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Send EmailTriethylene Glycol, Triethyleneglycol, Triglycol, TEG, 112-27-6
Product Name: Triethylene Glycol (TEG)
Chemical Formula: C₆H₁₄O₄ / HO–CH₂–CH₂–O–CH₂–CH₂–O–CH₂–CH₂–OH
CAS Number: 112-27-6
EINECS Number: 203-953-2
Molecular Weight: 150.17 g/mol
| Property | Value / Range |
|---|---|
| Appearance (20°C) | Colorless, clear, viscous liquid |
| Odor | Mild characteristic, nearly odorless |
| Freezing Point | -4.3 °C to -7.2 °C (pure) |
| Boiling Point (1013 hPa) | 285 – 288 °C |
| Flash Point (closed cup) | 166 °C (PMCC) – 177 °C (Cleveland) |
| Density (20°C) | 1.124 – 1.126 g/cm³ |
| Viscosity (20°C) | ~47 mPa·s (cP) |
| Viscosity (25°C) | ~36 mPa·s |
| Vapor Pressure (20°C) | <0.01 hPa |
| pH (50% in water) | 5.5 – 7.5 (neutral) |
| Solubility | Fully miscible with water, alcohols, glycols, ketones; immiscible with hydrocarbons |
| Log P (octanol/water) | -1.75 (hydrophilic) |
| Autoignition Temperature | 371 °C |
| Thermal Decomposition | Slow oxidation above 220°C; acidic products form above 250°C |
| Test | Typical Value | Method |
|---|---|---|
| Purity (wt%) | ≥99.0 – 99.8 | GC |
| Water Content (Karl Fischer) | ≤0.1 % | ASTM E203 |
| Color (APHA/Pt-Co) | ≤20 | ASTM D1209 |
| Acidity (as acetic acid) | ≤0.01 % | ASTM D1613 |
| Monoethylene + Diethylene Glycol | ≤0.5 % | GC |
| Iron Content | ≤1 ppm | ICP |
| Ash Content | ≤0.01 % | ASTM D482 |
Specific Heat Capacity (20°C): ~2.2 kJ/(kg·K)
Heat of Vaporization (at bp): ~450 kJ/kg
Thermal Conductivity (20°C): ~0.21 W/(m·K)
Dielectric Constant (20°C, 1 kHz): ~23
Incompatibilities: Strong oxidizers (HNO₃, H₂O₂), concentrated acids (H₂SO₄) – violent exothermic reaction.
Corrosion: Compatible with stainless steel (304, 316), carbon steel, aluminum, PP, PE. Long-term contact with copper and brass not recommended (yellow discoloration).
Hygroscopicity: Absorbs moisture from air; store in tightly closed containers.
Natural Gas Dehydration: Most common use – absorbs water vapor from natural gas.
Hydraulic Brake Fluids: Provides low volatility and high boiling point.
Plasticizer: For cellulosic films, printing inks, polyurethane elastomers.
Paints & Coatings: Coalescing solvent.
Heat Transfer Fluid: Closed-loop systems.
Gas Processing: Dehydration and aromatic extraction aid.
Storage Temperature: 15 – 40°C (protect from freezing; crystallization begins below -5°C – warm and mix to re-liquefy)
Container Material: Stainless steel, carbon steel, HDPE drum/tank. Use dry air or nitrogen blanket to prevent moisture ingress.
Shelf Life: 24 months in original sealed container, below 25°C, away from direct sunlight (monitor color and acidity).
Transport Classification: Not classified as dangerous goods (non-flammable, non-toxic).
| Parameter | Value |
|---|---|
| LD50 oral (rat) | ~15 – 17 g/kg (low toxicity) |
| Skin irritation | Mild irritant; prolonged exposure may cause dryness |
| Eye irritation | Mild to moderate irritant |
| Exposure limit (TWA) | 10 mg/m³ (for aerosol/mist) |
| Biodegradability | Readily biodegradable (OECD 301) |
| Water hazard class (WGK, Germany) | 1 (low hazard to water) |
Personal Protective Equipment (PPE):
Chemical goggles, nitrile gloves, protective clothing.
Normal ventilation is sufficient if no splashing risk.
TSCA (USA): Listed
EINECS (EU): 203-953-2 (existing substance)
AICS (Australia): Listed
GHS Classification (EU 1272/2008):
Not classified as hazardous (no hazard pictogram required). Some countries may require H316 (mild skin irritation) and H320 (eye irritation) labels.
