Triethylene glycol
Encyclopedia
Triethylene glycol, TEG, or triglycol is a colorless odorless viscous liquid with molecular formula HOCH2CH2OCH2CH2OCH2CH2OH. It is used as a plasticizer
for vinyl
. It is also used in air sanitizer products, such as "Oust" or "Clean and Pure." When aerosolized it acts as a disinfectant. Glycols are also used as liquid desiccant
s for natural gas and in air conditioning
systems. It is an additive for hydraulic fluid
s and brake fluid
s and is used as a base for "smoke machine" fluid in the entertainment industry.
and a high boiling point. Apart from its use as a raw material in the manufacture and synthesis of other products, TEG is known for its hygroscopic
quality and its ability to dehumidify
fluids. This liquid is miscible with water, and at a pressure of 100 kPa
has a boiling point of 285 degrees Celsius and a melting point of -7 degrees C. It is also soluble in ethanol
, acetone
, acetic acid
, glycerine, pyridine
, aldehydes; slightly soluble in diethyl ether
; and insoluble in oil, fat and hydrocarbons.
at high temperature in the presence of silver oxide catalyst, followed by hydration of ethylene oxide
to yield mono-, di-, tri- and tetraethylene glycols.
. It may also be used to dehydrate certain other gases. It is necessary to dry natural gas to a certain point, as humidity in natural gas can cause pipelines to freeze, and create other problems for end users of the natural gas. Triethylene glycol is placed into contact with natural gas, and strips the water out of the gas. Triethylene glycol is heated to a high temperature and put through a condensing
system, which removes the water as waste and reclaims the TEG for continuous reuse within the system. The waste TEG produced by this process has been found to contain enough benzene
to be classified as hazardous waste
(benzene concentration greater than 0.5 mg/L).
Triethylene glycol is well established as a relatively mild disinfectant toward a variety of bacteria
, influenza A viruses and spores of Penicillium notatum fungi. However, its exceptionally low toxicity, broad materials compatibility, and low odor combined with its antimicrobial properties indicates that it approaches the ideal for air disinfection purposes in occupied spaces. Much of the scientific work with triethylene glycol was done in the 1940s and 1950s, however that work has ably demonstrated the antimicrobial activity against airborne, solution suspension, and surface bound microbes. The ability of triethylene glycol to inactivate Streptococcus pneumoniae
(original citation: pneumococcus Type I), Streptococcus pyogenes
(original citation: Beta hemolytic streptococcus group A) and Influenza A virus in the air was first reported in 1943. Since the first report the following microorganisms have been reported in the literature to be inactivated in the air: Penicillium notatum spores, Chlamydophila psittaci
(original citation: meningopneumonitis virus strain Cal 10 and psittacosis virus strain 6BC), Group C streptococcus
, type 1 pneumococcus, Staphylococcus albus, Escherichia coli
, and Serratia marcescens
Bizio (ATCC 274). Solutions of triethylene glycol are known to be antimicrobial toward suspensions of Penicillium notatum spores, Streptococcus pyogenes
(original citation: Beta hemolytic streptococcus group A), Streptococcus pneumoniae
(original citation: pneumococcus Type I), Streptococcus pyogenes
(original citation: streptococcus Group A Types 1, 12 and 19), Streptococcus viridans
, and Mycobacterium bovis
(original citation: tubercle bacilli Ravenel bovine-type). Further, the inactivation of H1N1
influenza A virus
on surfaces has been demonstrated. The latter investigation suggests that triethylene glycol may prove to be a potent weapon against future influenza
epidemics and pandemics.
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...
for vinyl
Vinyl
A vinyl compound is any organic compound that contains a vinyl group ,which are derivatives of ethene, CH2=CH2, with one hydrogen atom replaced with some other group...
. It is also used in air sanitizer products, such as "Oust" or "Clean and Pure." When aerosolized it acts as a disinfectant. Glycols are also used as liquid desiccant
Desiccant
A desiccant is a hygroscopic substance that induces or sustains a state of dryness in its local vicinity in a moderately well-sealed container....
s for natural gas and in air conditioning
Air conditioning
An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...
systems. It is an additive for hydraulic fluid
Hydraulic fluid
Hydraulic fluids, also called hydraulic liquids, are the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water...
s and brake fluid
Brake fluid
Brake fluid is a type of hydraulic fluid used in hydraulic brake and hydraulic clutch applications in automobiles, motorcycles, light trucks, and some bicycles. It is used to transfer force into pressure...
s and is used as a base for "smoke machine" fluid in the entertainment industry.
Properties
Triethylene glycol is a member of a homologous series of dihydroxy alcohols. It is a colorless, odorless and stable liquid with low viscosityViscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
and a high boiling point. Apart from its use as a raw material in the manufacture and synthesis of other products, TEG is known for its hygroscopic
Hygroscopy
Hygroscopy is the ability of a substance to attract and hold water molecules from the surrounding environment. This is achieved through either absorption or adsorption with the absorbing or adsorbing material becoming physically 'changed,' somewhat, by an increase in volume, stickiness, or other...
quality and its ability to dehumidify
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...
fluids. This liquid is miscible with water, and at a pressure of 100 kPa
Pascal (unit)
The pascal is the SI derived unit of pressure, internal pressure, stress, Young's modulus and tensile strength, named after the French mathematician, physicist, inventor, writer, and philosopher Blaise Pascal. It is a measure of force per unit area, defined as one newton per square metre...
has a boiling point of 285 degrees Celsius and a melting point of -7 degrees C. It is also soluble in ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
, acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...
