Numerical study of gas separation using a membrane

Computational fluid dynamics simulations are conducted for multicomponent fluid flows in a channel containing spacers. A new and unique model has been presented for the treatment of the membrane boundaries in the separation CO2 from CH4 in a binary mixture. The equation governing the flux through the membrane is derived from first principles. The membrane is modeled as a functional surface, where the mass fluxes of each species will be determined based on the local partial pressures, the permeability, and the selectivity of the membrane. The approach introduced here is essential for simulating gas–gas separation. Baseline Reynolds stress, k–ω BSL, and large eddy simulation, LES, turbulence models are employed to study spatial and temporal characteristics of the flow for Reynolds number up to 1000. It is shown here that the spacers have a strong effect on the membrane performance. The process of separating CO2 from CH4 is improved by the presence of spacers in the membrane system. It is demonstrated that spacers should be an integral part of the membrane system design in the application of gas–gas separation.