200 – 250 kg steel drum
1100 – 1250 kg IBC (pallet tank)
Bulk: Tanker / isotank (20 – 23 tons)
| Sector | Suitability / Standards | Explanation |
|---|---|---|
| Natural Gas | GPSA, ISO 18453, NACE | Gold standard for dehydration. TEG absorbs water from gas due to low vapor pressure. |
| Automotive (Brake Fluids) | FMVSS 116 (DOT 3, DOT 4), ISO 4925 | TEG is reacted with boric acid to form borate esters for high-boiling brake fluids. |
| Pharmaceutical | USP/NF (Triethylene Glycol monograph), Ph. Eur. | Excipient (plasticizer, humectant, solvent). For oral, topical, injectable formulations. |
| Cosmetics & Personal Care | EC 1223/2009 (EU Cosmetics Regulation), CIR approved | Humectant, solvent, viscosity regulator. Shampoos, lotions, deodorants, creams. |
| Paints & Coatings | REACH, EPA TSCA | Coalescing solvent in water-based paints – improves film formation. |
| Printing Inks | EC 1935/2004 (if not food contact) | Improves flexibility and regulates drying time. |
| Heat Transfer Systems | ASTM E1177 (coolants) | Closed-loop heat transfer fluid, antifreeze additive. |
| Plastics & Polyurethane | RoHS compliant | Plasticizer for polyurethane elastomers – provides flexibility. |
| Textiles | OEKO-TEX (limited concentration) | Softener, antistatic agent, moisture retainer. |
| Aerospace | MIL-PRF-46170 (hydraulic fluids) | Low-temperature fluidity and high-temperature stability. |
Food Contact:
TEG is covered under FDA 21 CFR 178.3740 (indirect food contact – extractables in plastics) but is not generally approved as a direct food additive (unlike propylene glycol). Limited use as heat transfer fluid in food processing equipment.
| Parameter | Value |
|---|---|
| TEG Circulation Rate | 15 – 30 L TEG / kg water removed |
| Contactor Temperature | 25 – 40 °C (absorption) |
| Regeneration Temperature | 180 – 204 °C (atmospheric) |
| Vacuum Regeneration | 150 – 160 °C (under vacuum) |
| Regenerated TEG Purity | 98.5 – 99.9 % |
| Dew Point Depression | Down to -40 °C |
Note: Prevent oxygen ingress (oxidation → acid formation). Maintain pH 6-8.
| Component | % by Weight |
|---|---|
| TEG | 50 – 70 |
| Boric Acid (H₃BO₃) | 15 – 25 |
| Diethylene Glycol (DEG) | 5 – 15 |
| Antioxidant (BHT, etc.) | 0.1 – 0.5 |
| Corrosion Inhibitor | 0.2 – 1.0 |
Process:
TEG + Boric acid → esterification at 120-150°C (remove water) → cool → add other components.
Target: Dry boiling point >260°C (DOT 4 requires >230°C).
| Component | % by Weight |
|---|---|
| Acrylic emulsion (50% solids) | 70 – 80 |
| TEG | 2 – 5 |
| Water | 10 – 20 |
| Surfactant | 0.5 – 1 |
| Defoamer | 0.2 – 0.5 |
Effect: Lowers minimum film formation temperature (MFFT). TEG acts as a temporary plasticizer after water evaporates.
| Component | % by Weight |
|---|---|
| Water | 70 – 85 |
| TEG | 2 – 5 |
| Glycerin | 2 – 5 |
| Emulsifier (polysorbate, etc.) | 1 – 3 |
| Preservative (phenoxyethanol) | 0.5 – 1 |
| Fragrance | 0.1 – 0.3 |
Note: For cosmetics, use pharmaceutical / cosmetic grade TEG (heavy metals <10 ppm, DEG <0.1%).
| Component | % by Volume |
|---|---|
| TEG | 30 – 50 |
| Water | 50 – 70 |
| Corrosion inhibitor (nitrite, molybdate) | 0.5 – 2 |
| pH adjuster (borax) | pH 8.5 – 10.5 |
Operating Range: -10°C (freeze protection) to +150°C (pressurized system).
TEG alone has lower heat transfer coefficient than water; water mixture is preferred.
