The Logic Behind The Magic." Glycol Dehydration System 7"

TEG Reboiler
Rich glycol from TEG Still column flows into the shell side of glycol  reboiler. Hotoil comes from hot oil supply header is used as heating medium in reboiler tube side. The renegerated flows by gravity across the length of the TEG reboiler and enters the Stripping gas column operate at 204.4 degC at atmospheric pressure. TEG loss is reduced by increasing the flow of the rich TEG through tube side of TEG reflux condenser.

TEG Vent Exchanger
Water vapour from the shell side of the TEG reflux condenser passes through the shell side of an 8.36 kW double pipe type TEG Vent Exchanger before letting it go to the acid flare system. Water vapour is heated up to 150 degC by the hot oil passing through the tube side of the TEG vent exchanger for this purpose. The temperature of water vapor of the acid flare is controlled by an FC TC cascade control loop.

Stripping Gas Column

 The use of Stripping gas column is provided to reduce the water content of the regenerated glycol by counter current contact with hot fuel gas flowing upward through the stripping gas column. The stripping gas also reduces the partial pressure of the vapour in the TEG reboiler. Hence increasing the regeneration capability of the TEG reboiler. Regenerated glycol flows from the bottom of the stripping gas column by gravity into the hairpin type Hot Lean Rich TEG exchanger where it is cooled to approximately 124.8 degC and then goes into the other haipin type Cold Lean Rich TEG Exchanger where it is further cooled to approximately 85.55 degC.


TEG Accumulation Vessel
Lean glycol from Cold Lean/Rich TEG exchanger is sent to the TEG accumulator vessel. The TEG accumulator vessel is sized for a 22.3 minutes residence time between low-low liquid level and high-high liquid level, of lean glycol at pump maximum capacity (33 USgpm). The TEG accumulatoe vessel provides storage capacity for the TEG circulation pumps.

TEG Circulation Pumps
The TEG circulation pumps are rotary gear type pumps, operating at normal discharge pressure of approximately 52.06 Barg. The lean glycol from the discharge of the TEG circulation pumps is sent to the 235.8 kW TEG cooler,

TEG Cooler
The TEG coller is an air cooler where the lean glycol is cooled to 48.25 degC and sent to the TEG contactor for re-use. 2x5 kW fans are used to cool the lean TEG