Modeling of desorption at supercritical conditions

[[abstract]]©1989 Wiley - In recent papers, C.S. Tan and D.C. Liou (1988a, b) studied the desorption of activated carbon loaded with either ethyl acetate or toluene, by supercritical carbon dioxide. In their study, an optimal desorption temperature of around 313 K was observed when the operating pressure was over 10.13 MPa. A single-parameter model assuming linear desorption kinetics was proposed by these authors, and was found to match the experimental data quite well. The apparent desorption activation energies at fixed pressures could then be obtained through the plot of the desorption rate constants vs. the reciprocal of temperature, i.e., the Arrenhuis expression. In the past years it has been realized that density plays a important role at supercritical conditions. It may be more suitable to calculate the apparent desorption activation energies at fixed densities, than at fixed pressures. The objective of the present note is to see if this suitability exists, and to propose a proper relation between desorption rate constant, and density.[[department]]化學工程學