Theoretical Study of CO2/N2Gas Mixture Separation through a High-Silica PWN-type Zeolite Membrane

Abstract

PWN is classified as a member of the second generation of the RHO zeolite family, which is extended by embeddingisoreticular structures. Here, we report the performance of a pure silica PWN-type (Si-PWN) zeolite membrane for separation ofnitrogen (N2) and carbon dioxide (CO2) gas molecules using molecular dynamics simulations. The simulations were performed atdifferent temperatures and applied pressure up to 10 MPa. It is found that the N2molecules can easily penetrate through Si-PWN,whereas no CO2molecule passage was seen owing to the strong van der Waals (vdW) interactions between CO2molecules and theSi-PWN membrane. Hence, the results suggested that Si-PWN has a very high selectivity of N2over CO2. Furthermore, the best N2permeance of 7.24x105GPU across the membrane was obtained at 348 K and 0.25 MPa, which indicates the remarkableperformance of Si-PWN in N2/CO2separation