U.S. patent application number 09/789987 was filed with the patent office on 2001-07-12 for fischer-tropsch processes using xerogel and aerogel catalysts by destabilizing aqueous colloids.
Invention is credited to Kourtakis, Kostantinos, Manzer, Leo E..
Application Number | 20010007879 09/789987 |
Document ID | / |
Family ID | 27492894 |
Filed Date | 2001-07-12 |
United States Patent
Application |
20010007879 |
Kind Code |
A1 |
Manzer, Leo E. ; et
al. |
July 12, 2001 |
Fischer-tropsch processes using xerogel and aerogel catalysts by
destabilizing aqueous colloids
Abstract
A process is disclosed for producing hydrocarbons by contacting
a feed stream comprising hydrogen and carbon monoxide with a
catalyst in a reaction zone maintained at conversion-promoting
conditions effective to produce an effluent stream comprising
hydrocarbons. The process is characterized by using a catalyst
prepared by a method involving (1) forming a catalyst gel by
destabilizing an aqueous colloid comprising (a) at least one
catalytic metal for Fischer-Tropsch reactions (e.g., iron, cobalt,
nickel and/or ruthenium), (b) colloidal cerium oxide, zirconium
oxide, titanium oxide and/or aluminum oxide, and optionally (c)
Al(OR).sub.3, Si(OR).sub.4, Ti(OR).sub.4 and/or Zr(OR).sub.4 where
each R is an alkyl group having from 1 to 6 carbon atoms; and (2)
drying the gel.
Inventors: |
Manzer, Leo E.; (Wilmington,
DE) ; Kourtakis, Kostantinos; (Swedesboro,
NJ) |
Correspondence
Address: |
Joanna K. Payne
CONOCO INC.
1000 South Pine Street 2635 R.W.
P.O. Box 1267
Ponca City
OK
74602-1267
US
|
Family ID: |
27492894 |
Appl. No.: |
09/789987 |
Filed: |
February 21, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09789987 |
Feb 21, 2001 |
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09377008 |
Aug 18, 1999 |
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6235677 |
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60097192 |
Aug 20, 1998 |
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60097193 |
Aug 20, 1998 |
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60097194 |
Aug 20, 1998 |
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Current U.S.
Class: |
518/700 ;
518/713; 518/715; 518/716; 518/719; 518/721 |
Current CPC
Class: |
B01J 23/74 20130101;
B01J 23/894 20130101; B01J 37/0236 20130101; C07C 1/0435 20130101;
B01J 35/0013 20130101; C10G 2/331 20130101; B01J 29/0308 20130101;
B01J 21/063 20130101; C10G 2/332 20130101; B01J 21/06 20130101;
B01J 29/041 20130101; B01J 21/066 20130101; B01J 23/462 20130101;
C10G 2/333 20130101; B01J 23/8933 20130101; C10G 2/334 20130101;
B01J 23/8913 20130101 |
Class at
Publication: |
518/700 ;
518/719; 518/721; 518/713; 518/715; 518/716 |
International
Class: |
C07C 027/00; C07C
027/06; C07C 027/08 |
Claims
1. A process for producing hydrocarbons, comprising contacting a
feed stream comprising hydrogen and carbon monoxide with a catalyst
in a reaction zone maintained at conversion-promoting conditions
effective to produce an effluent stream comprising hydrocarbons,
wherein the catalyst comprises a catalytically active metal
selected from the group consisting of iron, cobalt, nickel,
ruthenium, and combinations thereof dispersed in a matrix material
comprising a derivative of a destabilized aquasol comprising a
colloidal oxide of a matrix metal selected from the group
consisting of cerium, zirconium, titanium, aluminum, silicon, and
combinations thereof.
2. The process of claim 1 wherein the matrix material content of
the catalyst is from about 99.9 to about 35 mole percent.
3. The process of claim 2 wherein the matrix material content of
the catalyst is from about 50 to 85 mole percent.
4. The process of claim 2 wherein the matrix metal is selected from
the group consisting of cerium, titanium, aluminum, and
combinations thereof.
5. The process of claim 4 wherein the matrix metal is a
combinations of titanium and aluminum, and the atomic ratio of
titanium to aluminum is from about 5:95 to about 95:1.
6. The process of claim 1 wherein the catalytically active metal
comprises from about 0.1 to 50 mole percent of the matrix metal and
catalyst metal combined.
7. The process of claim 6 wherein the catalytically active metal
comprises from about 10 to 50 mole percent of the matrix metal and
catalyst metal combined.
8. The process of claim 7 wherein the catalytically active metal
comprises cobalt and ruthenium and wherein the content of the
catalytically active metal comprises from about 5 to 50 mole
percent of the matrix metal and catalyst metal combined.
9. The process of claim 8 wherein the ruthenium content is from
about 0.001 to about 5 mole percent of the matrix metal and
catalyst metal combined.
10. The process of claim 9 wherein the matrix metal is selected
from the group consisting of titanium, cerium, aluminum, a mixture
of cerium and aluminum, a mixture of silicon and aluminum, and a
mixture of titanium and aluminum.