Triethylene Glycol (IUPAC) – TEG (most common abbreviation)
2,2'-(Ethylenedioxy)diethanol
Ethylene glycol bis(2-hydroxyethyl ether)
Triglycol
Triethyleneglycol (combined spelling)
Glycol bis(hydroxyethyl ether)
3,6-Dioxaoctane-1,8-diol (systematic)
CAS names: 1,2-Bis(2-hydroxyethoxy)ethane; 2,2'-Ethylenedioxydiethanol
Trade Names (Examples):
Carbowax™ (Dow) – Low molecular weight PEG fraction
Glycol TEG (Huntsman)
Triethylene Glycol (Shell Chemical)
TEG (SABIC)
Triethylene Glycol (INEOS)
Pluracol® E series (BASF) – Some are PEG blends
| Application | Alternative | Advantage / Disadvantage |
|---|---|---|
| Natural Gas Dehydration | DEG (Diethylene Glycol) | Lower viscosity, lower boiling point, higher vapor loss. TEG has better thermal stability. |
| MEG (Monoethylene Glycol) | Low cost but very volatile, high losses. Preferred for hydrate inhibition in cold climates. | |
| Ionic Liquids (e.g., [EMIM][Tf₂N]) | Very low vapor pressure, high selectivity, but very expensive, not yet widespread. | |
| Brake Fluid | DEG + Borate Ester | Lower viscosity, lower boiling point. TEG gives higher performance (DOT 4). |
| PEG (Polyethylene Glycol 200-400) | Higher viscosity, better lubrication. More expensive than TEG. | |
| Plasticizer (Aqueous systems) | Propylene Glycol (PG) | Lower toxicity, food contact approved, but higher cost. |
| Dipropylene Glycol (DPG) | Lower hygroscopicity, preferred in some coatings. | |
| Texanol™ (2,2,4-Trimethyl-1,3-pentanediol monoisobutyrate) | Very effective coalescent, lower water solubility, but VOC restrictions apply. | |
| Heat Transfer Fluid | Propylene Glycol (PG) | Less toxic, preferred in food processing. More expensive than TEG, similar low-temperature performance. |
| Ethylene Glycol (EG) | Lowest cost, best heat transfer, but high toxicity. | |
| Cosmetics / Pharma | Propylene Glycol (PG) | Lower skin irritation potential, more widely accepted. |
| Glycerin (Glycerol) | Natural origin, higher viscosity, sweeter taste. | |
| Butylene Glycol | Lighter feel, more expensive. | |
| Paint / Ink | DPG (Dipropylene Glycol) | Less hygroscopic, better water resistance. |
| PG | Lower toxicity, but higher volatility. |
Protect from Moisture: TEG is highly hygroscopic. Store under dry air or nitrogen blanket. Open TEG absorbs 1-2% water quickly.
Freeze Protection: Freezes around -7°C. Crystallization can expand and damage tanks. Use heated storage (15-40°C) or heat tracing.
Material Compatibility: HDPE, stainless steel (304/316), carbon steel are suitable. EPDM gaskets may swell – use Viton® or PTFE seals.
Temperature Limit: Above 220°C in air, TEG slowly oxidizes → acid formation (pH drops, corrosion increases). Use inert gas (N₂) blanket in regeneration units.
pH Monitoring: Maintain pH 6-8 in TEG circuits. If pH <5, neutralize (with monoethanolamine) or replace TEG.
Contamination Control: In gas applications, H₂S, CO₂, and hydrocarbons accumulate in TEG. Use filtration (activated carbon) and periodic purge.
Skin Contact: Prolonged contact causes dryness and cracking. Use nitrile gloves. Wash with soap and water.
Eye Contact: Mild irritant. Rinse eyes with water for 15 minutes.
Inhalation: Vapor pressure is very low at room temperature – no risk. Above 180°C, aerosol may form – local exhaust ventilation required.
Ingestion: Low toxicity, but large amounts may cause diarrhea and dehydration. Do not induce vomiting; drink water; consult a doctor.
Waste Management: TEG is biodegradable, but concentrated TEG should not be drained to sewer. Incineration (with energy recovery) or controlled discharge to wastewater treatment (EWC code: 07 02 99).
Substitution for Toxicity Concerns: For sensitive applications (food, baby products, pharmaceuticals), use Propylene Glycol or Glycerin. TEG has no reproductive toxicity or carcinogenicity data (Group 4 – probably not carcinogenic, IARC).
Cost Optimization: TEG is ~20-30% more expensive than DEG, and 50-80% more expensive than MEG. However, low vapor loss and high thermal stability in gas dehydration make it economical long-term.
Purity Grade:
Industrial grade (99%) → Natural gas, heat transfer, brake fluid
Pharmaceutical / Cosmetic grade (99.5%+, DEG <0.1%, EG <0.05%) → Drugs, cosmetics
Global Suppliers: Dow, Shell, Huntsman, SABIC, INEOS, BASF, Lotte Chemical
Request Certificates: Certificate of Analysis (CoA), DEG/EG content (GC), water content (KF), color (APHA)