Hydrodynamics and mass transfer phenomena in counter-current packed columnat elevated pressures

The aim of this study is to determine mass transfer parameters such as inte rfacial area a and volumetric liquid side mass transfer coefficient k(L)a d uring gas-liquid absorption in a packed column according to pressure within the range 0.1-1.3 MPa. A preliminary hydrodynamic study was carried out in order to characterize gas and liquid flows according to the operating pres sure. The residence time distribution method shows that fluids flows can be modeled as plug flow with axial dispersion. In contrast to the liquid flow , an effect of pressure on the gas flow has been observed. The axial disper sion coefficient of the gas increases with pressure. These results allow mo deling of the gas-liquid absorption in a packed column with or without chem ical reaction and at elevated pressures. The basic equations defining the h ydrodynamic profile of the gas and liquid films are completed by the terms describing mass transfer coupled with an irreversible chemical reaction in the liquid phase. The numerical resolution of the system of equations obtai ned has allowed the study of the influence of pressure on the interfacial a rea a. This parameter increases with pressure. The same result has been obs erved with the volumetric liquid side mass transfer coefficient k(L)a. The coefficient k(L) is independent of pressure. (C) 2000 Elsevier Science Ltd. All rights reserved.