Development and application of continuous thermodynamics for complex chemical equilibria calculations

Abstract

For the calculation of complex chemical equilibria of multicomponent mixtures containing species whose Gibbs free energies of formation depend very regularly on the structure of the molecules involved, statistical methods of continuous thermodynamics can successfully be put into use. Homologous series of n-alkanes and n-alkenes are examples of such systems. In this case the Gibbs free energy of formation is a linear function of the number of C atoms in the molecules. The application of statistical methods of continuous thermodynamics enables not only the calculation of equilibrium composition but also provides facilities for the demonstration of very interesting and striking regularities in behavior. In the case studies the increasing complexity of the system is considered. In most simple versions all chemical species constitute one homologous series only (alkanes or alkenes). In a more refined version the system is treated as a mixture of two ensembles (alkanes and alkenes). Furthermore, some individual components are added, such as hydrogen, carbon oxide, carbon dioxide and the first members of every homologous series.