process condenses and extracts water from the vapor phase using a cold tube bundle (“Coldfinger”).
The lean glycol
is routed from the regeneration still to a separate vessel which contains the Coldfinger process. The vessel is half filled with lean glycol, while the other half is occupied by vapor consisting of water and glycol. A cold bundle is inserted in the vapor space, condensing water from the vapor, which again is extracted from the vessel by the use of troughs. As all systems naturally seek equilibrium conditions, water will evaporate from the liquid glycol to restore equilibrium in the vapor phase, thereby concentrating the glycol. The glycol exiting the vessel therefore has a higher purity of glycol than the glycol entering, reaching as high as 99.9 wt% (Comart undated). In the most common applications, rich glycol from the absorber column is used as coolant for the Coldfinger bundle (GPSA (2004)).As for the Drizo process, the Coldfinger
process requires extra equipment added to the regeneration process. In addition to the Coldfinger vessel itself, equipment for processing the extracted water is also needed. The manufacturer (Comart (undated)) claims that 61 000 MMscfd is processed using the Coldfinger process for enhanced glycol regeneration. One of the largest gas processing facilities in Norway, Ormen Lange, exports alone approximately 2 500 MMscfd (StatoilHydro undated), indicating that use of the Coldfinger process also is limited.
