Thermodynamic stability of sulfur dioxide oxidation by Lyapunov function analysis against temperature perturbation

The present paper describes the thermodynamic stability study of the industrially important reaction of sulfur trioxide synthesis using a framework of comprehensive thermodynamic theory of stability of irreversible processes (CTTSIP). The mathematical steps involved, use the CTTSIP set-up. We construct an appropriate expression of L-s, the excess rate of entropy production, and use the constitutive equations of the perturbation coordinates and then establish the sign of the time rate of L-s. In doing so we expand L-s, in a Taylor expansion about the given non-equilibrium state (that is a point on the unperturbed trajectory). In the present case L-s has been defined using an appropriate irreversible thermodynamic expression for Sigma(s), the rate of entropy production, that includes the entropy production from the existence of heat flux and the chemical conversion occurring at a finite rate. The operative expression of dL(s)/dt has been derived using the above inputs and then by the help of 'Polymath 5.1' signs of L-s and dL(s)/d(t) and their profiles are computed. The effect of variation of the overall heat transfer coefficient on the stability of the process has been analysed.