Thermodynamic limitations on non-steady-state kinetic behaviour

3 THERMODYNAMIC LIMITATIONS ON NON-STEADY-STATE KINETIC BEHAVIOUR 

In the previous section we introduced the Lyapunov functions for chemical kinetic equations that are the dissipative functions G. The function RTG is treated as free energy. Since G 0 and the equality is obtained only at PDE, and for the construction of G it suffices to know only the position of equilibrium N, there exist limitations on the non-steady-state behaviour of a closed system that are independent of the reaction mechanism. If in the initial composition N = N, the other composition N can be realized during the reaction only in the case when 

The latter means that G is a monotonically decreasing function among the solutions for kinetic equations. 

It is clearly seen that, at a vertex of the reaction polyhedron, G achieves its local maximum value (due to the strict convexity of G and the fact that its minimum point is positive). Therefore near each vertex, as well as in the vicinity of some faces, the G function can be used to construct a region that is unattainable from outside. Let us consider the case of one vertex and then a more awkward general situation. 

Let be a vertex for the reaction polyhedron with outcoming edges d1, 

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