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 desiccants for natural gas and in air
conditioning systems. It is an additive for hydraulic fluids and brake fluids
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 high 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 quality and
its ability to dehumidify fluids. This liquid is miscible with water, and at a
pressure of 101.325 kPa has a boiling point of 286.5 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 most hydrocarbons.
Preparation TEG is prepared commercially as a
co-product of the oxidation of ethylene at high temperature in the presence of
silver oxide catalyst, followed by hydration of ethylene oxide to yield
mono(one)-, di(two)-, tri(three)- and tetraethylene glycols.
Applications TEG is used by the oil and gas industry
to "dehydrate" natural gas. It may also be used to dehydrate other gases,
including CO2, H2S, and other oxygenated 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. 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, Streptococcus pyogenes 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,
Group C streptococcus, type 1 pneumococcus, Staphylococcus albus,
Escherichia coli, and Serratia marcescens Bizio. Solutions of
triethylene glycol are known to be antimicrobial toward suspensions of
Penicillium notatum spores, Streptococcus pyogenes, Streptococcus
pneumoniae, Streptococcus viridans, and Mycobacterium bovis. 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.
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