• structured packing
• hold up mass transfer
• packed bubble column
• axial dispersion

Unsaturated polyesters are prepared through a classical esterification process in a batch wise operating reaction vessel connected to a distillation unit. This master thesis is part of the PhD project “Reactive Distillation for Multi-Product Continuous Plants” where the modelling and conceptual design of reactive distillation operations for multiple polyester products have been carrying out.
Therefore, the objectives of the master thesis are the selection and the characterization of hydrodynamics and mass transfer properties of promising internals with viscous liquids.
The internals we decided to test are Flexipac 2X-S, manufactured by Koch-Glitsch and SuperPak 250Y, manufactured by Raschig-Jaeger; additional experiments on bubble column were performed to evaluate the enhancement due to the packing.
The gas hold up measurements show that the packing increases the gas hold up in the column and the comparison between the packings also shows that at the low viscosities the SuperPak provides a higher increase while at the high viscosity the Flexipac does. The main reason to introduce the packings in the column is the reduction of the axial dispersion: the experiments show that axial dispersion coefficient decreases up to a factor 5 in comparison to the bubble column. On the other hand, the packings do not enhance the mass transfer significantly.
In conclusion, the packing of the column can be a promising alternative for the development of reactive distillation system mainly because of the reduction in the axial dispersion.