymer membranes relates to permeability, diffusivity, and solubility exponentially. Permeability decreases exponentially as density becomes larger. Furthermore, selectivity relates with density exponentially. The selectivity of O2/N2 of CYTOP is 4, and He/CH4 is about 300. It is 4 times and 40 times respectively as much as for AF-2400. CYTOP is expected to be an excellent separation membrane for O2 enrichment and Helium separation.