A Second-Order Time-Accurate Method for Determination of Concentration Distribution of Multicomponent Mixtures in Separation Cascades

Abstract

An implicit method is presented to study the transient process of concentration distribution of multicomponent mixtures in separation cascades for gases. The problems that the first-order method (the so-called “transient approach”) encounters have been overcome. The new method is second-order accurate in time and unconditionally stable. The nonlinear difference equations at each time step are solved by the q-iteration method. A simple cascade is studied as an example, and comparisons are made with the first-order “transient approach.” The results show that the new method is advantageous over the “transient approach” in both accuracy and computational efficiency.