Improved numerical methods for simulating complex mixture transport across asymmetric polymer membranes using a Maxwell–Stefan model

Improved numerical methods are presented for predicting the total flux and permeate composition of complex hydrocarbon mixtures permeating through asymmetric glassy polymer membranes. The proposed methods are comprehensively compared against a suite of existing methods for several challenging test cases; namely, three and nine component mixtures permeating through a glassy polymer, SBAD-1, and a five component mixture permeating through a glassy polymer, PIM-1. We find that the proposed shooting algorithm is the most accurate, efficient, and robust for these test cases. In comparison, existing methods based on common model simplifications suffered from large errors and frequent convergence failures for higher component mixtures, while those based on numerical discretization techniques suffered from higher cost and needed much more careful tuning to provide reliable solutions.