Converting DAE models to ODE models: application to reactive Rayleigh distillation

Karim Alloula (1) , Fabien Monfreda (2) , Raphaële Théry Hétreux (1) , Jean-Pierre Belaud (1)

1 LGC - Laboratoire de Génie Chimique
2 IMT - Institut de Mathématiques de Toulouse UMR5219

This paper illustrates the application of an index reduction method to some differential algebraic equations (DAE) modelling the reactive Rayleigh distillation. After two deflation steps, this DAE is converted to an equivalent first-order explicit ordinary differential equation (ODE). This ODE involves a reduced number of dependent variables, and some evaluations of implicit functions defined, either from the original algebraic constraints, or from the hidden ones. Consistent initial conditions are no longer to be computed; at the opposite of some other index reduction methods, which generate a drift-off effect, the algebraic constraints remain satisfied at any time; and, finally, the computational effort to solve the ODE may be less than the one associated to the original DAE.

Mots clés: Rayleigh distillation; Differential algebraic equations; DAE models; Ordinary differential equation; ODE models

Domaines: Génie chimique

Karim Alloula, Fabien Monfreda, Raphaële Théry Hétreux, Jean-Pierre Belaud. Converting DAE models to ODE models: application to reactive Rayleigh distillation. Chemical Engineering Transactions, 2013, vol. 32, ⟨10.3303/CET1332220⟩. ⟨hal-00926516⟩