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Monoethylene glycol is colorless transparent viscous liquid with sweet taste and moisture absorption capability.
Monoethylene glycol is also miscible with water, low-grade aliphatic alcohols, glycerol, acetic acid, acetone, ketones, aldehydes, pyridine and similar coal tar bases.
Monoethylene glycol is slightly soluble in ether but almost insoluble in benzene and its homologues, chlorinated hydrocarbons, petroleum ether and oils.
CAS Number: 107-21-1
Molecular Formula: C2H6O2
Molecular Weight: 62.07
EINECS Number: 203-473-3
Synonyms: ETHYLENE GLYCOL, Ethane-1,2-diol, 107-21-1, 1,2-ethanediol, glycol, monoethylene glycol, 1,2-Dihydroxyethane, 2-hydroxyethanol, Glycol alcohol, Ethylene alcohol, Macrogol, Fridex, Tescol, Ethylene dihydrate, Norkool, Macrogol 400 BPC, Dowtherm SR 1, Zerex, Ucar 17, Lutrol-9, ethanediol, ethyleneglycol, Aethylenglykol, Glycol, ethylene-, 1,2-Ethandiol, 1,2-ethylene glycol, Caswell No. 441, 146AR, MFCD00002885, NSC 93876, Athylenglykol, CCRIS 3744, ethylen glycol, DTXSID8020597, HSDB 5012, M.e.g., NCI-C00920, UNII-FC72KVT52F, EINECS 203-473-3, FC72KVT52F, Lutrol 9, EPA Pesticide Chemical Code 042203, NANOSILVER+EG, PEG, CHEBI:30742, AI3-03050, HOCH2CH2OH, NSC-93876, LOWENOL T-163A, DTXCID40597, EC 203-473-3, 1,2-Ethylene Glycol (Ethylene Glycol), Kollisolv PEG 300, ETHYLENE GLYCOL (II), ETHYLENE GLYCOL [II], Poly(ethylene Glycol) ~200, Poly(ethylene Glycol) ~400, Poly(ethylene Glycol) ~600, Poly(ethylene Glycol) ~1000, Poly(ethylene Glycol) ~2000, Poly(ethylene Glycol) ~4000, Poly(ethylene Glycol) ~6000, Poly(ethylene Glycol) ~9000, ETHYLENE GLYCOL (MART.), ETHYLENE GLYCOL [MART.], Poly(ethylene Glycol) ~20000, Ethylenglycol, Aethylenglykol [German], ethylene-glycol, Poly(ethylene Glycol) ~30,000, Poly(ethylene Glycol) ~40,000, 2 Hydroxyethanol, Glycol, Ethylene, PEG 1000, CAS-107-21-1, GLYCEROL IMPURITY B (EP IMPURITY), GLYCEROL IMPURITY B [EP IMPURITY], Macrogol 400, Glycol, Monoethylene, Dowtherm 4000, 1,2-dihydroxy ethane, PEG 4000, WLN: Q2Q, ethyleneglycole, Macrogola, ehtylene glycol, etylene glycol, 2-ethanediol, Ilexan E, MEG 100, Solbanon (TN), 1,2-ethane diol, 1,2-ethane-diol, ethane-1.2-diol, GXT, Hydroxyethyl Salicylate Imp. B (EP), Ethylene Glycol, Propan-1,2-diol, Glycerol Impurity B, Hydroxyethyl Salicylate Impurity B, 1,2-ethyleneglycol, ethan-1,2-diol, mono-ethylene glycol, Ethane-1,2-diol (Ethylene Glycol), Mono Ethylene Glycol, 1,2-ethylene-glycol, Lutrol E (TN), Ethylene glycol, 98%, DuPont Zonyl FSO Fluorinated Surfactants, Ethylene glycol, aerosol, Macrogol 400 (TN), Ethylene glycol 1000 microg/mL in Methanol, Poly(ethylene oxide), PEO, Macrogol 1500 (TN), Macrogol 4000 (TN), Polyethylene glycol 8000, Macrogol ointment (JP17), HO-CH2-CH2-OH, HO(CH2)2OH, NCIOpen2_001979, NCIOpen2_002019, NCIOpen2_002100, Poly(ethylene glycol) 200, Poly(ethylene glycol) 400, Poly(ethylene glycol) 3350, Macrogol 400 (JP17), ETHYLENE GLYCOL [MI], MLS002454404, BIDD:ER0283, Macrogol 1500 (JP17), Macrogol 4000 (JP17), ETHYLENE GLYCOL [HSDB], CHEMBL457299, Ethylene glycol, AR, >=99%, Ethylene glycol, LR, >=99%, Macrogol 20000 (JP17), CHEBI:46793, ETHYLENE GLYCOL [USP-RS], ETHYLENE GLYCOL [WHO-DD], PEG 300, PEG1000, HMS2267F07, Ethylene glycol, p.a., 99.5%, Poly(ethylene Glycol) (~2000), 1,2-ETHANEDIOL (GLYCOL), Ethylene Glycol Blank Standard in Multi-grade Diesel Engine Oil, HY-Y0338, Monoethylene