11. The process of claim 1 wherein the catalyst comprises one or
more promoters selected from the group consisting of Na, K, Rb, Cs,
Mg, Ca, Sr, Ba, Cu, Ag, Au, Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Rh,
Pd, Os, Ir, Pt, Mn, B, P, and Re.
12. The process of claim 11 wherein the promoter comprises from
about 0.001 to 20 mole percent of the total metal content.
13. The process of claim 12 wherein the promoter comprises from
about 2 to 5 mole percent of the total metal content.
14. The process of claim 12 wherein the catalytically active metal
is cobalt, the promoter is rhenium, wherein the combined cobalt and
rhenium content is from about 10 to about 50 mole percent of the
total metal, and the rhenium content is from about 0.001 to about 5
mole percent of the total metal.
15. The process of claim 12 wherein the promoter is rhenium, the
combined content of cobalt, ruthenium, and rhenium is from about 10
to about 50 mole percent, and the combined content of rhenium and
ruthenium is from about 0.001 to 5 mole percent.
16. The process of claim 14 wherein the matrix metal is selected
from the group consisting of titanium, cerium, aluminum, a mixture
of cerium and aluminum, a mixture of silicon and aluminum, and a
mixture of titanium and aluminum.
17. The process of claim 15 wherein the matrix metal is selected
from the group consisting of titanium, cerium, aluminum, a mixture
of cerium and aluminum, a mixture of silicon and aluminum, and a
mixture of titanium and aluminum.
18. A Fischer-Tropsch catalyst comprising a reduced aerogel or
xerogel formed from the destabilization of a colloidal mixture
comprising a catalytically active metal selected from the group
consisting of iron, cobalt, nickel, ruthenium, aluminum, and
combinations thereof and a colloidal sol of a matrix metal selected
from the group consisting of cerium, zirconium, titanium, aluminum,
silicon, and combinations thereof.
19. The catalyst of claim 18 wherein the colloidal mixture
comprises a soluble salt.
20. The catalyst of claim 19 wherein the soluble salt comprises one
or more chlorides or nitrates of one or more catalytically active
metals.
21. The catalyst of claim 18 wherein the colloidal mixture further
comprises one or more inorganic alkoxides selected from the group
consisting of Al(OR).sub.3, Si(OR).sub.4, Ti(OR).sub.5 and
Zr(OR).sub.4, where each R is an alkyl group having from 1 to 6
carbon atoms.
22. The catalyst of claim 18 wherein the matrix metal content of
the catalyst is from about 99.9 to about 35 mole percent.
23. The catalyst of claim 22 wherein the matrix metal content of
the catalyst is from about 50 to 85 mole percent.
24. The catalyst of claim 23 wherein the matrix metal is selected
from the group consisting of cerium, titanium, aluminum, and
combinations thereof.
25. The catalyst of claim 24 wherein the matrix metal is a
combination of titanium or silicon and aluminum, and the atomic
ratio of titanium or silicon to aluminum is from about 5:95 to
about 95:1.
26. The catalyst of claim 18 wherein the catalytically active metal
comprises from about 0.1 to 50 mole percent of the matrix metal and
catalyst metal combined.
27. The catalyst of claim 18 wherein the catalytically active metal
comprises from about 10 to 50 mole percent of the matrix metal and
catalyst metal combined.
28. The catalyst of claim 27 wherein the catalytically active metal
comprises cobalt and ruthenium and wherein the content of the
catalytically active metal comprises from about 10 to 50 mole
percent of the matrix metal and catalyst metal combined.
29. The catalyst of claim 28 wherein the ruthenium content is from
about 0.001 to about 5 mole percent of the matrix metal and
catalyst metal combined.
30. The catalyst of claim 29 wherein the matrix metal is selected
from the group consisting of titanium, cerium, aluminum, a mixture
of cerium and aluminum, and a mixture of titanium and aluminum.
31. The catalyst of claim 18 wherein the catalyst comprises one or
more promoters selected from the group consisting of Na, K, Rb, Cs,
Mg, Ca, Sr, Ba, Cu, Ag, Au, Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Rh,
Pd, Os, Ir, Pt, Mn, B, P, and Re.
32. The catalyst of claim 31 wherein the promoter comprises from
about 0.001 to 20 mole percent of the total metal content.
33. The catalyst of claim 32 wherein the promoter comprises from
about 2 to 5 mole percent of the total metal content.
34. The catalyst of claim 32 wherein the catalytically active metal
is cobalt, the promoter is rhenium, wherein the combined cobalt and
rhenium content is from about 10 to about 50 mole percent of the
total metal, and the rhenium content is from about 0.001 to about 5
mole percent of the total metal.
35. The catalyst of claim 32 wherein the promoter is rhenium, the
combined content of cobalt, ruthenium, and rhenium is from about 10
to about 50 mole percent, and the combined content of rhenium and
ruthenium is from about 0.001 to 5 mole percent.
36. The catalyst of claim 34 wherein the matrix metal is selected
from the group consisting of titanium, cerium, aluminum, a mixture
of cerium and aluminum, and a mixture of titanium and aluminum.
37. The catalyst of claim 35 wherein the matrix metal is selected
from the group consisting of titanium, cerium, aluminum, a mixture
of cerium and aluminum, and a mixture of titanium and aluminum.
