Abstract: There are large number of chemical reactions. However,
exothermic chemical reactions remain at the center of investigations because of
its sensitivity against temperature perturbation. In this paper, the
thermodynamic stability of an exothermic chemical reaction of ammonia synthesis
in a model chemical reactor against the spatially uniform temperature
perturbation has been studied using the thermodynamic Lyapunov function constructed using entropy
production rates on real and perturbed trajectories and the steps of
Lyapunov’s second (direct) method of stability of motion. In the method
adopted, the entropy production rate and thermodynamic Lyapunov function
are expanded in Taylor series in
terms of perturbation coordinates The behavior of the computed time
rate of change of Lyapunov function provides the desired information about the
stability. The above methodology has been termed as “comprehensive
thermodynamic theory of stability of irreversible processes (CTTSIP)”. The
present study reveals the regions of stability, asymptotic stability, stability
under constantly acting small disturbances and instability. The computations
were carried out using the software “Polymath 5.1” from The CACHE
Corporation, Michigan.
Keywords and phrases: Lyapunov analysis, thermodynamic stability, nonequilibrium thermodynamics, industrial chemical reactions.