glycol, 1,2-Ethanediol, NSC32853, NSC32854, NSC57859, NSC93876, PEG 3000, PEG 3600, PEG-1000, STR01171, Ethylene glycol, analytical standard, Tox21_202038, Tox21_300637, Ethylene glycol, anhydrous, 99.8%, MSK000065, NSC-32853, NSC-32854, NSC-57859, NSC152324, NSC152325, NSC155081, STL264188, 100 microg/g Ethylene Glycol Standard in Multi-grade Diesel Engine Oil, 1000 microg/g Ethylene Glycol Standard in Multi-grade Diesel Engine Oil, 2000 microg/g Ethylene Glycol Standard in Multi-grade Diesel Engine Oil, 500 microg/g Ethylene Glycol Standard in Multi-grade Diesel Engine Oil, AKOS000119039, FE15218, FP30596, FP45005, FP63569, FP71936, FP76475, NSC-152324, NSC-152325, NSC-155081, USEPA/OPP Pesticide Code: 042203, NCGC00091510-01, NCGC00091510-02, NCGC00091510-03, NCGC00254292-01, NCGC00259587-01, BP-13454, BP-31056, FP137457, FP153293, FP156996, FP159096, FP165659, FP166058, FP167517, FP171107, PEG 3350 - Average Mw approx 3350, SMR001262244, Ethylene glycol, ReagentPlus(R), >=99%, 1ST000065, DuPont Zonyl FSE Fluorinated Surfactants, Residual Solvent Class 2 - Ethylene Glycol, E0105, Ethylene glycol, puriss., >=99.5% (GC), NS00003552, 1,2-Ethane-1,1,2,2-d4-diol-d2(9ci), EN300-19312, Ethylene glycol, BioUltra, >=99.5% (GC), Ethylene glycol, SAJ first grade, >=99.0%, Poly(ethylene oxide) - average Mv 200,000, C01380, D03370, D06418, D06419, D06420, D06421, D06423, Ethylene glycol, JIS special grade, >=99.5%, Ethylene glycol, anhydrous, ZerO2(TM), 99.8%, Ethylene glycol, Vetec(TM) reagent grade, 98%, A851234, Ethylene glycol, spectrophotometric grade, >=99%, Q194207, InChI=1/C2H6O2/c3-1-2-4/h3-4H,1-2H, F0001-0142, Poly(ethylene glycol) Average Mn 600, Moist waxy solid, 004143F9-240E-472F-9D5A-B1B13BBA2A18, Poly(ethylene glycol) Average Mv ~ 3350, Granular powder, Poly(ethylene glycol) Average MV ~ 8,000, Crystalline powder, Ethylene glycol, United States Pharmacopeia (USP) Reference Standard, 600 microg/g Ethylene Glycol QC Check Standard in Multi-grade Diesel Engine Oil, Ethylene glycol, Pharmaceutical Secondary Standard; Certified Reference Material, Poly(ethylene oxide) - average Mv 400,000 (contains 200 - 500 ppm BHT), 203-473-3, 2-Hydroxyethanol;Aliphatic diol;Athylenglykol;Dihydroxyethane;dowtherm;Dowtherm SR 1;dowthermsr1;ethane-1,
Monoethylene glycol is the simplest aliphatic dihydric alcohol with chemical properties of alcohols such as being capable of generating ether, ester, or being oxidized into acid or aldehyde as well as being condensed to form ether or being substituted by halogen.
Its reaction with acyl chloride or acid anhydride generally forms di-esters.
Under heating in the presence of catalyst (manganese dioxide, aluminum oxide, zinc oxide or sulfuric acid), it can be subject to intermolecular or intramolecular dehydration to form the cyclic ethylene acetals, which can react with nitric acid to generate glycol dinitrate (an explosive).
Monoethylene glycol is the raw material for production of polyester resins, alkyd resins and polyester fiber.
It can also be used as the refrigerant agent for automobile and aircraft engines refrigerant.
In 1980, the glycol amount used as refrigerant agent is equal to the amount consumption for producing polyester.
In addition, it can also be used for synthesizing polymers such as polyester fibers.
Monoethylene glycol initrate, when used in combination with nitroglycerine can reduce the freezing point of explosives.
