U.S. patent application number 11/296913 was filed with the patent office on 2007-06-14 for catalyst for the production of polyols by hydrogenolysis of carbohydrates.
This patent application is currently assigned to Sud-Chemie Inc.. Invention is credited to Dale E. JR. Holcomb.
Application Number | 20070135301 11/296913 |
Document ID | / |
Family ID | 37882327 |
Filed Date | 2007-06-14 |
United States Patent
Application |
20070135301 |
Kind Code |
A1 |
Holcomb; Dale E. JR. |
June 14, 2007 |
Catalyst for the production of polyols by hydrogenolysis of
carbohydrates
Abstract
A catalyst for the hydrogenolysis of carbohydrates is disclosed.
The catalyst comprises nickel metal on an alumina-silica support.
Optionally, the catalyst may be promoted with noble metals selected
from the group consisting of copper, ruthenium, rhodium, palladium,
platinum, gold, silver, and combinations thereof.
Inventors: |
Holcomb; Dale E. JR.;
(Louisville, KY) |
Correspondence
Address: |
SUD-CHEMIE INC.
1600 WEST HILL STREET
LOUISVILLE
KY
40210
US
|
Assignee: |
Sud-Chemie Inc.
|
Family ID: |
37882327 |
Appl. No.: |
11/296913 |
Filed: |
December 8, 2005 |
Current U.S.
Class: |
502/244 ;
502/258; 502/259 |
Current CPC
Class: |
B01J 23/892 20130101;
B01J 37/03 20130101; B01J 23/755 20130101 |
Class at
Publication: |
502/244 ;
502/259; 502/258 |
International
Class: |
B01J 21/00 20060101
B01J021/00 |
Claims
1. A catalyst for use in a process for converting carbohydrates to
polyols and/or glycols, said process having an aqueous medium, and
said catalyst consisting essentially of from about 45 wt % to about
55 wt % nickel and up to about 0.5 wt % of a metal promoter,
selected from the group copper, ruthenium, rhodium, palladium,
platinum, gold, silver and compinations thereof, wherein said
nickel and said promoter are supported on a support comprising from
about 40 wt % to about 50 wt % alumina and from about 1 wt % to
about 10 wt % silica, wherein the ratio of alumina to silica
(Al:Si) is from about 4:1 to about 50:1.
2. (canceled)
3. The catalyst of claim 1 wherein said catalyst comprises from
about 48 wt % to about 53 wt % nickel, from about 43 wt % to about
46 wt % alumina, and from about 1 wt % to about 10 wt % silica.
4. (canceled)
5. (canceled)
6. The catalyst of claim 1 wherein said catalyst has a pore volume
of at least about 0.33 cm.sup.3/g.
7. The catalyst of claim 1 wherein said catalyst has a specific
surface area, measured by the BET procedure, of at least 150
m.sup.2/g.
8. The catalyst of claim 1 wherein said nickel is introduced to
said catalyst in the form of nickel nitrate, said alumina is
introduced to said catalyst in the form of aluminun nitrate, and
said silica is introduced to said catalyst as precipitated silica
or high surface area silica or bentonite or montmorillonite or
attapulgite.
9. The catalyst of claim 9 wherein said nickel nitrate and aluminum
nitrate are added together to form a pre-mix to which said promoter
is added and then said soda ash is then added the soda ash/pre-mix
mixture is allowed to form a precipitate which ages for a
predetermined period of time and then the precipitate is thoroughly
wash and dried, and then calcined to form an oxide lump which is
further ground and mixed with said silica before being formed into
predetermined shapes.
10. A catalyst for converting carbohydrates to polyols and/or
glycols, said catalyst comprising from about 45 wt % to about 55 wt
% nickel metal, form about 40 wt % to about 50 wt % alumina, and
from about 1 wt % to about 10 wt % silica, wherein the ratio of
alumina to silica (Al:Si) is from about 4:1 to about 50:1.
11. The catalyst of claim 10 further comprising up to about 0.5 wt
% of a metal promoter, selected from the group consisting of
copper, rutheninum, rhodium, palladium, platinum, gold, silver and
combinations thereof.
12. (canceled)
13. The catalyst of claim 10 wherein said silica is selected from
the group consisting of precipitated silica, high surface area
silica, bentonite, montmorillonite, attapulgite or combinations
thereof.
