Glycol Dehydration

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Common problems in a glycol dehydration unit are fouling and foaming. Many problems in a glycol dehydration plant such as foaming, reboiler and exchanger fouling, tray plugging and pump failures can be traced to an excessive amount of liquid and solid contaminants present in the process stream.  (more)

Foaming in the contactor can result in huge glycol losses, reduced operating capacity, and off-spec product. Glycol carried over into the dry gas can result in fouling of downstream equipment like desiccant beds, compressors, heat transfer equipment, and burners. Foam stability is dramatically increased by the introduction of heavy hydrocarbons, organic materials, amines, and suspended solids into the recirculating glycol.

Ein Fouling kann zu einem Versagen der Reboilerrohre, einer Verstopfung sowohl im Kontaktor als auch Regenerator, Versagen im Austauscher und häufigem Ersatz von Pumpendichtungen führen. The typical contaminant is iron oxide which is formed in the circulating glycol system. Iron oxide particulates tend to be less than 10 micron in size.

 

Pall Solutions

 

A Pall SepraSol™ Liquid/Gas coalescer in the gas feed line will remove virtually all of the entrained liquids in the feed gas. This eliminates the problem of hydrocarbons and amines mixing with the glycol, minimizing any problems with foaming.

Pall disposable filters are recommended on the recirculating glycol stream to remove iron oxide particulates. Since the glycol is a circulating system, the solids concentration will gradually increase unless removed by a filter. Der hohe Feststoffgehalt führt zu einem Fouling von Geräten und stabilisiert die Schaumbildung. The circulating glycol should contain less than 1ppm by weight of suspended solids and should be filtered to an efficiency of 10 µm absolute. This circulating glycol system often requires that coarser filters be installed at first to clean the system of solids which have been accumulating over a period of time. Progressively finer filters are introduced to the system until a filter efficiency of 10 µm absolute is obtained.

 Abbildung 1. Glycol Dehydration System

 

Table 1.Filter Recommendations

Positionierung der Filter Recommended Pall Assembly Zweck
of Filtration
Vorteile
of Filtration
1 Pall SepraSol Liquid/Gas
Koalescer:
CC3LG7A
CC3LGO2-H13
CS604LGH13
Removes water, hydrocarbon, carried over amines and other liquids and solids from gas feed
  • Reduziert die Schaumbildung
  • Increases absorber efficiency
  • Verhindert ein Fouling von Austauschern und Reboilern
2 Pall Profile® II or
Ultipleat® High Flow cartridge: 10 µm
Zur Entkalkung und Abscheidung fester Partikel
  • Reduziert die Schaumbildung
  • Reduces glycol losses
  • Increases energy efficiency
  • Increases absorber efficiency
  • Verhindert ein Fouling von Austauschern und Reboilern
3 Pall SepraSol Liquid/Gas Coalescer:
CC3LG7A
CC3LGO2-H13
CS604LGH13
Removes water, carried over glycol, and liquid hydrocarbon
  • Protects downstream processes
  • Reduces downstream equipment maintenance costs

 

If glycol losses are significant due to operating at higher than design capacity, Pall’s SepraSol Liquid/Gas coalescers can be installed downstream of the contactor overheads to recover glycol and protect downstream equipment like compressors, desiccant beds and heat transfer equipment.