Modelling of a dynamic multiphase flash: the positive flash. Application to the calculation of ternary diagrams

Raphaële Théry Hétreux (1) , Felix Llovell (1) , Xuân-Mi Meyer (1) , Vincent Gerbaud (1) , Xavier Joulia (1)

1 LGC - Laboratoire de Génie Chimique

A general and polyvalent model for the dynamic simulation of a vapor, liquid, liquid-liquid, vapor-liquid or vapor-liquid-liquid stage is proposed. This model is based on the -method introduced as a minimization problem by Han & Rangaiah (1998) for steady-state simulation. They suggested modifying the mole fraction summation such that the same set of governing equations becomes valid for all phase regions. Thanks to judicious additional switch equations, the -formulation is extended to dynamic simulation and the minimization problem is transformed into a set of differential algebraic equations (DAE). Validation of the model consists in testing its capacity to overcome phase number changes and to be able to solve several problems with the same set of equations: calculation of heterogeneous residue curves, azeotropic points and distillation boundaries in ternary diagrams.

Mots clés: Distillation; Dynamic simulation; Phase Equilibrium

Domaines: Génie chimique

Raphaële Théry Hétreux, Felix Llovell, Xuân-Mi Meyer, Vincent Gerbaud, Xavier Joulia. Modelling of a dynamic multiphase flash: the positive flash. Application to the calculation of ternary diagrams. Computers & Chemical Engineering, 2004, 2 (12), pp.2469-2480. ⟨10.1016/j.compchemeng.2004.06.005⟩. ⟨hal-03602723⟩