A TEG Dehydration Unit (Tri-Ethylene Glycol Dehydration Unit) is designed to remove water from wet feed gas. Dehydration is essential in gas production to prevent the formation of hydrates, which occur when free water combines with natural gas under low temperatures (<20°C) and high pressure. Hydrates can block export pipelines and cause costly downtime. Free water also leads to corrosion in downstream systems, making dehydration a critical step for plant reliability and safety.
This glycol-based process can also be applied to the dehydration of hydrogen and carbon dioxide, ensuring gases meet strict network or storage specifications.
How the TEG Dehydration process works
In this skid-mounted package, Tri-Ethylene Glycol (TEG) is used as a liquid desiccant. Lean TEG is brought into contact with wet gas in a glycol contactor, where it flows countercurrent to the gas stream. As the glycol absorbs water, the dew point of the gas is lowered, preventing condensation and hydrate formation.
The water-rich glycol is then sent to the TEG Regeneration Unit, where heat removes the absorbed water, restoring the glycol to lean condition for reuse.
1. TEG regeneration and reboiler system
Rich glycol collected at the bottom of the contactor passes through a reflux condenser and heat exchangers before entering the still column and then the reboiler. In the reboiler, water is distilled from the glycol at near atmospheric pressure.
The heater can be either:
- An electric heater bundle, controlled by a thyristor control panel with overtemperature and low-level protection, or
- A gas-fired firetube heater, managed by a burner control system.
Strict safeguarding ensures glycol is never heated above its decomposition temperature of 206°C. Internal design guarantees the heater bundle remains fully immersed during operation.
2. Lean glycol cooling and circulation
The regenerated lean glycol flows through a stripping column for further purification before being cooled in a lean/rich exchanger and collected in the surge drum. From there, the glycol circulation pump pressurizes the lean glycol, which is cooled by ambient air in the lean glycol cooler before returning to the contactor.
3. Stripping gas facilities for higher purity
For higher glycol purity, stripping gas facilities are included. Nitrogen or fuel gas is heated in the reboiler and introduced into the stripping column. This additional process step allows:
- Higher lean glycol purity
- Reduced heat input in the reboiler
- Operation at slightly elevated pressure
4. Overhead vapor handling
Vapors leaving the still column are cooled in an overhead vapor cooler. Condensable liquids are separated in the Overhead Vapor Knock-Out Drum, where liquids are collected locally and vapors are safely vented to the atmosphere.
Benefits of a TEG Dehydration Unit
A well-designed TEG Dehydration Unit offers:
- Effective removal of water from natural gas, hydrogen, or CO₂
- Prevention of hydrates and corrosion in pipelines
- Stable operation with safe heating and safeguarding systems
- High-purity lean glycol for reliable dehydration performance
- Flexible operation with stripping gas facilities
Get in Touch with FB Group for your new TEG Dehydration Unit
Are you looking for a dependable TEG Dehydration Unit for your gas processing installation? Our experts at FB Group provide tailor-made solutions to ensure your gas meets strict specifications safely and efficiently. Contact FB Group today and discover how we can support your project with reliable gas dehydration technology.
