Rate-based simulation of a high pressure counter-current packed column for supercritical CO2 extraction of alcohol from dilute aqueous mixtures

GAÑÁN, NICOLÁS A.; MORCHAIN, JEROME; CAMY, SÉVERINE; CONDORET, JEAN-STÉPHANE

JOURNAL OF SUPERCRITICAL FLUIDS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 135 p. 168 - 179

0896-8446

In this work, the modelling and simulation of a fractionation packed column for the recovery of isopropanol from dilute aqueous mixtures using supercritical CO2 is presented. The model, developed using the Matlab software, is based on the numerical resolution of differential mass balances for each component over the column height. The multicomponent mass transfer between phases is described using a "rate-based" or "non-equilibrium" approach and the conventional concept of local mass transfer coefficients. The thermodynamic equilibrium at the interface is calculated using a combined equation of state/activity model approach. The model was validated by reproduction of experimental steady-state results for the fractionation of 5% isopropanol aqueous solutions obtained in a bench scale counter-current column (17.5 mm internal diameter and 2 m height). The effect of operation temperature, pressure and CO2 flow rate on the separation performance was satisfactorily described by the model calculations.