Nonequilibrium thermodynamics of heat waves in a catalytic bed. Functional of an autowave solution

The thermodynamic description of the physicochemical processes in a fixed catalytic bed is considered in the approximation of the simplest (quasihomogeneous) model in the presence of a first-order reversible reaction. It is shown that the physical nature of slow heat waves is amenable to the second law of thermodynamics, and the total entropy production in a distributed open and strongly nonequilibrium system is a functional of the autowave solution of a mathematical model. Of the one-parameter family of autowave solutions, the minimum value of the functional corresponds to the unique physically valid solution. The methods of nonequilibrium thermodynamics are used to substantiate the technique of “cutting off” the reaction function. At the same time, a variational problem that is solved without using this technique is formulated.