adsorbed during feed steps of the cycle. Clearly the energy Isosteric heats of gas-mixture adsorption required in the energy balance cannot be ignored or treated with poor, approximate balances of adsorption process design are calculated using a thermodels if such processes are to be commercialized. Indeed, modynamically consistent multicomponent isotherm. This isothe first pressure swing adsorbers (PSA) were marketed as therm and the resulting heats of adsorption possess proper limiting ''heatless driers'' because the beds were sized so that the behavior and account for adsorbates of different sizes. Binary and heat of adsorption was retained within the bed (1). The ternary mixtures are used as examples. Consideration of the temeffects of temperature on the adsorption isotherm and conseperature dependence of the adsorbed phase density or alternately quently on a PSA operation have also been recognized in of the saturation capacity leads to coupling of contributions from the industry (2, 3). each component to isosteric heats of adsorption of other components in the mixture. For the binary example used, this reduces
While modern bed design has certainly evolved since the difference between isosteric heats in the mixture and correthose early days by taking advantage of powerful computing sponding pure gas heats at the same fractional loading, in comparito perform model simulations, there are still some aspects son to predictions where the saturation capacity is assumed to be of the incorporation of the heat of adsorption that require independent of temperature.