Monoethylene glycol can also be used as the raw material of pharmaceuticals and plastics and high-boiling solvents.
Industry applied ethylene as a raw material with first converting it to ethylene oxide and then hydrolyzing to produce ethylene glycol.
Monoethylene glycol is of fire and explosion hazards.
It is irritating to skin and mucous membrane with inhalation of vapors or skin absorption producing a narcotic effect on the central nervous as well as causing kidney damage.
Monoethylene glycol is an organic compound (a vicinal diol) 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.
Monoethylene glycol is an odorless, colorless, flammable, viscous liquid.
Monoethylene glycol has a sweet taste, but is toxic in high concentrations.
This molecule has been observed in outer space.
Monoethylene glycol is of low toxicity. Rat LD50: 5.5ml/kg~8.54ml/kg people who is subject to oral administration by once has a LD50 of 80g~100g.
The plasma concentration of ethylene glycol is 2.4g/L and can cause acute renal failure.
Monoethylene glycol can be absorbed through the digestive tract, respiratory tract and skin.
Monoethylene glycol can be discharged from the kidney in the form of prototype or ethanedioic acid (oxalate) from through oxidation.
Monoethylene glycol, after being oxidized into carbon dioxide, can be discharged from the respiratory tract.
Although Monoethylene glycol has a high toxicity but its volatility is small.
Therefore, it is unlikely that the inhalation of it during production can cause severe poisoning.
Inhalation poisoning is manifested as blurred consciousness, nystagmus and urine containing protein, calcium oxalate crystals and red blood cells.
Oral toxicity in clinical practice can be divided into three stages: the first stage is mainly the central nervous system symptoms, such as the performance of ethanol poisoning; the second phase of the main symptoms mainly include shortness of breath, cyanosis, and various manifestations of pulmonary edema or bronchopneumonia; at the third stage, there may be significant renal disease, low back pain, kidney area percussion pain, renal dysfunction, proteinuria, hematuria, urine containing calcium oxalate crystals, as well as oliguria, anuria and even acute renal failure.
Patients mistakenly take Monoethylene glycol should be subject to the treatment based on the general principles of first aid for oral poisoning and can be given 600 mL of 1/6 mol of sodium lactate solution and 10 mL of 10% calcium gluconate through intravenous infusion.
Patients of severe poisoning can subject to treatment of artificial kidney dialysis.
Container of ethylene glycol should have "toxic agents" mark.
Monoethylene glycol, upon heating, should be sealed, vented to prevent inhalation of the vapor or aerosol
Monoethylene glycol avoid long-term direct skin contact with the product.
Monoethylene glycol, commonly known as ethylene glycol, is an organic compound with the chemical formula C₂H₆O₂.
Monoethylene glycol is a colorless, odorless, and tasteless liquid that is commonly used as an antifreeze and coolant in automotive engines, refrigeration systems, and HVAC systems.
It is also used in the production of plastics, as a solvent, and in the manufacture of various industrial and consumer products.
Monoethylene glycol is produced by the hydration of ethylene oxide, and it has a variety of applications due to its properties as a hygroscopic substance, meaning it readily absorbs moisture.
In addition to its role in coolants and antifreeze, Monoethylene glycol is a key component in the synthesis of polyester fibers and resins, which are commonly used in clothing, packaging, and other products.
Monoethylene glycol is produced from ethylene (ethene), via the intermediate ethylene oxide.
Monoethylene glycol reacts with water to produce ethylene 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 ethylene glycol occur at acidic or neutral pH with a large excess of water.
Under these conditions, ethylene glycol yields of 90% can be achieved.
The major byproducts are the oligomers diethylene glycol, Monoethylene glycol, and tetraethylene glycol.
The separation of these oligomers and water is energy-intensive.
World production of ethylene glycol was ~20 Mt in 2010.
A higher selectivity is achieved by the use of Shell's OMEGA process.
In the OMEGA process, the ethylene oxide is first converted with carbon dioxide (CO2) to ethylene carbonate.
This ring is then hydrolyzed with a base catalyst in a second step to produce mono-ethylene glycol in 98% selectivity.
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 ethylene oxide production, where a part of the ethylene is completely oxidized.
Monoethylene 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 C 1-based ethylene glycol.
Monoethylene glycol can be converted into ethylene glycol in high yields (94.7%) by hydrogenation with a copper catalyst.
Because the methanol is recycled, only carbon monoxide, hydrogen, and oxygen are consumed.
One plant with a production capacity of 200000 tons of ethylene glycol per year is in Inner Mongolia, and a second plant in the Chinese province of Henan with a capacity of 250000 tons per year was scheduled for 2012.
