A non-equilibrium approach to model flash dynamics with interface transport. (August 2019)

• Record Type: Journal Article
• Authors: Romo-Hernandez, Aarón; Hudon, Nicolas; Erik Ydstie, B.; Dochain, Denis
• Is Part Of: Journal of process control. Volume 80(2019)
• Page Start: 211
• Page End: 222
• Publication Date: 2019-08
• Subjects: Non-equilibrium thermodynamics -- Multiphase systems -- Differential-algebraic systems -- Flash-drum dynamics -- Lyapunov stability -- Entropy production; Process control -- Periodicals; Fabrication -- Contrôle -- Périodiques; Process control; Periodicals; Electronic journals; 660.281
• DOI: 10.1016/j.jprocont.2019.04.012
• Languages: English
• ISSNs: 0959-1524

Abstract

Abstract: In this paper, we present a modeling framework for a class of multiphase chemical systems based on non-equilibrium thermodynamics. Compartmental modeling is used to establish the dynamic properties of liquid–vapor systems operating far from thermodynamic equilibrium. In addition to the bulk-phase molar/energetic dynamics, interface transport processes yield to algebraic constraints in the model description. The irreversible system is thus written as a system of differential-algebraic equations (DAEs). The non-equilibrium liquid–vapor DAE system is shown to be of index one. A local stability analysis for the model shows that the equilibrium state is unstable for non-isobaric operation regimes, whereas numerical evidence shows that isobaric operation regimes are stable. To extend the stability analysis, internal entropy production for the irreversible flash-drum is presented as a Lyapunov function candidate.