Hydrodynamic behaviour and mass transfer performance of SiC foam

Abstract

This work presents an experimental study of hydrodynamic behaviour and mass transfer performance of ceramic foam (SiC) as column packing. Foam studied is open celled from Sicat Company, their manufacturing method, which is well controlled, allows modifying the characteristics of foam like voidage, specific area and PPI (Pore Per Inch) number. Voidage of the foam studied is of 91% with 640 m2/m3 specific area and 5 PPI. Hydrodynamics experiments are realised with air-water system in counter current in a 150 mm diameter column with a packing height of one meter. Parameters studied are pressure drop for dry and wet packing, flooding and liquid hold-up. Total reflux experiments with n-heptane/cyclohexane mixture were carried out in a distillation column at atmospheric pressure to study mass transfer by determination of HETP (Height Equivalent to Theoretical Plate). Performance in term of pressure drop per unit height and flooding are quite lower in comparison with classical packings of distillation. Pressure drop obtained is about few millibars per meter (0-10 mbar.m-1) for F-Factor from the range of 0 to 1 and liquid superficial velocities from 1 to 10 m3.m-2.h-1. Liquid hold-up values, measured in the same range of flow, are in a range of 5 to 10%.