38. A method for preparing a Fischer-Tropsch catalyst comprising
mixing a colloidal sol of an oxide of a metal selected from the
group consisting of cerium, zirconium, titanium, aluminum, silicon,
and combinations thereof with a soluble salt of one or more
catalytically active metals selected from the group consisting of
iron, cobalt, nickel, and ruthenium, destabilizing the colloid to
form a gel, and removing solvent from the gel.
39. The method of claim 38 comprising removing solvent from the gel
under vacuum.
40. The method of claim 39 comprising aging the gel.
41. The method of claim 40 comprising reducing the catalyst.
42. The method of claim 41 comprising reducing the catalyst in a
hydrogen-containing stream.
43. The method of claim 41 wherein the soluble salt is a chloride
or nitrate.
44. The method of claim 38 comprising destabilizing the colloid by
varying the pH.
45. The method of claim 38 comprising removing solvent from the gel
by supercritical extraction.
46. The method of claim 45 wherein the supercritical extraction
comprises the use of one or more extraction fluids selected from
the group consisting of CCl.sub.3F, CCl.sub.2F.sub.2,
CClF.sub.2CClF.sub.2, ammonia, and carbon dioxide.
47. The method of claim 46 comprising reducing the catalyst in a
hydrogen-containing stream.
48. The method of claim 38 comprising mixing the colloidal sol with
at least one inorganic alkoxide selected from the group consisting
of Al(OR).sub.3, Si(OR).sub.4, Ti(OR).sub.5 and Zr(OR).sub.4, where
each R is an alkyl group having from 1 to 6 carbon atoms.
49. A process for producing hydrocarbons by contacting a feed
stream comprising hydrogen and carbon monoxide with a catalyst in a
reaction zone maintained at conversion-promoting conditions
effective to produce an effluent stream comprising said
hydrocarbons, characterized by using a catalyst prepared by a
method comprising (1) forming a catalyst gel by destabilizing an
aqueous colloid comprising (a) at least one catalytic metal for
Fischer-Tropsch reactions, (b) at least one colloidal oxide
selected from the group consisting of cerium oxide, zirconium
oxide, titanium oxide and aluminum oxide, and optionally (c) at
least one alkoxide selected from the group consisting of
Al(OR).sub.3, Si(OR).sub.4, Ti(OR).sub.5 and Zr(OR).sub.4, where
each R is an alkyl group having from 1 to 6 carbon atoms; and (2)
drying the gel.
50. The process of claim 49 wherein the catalytic metal of (a) is a
combination of cobalt and ruthenium.
51. The process of claim 49 wherein the drying (2) is accomplished
by vacuum drying or heating in air.
52. The process of claim 49 wherein the drying (2) is accomplished
by allowing supercritical fluid to flow through the gel
material.
53. The process of claim 49 wherein the catalyst preparation
further comprises reduction treatment of the dried gel from (2).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
patent application Ser. No. 60/097,192, filed Aug. 20, 1998, U.S.
provisional patent application Ser. No. 60/097,193, filed Aug. 20,
1998, and U.S. provisional patent application Ser. No. 60/097,194,
filed Aug. 20, 1998, all of which are incorporated herein by
reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a process for the
preparation of hydrocarbons from synthesis gas, (i.e., a mixture of
carbon monoxide and hydrogen), typically labeled the
Fischer-Tropsch process. Particularly, this invention relates to
catalysts containing a xerogel or aerogel matrix, containing cerium
oxide, titanium oxide, zirconium oxide or aluminum oxide, for the
Fischer-Tropsch process.
BACKGROUND OF THE INVENTION
[0003] Large quantities of methane, the main component of natural
gas, are available in many areas of the world. Methane can be used
as a starting material for the production of hydrocarbons. The
conversion of methane to hydrocarbons is typically carried out in
two steps. In the first step methane is reformed with water or
partially oxidized with oxygen to produce carbon monoxide and
hydrogen (i.e., synthesis gas or syngas). In a second step, the
syngas is converted to hydrocarbons.
[0004] The preparation of hydrocarbons from synthesis gas is well
known in the art and is usually referred to as Fischer-Tropsch
synthesis, the Fischer-Tropsch process, or Fischer-Tropsch
reaction(s). Catalysts for use in such synthesis usually contain a
catalytically active Group VIII (CAS) metal. In particular, iron,
cobalt, nickel, and ruthenium have been abundantly used as the
catalytically active metals. Cobalt and ruthenium have been found
to be most suitable for catalyzing a process in which synthesis gas
is converted to primarily hydrocarbons having five or more carbon
atoms (i.e., where the C.sub.5.sup.+ selectivity of the catalyst is
high). Additionally, the catalysts often contain one or more
promoters and a support or carrier material. Rhenium is a widely
used promoter.
[0005] The Fischer-Tropsch reaction involves the catalytic
hydrogenation of carbon monoxide to produce a variety of products
ranging from methane to higher aliphatic alcohols. The methanation
reaction was first described in the early 1900's, and the later
work by Fischer and Tropsch dealing with higher hydrocarbon
synthesis was described in the 1920's.
