ABSTRACT
The procedure laid down in the text showed three requirements for the evaluation of this case: equilibrium feed compositions for light and heavy component, and the pure component isotherm for the light species. These isotherms, although of elementary form, yield a surprisingly good picture of the general behavior of binary systems and are therefore retained for general instructional purposes. Binary feeds can contact a bed under a variety of different conditions: the bed may be clean, or it may be preloaded with either heavy or light component, or even both. Mathematically, the watershed point and its concentrations result from the special case when the quadratic differential Equation exhibits a double root, much as simple second-order differential equations exhibit double roots which signal the transition from exponential to periodic solutions. For desorption the path leads along characteristics and isotherms and results in two broadening fronts because of the increase in slope.
