EFFECTS OF HEAT RELEASE AND NONLINEAR EQUILIBRIUM ON TRANSIENT ADSORPTION

The presence of a thermal effect on the chromatographic peak has been demonstrated. The apparent retention times and adsorption equilibrium constants when a thermal effect exists are significantly less than the true values. The temperature rise due to the heat of adsorption is insufficient by itself to explain the phenomenon. It is believed that intraparticle temperature gradients causing localized desorption account for the observed results. The dispersion (second moment) of the peak is much less affected by thermal and nonlinear rate effects. Data obtained for n-butane adsorbed on a bed of silica gel indicate that linear theory can be used to obtain reasonably accurate values for the axial dispersion coefficient and intraparticle diffusivity. © 1969, American Chemical Society. All rights reserved.