[0006] The Fischer-Tropsch synthesis reactions are highly
exothermic and reaction vessels must be designed for adequate heat
exchange capacity. Because the feed streams to Fischer-Tropsch
reaction vessels are gases while the product streams include
liquids, the reaction vessels must have the ability to continuously
produce and remove the desired range of liquid hydrocarbon
products. The process has been considered for the conversion of
carbonaceous feedstock, e.g., coal or natural gas, to higher value
liquid fuel or petrochemicals. The first major commercial use of
the Fischer-Tropsch process was in Germany during the 1930's. More
than 10,000 B/D (barrels per day) of products were manufactured
with a cobalt based catalyst in a fixed-bed reactor. This work has
been described by Fischer and Pichler in Ger. Pat. No. 731,295
issued Aug. 2, 1936.
[0007] Motivated by production of high-grade gasoline from natural
gas, research on the possible use of the fluidized bed for
Fischer-Tropsch synthesis was conducted in the United States in the
mid-1940s. Based on laboratory results, Hydrocarbon Research, Inc.
constructed a dense-phase fluidized bed reactor, the Hydrocol unit,
at Carthage, Tex., using powdered iron as the catalyst. Due to
disappointing levels of conversion, scale-up problems, and rising
natural gas prices, operations at this plant were suspended in
1957. Research has continued, however, on developing
Fischer-Tropsch reactors such as slurry-bubble columns, as
disclosed in U.S. Pat. No. 5,348,982 issued Sep. 20, 1994.
[0008] Commercial practice of the Fischer-Tropsch process has
continued from 1954 to the present day in South Africa in the SASOL
plants. These plants use iron-based catalysts, and produce gasoline
in relatively high-temperature fluid-bed reactors and wax in
relatively low-temperature fixed-bed reactors.
[0009] Research is likewise continuing on the development of more
efficient Fischer-Tropsch catalyst systems and reaction systems
that increase the selectivity for high-value hydrocarbons in the
Fischer-Tropsch product stream. In particular, a number of studies
describe the behavior of iron, cobalt or ruthenium based catalysts
in various reactor types, together with the development of catalyst
compositions and preparations.
[0010] There are significant differences in the molecular weight
distributions of the hydrocarbon products from Fischer-Tropsch
reaction systems. Product distribution or product selectivity
depends heavily on the type and structure of the catalysts and on
the reactor type and operating conditions. Accordingly, it is
highly desirable to maximize the selectivity of the Fischer-Tropsch
synthesis to the production of high-value liquid hydrocarbons, such
as hydrocarbons with five or more carbon atoms per hydrocarbon
chain.
[0011] U.S. Pat. No. 4,659,681 issued on Apr. 21, 1987, describes
the laser synthesis of iron based catalyst particles in the 1-100
micron particle size range for use in a slurry reactor for
Fischer-Tropsch synthesis.
[0012] U.S. Pat. No. 4,619,910 issued on Oct. 28, 1986, U.S. Pat.
No. 4,670,472 issued on Jun. 2, 1987, and U.S. Pat. No. 4,681,867
issued on Jul. 21, 1987, describe a series of catalysts for use in
a slurry Fischer-Tropsch process in which synthesis gas is
selectively converted to higher hydrocarbons of relatively narrow
carbon number range. Reactions of the catalyst with air and water
and calcination are specifically avoided in the catalyst
preparation procedure. The catalysts are activated in a fixed-bed
reactor by reaction with CO+H.sub.2 prior to slurrying in the oil
phase in the absence of air.
[0013] Catalyst supports for catalysts used in Fischer-Tropsch
synthesis of hydrocarbons have typically been oxides (e.g., silica,
alumina, titania, zirconia or mixtures thereof, such as
silica-alumina). It has been claimed that the Fischer-Tropsch
synthesis reaction is only weakly dependent on the chemical
identity of the metal oxide support (see E. Iglesia et al. 1993,
In: "Computer-Aided Design of Catalysts," ed. E. R. Becker et al.,
p. 215, New York, Marcel Dekker, Inc.). The products prepared by
using these catalysts usually have a very wide range of molecular
weights.
[0014] U.S. Pat. No. 4,477,595 discloses ruthenium on titania as a
hydrocarbon synthesis catalyst for the production of C.sub.5 to
C.sub.40 hydrocarbons, with a majority of paraffins in the C.sub.5
to C.sub.20 range. U.S. Pat. No. 4,542,122 discloses a cobalt or
cobalt-thoria on titania having a preferred ratio of rutile to
anatase, as a hydrocarbon synthesis catalyst. U.S. Pat. No.
4,088,671 discloses a cobalt-ruthenium catalyst where the support
can be titania but preferably is alumina for economic reasons. U.S.
Pat. No. 4,413,064 discloses an alumina supported catalyst having
cobalt, ruthenium and a Group IIIA or Group IVB metal oxide, e.g.,
thoria. European Patent No. 142,887 discloses a silica supported
cobalt catalyst together with zirconium, titanium, ruthenium and/or
chromium.
