The Statistical Thermodynamic Approach to the Correlation of Equilibrium Data

Abstract

Statistical thermodynamics provides a useful alternative to the classical approach to the correlation and prediction of adsorption equilibria. In statistical thermodynamics the equilibrium properties of a system are deduced by considering the statistical behaviour of a large number of loosely coupled identical subsystems (the ensemble) which can exist with equal probability in any allowable quantum state, subject to the Boltzmann Law of energy distribution. This method of statistical averaging is particularly appropriate for a zeolite since, to a first approximation, a zeolite crystal does indeed consist of a large number of identical subsystems (the individual cells or cages) which are loosely coupled so that they can exchange energy or guest molecules, but are independent of one another in the sense that the guest molecules within one cage are not significantly affected by the molecules in neighbouring cages.