Triethylene glycol (CAS 112-27-6), often shortened to TEG, is a colourless, odourless and viscous liquid. It dissolves readily in water and in many organic solvents, has a high boiling point and low volatility, and remains stable at room temperature. That combination of properties keeps it in demand across gas processing, climate control, polymer formulation and personal care manufacturing.
Identification and Typical Characteristics
| Parameter | Detail |
|---|---|
| Chemical name | Triethylene glycol |
| CAS number | 112-27-6 |
| Appearance | Colourless, viscous liquid |
| Odour | Essentially odourless |
| Solubility | Readily soluble in water and many organic solvents |
| Volatility | High boiling point, low volatility |
| Stability | Stable under normal ambient storage conditions |
Dehydration Agent in Natural Gas Processing
One of the main uses of triethylene glycol is dehydration of natural gas. Raw gas carries water vapour that can corrode pipelines and equipment and can form hydrates that restrict or block flow. In a glycol contactor, lean triethylene glycol absorbs water vapour from the gas stream and is then regenerated by heating, producing a continuous loop that lowers the water dew point of the gas. Dry gas is safer to transport and protects downstream compression and processing equipment.
Moisture Control in HVAC Systems
In heating, ventilation and air conditioning systems, triethylene glycol takes part in humidity control. It can release moisture into dry air, improving indoor comfort and air quality, and it can also absorb excess moisture, which reduces condensation on surfaces and limits the conditions that favour mould growth.
Plasticiser, Solvent and Personal Care Uses
In the chemical industry, triethylene glycol works as a plasticiser in the production of plastics and rubber. Adding it to these materials increases flexibility and durability. It also acts as a solvent, helping to dissolve a range of substances in the formulation of paints, inks and adhesives so that the finished product stays smooth and consistent.
Triethylene glycol is used in cosmetics and personal care items as well. In lotions and creams it helps to retain moisture and keep the skin hydrated, and it also serves as a solvent for other ingredients, ensuring that they blend well and stay evenly distributed through the formulation.
Packaging, Storage and Quality Checks
Triethylene glycol is hygroscopic, so containers should be kept closed and the material stored in a cool, dry, well-ventilated area away from strong oxidisers. Bulk parcels are typically supplied in drums or intermediate bulk containers, and moisture pickup during transfer should be monitored because water content affects dehydration performance.
Confirm assay and water content against the incoming specification before use
Keep transfer lines and pumps dedicated where possible to limit contamination
Retain lot documentation for traceability in regulated applications
Frequently Asked Questions
Q: What is the CAS number of triethylene glycol?
Triethylene glycol is registered under CAS 112-27-6 and is commonly abbreviated as TEG.
Q: Why is triethylene glycol used to dry natural gas?
It absorbs water vapour efficiently from the gas stream and can be regenerated by heating, so it can be circulated in a continuous dehydration loop that lowers the gas water dew point.
Q: Is triethylene glycol the same as diethylene glycol?
No. Triethylene glycol contains three ethylene oxide units, while diethylene glycol contains two; they have different CAS numbers and different physical properties.
Q: Can triethylene glycol be used in cosmetics?
Yes. It is used in lotions and creams as a humectant and solvent, helping formulations retain moisture and stay evenly blended.
Q: How should triethylene glycol be stored?
Keep containers closed in a cool, dry, ventilated place, away from strong oxidising agents, and protect the product from moisture pickup during transfer.
Q: What industries use triethylene glycol?
Natural gas processing, HVAC and humidity control, plastics and rubber, paints, inks and adhesives, and cosmetics and personal care.