14. A catalyst for converting carbohydrates to polyols and/or
glycols, said catalyst comprising from about 45 wt % to about 55 wt
% nickel metal, from about 40 wt % to about 50 wt % alumina, and
from about 1 wt % to about 10 wt % silica, and wherein said
catalyst is prepared by mixing nickel nitrate and aluminum nitrate
together to form a pre-mix to which soda ash is then added, then
the soda ash/pre-mix mixture is allowed to form a precipitate which
ages for a predetermined period of time, and then the precipitate
is thoroughly washed and dried, and then calcined to form an oxide
lump which is further ground and mixed with said silica before
being formed into predetermined shapes.
15. The catalyst of claim 14 further comprising up to about 0.5 wt
% of a metal promoter selected from the group consisting of copper,
ruthenium, rhodium, palladium, platinum, gold, silver, and
combinations thereof wherein said promoter is added concurrent with
the soda ash.
16. The catalyst of claim 14 further comprising up to about 0.5 wt
% of a metal promoter selected from the group consisting of copper,
ruthenium, rhodium, palladium, platinum, gold, silver, and
combinations thereof wherein said promoter is added before the soda
ash.
17. The catalyst of claim 8 wherein said nickel nitrate and
aluminum nitrate are added together to form a pre-mix mixture to
which said promoter and said soda ash is then added concurrently,
the soda ash/pre-mix mixture is allowed to form a precipitate which
ages for a predetermined period of time, and then the precipitate
is thoroughly washed and dried, and then calcined to form an oxide
lump which is further ground and mixed with said silica before
being formed into predetermined shapes.
Description
BACKGROUND
[0001] The present development is a catalyst useful for the
production of polyols. Specifically, the invention is directed to
the use of a nickel on alumina-silica catalyst for the
hydrogenolysis of carbohydrates. Optionally, the catalyst may be
promoted with noble metals.
[0002] Polyols are commonly derived from sugars or carbohydrates.
An aqueous solution of sugar is treated with hydrogen in the
presence of a nickel catalyst to produce a sugar alcohol. The sugar
alcohol, when further treated with hydrogen in the presence of the
nickel catalyst, can be converted to polyols and glycols.
[0003] Because the media for these hydrogenation reactions is
water, it can be challenging to identify an effective, relatively
long-lived catalyst for these processes. One approach identified in
the prior art was to use colloidal metal. This avoided the problem
that many common catalyst supports are not stable in water.
However, it was difficult and expensive to remove the colloidal
metal from the resulting polyols and glycols. In U.S. Pat. No.
5,162, 517 (issued to Darsow on Nov. 10, 1992), carrier-free
catalysts are processed into mouldings from metal powders. The
metal powders include elements of the iron group, such as nickel,
cobalt, iron and mixtures and alloys of these metals. The mouldings
comprise at least 70% metal.
[0004] Supported metal catalysts have also been proposed for use in
carbohydrate hydrogenation processes. Silica-alumina carriers are
known in the art, but the '517 patent found these to be
problematic: "nickel catalysts on a carrier
(SiO.sub.2/Al.sub.2O.sub.3)[have] extremely high active surfaces of
140-180 m.sup.2/g so that the catalysts are so active that they
must be stabilized by additional chemical treatment methods . . .
However, the deactivating stabilization of the catalyst then
requires such high reaction temperatures during the hydrogenation
of sugars (130-180.degree. C.) that uncontrollable side reactions
can occur . . ." In U.S. Pat. No. 4,382,150 (issued to Arena on May
3, 1983), the catalyst proposed is a zerovalent Group VIII metal
dispersed on titanium dioxide: "whereas substantial amounts of
silica and alumina, which are to (sic) commonly employed support
materials, dissolve in the aqueous medium during hydrogenation of
carbohydrates, virtually no leaching of titanium dioxide occurs
under comparable hydrogenation conditions."
[0005] Raney catalysts are known in the art of carbohydrate
conversion. For example, U.S. Pat. No. 6,414,201 (issued to Shimazu
et al. on Jul. 2, 2002), teaches and claims a process that uses a
Raney catalyst formed by melting a mixture of nickel and aluminum
and then quenching droplets of the mixture to form a lump alloy,
from which particles are broken. However, it is generally known in
the art that Raney catalysts work well in static operations, but
are not well-adapted to function effectively in continuous
processes. Further, similar to the processes using colloid metal,
Raney catalysts must be separated and recovered from the reaction
mixture at the end of the process.
