Multicomponent separation calculations by the modified form of Newton's method

Abstract

A method for solving multicomponent separation processes at steady state is described. The modified form of Newton's method was applied to solve the equations set equal to zero where the variables were the temperature and vapor flow profiles. The modified form of Newton's method keeps the Jacobian matrix unchanged for several iterations and thereby saves computer time. The method presented here was extended to include the use of vapor-liquid equilibria (K values), which depend not only upon temperature but also upon composition. It is apparent that the use of composition-dependent K values improves the steady state results of simulation of multicomponent separation processes. The method is applied to the steady state calculation of two cases: absorber with reboiler and distillation column.