[0015] U.S. Pat. No. 4,801,573 discloses a promoted cobalt and
rhenium catalyst, preferably supported on alumina that is
characterized by low acidity, high surface area, and high purity,
which properties are said to be necessary for high activity, low
deactivation, and high molecular weight products. The amount of
cobalt is most preferably about 10 to 40 wt % of the catalyst. The
content of rhenium is most preferably about 2 to 20 wt % of the
cobalt content. Related U.S. Pat. No. 4,857,559 discloses a
catalyst most preferably having 10 to 45 wt % cobalt and a rhenium
content of about 2 to 20 wt % of the cobalt content. In both of the
above patents the method of depositing the active metals and
promoter on the alumina support is described as not critical.
[0016] U.S. Pat. No. 5,545,674 discloses a cobalt-based catalyst
wherein the active metal is dispersed as a very thin film on the
surface of a particulate support, preferably silica or titania or a
titania-containing support. The catalyst may be prepared by spray
techniques.
[0017] U.S. Pat. No. 5,028,634 discloses supported cobalt-based
catalysts, preferably supported on high surface area aluminas. High
surface area supports are said to be preferred because greater
cobalt dispersion can be achieved as cobalt is added, with less
tendency for one crystal of cobalt to fall on another crystal of
cobalt. The cobalt loading on a titania support is preferably 10 to
25 wt %, while the preferred cobalt loading on an alumina support
is 5 to 45 wt %.
[0018] International Publication Nos. WO 98/47618 and WO 98/47620
disclose the use of rhenium promoters and describe several
functions served by the rhenium.
[0019] U.S. Pat. No. 5,248,701 discloses a copper promoted
cobalt-manganese spinel that is said to be useful as a
Fischer-Tropsch catalyst with selectivity for olefins and higher
paraffins.
[0020] U.S. Pat. No. 5,302,622 discloses a supported cobalt and
ruthenium based catalyst including other components and preferably
prepared by a gelling procedure to incorporate the catalyst
components in an alcogel formed from a hydrolyzable compound of
silicon, and/or aluminum, and optional compounds. The cobalt
content after calcination is preferably between 14 and 40 wt % of
the catalyst.
[0021] UK Patent Application GB 2,258,414A, published Feb. 10,
1993, discloses a supported catalyst containing cobalt, molybdenum
and/or tungsten, and an additional element. The support is
preferably one or more oxides of the elements Si, Al, Ti, Zr, Sn,
Zn, Mg, and elements with atomic numbers from 57 to 71. After
calcination, the preferred cobalt content is from 5 to 40 wt % of
the catalyst. A preferred method of preparation of the catalyst
includes the preparation of a gel containing the cobalt and other
elements.
[0022] International Publication No. WO 96/19289 discloses active
metal coated catalysts supported on an inorganic oxide, and notes
that dispersion of the active metal on Fischer-Tropsch catalysts
has essential effects on the activity of the catalyst and on the
composition of the hydrocarbons obtained.
[0023] Despite the vast amount of research effort in this field,
there is still a great need for new catalysts for Fischer-Tropsch
synthesis, particularly catalysts that provide high C.sub.5.sup.+
hydrocarbon selectivities to maximize the value of the hydrocarbons
produced and thus enhance the process economics.
SUMMARY OF THE INVENTION
[0024] This invention provides a process and catalyst for producing
hydrocarbons, and a method for preparing the catalyst. The process
comprises contacting a feed stream comprising hydrogen and carbon
monoxide with a catalyst in a reaction zone maintained at
conversion-promoting conditions effective to produce an effluent
stream comprising hydrocarbons wherein the catalyst comprises a
catalytically active metal selected from the group consisting of
iron, cobalt, nickel, ruthenium, and combinations thereof dispersed
in a matrix material comprising a derivative of a destabilized
aquasol comprising a colloidal oxide of a matrix metal selected
from the group consisting of cerium, zirconium, titanium, aluminum,
silicon, and combinations thereof.
[0025] In accordance with this invention, another catalyst used in
the process comprises a reduced aerogel or xerogel formed from the
destabilization of a colloidal mixture comprising a catalytically
active metal selected from the group consisting of iron, cobalt,
nickel, ruthenium, aluminum, and combinations thereof and a
colloidal sol of a matrix metal selected from the group consisting
of cerium, zirconium, titanium, aluminum, silicon, and combinations
thereof.
[0026] This invention also includes a method for the preparation of
a Fischer-Tropsch catalyst comprising comprising mixing a colloidal
sol of an oxide of a metal selected from the group consisting of
cerium, zirconium, titanium, aluminum, silicon, and combinations
thereof with a soluble salt of one or more catalytically active
metals selected from the group consisting of iron, cobalt, nickel,
and ruthenium, destabilizing the colloid to form a gel, and
removing solvent from the gel.
[0027] This invention also provides a process for producing
hydrocarbons by contacting a feed stream comprising hydrogen and
carbon monoxide with a catalyst in a reaction zone maintained at
conversion-promoting conditions effective to produce an effluent
stream comprising the hydrocarbons. The process of this invention
is characterized by using a catalyst prepared by a method
comprising (1) forming a catalyst gel by destabilizing an aqueous
colloid comprising (a) at least one catalytic metal for
Fischer-Tropsch reactions (e.g., at least one metal selected from
the group consisting of iron, cobalt, nickel and ruthenium), (b) at
least one colloidal oxide selected from the group consisting of
cerium oxide, zirconium oxide, titanium oxide and aluminum oxide,
and optionally (c) at least one alkoxide selected from the group
consisting of Al(OR).sub.3, Si(OR).sub.4, Ti(OR).sub.4 and
Zr(OR).sub.4, where each R is an alkyl group having from 1 to 6
carbon atoms; and (2) drying the gel.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The feed gases charged to the process of the invention
comprise hydrogen, or a hydrogen source, and carbon monoxide.