Monoethylene glycol is produced from ethylene, via the intermediate ethylene oxide
Monoethylene glycol reacts with water to produce ethylene 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 ethylene glycol occur at acidic or neutral pH with a large excess of water. Under these conditions, ethylene glycol yields of 90% can be achieved.
The major byproducts are the ethylene glycol oligomers diethylene glycol, triethylene glycol, and tetraethylene glycol.
Monoethylene glycol is used in the following products: textile treatment products and dyes, washing and cleaning products, coating products, inks and toners, non-metallic surface treatment products, leather treatment products, lacquers and waxes, adhesives and sealants, polymers, heat transfer fluids, hydraulic fluids, antifreeze products and biocides (eg disinfectants, pest control products).
Monoethylene glycol is used in machine wash fluids/detergents, automotive care products, paints, coatings or adhesives, fragrances, air fresheners, coolants in refrigerators, oil-based electric heaters, hydraulic fluids in automotive suspension, lubricants in engine oil and brake fluids.
Monoethylene glycol is the simplest aliphatic dihydric alcohol with chemical properties of alcohols such as being capable of generating ether, ester, or being oxidized into acid or aldehyde as well as being condensed to form ether or being substituted by halogen.
Its reaction with acyl chloride or acid anhydride generally forms di-esters.
Under heating in the presence of catalyst (manganese dioxide, aluminum oxide, zinc oxide or sulfuric acid), Monoethylene glycol can be subject to intermolecular or intramolecular dehydration to form the cyclic ethylene acetals, which can react with nitric acid to generate glycol dinitrate (an explosive).
Monoethylene glycol is the raw material for production of polyester resins, alkyd resins and polyester ber.
Monoethylene glycol can also be used as the refrigerant agent for automobile and aircraft engines refrigerant.
In 1980, the glycol amount used as refrigerant agent is equal to the amount consumption for producing polyester.
In addition, Monoethylene glycol can also be used for synthesizing polymers such as polyester bers.
Monoethylene glycol dinitrate, when used in combination with nitroglycerine can reduce the freezing point of explosives.
Monoethylene glycol can also be used as the raw material of pharmaceuticals and plastics and high-boiling solvents.
Industry applied ethylene as a raw material with rst converting Monoethylene Glycol to ethylene oxide and then hydrolyzing to produce ethylene glycol.
Though it has many industrial and commercial uses, ethylene glycol is toxic when ingested, inhaled, or absorbed through the skin.
Its toxicity is due to the metabolic conversion of the glycol into compounds that can cause damage to the kidneys, liver, and other organs. Therefore, safety precautions are necessary when handling it.
Monoethylene glycol can be found in antifreeze mixtures, de-icing products for vehicles, and in the production of solvents and plastics.
In addition to its practical applications, it is sometimes used as a humectant in food products, cosmetics, and pharmaceuticals.
However, due to its toxic nature, its use in food and drink products is highly regulated.
Melting point: -13 °C (lit.)
Boiling point: 195-198 °C
Density: 1.113 g/mL at 25 °C (lit.)
vapor density: 2.1 (vs air)
vapor pressure: 0.08 mm Hg ( 20 °C)
refractive index: n20/D 1.431(lit.)
Flash point: 230 °F
storage temp.: 2-8°C
solubility: water: miscible
form: Viscous Liquid
pka: 14.22(at 25℃)
color: blue
Relative polarity: 0.79
PH: 6-7.5 (100g/l, H2O, 20℃)
Odor: Odorless
Evaporation Rate: 1
explosive limit 3.2%(V)
Water Solubility: miscible
FreezingPoint: -11.5℃
Sensitive: Hygroscopic
λmax λ: 260 nm Amax: ≤0.03
λ: 280 nm Amax: ≤0.01
Merck: 14,3798
BRN: 505945
Exposure limits Ceiling limit in air for vapor and mist 50 ppm (~125 mg/m3) (ACGIH); TWA 10 mg/m3 (particulates) (MSHA).
Dielectric constant 37.0（20℃）
LogP: -1.36 at 25℃
Surface tension 47.7mN/m at 20°C
Monoethylene glycol is an organic compound with the formula C2H6O2.
Monoethylene glycol is a slightly viscous liquid with a clear, colourless appearance and a sweet taste that emits virtually no odour.
Monoethylene glycol’s miscible with water, alcohols, and many other organic compounds and is primarily used in the industry for manufacturing polyester fibres and as a component in the production of antifreeze, coolants, aircraft anti-icers and de-icers.
Monoethylene glycol is a clear, colorless syrupy liquid.
The primary hazard is the threat to the environment.
