Tomographic measurement of liquid hold up and effective interfacial area distributions in a column packed with high performance structured packings

In this paper, we report on the use of a high energy and high resolution X-ray tomograph to visualize and quantify the distribution of liquid hold up and of gas–liquid interfacial area in a 0.1 m diameter column filled with MellapakPlus 752.Y packing elements. A standard air–water system at room temperature and atmospheric pressure were used. Tomographic measurements have been carried out in a large number of packing cross sections situated at different heights between the top and the bottom of the packed column, giving access to the evolution of axial profiles of liquid hold up and of gas–liquid interfacial area as a function of the operating conditions. Gas–liquid interfacial area values were also measured by a chemical method (CO2 absorption from air into a caustic solution). For the first time, a whole set of gas–liquid interfacial area values evaluated from tomographic images are interestingly compared with values measured by a chemical method. A comparison is also presented with literature models.