, acetic acid
Acetic acid
Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...
, glycerine, pyridine
Pyridine
Pyridine is a basic heterocyclic organic compound with the chemical formula C5H5N. It is structurally related to benzene, with one C-H group replaced by a nitrogen atom...
, aldehydes; slightly soluble in diethyl ether
Diethyl ether
Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound in the ether class with the formula . It is a colorless, highly volatile flammable liquid with a characteristic odor...
; and insoluble in oil, fat and hydrocarbons.
Preparation
TEG is prepared commercially as a co-product of the oxidation of ethyleneEthylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...
at high temperature in the presence of silver oxide catalyst, followed by hydration of ethylene oxide
Ethylene oxide
Ethylene oxide, also called oxirane, is the organic compound with the formula . It is a cyclic ether. This means that it is composed of two alkyl groups attached to an oxygen atom in a cyclic shape . This colorless flammable gas with a faintly sweet odor is the simplest epoxide, a three-membered...
to yield mono-, di-, tri- and tetraethylene glycols.
Applications
TEG is used by the oil and gas industry to "dehydrate" natural gasNatural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
. It may also be used to dehydrate certain other gases. It is necessary to dry natural gas to a certain point, as humidity in natural gas can cause pipelines to freeze, and create other problems for end users of the natural gas. Triethylene glycol is placed into contact with natural gas, and strips the water out of the gas. Triethylene glycol is heated to a high temperature and put through a condensing
Condensation
Condensation is the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of vaporization. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition....
system, which removes the water as waste and reclaims the TEG for continuous reuse within the system. The waste TEG produced by this process has been found to contain enough benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
to be classified as hazardous waste
Hazardous waste
A hazardous waste is waste that poses substantial or potential threats to public health or the environment. According to the U.S. environmental laws hazardous wastes fall into two major categories: characteristic wastes and listed wastes.Characteristic hazardous wastes are materials that are known...
(benzene concentration greater than 0.5 mg/L).
Triethylene glycol is well established as a relatively mild disinfectant toward a variety of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, influenza A viruses and spores of Penicillium notatum fungi. However, its exceptionally low toxicity, broad materials compatibility, and low odor combined with its antimicrobial properties indicates that it approaches the ideal for air disinfection purposes in occupied spaces. Much of the scientific work with triethylene glycol was done in the 1940s and 1950s, however that work has ably demonstrated the antimicrobial activity against airborne, solution suspension, and surface bound microbes. The ability of triethylene glycol to inactivate Streptococcus pneumoniae
Streptococcus pneumoniae
Streptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. A significant human pathogenic bacterium, S...
(original citation: pneumococcus Type I), Streptococcus pyogenes
Streptococcus pyogenes
Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of group A streptococcal infections. S. pyogenes displays streptococcal group A antigen on its cell wall. S...
(original citation: Beta hemolytic streptococcus group A) and Influenza A virus in the air was first reported in 1943. Since the first report the following microorganisms have been reported in the literature to be inactivated in the air: Penicillium notatum spores, Chlamydophila psittaci
Chlamydophila psittaci
Chlamydophila psittaci is a lethal intracellular bacterial species that may cause endemic avian chlamydiosis, epizootic outbreaks in mammals, and respiratory psittacosis in humans. Chlamydophila psittaci is transmitted by inhalation, contact or ingestion among birds and to mammals...
(original citation: meningopneumonitis virus strain Cal 10 and psittacosis virus strain 6BC), Group C streptococcus
Streptococcus
Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
, type 1 pneumococcus, Staphylococcus albus, Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
, and Serratia marcescens
Serratia marcescens
Serratia marcescens is a species of Gram-negative, rod-shaped bacterium in the family Enterobacteriaceae. A human pathogen, S. marcescens is involved in nosocomial infections, particularly catheter-associated bacteremia, urinary tract infections and wound infections, and is responsible for 1.4% of...
Bizio (ATCC 274). Solutions of triethylene glycol are known to be antimicrobial toward suspensions of Penicillium notatum spores, Streptococcus pyogenes
Streptococcus pyogenes
Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of group A streptococcal infections. S. pyogenes displays streptococcal group A antigen on its cell wall. S...
(original citation: Beta hemolytic streptococcus group A), Streptococcus pneumoniae
Streptococcus pneumoniae
Streptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. A significant human pathogenic bacterium, S...
(original citation: pneumococcus Type I), Streptococcus pyogenes
Streptococcus pyogenes
Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of group A streptococcal infections. S. pyogenes displays streptococcal group A antigen on its cell wall. S...
(original citation: streptococcus Group A Types 1, 12 and 19), Streptococcus viridans
Streptococcus viridans
Viridans Streptococcus is a pseudotaxonomic non-Linnaenan term for a large group of commensal streptococcal bacteria that are either α-hemolytic, producing a green coloration on blood agar plates , or nonhemolytic...
, and Mycobacterium bovis
Mycobacterium bovis
Mycobacterium bovis is a slow-growing , aerobic bacterium and the causative agent of tuberculosis in cattle...
(original citation: tubercle bacilli Ravenel bovine-type). Further, the inactivation of H1N1
H1N1
'Influenza A virus is a subtype of influenza A virus and was the most common cause of human influenza in 2009. Some strains of H1N1 are endemic in humans and cause a small fraction of all influenza-like illness and a small fraction of all seasonal influenza. H1N1 strains caused a few percent of...
influenza A virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
on surfaces has been demonstrated. The latter investigation suggests that triethylene glycol may prove to be a potent weapon against future influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
epidemics and pandemics.