Immediate steps should be taken to limit its spread to the environment.
Since Ethylene glycol is a liquid Ethylene glycol can easily penetrate the soil and contaminate groundwater and nearby streams.
Because of its high boiling point and affinity for water, ethylene 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, ethylene 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.
In addition to its uses in manufacturing and industrial settings, MEG plays an important role in the pharmaceutical industry.
Monoethylene glycol is sometimes found in formulations of oral medications, particularly in syrups, where it serves as a humectant, helping to retain moisture and improve the texture of the product. Its water-retaining properties are also employed in cosmetic products like lotions, shampoos, and deodorants, where it can help maintain moisture and prevent drying.
Despite its broad range of uses, monoethylene glycol is highly toxic, particularly when ingested.
Monoethylene glycol can be fatal if consumed in large quantities due to its conversion into toxic metabolites in the body.
This can lead to kidney failure, metabolic acidosis, and central nervous system depression. Because of its toxicity, it is critical to handle MEG with care, especially in environments where the substance could be accidentally ingested or exposed to children and pets.
As a result, the use of MEG in household and consumer products is tightly regulated in many countries to minimize risks to health.
Monoethylene glycol was first synthesized in 1859; however, it did not become a public health concern until after World War II.
In fact, the first published series of deaths from ethylene glycol consumption involved 18 soldiers who drank antifreeze as a substitute for ethanol.
Despite the early recognition that patients who drank ethanol in addition to ethylene glycol had prolonged survival when compared to those drinking ethylene glycol alone, antidotal treatment of ethylene glycol toxicity with ethanol was not evaluated until the 1960s.
Today, ethylene glycol poisoning continues to be a public health problem, particularly in the southeastern United States.
In 2009, US poison control centers received 5282 calls about possible ethylene glycol exposures, and the toxicology community believes these exposures are underreported.
Monoethylene glycol is a colorless, viscous, hydroscopic liquid with a sweetish taste.
Often colored fluorescent yellow-green when used in automotive antifreeze.
Monoethylene glycol is odorless and does not provide any warning of inhalation exposure to hazardous concentrations.
The Odor Threshold in air is 25 ppm.
Ethylene glycol,CH20HCH20H, also known as glycol,ethylene alcohol, glycol alcohol, and dihydric alcohol, is a colorless liquid.
Monoethylene glycol is soluble in water and in alcohol.
Monoethylene glycol has a low freezing point,-25°C (-13 OF), and is widely used as an antifreeze in automobiles and in hydraulic fluids.
Monoethylene glycol is used as a solvent for nitrocellulose and in the manufacture of acrylonitrile, dynamites, and resins.
Historically, Monoethylene glycol has been manufactured by hydrolyzing ethylene oxide.
Presently, it is also produced commercially by oxidizing ethylene in the presence of acetic acid to form ethylene diacetate, which is hydrolyzed to the glycol, and acetic acid is recycled in the process .
Monoethylene glycol is used in antifreeze (especially as car radiator antifreeze) and in production of polyethylene terephthalate fibers and films; in hydraulic fluids; antifreeze and coolant mixtures for motor vehicles; electrolytic condensers; and heat exchangers.
Monoethylene glycol is also used as a solvent and as a chemical intermediate for ethylene glycol dinitrate, glycol esters; resins, and for pharmaceuticals.
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids.
If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water
If this chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped.
Transfer promptly to a medicalfacility. When this chemical has been swallowed, getmedical attention.
Give large quantities of water and inducevomiting.
Monoethylene glycol is very hygroscopic, and also likely to contain higher diols.
Dry it with CaO, CaSO4, MgSO4 or NaOH and distil it under vacuum.
Dry further by reaction with sodium under nitrogen, reflux for several hours and distil.
The distillate is then passed through a column of Linde type 4A molecular sieves and finally distil under nitrogen, from more molecular sieves.
Monoethylene glycol is widely used in the production of polyethylene terephthalate (PET), which is a polymer commonly used in the manufacturing of plastic bottles, food containers, and synthetic fibers.
This makes MEG a critical component in the global plastics industry, contributing to the production of millions of tons of PET annually.
Additionally, it serves as a raw material for the production of resins and plastics used in the automotive, packaging, and textile industries.
As an industrial solvent, ethylene glycol is used in applications such as the formulation of paints, coatings, and varnishes, where it helps in dissolving resins and pigments.
Monoethylene glycol is also utilized in hydraulic fluids, brake fluids, and as a component of cooling fluids in industrial and scientific systems.
MEG’s excellent heat-transfer properties make it particularly useful in applications where thermal management is critical, such as in cooling systems for electronics and machinery.
