MONOETHYLENE GLYCOL

Synonyms:

MONOETHYLENE GLYCOL; Mono Etilen glikol; Le monoéthylène glycol; MEG; meg; Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol; MONOETHYLENE GLYCOL; Le monoéthylène glycol; MEG; meg; MONOETHYLENE GLYCOL; Le monoéthylène glycol; MEG; meg; Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol; MONOETHYLENE GLYCOL; Le monoéthylène glycol; MEG; meg; Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol; MONO Monoethylene glycol; 1, 2-Ethanediol; Glycol; EG; Monoethylene glycol;Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol; MONO Monoethylene glycol; MONOETHYLENE GLYCOL; Le monoéthylène glycol; MEG; meg; Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol; MONOETHYLENE GLYCOL; Le monoéthylène glycol; MEG; meg; MONOETHYLENE GLYCOL; Le monoéthylène glycol; MEG; meg; Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol; MONOETHYLENE GLYCOL; Le monoéthylène glycol; MEG; meg; Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol; MONO Monoethylene glycol; 1, 2-Ethanediol; Glycol; EG; Monoethylene glycol;Meg; 1,2-DIHYDROXYETHANE; 2-HYDROXYETHANOL; ETHANE-1,2-DIOL; ETHANEDIOL-1,2; ETHYLENE ALCOHOL; Glycol d'éthylène; Monoéthylène glycol; Éthylène glycol; 1,2-Ethanediol; Monoethylene glycol;1, 2-Ethanediol; Glycol; EG; Monoethylene glycol; monoetilenglikol; monoetilen glikol; Monoetilen glikol; monoethilenglikol

Monoethylene glycol

Not to be confused with Polyethylene glycol, Diethylene glycol, Propylene glycol, or Glycol.
Ethylene glycol
Wireframe model ofMonoethylene glycol
Spacefill model ofMonoethylene glycol
Ball and stick model of Monoethylene glycol
Sample of Monoethylene glycol
Names
Preferred IUPAC name
Ethane-1,2-diol
Other names
Ethylene glycol
1,2-Ethanediol
Ethylene alcohol
Hypodicarbonous acid
Monoethylene glycol
1,2-Dihydroxyethane
Identifiers
CAS Number    
107-21-1 ☑
3D model (JSmol)    
Interactive image
3DMet    
B00278
Abbreviations    MEG
Beilstein Reference    505945
ChEBI    
CHEBI:30742 ☑
ChEMBL    
ChEMBL457299 ☑
ChemSpider    
13835235 ☑
ECHA InfoCard    100.003.159 Edit this at Wikidata
EC Number    
203-473-3
Gmelin Reference    943
KEGG    
C01380 ☑
MeSH    Ethylene+glycol
PubChem CID    
174
RTECS number    
KW2975000
UNII    
FC72KVT52F ☑
UN number    3082
CompTox Dashboard (EPA)    
DTXSID8020597 Edit this at Wikidata
InChI[show]
SMILES[show]
Properties
Chemical formula    C2H6O2
Molar mass    62.068 g·mol−1
Appearance    Clear, colorless liquid
Odor    Odorless[1]
Density    1.1132 g/cm3
Melting point    −12.9 °C (8.8 °F; 260.2 K)
Boiling point    197.3 °C (387.1 °F; 470.4 K)
Solubility in water    Miscible
Solubility    Soluble in most organic solvents
log P    -1.69[2]
Vapor pressure    0.06 mmHg (20 °C)[1]
Viscosity    1.61×10−2 Pa·s[3]
Hazards
Main hazards    Harmful
Safety data sheet    See: data page
External MSDS
GHS pictograms    GHS07: HarmfulGHS08: Health hazard
GHS Signal word    Warning
GHS hazard statements    H302, H373
GHS precautionary statements    P260, P264, P270, P301+312, P314, P330, P501
NFPA 704 (fire diamond)    
NFPA 704 four-colored diamond
120
Flash point    111 °C (232 °F; 384 K) closed cup
Autoignition
temperature    410 °C (770 °F; 683 K)
Explosive limits    3.2–15.2%[1]
NIOSH (US health exposure limits):
PEL (Permissible)    None[1]
REL (Recommended)    None established[1]
IDLH (Immediate danger)    None[1]
Related compounds
Related diols    Propylene glycol
Diethylene glycol
Triethylene glycol
Polyethylene glycol
Supplementary data page
Structure and
properties    Refractive index (n),
Dielectric constant (εr), etc.
Thermodynamic
data    Phase behaviour
solid–liquid–gas
Spectral data    UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒ verify (what is ☑☒ ?)
Infobox references
Monoethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound with the formula (CH2OH)2. It is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odorless, colorless, sweet-tasting, viscous liquid.

