화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.52, No.3, 1079-1088, 2013
Modeling Gas Permeation by Linking Nonideal Effects
Conventional models for simulating gas-separation processes often neglect nonideal effects such as concentration polarization, the Joule-Thomson Effect, pressure losses, and real gas behavior. This study presents a comprehensive model which accounts for such nonideal effects and can be applied in commercial process simulations. A model of a hollow-fiber gas permeation module was programmed in Aspen Custom Modeler. In general, pure gas measurements at a single feed pressure were sufficient to predict the mixed gas behavior of the module. The influence of nonideal effects on the module efficiency was investigated in two case studies addressing the separation of CO2/propane and CO2/methane gas mixtures. For the first case, the curves of CO2 concentration versus module length were congruent for both ideal and realistic scenarios. The divergence of the curves in the second case was attributed to the influence of cummulating nonideal effects. The simulations are in agreement with the new data obtained for these gas mixtures measured at a commercial polyimide membrane module. The model predicts the experimental gas permeation data, in particular, when nonideal effects are pronounced. Ultimately, this model can easily be used in process simulation and enables optimization of large-scale gas separation systems.