Drizo process : enhance glycol regeneration unit

Drizo process equipment (red labeled)

The Drizo process utilizes superheated HCs as stripping gas in a column placed after the regeneration still to lower the water vapor pressure. After the stripping column the stripping gas is cooled, and the HCs are separated from the water and off gas in a three-phase
separator. The gas is vented to the atmosphere and the water discarded, while the HCs are recovered and recycled to be used for stripping gas again. As the glycol absorbs some HCs in the absorption column, the Drizo process can even produce liquid HC products, enhancing the overall
process efficiency (Kohl & Nielsen (1997)).


Using the Drizo process for glycol regeneration has been shown to result in glycol purities higher than 99.99 wt% (GPSA (2004)), which allows for dew point depressions as high as 100 C (Prosernat). To obtain even higher glycol purities, the superheated HC stripping gas can be dehydrated using a solid desiccant in an adsorption bed before it is injected into the stripping column.