Production
Industrial routes
Ethylene glycol is produced from ethylene (ethene), via the intermediate ethylene oxide. Ethylene oxide reacts with water to produce Monoethylene glycol according to the chemical equation:

C2H4O + H2O → HO−CH2CH2−OH
This reaction can be catalyzed by either acids or bases, or can occur at neutral pH under elevated temperatures. The highest yields of Monoethylene glycol occur at acidic or neutral pH with a large excess of water. Under these conditions, Monoethylene glycol yields of 90% can be achieved. The major byproducts are the oligomers diethylene glycol, triethylene glycol, and tetraethylene glycol. The separation of these oligomers and water is energy-intensive. About 6.7 million tonnes are produced annually.[4]

A higher selectivity is achieved by use of  's OMEGA process. In the OMEGA process, the ethylene oxide is first converted with carbon dioxide (CO
2) to ethylene carbonate. This ring is then hydrolyzed with a base catalyst in a second step to produce mono-ethylene glycol in 98% selectivity.[5] The carbon dioxide is released in this step again and can be fed back into the process circuit. The carbon dioxide comes in part from the ethylene oxide production, where a part of the ethylene is completely oxidized.

Ethylene glycol is produced from carbon monoxide in countries with large coal reserves and less stringent environmental regulations. The oxidative carbonylation of methanol to dimethyl oxalate provides a promising approach to the production of C1-based Monoethylene glycol.[6] Dimethyl oxalate can be converted into Monoethylene glycol in high yields (94.7%[7]) by hydrogenation with a copper catalyst:[8]

MEG ex CO.svg
Because the methanol is recycled, only carbon monoxide, hydrogen, and oxygen are consumed. One plant with a production capacity of 200 000 tons of Monoethylene glycol per year is in Inner Mongolia, and a second plant in the Chinese province of Henan with a capacity of 250 000 tons per year was scheduled for 2012.[9] As of 2015, four plants in China with a capacity of 200 000 t/a each were operating with at least 17 more to follow.[10]

Biological routes
The caterpillar of the Greater wax moth, Galleria mellonella, has gut bacteria with the ability to degrade polyethylene (PE) into Monoethylene glycol.[11][12][13]

Historical routes
According to most sources, French chemist Charles-Adolphe Wurtz (1817–1884) first prepared Monoethylene glycol in 1856.[14] He first treated "ethylene iodide" (C2H4I2) with silver acetate and then hydrolyzed the resultant "ethylene diacetate" with potassium hydroxide. Wurtz named his new compound "glycol" because it shared qualities with both ethyl alcohol (with one hydroxyl group) and glycerin (with three hydroxyl groups).[15] In 1859, Wurtz prepared Monoethylene glycol via the hydration of ethylene oxide.[16] There appears to have been no commercial manufacture or application of Monoethylene glycol prior to World War I, when it was synthesized from ethylene dichloride in Germany and used as a substitute for glycerol in the explosives industry.

In the United States, semicommercial production of Monoethylene glycol via ethylene chlorohydrin started in 1917. The first large-scale commercial glycol plant was erected in 1925 at South Charleston, West Virginia, by Carbide and Carbon Chemicals Co. (now Union Carbide Corp.). By 1929, Monoethylene glycol was being used by almost all dynamite manufacturers. In 1937, Carbide started up the first plant based on Lefort's process for vapor-phase oxidation of ethylene to ethylene oxide. Carbide maintained a monopoly on the direct oxidation process until 1953, when the Scientific Design process was commercialized and offered for licensing.

Uses
Ethylene glycol is primarily used in antifreeze formulations (50%) and as a raw material in the manufacture of polyesters such as polyethylene terephthalate (PET) (40%).[4]

Coolant and heat-transfer agent
The major use of Monoethylene glycol is as a medium for convective heat transfer in, for example, automobiles and liquid-cooled computers. Monoethylene glycol is also commonly used as a coolant for chilled-water air-conditioning systems that either place the chiller or air handlers outside or must cool below the freezing temperature of water. In geothermal heating/cooling systems, Monoethylene glycol is the fluid that transports heat through the use of a geothermal heat pump. The Monoethylene glycol either gains energy from the source (lake, ocean, water well) or dissipates heat to the sink, depending on whether the system is being used for heating or cooling.

