The nonequilibrium dynamics of adsorption in a stationary bed of aluminosilicate adsorbent was mathematically described on the example of dearomatization of the 200-320 degrees C fraction of liquid paraffins. The characteristics obtained indicate the important effect of the initial concentration of adsorbate in the feedstock and the temperature and flow rate of the feedstock on the process diffusion parameters. This effect must be taken into consideration in designing industrial adsorbers.