H.sub.2/CO mixtures suitable as a feedstock for conversion to
hydrocarbons according to the process of this invention can be
obtained from light hydrocarbons such as methane by means of steam
reforming, partial oxidation, or other processes known in the art.
The hydrogen is preferably provided by free hydrogen, although some
Fischer-Tropsch catalysts have sufficient water gas shift activity
to convert some water to hydrogen for use in the Fischer-Tropsch
process. It is preferred that the molar ratio of hydrogen to carbon
monoxide in the feed be greater than 0.5:1 (e.g., from about 0.67
to 2.5). When cobalt, nickel, and/or ruthenium catalysts are used,
the feed gas stream preferably contains hydrogen and carbon
monoxide in a molar ratio of about 2:1. When iron catalysts are
used, the feed gas stream preferably contains hydrogen and carbon
monoxide in a molar ratio of about 0.67:1. The feed gas may also
contain carbon dioxide. The feed gas stream should contain a low
concentration of compounds or elements that have a deleterious
effect on the catalyst, such as poisons. For example, the feed gas
may need to be pre-treated to ensure that it contains low
concentrations of sulfur or nitrogen compounds, such as hydrogen
sulfide, ammonia and carbonyl sulfides.
[0029] The feed gas is contacted with the catalyst in a reaction
zone. Mechanical arrangements of conventional design may be
employed as the reaction zone including, for example, fixed bed,
fluidized bed, slurry phase, slurry bubble column or ebullating bed
reactors, among others, may be used. Accordingly, the size and
physical form of the catalyst particles may vary depending on the
reactor in which they are to be used.
[0030] Catalyst Preparation
[0031] A component of the catalysts used in this invention is the
matrix material, which is essentially derived from at least one
colloidal oxide and optionally at least one metal alkoxide, and
which incorporates at least one catalytic metal for Fischer-Tropsch
reactions.
[0032] A matrix is a skeletal framework of oxides and oxyhydroxides
which in the present invention is derived from the colloids used.
The framework typically comprises 35% or more, by weight, of the
total catalyst composition. Preferably, the matrix material (i.e.,
cerium oxide, zirconium oxide, titanium oxide and/or aluminum oxide
and optionally silicon oxide) totals from 99.9 to 35 mole %,
preferably from 50 to 85 mole % of the catalyst composition. More
preferable are combinations where the matrix is cerium oxide,
titanium oxide or a mixture of titanium and aluminum oxides (e.g.,
a mixture wherein the Ti:Al atomic ratio is between about 5:95 and
95:1).
[0033] A gel may be described as a coherent, rigid
three-dimensional polymeric network. The present gels are formed in
a liquid medium, usually water, alcohol, or a mixture thereof. The
term "alcogel" describes gels in which the pores are filled with
predominantly alcohol. Gels whose pores are filled primarily with
water may be referred to as aquagels or hydrogels.
[0034] A "xerogel" is a gel from which the liquid medium has been
removed and replaced by a gas. In general, the structure is
compressed and the porosity reduced significantly by the surface
tension forces that occur as the liquid is removed. As soon as
liquid begins to evaporate from a gel at temperatures below the
critical temperature, surface tension creates concave menisci in
the gel's pores. As evaporation continues, the menisci retreat into
the gel body, compressive forces build up around its perimeter, and
the perimeter contracts, drawing the gel body inward. Eventually,
surface tension causes significant collapse of the gel body and a
reduction of volume, often as much as two-thirds or more of the
original volume. This shrinkage causes a significant reduction in
the porosity, often as much as 90 to 95 percent depending on the
system and pore sizes.
[0035] In contrast, an "aerogel" is a gel from which the liquid has
been removed in such a way as to prevent significant collapse or
change in the structure as liquid is removed. This is typically
accomplished by heating the liquid-filled gel in an autoclave while
maintaining the prevailing pressure above the vapor pressure of the
liquid until the critical temperature of the liquid has been
exceeded, and then gradually releasing the vapor, usually by
gradually reducing the pressure either incrementally or
continuously, while maintaining the temperature above the critical
temperature. The critical temperature is the temperature above
which it is impossible to liquefy a gas, regardless of how much
pressure is applied. At temperatures above the critical
temperature, the distinction between liquid and gas phases
disappears and so do the physical manifestations of the gas/liquid
interface. In the absence of an interface between liquid and gas
phases, there is no surface tension and hence no surface tension
forces to collapse the gel. Such a process may be termed
"supercritical drying." Aerogels produced by supercritical drying
typically have high porosities, on the order of from 50 to 99
percent by volume.
