Phenomenological Sorption Thermodynamics

The thermodynamics of sorption of pure substances and of mixtures from the vapour or the liquid phase on sorbents of different types are discussed. The stoichiometric theory of adsorption and the osmotic theory (based on the vacancy solution model) are analysed in detail, as well as the most recent advances in the theory of volume filling of micropores. The following problems are examined: the validation of the model, and of the choice of components of the sorption solution, the methods of calculating the appropriate activity coefficients, the internal thermodynamic consistency of data on adsorption from the vapour and the liquid phase, and the prediction of equilibrium adsorption characteristics from the smallest possible amount of experimental data. Capillary phenomena are examined from the standpoint of maximising the information on the pore structure of the adsorbent. 80 references.