THERMODYNAMICS AND KINETICS OF COMPLEX-MIXTURES

Analysis of the chemistry and kinetics of mixtures with very large num bers of chemical compounds, such as petroleum fractions and their reac tion products, can be simplified by assuming an infinite number of com pounds with properties that are continuous functions of one or more va riables. The limiting forms of stoichiometric, thermodynamic and kinet ic concepts as the number of compounds tends to infinity is of interes t for these systems. Previous treatments of this subject, such as thos e by De Donder (1931) and Aris and Gavalas (1966), did not exploit an important property of these systems; that the subspace of stoichiometr ic constraints is of finite, and in fact small, dimension even when th e reaction subspace is infinite. This profoundly simplifies the geomet ry of the equilibrium surface in composition space. Another very usefu l property of kinetic functions is the derailed balance principle. Her e, this is expressed in a very general form, reminiscent of the Onsage r principle. The concepts are illustrated by means of concrete example s.