[0036] In the practice of this invention one or more inorganic
metal colloids may be used as starting material for preparing the
gels. These colloids include colloidal alumina sols, colloidal
ceria sols, colloidal zirconia sols or their mixtures. The
colloidal sols are commercially available. There are also several
methods of preparing colloids, as described in "Inorganic Colloid
Chemistry", Volumes 1, 2 and 3, J. Wiley and Sons, Inc., 1935.
Colloid formation involves either nucleation and growth, or
subdivision or dispersion processes. For example, hydrous titanium
dioxide sols can be prepared by adding ammonia hydroxide to a
solution of a tetravalent titanium salt, followed by peptization
(re-dispersion) by dilute alkalis. Zirconium oxide sol can be
prepared by dialysis of sodium oxychlorides. Cerium oxide sol can
be prepared by dialysis of a solution of ceric ammonium
nitrate.
[0037] Commercially available alkoxides, such as
tetraethylorthosilicate and Tyzor.TM. organic titanate esters, can
be used. However, inorganic alkoxides can be prepared by various
routes. Examples include direct reaction of zero valent metal with
alcohols in the presence of a suitable catalyst; and the reaction
of metal halides with alcohols. Alkoxy derivatives can be
synthesized by the reaction of the alkoxide with alcohol in a
ligand interchange reaction. Direct reactions of metal dialkamides
with alcohol also form alkoxide derivatives. Additional examples
are disclosed in D. C. Bradley et al., "Metal Alkoxides" (Academic
Press, 1978).
[0038] In a preferred embodiment of the process of this invention,
preformed colloidal sols in water, or aquasols, are used. The
aquasols are comprised of colloidal particles ranging in size from
2 to 50 nanometers. In general, the smaller primary particle sizes
(2 to 5 nm) are preferred. The pre-formed colloids contain from 10
to 35 weight % of colloidal oxides or other materials, depending on
the method of stabilization. Generally, after addition of the
active (for Fischer-Tropsch reactions, either as a catalyst or
promoter) metal components, the final destabilized colloids can
possess from about 1 to 35 weight % solids, preferably from about 1
to 20 weight %.
[0039] The colloidal oxides or their mixtures are destabilized
during the addition of soluble salts of the primary and promoter
cation species by the addition of acids or bases or by solvent
removal, both of which alter pH. These changes modify the colloidal
particle's electrical double layer. Each colloidal particle
possesses a double layer when suspended in a liquid medium. For
instance, a negatively charged colloid causes some of the positive
ions to form a firmly attached layer around the surface of a
colloid. Additional positive ions are still attracted by the
negative colloid, but now they are repelled by the primary positive
layer as well as the positive ions, and form a diffuse layer of
counterions. The primary layer and the diffuse layer are referred
to as the double layer. The tendencies of a colloid to either
agglomerate (flocculate and precipitate) or polymerize when
destabilized will depend on the properties of this double layer.
The double layer, and resulting electrostatic forces can be
modified by altering the ionic environment, or pH, liquid
concentration, or by adding a surface active material directly to
affect the charge of the colloid.
[0040] Once the particles come in close enough contact when
destabilized, polymerization and crosslinking reaction between
surface functional groups, such as surface hydroxyls, can occur. In
this invention, the colloids, which are originally stable
heterogeneous dispersions of oxides and other species in solvents,
are destabilized to produce colloidal gels. Destabilization is
induced, in some cases, by the addition of soluble salts, e.g.,
chlorides or nitrates, which change the pH and the ionic strength
of the colloidal suspensions; by the addition of acids or bases; or
by solvent removal. pH changes generally accompany the addition of
soluble salts; in general, this is preferred over solvent removal.
Generally, a pH range of from about 0 to about 12 can be used to
destabilize the colloids; however, very large extremes in pH (such
as pH 12) can cause flocculation and precipitation. For this
reason, a pH range of from about 2 to 8 is generally preferred.
[0041] The medium utilized in this process is typically aqueous,
although non-aqueous colloids can also be used. The additional
metal or inorganic reagents (e.g., salts of Ru, Co, or promoters)
used should be soluble in the appropriate aqueous and non-aqueous
media.
[0042] Removal of solvent from the gels can be accomplished by
several methods. Removal by vacuum drying or heating in air results
in the formation of a xerogel. An aerogel of the material can
typically be formed by charging in a pressurized system such as an
autoclave. In some cases, water solvent (which may be present in
the gels formed) may need to be exchanged with a non-aqueous
solvent prior to supercritical pressure extraction. The
solvent-containing gel which is formed in the practice of the
invention is placed in an autoclave, where it can be contacted with
a fluid above its critical temperature and pressure by allowing the
supercritical fluid to flow through the gel material until the
solvent is no longer being extracted by the supercritical fluid. In
performing this extraction to produce an aerogel material, various
fluids can be utilized at their critical temperature and pressure.
For instance, fluorochlorocarbons typified by Freon.RTM.
fluorochloromethanes (e.g., Freon.RTM. 11 (CCl.sub.3F), 12
(CCl.sub.2F.sub.2) or 114 (CClF.sub.2CClF.sub.2), ammonia and
carbon dioxide are all suitable for this process. Typically, the
extraction fluids are gases at atmospheric conditions, so that pore
collapse due to the capillary forces at the liquid/solid interface
is avoided during drying. The material dried under supercritical
conditions will, in most cases, possess a higher surface area than
the materials dried by other means.