SUMMARY OF THE INVENTION
[0006] The present development is a catalyst for the hydrogenolysis
of carbohydrates comprising nickel metal on an alumina-silica
support. Optionally, the catalyst may be promoted with noble
metals. In particular, the catalyst of the present invention
comprises from about 45 wt % to about 55 wt % nickel, from about 40
wt % to about 50 wt % alumina, and from about 1 wt % to about 10 wt
% silica. The catalyst may further comprise up to about 0.5 wt %
promoter.
[0007] The catalyst is intended to be used in an aqueous medium
process for converting carbohydrates to polyols and/or glycols.
Further, the catalyst is intended to be used as a fixed bed of
catalyst in a continuous process for converting carbohydrates to
polyol and/or glycols.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0008] The present development is a catalyst for use in processes
for converting carbohydrates to polyols and glycols. The
carbohydrates are treated with hydrogen in an aqueous medium and in
the presence of a hydrogenation catalyst comprising nickel metal on
an alumina and silica support. Optionally, the catalyst may be
promoted with a noble metal.
[0009] The catalyst of the present invention comprises nickel
metal, alumina and silica. The nickel metal comprises from about 45
wt % to about 55 wt % of the total catalyst weight. The alumina to
silica ratio preferably ranges from about 4:1 to about 50:1, with
the alumina comprising from about 40 wt % to about 50 wt % of the
total catalyst weight, and the silica comprising from about 1 wt %
to about 10 wt % of the total catalyst weight. In an exemplary
embodiment of the catalyst, the nickel comprises from about 48 wt %
to about 53 wt % of the total catalyst weight, the alumina
comprises from about 43 wt % to about 46 wt % of the total catalyst
weight, and the silica comprises from about 1 wt % to about 10 wt %
of the total catalyst weight.
[0010] The pore volume of the catalyst is preferably at least about
0.33 cm.sup.3/g, and the specific surface area, measured by the BET
procedure, is preferably at least 150 m.sup.2/g. In an exemplary
embodiment, greater than about 45% of the volume of the catalyst
has a pore size of less than about 100 .ANG. and greater than about
40% of the volume of the catalyst has a pore size of from about 100
.ANG. to about 300 .ANG..
[0011] The nickel is introduced to the catalyst in the form of
nickel nitrate. In an exemplary embodiment, the nickel nitrate is
in the form of a solution containing about 13.8 wt % nickel. The
alumina is introduced to the catalyst in the form of aluminum
nitrate. In an exemplary embodiment, the aluminum nitrate is in the
form of a solution containing about 60 wt % solids. The silica is
introduced to the catalyst typically as a silica-containing binder
in a variety of forms that are known in the art, such as
precipitated silica, high surface area silica, bentonite,
montmorillonite, and attapulgite.
[0012] In an exemplary process, the catalyst is prepared by a
copreciptiation method. The nickel nitrate and aluminum nitrate are
added together to form a pre-mix. Soda ash is then added to the
pre-mix, and the mixture is allowed to precipitate and age for a
period of time. The resulting precipitate is thoroughly washed,
dried, and then calcined to an oxide lump. The lump is further
ground and mixed with a silica-containing binder. The resulting
ground lump is formed into the desired extrusions or tablets. The
resulting catalyst comprises about 50.6 wt % Ni, 44.2 wt %
Al.sub.2O.sub.3, and 5.2 wt % SiO.sub.2, and has a pore volume of
0.44 cm.sup.3/g, a BET specific surface area of 161 m.sup.2/g, and
a loss of ignition at 540.degree. C. of less than about 5%.
[0013] Optionally, the catalyst may comprise up to about 0.5 wt %
of a metal promoter, such as copper, ruthenium, rhodium, palladium,
platinum, gold, silver. The promoter is may be added during
precipitation or may be added into the premix--methods that are
known in the art.
[0014] The catalyst of the present invention is intended for use in
the hydrogenolysis of carbohydrates in aqueous media. The catalyst
differs from the catalysts of the prior art by requiring that
nickel metal be supported on a predominantly alumina-based support.
It is understood that the composition of the catalyst and the
specific processing conditions may be varied without exceeding the
scope of this development.
* * * * *