Estimation of minimum reflux in distillation and multipoint boundary value problems

Abstract The problem of estimating the minimum reflux ratio is treated as a non-linear multipoint boundary value problem in difference equations. If the problem has a solution, the minimum reflux ratio and the compositions in the column are obtained simultaneously by quasilinearization iteration. With very rough initial approximations or starting values, only nine iterations are needed to obtain a four digit accuracy in concentration. A three digit accuracy in distillate rate is obtained in seven iterations.