Atomistic understanding of gas separation through nanoporous DDR-type zeolite membrane

Abstract Molecular dynamics simulations were applied to evaluate the Kr/Xe separation performance by a pure silica DDR type membrane. The external pressure was used up to 50 MPa in order to transfer the gas atoms through the membrane. The process was also studied at temperatures ranging from 293 to 373 K. The membrane exhibited best Kr atoms permeation (177.25×10-5 mol/(m2∙s∙Pa)) and selectivity at P=10 MPa and T=373K, which indicates by increasing temperature without applying higher pressures, the best separation performance can be achieved. The potential of the mean force (PMF) of Kr and Xe confirmed the necessity of applying the driving force for penetration of Kr or Xe atoms through the DDR membrane. Furthermore, the PMF curve demonstrated the higher energy barrier for the passage of Xe through the DDR membrane compared with Kr, which was also verified by simulation outcomes.