Axial Dispersion Model for a Chromatography Column

Generally for modelling chromatograph systems, component mass balances are required for each component in each phase. The differential liquid phase component balances for a chromatographic column with non-porous packing take the partial differential equation form 

The linear superficial flow velocity in the packing voids v, is calculated from volumetric flow rate Ljn, voidage fraction of the adsorbant bed e and column diameter d as 

The transfer rate of the sorbate from the liquid phase to the solid adsorbant rajs can be written as 

Here the rate is specific to a unit volume of solids (g/cm s) and k is a mass transfer rate coefficient (1/s). 

The solid phase concentrations are influenced only by the rate of mass transfer, with convection and dispersion effects both being zero for this phase. 

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