Pure Monoethylene glycol has a specific heat capacity about one half that of water. So, while providing freeze protection and an increased boiling point, Monoethylene glycol lowers the specific heat capacity of water mixtures relative to pure water. A 1:1 mix by mass has a specific heat capacity of about 3140 J/(kg·°C) (0.75 BTU/(lb·°F)), three quarters that of pure water, thus requiring increased flow rates in same-system comparisons with water. The formation of large bubbles in cooling passages of internal combustion engines will severely inhibit heat flow (flux) from the area, so that allowing nucleation (tiny bubbles) to occur is not advisable. Large bubbles in cooling passages will be self-sustaining or grow larger, with a virtually complete loss of cooling in the area. With pure MEG (mono-ethylene glycol) the hot spot will reach 200 °C (392 °F). Cooling by other effects such as air draft from fans (not considered in pure nucleation analysis) will assist in preventing large-bubble formation.

The mixture of Monoethylene glycol with water provides additional benefits to coolant and antifreeze solutions, such as preventing corrosion and acid degradation, as well as inhibiting the growth of most microbes and fungi.[17]

Antifreeze
Pure Monoethylene glycol freezes at about −12 °C (10.4 °F) but, when mixed with water, the mixture freezes at a lower temperature. For example, a mixture of 60% Monoethylene glycol and 40% water freezes at −45 °C (−49 °F).[4] Diethylene glycol behaves similarly. The freezing point depression of some mixtures can be explained as a colligative property of solutions but, in highly-concentrated mixtures such as the example, deviations from ideal solution behavior are expected due to the influence of intermolecular forces.

There is a difference in the mixing ratio, depending on whether it is Monoethylene glycol or propylene glycol. For Monoethylene glycol, the mixing ratios are typically 30/70 and 35/65, whereas the propylene glycol mixing ratios are typically 35/65 and 40/60. It is important that the mixture is frost-proof at the lowest operating temperature.[18] (in Danish)

Because of the depressed freezing temperatures, Monoethylene glycol is used as a de-icing fluid for windshields and aircraft, as an antifreeze in automobile engines, and as a component of vitrification (anticrystallization) mixtures for low-temperature preservation of biological tissues and organs. Mixture of Monoethylene glycol and water can also be chemically termed as glycol concentrate/compound/mixture/solution.

The use of Monoethylene glycol not only depresses the freezing point of aqueous mixtures, but also elevates their boiling point. This results in the operating temperature range for heat-transfer fluids being broadened on both ends of the temperature scale. The increase in boiling temperature is due to pure Monoethylene glycol having a much higher boiling point and lower vapor pressure than pure water, as is typical with most binary mixtures of volatile liquids.

Precursor to polymers
In the plastic industry, Monoethylene glycol is an important precursor to polyester fibers and resins. Polyethylene terephthalate, used to make plastic bottles for soft drinks, is prepared from Monoethylene glycol.

Ethylene glycol is one precursor to polyethyleneterephthalate, which is produced on the multimillion ton scale annually.
Other uses
Dehydrating agent
Ethylene glycol is used in the natural gas industry to remove water vapor from natural gas before further processing, in much the same manner as triethylene glycol (TEG).

Hydrate inhibition
Because of its high boiling point and affinity for water, Monoethylene glycol is a useful desiccant. Monoethylene glycol is widely used to inhibit the formation of natural gas clathrates (hydrates) in long multiphase pipelines that convey natural gas from remote gas fields to a gas processing facility. Monoethylene glycol can be recovered from the natural gas and reused as an inhibitor after purification treatment that removes water and inorganic salts.

Natural gas is dehydrated by Monoethylene glycol. In this application, Monoethylene glycol flows down from the top of a tower and meets a rising mixture of water vapor and hydrocarbon gases. Dry gas exits from the top of the tower. The glycol and water are separated, and the glycol recycled. Instead of removing water, Monoethylene glycol can also be used to depress the temperature at which hydrates are formed. The purity of glycol used for hydrate suppression (monoethylene glycol) is typically around 80%, whereas the purity of glycol used for dehydration (triethylene glycol) is typically 95 to more than 99%. Moreover, the injection rate for hydrate suppression is much lower than the circulation rate in a glycol dehydration tower.

