Calculation procedures for binary batch rectification

AbstractA rigorous mathematical description, consisting of differential‐difference equations, is presented for binary batch rectification in the plate type of column. Two approaches are taken to solving these equations for the condition of constant reflux ratio: an integration by numerical means employing an IBM 650 computer, and a hand calculation procedure that involves trial‐and‐error computation of batch‐rectification curves, which is of interest primarily where high‐speed computing equipment is not available.Enthalpy balances are used to avoid assumption of equal rate of overflow in the tower; weight units are used instead of mole units; means for accounting for holdup in the condenser‐accumulator system are described. Criteria of convergence and stability of the numerical solution are presented. The validity of the results of the proposed calculation procedures is substantiated by the close agreement of experimental and calculated batch‐rectification curves.