The rich glycol from the cold separators enters the reflux coils above the packing in the still columns of the ethylene glycol Re-boilers, where self refluxing occurs. The rich glycol is then passed through integral lean / rich glycol coils in the surge tank section of the Ethylene Glycol Re-boilers. After being preheated by the lean Ethylene Glycol in the accumulator, the rich glycol stream flows to the Glycol Flash tanks where any free gases that exist are flashed off and sent to flare. Any liquid Hydrocarbon that have been carried over to the flash tank is also removed utilizing the Hydrocarbon skimmer connection.
Glycol from flash tank flows under level control to the top of the packed section in the glycol still column through Particulate filters and carbon filters. In the glycol still column, water is stripped out of the rich MEG as it flows downward through the packed section consisting of PALL rings, counter-current to the steam that is generated in the Ethylene Glycol Re-boilers. The steam is discharged to the LowPressure flare header at the top of the still column. Once the desired concentration (temperature) is achieved in the Ethylene Glycol
Re-boilers, lean MEG flows by gravity to the Glycol surge tank (integral with the glycol re-concentrator) where it is cooled by heat exchange with the rich MEG flowing through the integral lean/rich glycol coils.
Re-boilers, lean MEG flows by gravity to the Glycol surge tank (integral with the glycol re-concentrator) where it is cooled by heat exchange with the rich MEG flowing through the integral lean/rich glycol coils.
From the surge tank, the glycol flows to the suction of the glycol pumps, where it is pressurized for reinjection in the gas/gas exchangers. The lean glycol concentration leaving the EG regeneration skids is maintained at approximately 80% as glycol concentrations outside of these ranges may lead to crystallization at low temperatures, high plant pressure drops, and ultimately freezing – off of the Gas/Gas Heat exchangers.
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