Chemical Engineering Science, Vol.199, 508-527, 2019
Equilibrium theory of ion exchange chromatography with variable solution normality and steric hindrance
The paper extends equilibrium theory of ion exchange chromatography to account for variable solution normality and steric hindrance. Both effects are crucial for many separations including the separation of proteins. Analytical solutions are given for a full chromatographic cycle consisting of the loading of an empty bed equilibrated at different salt concentrations followed by a regeneration step. Special emphasis is on selectivity reversals. It is shown that additional reversals may occur due to a change in solution normality. Results are illustrated step by step and relation to ion exchange chromatography with constant solution normality and/or mass action equilibrium without steric hindrance is discussed. Theoretical findings are validated by comparison with numerical simulation. (C) 2019 Elsevier Ltd. All rights reserved.