Applications
Minor uses of Monoethylene glycol include the manufacture of capacitors, as a chemical intermediate in the manufacture of 1,4-dioxane, as an additive to prevent corrosion in liquid cooling systems for personal computers, and inside the lens devices of cathode-ray tube type of rear projection televisions. Monoethylene glycol is also used in the manufacture of some vaccines, but it is not itself present in these injections. It is used as a minor (1–2%) ingredient in shoe polish and also in some inks and dyes. Monoethylene glycol has seen some use as a rot and fungal treatment for wood, both as a preventative and a treatment after the fact. It has been used in a few cases to treat partially rotted wooden objects to be displayed in museums. It is one of only a few treatments that are successful in dealing with rot in wooden boats, and is relatively cheap. Monoethylene glycol may also be one of the minor ingredients in screen cleaning solutions, along with the main ingredient isopropyl alcohol. Monoethylene glycol is commonly used as a preservative for biological specimens, especially in secondary schools during dissection as a safer alternative to formaldehyde. It is also used as part of the water-based hydraulic fluid used to control subsea oil and gas production equipment.

Ethylene glycol is used as a protecting group in organic synthesis to protect carbonyl compounds such as ketones and aldehydes.[19]

Silicon dioxide reacts in heated reflux under dinitrogen with Monoethylene glycol and an alkali metal base to produce highly reactive, pentacoordinate silicates which provide access to a wide variety of new silicon compounds.[20] The silicates are essentially insoluble in all polar solvent except methanol.

It also can be used in vaccine manufacture or as a formaldehyde substitute when preserving biological specimens.[21]

Chemical reactions
Ethylene glycol is used as a protecting group for carbonyl groups in organic synthesis. Treating a ketone or aldehyde with Monoethylene glycol in the presence of an acid catalyst (e.g., p-toluenesulfonic acid; BF3·Et2O) gives the corresponding a 1,3-dioxolane, which is resistant to bases and other nucleophiles. The 1,3-dioxolane protecting group can thereafter be removed by further acid hydrolysis.[22] In this example, isophorone was protected using Monoethylene glycol with p-toluenesulfonic acid in moderate yield. Water was removed by azeotropic distillation to shift the equilibrium to the right.[23]

Ethylene glycol protecting group.png
Toxicity
Main article: Monoethylene glycol poisoning
Ethylene glycol is moderately toxic, with an oral LDLo = 786 mg/kg for humans.[24] The major danger is due to its sweet taste, which can attract children and animals. Upon ingestion, Monoethylene glycol is oxidized to glycolic acid, which is, in turn, oxidized to oxalic acid, which is toxic. It and its toxic byproducts first affect the central nervous system, then the heart, and finally the kidneys. Ingestion of sufficient amounts is fatal if untreated.[25] Several deaths are recorded annually in the U.S. alone.[26]

Antifreeze products for automotive use containing propylene glycol in place of Monoethylene glycol are available. They are generally considered safer to use, as propylene glycol isn't as palatable[note 1] and is converted in the body to lactic acid, a normal product of metabolism and exercise.[29]

Australia, the UK, and seventeen US states (as of 2012) require the addition of a bitter flavoring (denatonium benzoate) to antifreeze. In December 2012, US antifreeze manufacturers agreed voluntarily to add a bitter flavoring to all antifreeze that is sold in the consumer market of the US.[30]

Environmental effects
Ethylene glycol is a high-production-volume chemical; it breaks down in air in about 10 days and in water or soil in a few weeks. It enters the environment through the dispersal of Monoethylene glycol-containing products, especially at airports, where it is used in deicing agents for runways and airplanes.[31] While prolonged low doses of Monoethylene glycol show no toxicity, at near lethal doses (≥ 1000 mg/kg per day) Monoethylene glycol acts as a teratogen. "Based on a rather extensive database, it induces skeletal variations and malformations in rats and mice by all routes of exposure."[32] This molecule has been observed in outer space.[33]

Notes
 Pure propylene glycol does not taste bitter, and pure propylene glycol is often used as a food additive, for instance in cake icing and shelf-stable whipped cream. Industrial-grade propylene glycol usually has a slightly bitter or acrid taste due to impurities. See the article on propylene glycol for more information. The relative sweetness of Monoethylene glycol[27] and propylene glycol[28] is discussed in the Merck Index, and neither compound is described as bitter.

Factsheet about Mono-ethylene glycol

Did you know that…?
Mono-ethylene glycol - or Monoethylene glycol - is a vital ingredient for the production of polyester fibres and film, polyethylene terephthalate (PET) resins and engine coolants.

End uses for Monoethylene glycol range from clothing and other textiles, through packaging to kitchenware, engine coolants and antifreeze. Polyester and fleece fabrics, upholstery, carpets and pillows, as well as light and sturdy polyethylene terephthalate drink and food containers originate fromMonoethylene glycol. The humectant (water attracting) properties of Monoethylene glycol products also make them ideal for use in fibres treatment, paper, adhesives, printing inks, leather and cellophane.

