Thermodynamics and kinetics of complex mixtures

• Published in: Chemical engineering science 1994, Vol.49 (24), p.4179-4189
• Main Author: Krambeck, Frederick J.
• Format: Article
• Language: English
• Subjects: Chemical reactions; Chemistry; Composition; Exact sciences and technology; General and physical chemistry; Petroleum distillates; Reaction kinetics; Stoichiometry; Theory of reactions, general kinetics; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Thermodynamics; Vectors
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/S0009-2509(05)80014-4

Analysis of the chemistry and kinetics of mixtures with very large numbers of chemical compounds, such as petroleum fractions and their reaction products, can be simplified by assuming an infinite number of compounds with properties that are continuous functions of one or more variables. The limiting forms of stoichiometric, thermodynamic and kinetic concepts as the number of compounds tends to infinity is of interest for these systems. Previous treatments of this subject, such as those by De Donder (1931) and Aris and Gavalas (1966), did not exploit an important property of these systems; that the subspace of stoichiometric constraints is of finite, and in fact small, dimension even when the reaction subspace is infinite. This profoundly simplifies the geometry of the equilibrium surface in composition space. Another very useful property of kinetic functions is the detailed balance principle. Here, this is expressed in a very general form, reminiscent of the Onsager principle. The concepts are illustrated by means of concrete examples.