Production method:
Direct hydration of ethylene oxide is currently the only way for industrial-scale production of ethylene glycol.
Monoethylene glycol and water, under pressure (2.23MPa) and 190-200 ℃ conditions, and can directly have liquid-phase hydration reaction in a tubular reactor to generate ethylene glycol while being with byproducts diethylene glycol, tripropylene ethylene gl]ycol and multi-uret poly ethylene glycol.
The dilute ethylene glycol solution obtained from the reaction further undergoes thin film evaporator condensation, and then dehydration, refinement to obtain qualified products and by-products.
Monoethylene glycol catalyzed hydration of ethylene oxide; ethylene oxide can react with water, in the presence of sulfuric acid as the catalyst, at 60-80 ℃ and pressure of 9.806-19.61kPa for hydration to generate ethylene glycol.
The reaction mixture can be neutralized by liquid alkaline and evaporated of the water to obtain 80% ethylene glycol, and then distilled and concentrated in distillation column to obtain over 98% of the finished product.
This method is developed in early time. Owing to the presence of corrosion, pollution and product quality problems, together with complex refining process, countries have gradually discontinued and instead change to direct hydration.
Direct ethylene hydration; directly synthesize ethylene glycol from ethylene instead of being via ethylene oxide.
Industrial preparation of ethylene glycol adopts chlorine ethanol method, ethylene oxide hydration and direct ethylene hydration with various methods having their characteristics, as described below.
Take chloroethanol as raw materials for hydrolysis in alkaline medium to obtain it.
The reaction is carried out at 100 ℃ first generate ethylene oxide then pressurize at 1.01 MPa pressure to obtain ethylene glycol.
Hydration of ethylene oxide contains catalytic hydration and direct hydration.
The hydration process can be carried out under either normal pressure or under compression.
Normal pressure method generally take a small amount of inorganic acid as catalyst for reaction at 50~70 ℃.
Pressurized hydration had a high demand for the molar ratio of ethylene oxide over water which is higher than 1:6, to reduce the side reaction of producing the ether with the reaction temperature being at 150 °C and the pressure being 147kPa with hydration generating ethylene glycol.
There are currently gas phase catalytic hydration with silver oxide being the catalyst and the alumina oxide being the carrier for reaction at 150~240 ℃ to generate ethylene glycol.
Ethylene, in the presence of catalyst (e.g., antimony oxide TeO2 with palladium catalyst) can be oxidized in acetic acid solution to generate monoacetate ester or diacetate ester with further hydrolysis obtaining the ethylene glycol.
The above several methods takes ethylene oxide hydration as good with simple process and is suitable for industrialization.
Uses:
Monoethylene glycol is mainly used as the antifreeze agent for preparation of the automobile cooling systems and the raw material for the production of polyethylene terephthalate (the raw material of polyester fibers and plastics material).
Monoethylene glycol can also be used for the production of synthetic resins, solvents, lubricants, surfactants, emollients, moisturizers, explosives and so on.
Monoethylene glycol can often used as alternative of glycerol and can often be used as hydration agent and solvent in the tanning industry and pharmaceutical industry.
Monoethylene glycol has a strong dissolving capability but it is easily to be oxidized to toxic metabolic oxalic acid and therefore can’t be widely used as a solvent.
The ethylene glycol can be supplemented to the hydraulic fluid and can be used for preventing the erosion of oil-based hydraulic fluid on the rubber of the system; the water-based hydraulic fluid with ethylene glycol as a main component is an inflammable hydraumatic fluid and can be applied to the molding machine in aircraft, automobiles and high-temperature operation.
There are many important derivatives of ethylene glycol.
Low molecular weight polyethylene glycol (mono-uret ethylene glycol, bi-uret ethylene glycol, tri-uret ethylene glycol or respectively called as diethylene glycol, triethylene glycol, tetraethylene glycol) is actually the byproduct during the hydration of ethylene oxide B for preparation of ethylene glycol.
In hydraulic brake fluids and de-icing solutions. Industrial humectant.
Ingredient of electrolytic condensers (where it serves as solvent for boric acid and borates). Solvent in the paint and plastics industries.
In the formulation of printers' inks, stamp pad inks, ball-point pen ink. Softening agent for cellophane. Stabilizer for soybean foam used to extinguish oil and gasoline fires.
In the synthesis of safety explosives, glyoxal, unsatd ester type alkyd resins, plasticizers, elastomers, synthetic fibers (Terylene, Dacron), and synthetic waxes.
To create artificial smoke and mist for theatrical uses.
Monoethylene glycol is used as an antifreeze inheating and cooling systems (e.g., automobileradiators and coolant for airplane motors).
