Gas Dehydration - Glycol

Gas Dehydration
- Glycol
A.01
Introduction
The use of Glycol to dehydrate gas streams is an established method
that has proven its functionality and versatility over many years.
There are 3 common types of Glycol used for Gas Dehydration:
• Mono-Ethylene Glycol (MEG)
• Di-Ethylene Glycol (DEG)
• Tri-Ethylene Glycol (TEG)
The type of Glycol used and the package design depends on several
factors, and the end-users specific requirements and objectives for
the gas stream being processed.
Each package is typically designed in close consultation with the
client to ensure the best overall design is achieved.
Design Basis
The design of TEG and MEG Dehydration Systems is unique for
every requirement and the overall package design will vary to meet
the specified moisture content of the gas at the process conditions.
Each system is typically designed and built as a complete turn-key
package with particular emphasis given to the following issues:
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Discharge gas moisture content
High gas dehydration capacity
Minimum glycol losses
Minimum power consumption
Optimum plant efficiency & design integrity
Compliance with HSE requirements
Environmentally conscientious design
Process Description
In a typical TEG package, water saturated gas enters near the
bottom of the Contactor Tower and flows upwards through the
internal trays/packing (1). Lean Glycol enters the Contactor Tower
near the top and cascades down through the Contactor internals
(9), making contact with the up-flowing gas stream. The countercurrent flow path of the Glycol and the high contact surface area
enhances water absorption into the Glycol from the gas stream.
Rev 11/2012
Spring Gully TEG Dehydration Package.
Duty: 50 MMscfd / 10.4 usgpm TEG.
Location: Queensland, Australia (installed 2004).
Australia
Process Group Pty Ltd
5 Hobbs Court, Rowville, (Melbourne), VIC 3178, Australia.
Phone: +61 3 9212 7100 Fax: +61 3 9212 7199
E-mail: sales@processgroup.com.au Web: www.processgroup.com.au
Singapore
Process Group Pte Ltd
298 Tiong Bahru Road,#12-02/03 Central Plaza, Singapore 168730
Phone: +65 6276 8349 Fax: +65 6274 2005
E-mail: sales@processgroup.com.sg Web: www.processgroup.com.sg
Middle East
Process Group International Ltd
P.O. Box 46153, Abu Dhabi, UAE.
Phone: +971 2 5500 899 Fax: +971 2 5500898
E-mail: sales@processgroupintl.com Web: www.processgroupintl.com
Represented by:
Gas Dehydration
- Glycol
A.01
Dehydrated gas flows out of the top of the Contactor, while
the Rich Glycol flows out of the bottom of the Contactor and
to the Glycol Regeneration Package.
Reference Clients
The TEG Regeneration process typically involves passing the
Rich Glycol through the still column to gain some heat (2)
before entering the Flash Drum (3).
• Shell
The Glycol is then passed through Particle Filters to remove
particulates and Activated Carbon Filters to remove any
dissolved hydrocarbon and/or chemical compounds (4).
The Rich Glycol is heated in a cross exchanger to preheat
the feed (5) to the Still Column where the Glycol present in
the water vapour leaving the Reboiler is recovered (6).
• Santos Australia
Depending on the application, it may be necessary to increase
the Lean Glycol concentration by using stripping gas (7), or
running the Reboiler/Still Column under a slight vacuum. Lean
TEG (typically >99wt%) is then cooled and pumped back to
the top of the Contactor Tower (8) to repeat the process.
• Iranian Offshore Oil Co.
• Chevron
• ENI Australia
• Origin Energy
• Cairn Energy
• Bahrain Petroleum
• Arrow Energy
• Anzon Australia
• Chinese National Offshore Oil Co.
• Japan-Vietnam Petroleum Co.
A ‘typical’ Glycol Dehydration Package:
a number of process components are added / modified / removed to suit the requirements of each individual application
© Process Group Pty Ltd, 2008 – 2012.