(146c) Structured Packings for Distillation and Absorption

In the industrial practice, there are many structured packings available that can be broadly classified into three generations: wire gauze, standard and high capacity corrugated sheet metal.  These packings are favored in high vapor /low liquid rate distillation services and in absorption.  They are particularly advantageous in vacuum columns, where low pressure drops are sometimes critical.  For example in Ethyl Benzene-Styrene Monomer columns, low pressure drops yield lesser liquid temperatures and reduced renegade polymerization. To obtain a good understanding of structured packings, basic performance principles such as HETP, the importance of packing installation and liquid distribution quality are necessary.  Standard structured packings were a popular choice in the industry for many years but suffered from liquid build up between packing layers at the load point.  High capacity structured packings, which comprise of either “half-S” or “full-S” crimp angle shapes, can operate at much higher load points known as maximum useful capacities (MUC’s).  A 20 minute video will be employed to illustrate these aspects pertaining to structured packings.