Distillation Tray Efficiency

Distillation tray efficiency is an important performance indicator for trayed towers. Tray efficiency converts stages calculated in a process simulator to actual trays to be installed. Tray efficiency is a measure of whether an existing tower is operating to specifications. Tray efficiency provides context to tower capacity – with definitions such as useful capacity. Tray efficiency is central to the very objective of a distillation tower.

However, the measurement, prediction, and application of tray efficiency has been one of the most challenging aspects of tray performance - because a large number of variables effect efficiency – and moreover, the effects are correlated, varied, and sometimes counter-acting. Physical properties, liquid and vapor flow rates, and the geometry of the various elements of a tray all play a role in determining the tray efficiency.

In this talk, I will present advances in measurement and prediction of distillation tray efficiency with references to work performed at Oklahoma State University and Fractionation Research, Inc.