Process systems and passivity via the Clausius-Planck inequality

In this paper we define a process system to be a system which has actions with the Clausius-Planck and conservation properties. We use standard and well established results derived from macroscopic thermodynamics to show that a process system has actions which satisfy the dissipation inequality. Furthermore, these actions have an inner product structure and a link between the thermodynamic theory of process systems and the input-output passivity theory of nonlinear control is established. The paper therefore represents a step towards developing a passivity based approach for distributed control system design for chemical processes. A review of relevant concepts from thermodynamics is given in an appendix.