Computation of Feasible Solutions in Multicomponent Distillation Columns Using Stage-to-Stage Method

This paper presents a simulation method for obtaining feasible and optimal solutions for multicomponent distillation columns. The method employs a stage-to-stage computational procedure by adjusting the bottom liquid compositions as independent variables. For infeasible solutions, computation is continued by assuming the vapor-liquid equilibrium ratio to be constant, and the objective function is evaluated to find both feasible and infeasible solutions. By minimizing the objective function iteratively, feasible solutions are obtained at a location near the optimal solutions. The McCabe-Thiele method used as a trial-and-error method is proved to converge by use of the present procedures. Numerical results are shown for ideal mixtures of solutions.