Restrictions on chemical kinetic models

Abstract

When constructing kinetic models of chemical processes, one needs to insure that certain qualitative features are incorporated. Ideally one would like to have a minimal set of postulates such that any system obeying these postulates would necessarily exhibit the behavior observed in chemical systems. One of the most primitive properties of a chemical system is that concentrations cannot be driven to zero. On the basis of topological arguments we show that any system which obeys the laws of thermodynamics will have this property. Furthermore, by imposing constraints, such as structural stability, on the behavior of chemical systems under small perturbations of their vector fields, we show that there are no stable steady states on the boundary of a reaction simplex. The existence and uniqueness of thermodynamic equilibrium states is also discussed.