Monoethylene glycol is a colourless, odourless liquid with a syrup-like consistency.

55% of Monoethylene glycol is used to make polyester fibres. 25% of Monoethylene glycol is used in polyethylene terephthalate - or PET - packaging and bottles.

45% of the world’s Monoethylene glycol output is consumed in China.

Global Monoethylene glycol demand was around 21 million tonnes in 2010. Forecasts suggest that by 2015, demand could be above 28 million tonnes per year. In China, Monoethylene glycol demand continues to grow at around 7% each year.

  opened one of the world’s largest Monoethylene glycol plants in November 2009 at its integrated refinery and petrochemicals hub in Singapore. The plant has an annual capacity of 750,000 tonnes.

Annual output from the Monoethylene glycol plant in Singapore could produce over two million tonnes of polyester, enough to make 6.7 billion polyester shirts - more shirts than there are people in the world.

Monoethylene glycol is produced from ethylene via ethylene oxide, which in turn is hydrated by using either a thermal or catalytic production process.

process technology, which uses a catalyst to convert ethylene and oxygen into ethyelene oxide, followed by a thermal process, also produces smaller amounts of the co-products diethylene glycol (DEG) and triethylene glycol (TEG).

 catalytic process technology produces onlyMonoethylene glycol.

More information on MEG and ethylene oxide process technology, including OMEGA, is on a separate factsheet.

 monoethylene glycol (MEG) is a basic building block used for applications that require:

Chemical intermediates for resins
Solvent couplers
Freezing point depression solvents
Humectants and chemical intermediates
Application Usage
These applications are vital to the manufacture of a wide variety of products, including:

Resins
Deicing fluids
Heat transfer fluids
Automotive antifreeze and coolants
Water-based adhesives
Latex paints and asphalt emulsions
Electrolytic capacitors
Textile fibers
Paper
Leather
Ethylene glycol (monoethylene glycol) in its pure form, is an odorless, colorless, syrupy liquid.

Production
Monoethylene glycol is produced from ethylene, via the intermediate ethylene oxide
Ethylene oxide reacts with water to produce Monoethylene glycol according to the chemical equation

  C2H4O + H2O → HOCH2CH2OH

This reaction can be catalyzed by either acids or bases, or can occur at neutral pH under elevated temperatures. The highest yields of Monoethylene glycol occur at acidic or neutral pH with a large excess of water. Under these conditions, Monoethylene glycol yields of 90% can be achieved. The major byproducts are the Monoethylene glycol oligomers diethylene glycol, triethylene glycol, and tetraethylene glycol.

Precautions: Carefully review Material Safety Data Sheets (MSDS). Overexposure through improper storage, handling or use could lead to serious health risks.

MONOETHYLENE GLYCOL
View: Sticky liquid

Chemical Name: 1,2-Dihydroxyethane

Chemical Formula: (CH2OH) 2

Packaging shape: 230 Kg. In barrels, IBCs, Tanker

Definition and Usage Areas:

It is a colorless transparent viscous liquid with a sweet taste and moisture absorption ability. Water can also be miscible with low-grade aliphatic alcohols, glycerol, acetic acid, acetone, ketones, aldehydes, pyridine and similar coal tar bases. It is slightly soluble in ether but virtually insoluble in benzene and its homologues, chlorinated hydrocarbons, petroleum ether and oils.

Usage areas

Monoethylene glycol is mainly used as a raw material for the production of antifreeze agent and polyethylene terephthalate (polyester fiber raw material and plastic material) for the preparation of automobile cooling systems.
Also, synthetic resins, solvents, lubricants, surfactants, softeners, moisturizers, explosives, etc. Monoethylene glycol can be used in its production.
Monoethylene Glycol can often be used as an alternative to glycerol and can often be used in the tanning industry and pharmaceutical industry as a hydration agent and solvent.
Monoethylene Glycol has a strong solubility, but it can be easily oxidized against toxic metabolic oxalic acid and therefore cannot be widely used as a solvent. Monoethylene glycol can be added to the hydraulic fluid and used to prevent the oil-based hydraulic fluid from melting on the rubber of the system.
Water-based hydraulic fluid with Monoethylene glycol as the main component is a flammable hydraumatic fluid and can be applied to aircraft, automobiles and high temperature molding machine.
As antifreeze agent in emulsion paints and aqueous systems.
Monoethylene glycol is used as a solvent for casein, gelatin, dextrin, some phenol-formaldehyde resin, alkyd resins and dyes.
It also gives the paint slipperiness and ease of application. Monoethylene glycol is also used as a heat-transfer agent.