Distillation in packed columns

The purpose of packing in a column is to provide a large surface area for interphase mass transfer. With that objective in mind, almost any material that will survive the environment in the column while providing adequate surface area at a moderate to low pressure drop could be used. Indeed, Fair (1987) reports that in the 1930s chain and carpet tacks were tested as column packing material. 

there are two main types of packing commonly employed in distillation and absorption columns  

Vapor and liquid flows in a packed column truly flow in opposite directions. Contrast this with the flow in a tray column where the vapor-liquid contact is between the vapor as it rises up through a liquid that is flowing laterally across the column prior to flowing down to the tray below. 

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The concept of a transfer unit for a countercurrent mass transfer process, introduced in Volume 1, is developed further for distillation in packed columns in Section 11.11. The number of transfer units is defined as the integrated value of the ratio of the change in composition to the driving force. Thus, considering the vapour phase, the number of overall gas transfer, units Nog is given by ... 

Harrison. M.K. Consider Three-Phase Distillation in Packed Columns. Chem. F.ng. Progress. 80 iNuvember 1990). 

For total-reflux distillation in packed columns, regions of loading and flooding are identified by their effects on mass-transfer efficiency, as shown in Fig. 14-54. Gas and liquid rate increase together, and a... 

Pelkonen S., Gorak A., Ohligschlager A., Kaesemann R. Experimental Study on Multicomponent Distillation in Packed Columns. Chem. Eng. Process, Vol. 40, 235-243,2001. 

Gorak, A., Simulation Methods for Steady State Multicomponent Distillation in Packed Columns, The Institution of Chemical Engineers Symposium Series No. 104, Distillation and Absorption 1987, A413-A424 (1987). 

There are only a few experimental investigations for the analysis of three-phase distillation in packed columns. Most of them deal with random packing and only a very rare number treat structured packing. An overview of the investigations of three-phase... 

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