Ethylene Glycol Manufacturing
Ethylene Glycol Introduction
Mono ethylene glycol is a commercially important raw material in
the manufacture of PET (poly ethylene terephthalate) polyester (fiber, film and
bottle grade) , one of ethylene glycol’s two major chemical uses which consumes
a large portion of total MEG production.
Mono ethylene glycol’s other major use, a non polymer one, is as
an antifreeze blending for liquid-cooled motor vehicles to lower the freezing
point when mixed with water.
DEG is used mainly as an intermediate in the production of
unsaturated polyester resin and as an alcohol component in polyurethane manufacturing.
TEG has similar properties to DEG and is frequently preferred when
a less volatile compound is required. TEG is the preferred agent for drying
natural gas and in other moisture removing applications.
Ethylene Oxide is produced
commercially by the direct catalytic oxidation of ethylene with oxygen over
silver based catalyst under 220-270oC by the
the ethylene glycol section, the liquid phase thermal hydration of ethylene
oxide with excess water is desired reaction to produce predominantly mono
ethylene glycol which undergoes side reactions yield approx. 10%wt of oligomers
(DEG & TEG) as co-products. Purification of this mixture requires repeated
fractional vacuum distillation to remove the water and to separate the MEG from
the higher glycols.