Modeling shock layers in ion-exchange displacement chromatography

In ideal displacement chromatography (systems with infinite mass-transfer k inetics), various solutes are separated by sharp discontinuities In real sy stems, however, the shocks are eroded into shock layers because of the fini te rates of mass transfer The thickness of these shock layers, which can re duce the yields achievable in these systems, depend on the flow rate, parti cle diameter and the "difficulty" of these separations. The steric mass act ion formalism of ion-exchange chromatography was toed in concert with a sol id film lineal driving force model to describe the effects of flow rate, pa rticle diameter; and the degree of difficulty of the separation on ion-exch ange displacement systems. Simple pulse techniques are employed to estimate the thermodynamic and mass-transfer parameters. The simulations are then c ompared to experimental results over a range of conditions. The results dem onstrate that this relatively simple modeling approach can be employed to d escribe the behavior of these nonideal displacement systems.