| IPCI |
International Polyol Chemicals, Inc. PO BOX 190 - Blue River, OR 97413 - (541) 822-8400
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Technology
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IPCI TECHNOLOGY
1.
IPCI HYDROGENATION A
variety of methods have been developed for the conversion of sugars to
sugar alcohols, including treatment with sodium amalgam, enzymatic
conversions, fermentation, electrolytic reduction and catalytic
hydrogenation. Thermal
catalytic hydrogenation is, by far, the technology most widely
used for sugar alcohol production.
The IPCI hydrogenation technology is applicable to manufacture of
most of the commercial sugar alcohols. The basic chemistry for hydrogenation of a sugar to a sugar alcohol is according to the following equation:
The
most common sugar alcohol, sorbitol, is commercially produced in large
volume today using batch processes, and, typically, a Raney nickel
catalyst usually prepared fresh for each batch.
A few continuous sorbitol processes have been developed, and
plants built - but we believe most, if not all, have been abandoned in
favor of the better established batch process. IPCI's
hydrogenation process to produce sorbitol or other sugar alcohols is
characterized by: ·
Continuous process ·
Uses a robust, high activity, supported nickel
catalyst ·
Typical glucose conversion >98.5% ·
Produces specification sorbitol from a glucose feed ·
Can utilize invert sugar (glucose and fructose) to
produce mannitol and sorbitol ·
Flexible Reactor System designs
2.
IPCI HYDROGENOLYSIS Hydrogenolysis is a
term describing chemical reactions in which hydrogen is used to break
molecular bonds in larger organic molecules in order to provide smaller,
higher value or more useful molecules.
Hydrogenolysis reactions are usually conducted over a catalyst of
some type, and at an elevated temperature (typically for carbohydrates,
100 to 300 oC) and high hydrogen pressures (typically 70 to 300 atmospheres).
In glycols and carbohydrates it is known that both C-C and C-O
bonds can be broken by hydrogenolysis or hydrocracking, as it is
sometimes called. In
contrast to the case for hydrogenation of carbohydrates, the chemistry
of hydrogenolysis of the sugar alcohols (alditols) is complex, not well
understood, and variable with even small changes in the catalyst system
or the process conditions - particularly the reaction temperature.
It is therefore difficult to describe the exact process chemistry
taking place. In fact,
there appears to be a chain or series of reactions, where primary
reaction products are further hydrocracked to smaller molecule polyols
and alcohols in secondary and tertiary reactions. Theoretically,
the primary reaction is a hydrogen splitting of the alditol molecule at
the center C-C bond to produce glycerin, or propylene glycol and water.
However, there seems to be no proof that these reactions occur
completely, since it is almost always the case that both glycerin and
propylene glycol are produced in alditol hydrocracking. Following are
the simple chemical equations for formation of glycerin and propylene
glycol from sorbitol or mannitol:
It
has been shown conclusively that glycerin will hydrocrack to propylene
glycol, as in (3):
Smaller
molecule compounds such as EG, the 1-3 carbon alcohols and the
butanediols could be formed from various alditol cracking schemes, but
it seems more likely that they are produced from glycerin hydrocracking
under more severe process conditions (although the butanediols are more
likely formed by a 4 - 2 split of the alditol carbon chain, together
with EG or ethanol). In
any case, it is typical of hydrogenolysis of sugar alcohols to produce
several polyol and specialty chemical products. We
believe that other than the IPCI hydrogenolysis technology, no
commercial process is available to use for producing polyols from sugar
alcohols. The
IPCI hydrogenolysis process is characterized by: ·
Use of reliable, long-lived (> ~1600 hour life
test with no degradation) supported nickel catalyst ·
Produces primarily propylene glycol, ethylene
glycol and glycerin ·
Water solvent system ·
High conversion to polyols ·
Provisions for recycle of unreacted sorbitol and
unwanted byproducts ·
Proven separation system for isolation of the
individual polyol products ·
Ability to adjust product slate, and to produce and
separate selected byproducts such as the butanediols, isosorbide and THF
glycol ·
Flexible in feedstock as to using either single or
multiple component sugar alcohols
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