Calculation of multistage countercurrent separation processes-I. Multicomponent multistage rectification by differentiation with respect to an actual parameter

The method proposed generates without trial-and-error a family of solutions depending on a sequence of values of a parameter under consideration, e.g. reflux ratio, side-stream flows, condenser duty etc. The technique may be successfully used for a parametric study of a particular column. The method requires the knowledge of the solution of the distillation problem for the initial value of the parameter considered. The procedure is effective for cases where solution for a great number of parameter values is required.