Abstract
A very general form of the basic column equations is presented which allows a wide choice in the form of the specifications of variables required to define the column operation. Variable plate holdups, variable plate efficiencies, heat losses from the column, and finite time liquid flow dynamics are some of the specifications considered. The values of the implicit column variables during the unsteady state period are found by a method which is independent of the numerical procedure chosen to solve the differential equations. Computer runs with the Kutta‐Merson method used to solve the differential equations were made for a column approaching steady state at total reflux. The effect of different variable specifications on this computer column are discussed.