Monoethylene glycol is also used in the hydraulic brake fluids;as a solvent for paints, plastics, and inks; as a softening agent for cellophane; and in themanufacture of plasticizers, elastomers, alkydresins, and synthetic fibers and waxes.
Monoethylene glycol is used in the following products: laboratory chemicals, inks and toners, coating products, pH regulators and water treatment products, anti-freeze products and polymers.
Monoethylene Glycol is used in the following areas: scientic research and development, agriculture, forestry and shing, printing and recorded media reproduction and health services.
Monoethylene Glycol is used for the manufacture of: chemicals.
Monoethylene Glycol is used in the following products: adhesives and sealants, water treatment chemicals, polymers and adsorbents.
Release to the environment of Monoethylene Glycol can occur from industrial use: formulation of mixtures, formulation in materials, for thermoplastic manufacture, in processing aids at industrial sites, in the production of articles, as an intermediate step in further manufacturing of another substance (use of intermediates), as processing aid, as processing aid, of substances in closed systems with minimal release and manufacturing of the substance.
Monoethylene Glycol is used in the following products: textile treatment products and dyes, laboratory chemicals, polymers and coating products.
Monoethylene Glycol is used in the following areas: mining.
Release to the environment of Monoethylene Glycol can occur from industrial use: in processing aids at industrial sites, of substances in closed systems with minimal release, for thermoplastic manufacture, formulation in materials, as an intermediate step in further manufacturing of another substance (use of intermediates), in the production of articles, formulation of mixtures and manufacturing of the substance.
Release to the environment of Monoethylene glycol can occur from industrial use: manufacturing of the substance, in processing aids at industrial sites, as processing aid, formulation of mixtures, formulation in materials, as an intermediate step in further manufacturing of another substance (use of intermediates), as processing aid, for thermoplastic manufacture, of substances in closed systems with minimal release and in the production of articles.
Reagent typically used in cyclocondensation reactions with aldehydes1 and ketones1,2 to form 1,3-dioxolanes.
The major use of ethylene glycol is as an antifreeze agent in the coolant in for example, automobiles and 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, ethylene glycol is the fluid that transports heat through the use of a geothermal heat pump.
The ethylene 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, ethylene 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 mixture of ethylene 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.
Monoethylene glycol and water are sometimes informally referred to in industry as glycol concentrates, compounds, mixtures, or solutions.
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.
Monoethylene glycol 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.
Monoethylene glycol has been used in a few cases to treat partially rotted wooden objects to be displayed in museums.
Monoethylene glycol is one of only a few treatments that are successful in dealing with rot in wooden boats, and is relatively cheap. Ethylene 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.
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 cathoderay tube type of rear projection televisions.
Monoethylene glycol is also used in the manufacture of some vaccines, but Monoethylene Glycol is not itself present in these injections.
Monoethylene Glycol 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.
Monoethylene Glycol has been used in a few cases to treat partially rotted wooden objects to be displayed in museums.
Monoethylene Glycol 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.
Monoethylene Glycol is also used as part of the water-based hydraulic uid used to control subsea oil and gas production equipment.
Monoethylene Glycol is used as a protecting group in organic synthesis to protect carbonyl compounds such as ketones and aldehydes.
Silicon dioxide reacts in heated reux 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.
The silicates are essentially insoluble in all polar solvent except methanol.
Monoethylene Glycol also can be used in vaccine manufacture or as a formaldehyde substitute when preserving biological specimens.
Monoethylene Glycol is used in the following products: textile treatment products and dyes, washing & cleaning products, coating products, inks and toners, non-metal-surface treatment products, leather treatment products, polishes and waxes, adhesives and sealants, heat transfer uids, polymers, hydraulic uids, anti-freeze products and biocides (e.g. disinfectants, pest control products).
Other release to the environment of Monoethylene Glycol is likely to occur from: outdoor use, indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners), indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters) and outdoor use in close systems with minimal release (e.g. hydraulic liquids in automotive suspension, lubricants in motor oil and break uids).
Release to the environment of Monoethylene Glycol can occur from industrial use: manufacturing of the substance and in processing aids at industrial sites.
Other release to the environment of Monoethylene Glycol is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners), outdoor use, indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters) and outdoor use in long-life materials with low release rate (e.g. metal, wooden and plastic construction and building materials).
Monoethylene Glycol can be found in complex articles, with no release intended: machinery, mechanical appliances and electrical/electronic products (e.g. computers, cameras, lamps, refrigerators, washing machines), machinery, mechanical appliances and electrical/electronic products e.g. refrigerators, washing machines, vacuum cleaners, computers, telephones, drills, saws, smoke detectors, thermostats, radiators, large-scale stationary industrial tools), vehicles and electrical batteries and accumulators.
