Energy and entropy on irreversible chemical reaction-diffusion systems with asymptotic stability

Abstract

In the framework of irreversible thermodynamics, we study autonomous systems of reaction-diffusion equations to show how the entropy and free energy of an open and irreversible reactor depend on concentrations. To do this, we find a Lyapunov function that depends directly on the eigenvalues and eigenvectors of the linearized problem valid for linear and asymptotically stable systems. By suggesting the role of this Lyapunov function as internal free energy, we were able to reflect the properties of the dynamical system directly into the second law of thermodynamics making a redefinition of the chemical potentials. We demonstrate the consistency of our hypotheses with basic thermodynamic principles such as the proportionality between flows and forces proposed by Onsager, the spectral decomposition of entropy production and the Glansdorff-Prigogine evolution criterion of a thermodynamic system.