Improved and Innovative Methods for the Characterization of Random and Structured Packings

Abstract

Design and scale-up of packed absorption columns are based on experimental data from pilot columns and on expert knowledge as well as experience of the packing manufacturers. The characterization of column internals itself depends on the respective test facility, where the experiments are carried out (Schultes, 2013). In contrast to columns in industrial scale, smaller ones are significantly affected by wall flow, which is a major reason for parameter uncertainties. To overcome these uncertainties in the design procedure of packed columns, three approaches are suggested. One is based on an improved characterization of maldistribution by the use of a wire-mesh-sensor. It is reviewed, that the sensor can be flexibly used by simple investigation of the distribution of the measured phase fractions and to determine dynamics during column operation. Furthermore, more detailed knowledge about axial and radial spreading of the liquid can be obtained by residence time distribution experiments. The two other approaches are the development of new characterization methods: A miniaturized experimental setup and a newly developed model. The miniaturized experimental setup is based on the idea of eliminating the influence of end effects for structured packings. The new model approach considers large scale maldistributions, instationary hold-up and mass transfer.