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Monoethylene glycol (MEG, glycol, 1,2-ethanediol) is the most important of
the commercially available glycols (1,2-alkanediols). Diethylene glycol (DEG)
and triethylene glycol (TEG) are obtained as coproducts in the manufacture
of MEG from ethylene oxide. MEG is consumed predominantly in antifreeze and
in polyesters (polyethylene terephthalate or PET) used for fibers, film, solid-state
resins and other products. DEG and TEG are used in a wide variety of end products
and as chemical intermediates.
The following pie chart shows world consumption of monoethylene glycol, which
accounts for 90% of total consumption of ethylene glycols:
In 2006, 82% of the MEG consumed worldwide went into the production of polyethylene
terephthalate, which in turn was converted into fibers, film and bottles. Another
12% was consumed in antifreeze.
DEG and TEG are obtained as coproducts in the manufacture of MEG from ethylene
oxide. Not all MEG producers recover DEG and TEG; some recover and sell glycols
above MEG as unspecified polyglycols. In addition, TEG can be produced by the
reaction of ethylene oxide with DEG. U.S. and Japanese producers often supplement
coproduct TEG supply using this method.
Since diethylene glycol is a coproduct of monoethylene glycol production,
the global DEG market is amply supplied. The current global TEG supply/demand
is tight and may continue to be so because of the high capital cost for higher
glycol refining and manufacturing processes without higher glycol coproducts.
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