In thermal parametric pumping, the temperature change can be imposed through the bed jacket (direct mode) or through temperature change of the fluid stream (recuperative mode). The process to be addressed here is thermal parametric pumping operating in a combined mode of operation by changing the temperature of the fluid stream before entering the packed bed through a heat exchanger (recuperative mode) at the same time as imposing a temperature change through the bed jacket (direct mode). Axial dispersion and the general non-linear form of the equilibrium isotherm were taken into account in the mathematical model used to verify the experimental results of separating a binary liquid mixture of a benzene/n-hexane/silica gel system. (C) 2003 Society of Chemical Industry.