Monoethylene Glycol can be found in products with material based on: paper (e.g. tissues, feminine hygiene products, nappies, books, magazines, wallpaper).
Storage:
General storage may be used.Prior to working with this chemical should be trainedon its proper handling and storage. Before entering confinedspace where this chemical may be present, check to makesure that an explosive concentration does not exist.Ethylene glycol must be stored to avoid contact with sulfuric acid since violent reactions occur.
Store in tightly closedcontainers in a cool, well-ventilated area away from oxidizing agents (such as perchlorates, peroxides, permanganates,chlorates, and nitrates).
Safety Profile:
Human poison by ingestion moderately toxic to humans by an unspecified route.
Moderately toxic experimentally by ingestion, subcutaneous, intravenous, and intramuscular routes.
Human systemic effects by ingestion and inhalation: eye lachrymation, general anesthesia, headache, cough, respiratory stimulation, nausea or vomiting, pulmonary, kidney, and liver changes.
If ingested it causes initial central nervous system stimulation followed by depression.
Later, Monoethylene glycol causes potentially lethal kidney damage very toxic in particulate form upon inhalation.
An experimental teratogen. Other experimental reproductive effects human mutation data reported.
A skin, eye, and mucous membrane irritant.
Combustible when exposed to heat or flame; can react vigorously with oxidants.
Moderate explosion hazard when exposed to flame.
Iptes on contact with chromium trioxide, potassium permanganate, and sodium peroxide.
Mixtures with ammonium dichromate, silver chlorate, sodium chlorite, and uranyl nitrate ipte when heated to 100°C.
Can react violently with chlorosulfonic acid, oleum, H2SO4, HClO4, and Pass.
Aqueous solutions may ignite silvered copper wires that have an applied D.C. voltage.
To fight fire, use alcohol foam, water, foam, CO2, dry chemical.
When heated to decomposition it emits acrid smoke and irritating fumes.
Monoethylene glycol is considered an inert ingredient in pesticides.
Monoethylene glycol typically enters the environment through waste streams after use of deicing products, where it is highly mobile in soil and contaminates groundwater.
Monoethylene glycol is considered ‘readily biodegradable.’
Monoethylene glycol biodegrades relatively quickly; its half-life (t1/2) is 2–12 days in soil.
Monoethylene glycol is biodegraded in water under both aerobic and anaerobic conditions within a day to a few weeks. In the atmosphere, ethylene glycol photochemically degrades with a t1/2 of approximately 2 days.
The acute inhalation toxicity of 1,2-ethanediolis low.
This is due to its low vaporpressure, 0.06 torr at 20°C (68°F). Its saturationconcentration in air at 20°C (68°F)is 79 ppm and at 25°C (77°F) is 131 ppm(ACGIH 1986). Both concentrations exceedthe ACGIH ceiling limit in air, which is50 ppm.
In humans, exposure to its mist orvapor may cause lacrimation, irritation ofthroat, and upper respiratory tract, headache,and a burning cough.
These symptoms maybe manifested from chronic exposure toabout 100 ppm for 8 hours per day for severalweeks.
The acute oral toxicity of 1,2-ethanediol islow to moderate.
The poisoning effect, however,is much more severe from ingestionthan from inhalation.
Accidental ingestion of80–120 mL of this sweet-tasting liquid canbe fatal to humans.
The toxic symptoms inhumans may be excitement or stimulation,followed by depression of the central nervoussystem, nausea, vomiting, and drowsiness,which may, in the case of severe poisoning, progress to coma, respiratory failure, anddeath. When rats were administered sublethaldoses over a long period, there was depositionof calcium oxalate in tubules, causinguremic poisoning.
Ingestion of 1,2-ethanediol produced reproductiveeffects in animals, causing fetotoxicity, postimplantation mortality, andspecific developmental abnormalities.
Monoethylene glycol tested negativeto the histidine reversion–Ames test.
Monoethylene glycol has low toxicity but it is metabolized to a variety of toxic metabolites.
Monoethylene glycol and glycolaldehyde have an intoxicating effect on the central nervous system that can lead to ataxia, sedation, coma, and respiratory arrest similar to ethanol intoxication.
However, the profound metabolic acidosis reported in toxicity is secondary to accumulation of acid metabolites, especially glycolic acid.
The oxalic acid metabolite complexes with calcium and precipitates as calcium oxalate crystals in the renal tubules, leading to acute renal injury.
Further, oxalate’s ability to chelate calcium may cause clinically relevant serum hypocalcemia.