[0043] Catalytically Active Metals
[0044] Another component of the catalyst of the present invention
is the catalytic metal. The catalytic metal is preferably selected
from iron, cobalt, nickel and/or ruthenium. Normally, the metal
component on the support or matrix is reduced to provide elemental
metal (e.g., elemental iron, cobalt, nickel and/or ruthenium)
before use. The catalyst must contain a catalytically effective
amount of the metal component(s). Typically, the catalyst comprises
from about 0.1 to 50 mole % (as the metal) of total supported iron,
cobalt, nickel and/or ruthenium per total moles of catalytic metal
and matrix metal (i.e., Ce, Zr, Ti, Al and Si), preferably from
about 5 to 50 mole %.
[0045] Each of the catalytic metals can be used individually or in
combination, especially cobalt and ruthenium. In one preferred
embodiment, catalysts of this invention comprise from about 10 to
50 mole percent of a combination of cobalt and ruthenium where the
ruthenium content is from about 0.001 to about 5 mole percent. Also
preferred are embodiments where these combinations are combined
with a matrix of titanium oxide, cerium oxide, aluminum oxide, a
mixture of cerium and aluminum oxides, or a mixture of titanium and
aluminum oxides.
[0046] In another preferred embodiment, the catalysts of the
present invention may comprise one or more additional promoters or
modifiers known to those skilled in the art. When the catalytic
metal is iron, cobalt, nickel and/or ruthenium, suitable promoters
include at least one metal selected from the group consisting of
Group IA (CAS) metals (i.e., Na, K, Rb, Cs), Group IIA metals
(i.e., Mg, Ca, Sr, Ba), Group IB metals (i.e., Cu, Ag, and Au)
Group IIIB metals (i.e., Sc, Y and La), Group IVB metals (i.e., Ti,
Zr and Hf), Group VB metals (i.e., V, Nb and Ta), and Rh, Pd, Os,
Ir, Pt, Mn, B, P, and Re. Preferably, any additional promoters for
the cobalt and/or ruthenium are selected from Sc, Y, La, Ti, Zr,
Hf, Rh, Pd, Os, Ir, Pt, Re, Nb, Cu, Ag, Mn, B, P, and Ta.
Preferably, any additional promoters for the iron catalysts are
selected from Na, K, Rb, Cs, Mg, Ca, Sr and Ba.
[0047] The amount of additional promoter, if present, is typically
between 0.001 and 20 mole %, preferably from 2 to 5 mole %. More
preferably, the catalysts comprise from about 5 to about 50 mole
percent of a combination of cobalt and rhenium where the rhenium
content is from about 0.001 to about 5 mole percent; and catalysts
comprising from about 5 to about 50 mole percent a combination of
cobalt and both rhenium and ruthenium where the rhenium and
ruthenium together total from about 0.001 to about 5 mole percent.
Preferably, these combinations are combined with a matrix of
titanium oxide, cerium oxide, aluminum oxide, a mixture of cerium
and aluminum oxides, a mixture of titanium and aluminum oxides, or
a mixture of silicon and aluminum oxides.
[0048] The most preferred method of preparation may vary among
those skilled in the art, depending for example on the desired
catalyst particle size. Those skilled in the art are able to select
the most suitable method for a given set of requirements.
[0049] Process and Conditions
[0050] Typically, at least a portion of the metal(s) of the
catalytic metal component (a) of the catalysts of the present
invention is present in a reduced state (i.e., in the metallic
state). Therefore, it is normally advantageous to activate the
catalyst prior to use by a reduction treatment, in the presence of
hydrogen at an elevated temperature. Typically, the catalyst is
treated with hydrogen at a temperature in the range of from about
75.degree. C. to about 500.degree. C., for about 0.5 to about 24
hours at a pressure of about 1 to about 75 atm. Pure hydrogen may
be used in the reduction treatment, as well as a mixture of
hydrogen and an inert gas such as nitrogen. The amount of hydrogen
may range from about 1% to about 100% by volume.
[0051] The Fischer-Tropsch process is typically run in a continuous
mode. In this mode, the gas hourly space velocity through the
reaction zone typically may range from about 100
volumes/hour/volume catalyst (v/hr/v) to about 10,000 v/hr/v,
preferably from about 300 v/hr/v to about 2,000 v/hr/v. The
reaction zone temperature is typically in the range from about
160.degree. C. to about 300.degree. C. Preferably, the reaction
zone is operated at conversion promoting conditions at temperatures
from about 190.degree. C. to about 260.degree. C. The reaction zone
pressure is typically in the range of about 80 psig (653 kPa) to
about 1000 psig (6994 kPa), preferably, from 80 psig (653 kPa) to
about 600 psig (4237 kPa), and still more preferably, from about
140 psig (1066 kPa) to about 400 psig (2858 kPa).
[0052] The products resulting from the process will have a great
range of molecular weights. Typically, the carbon number range of
the product hydrocarbons will start at methane and continue to the
limits observable by modern analysis, about 50 to 100 carbons per
molecule. The process is particularly useful for making
hydrocarbons having five or more carbon atoms, especially when the
above-referenced preferred space velocity, temperature and pressure
ranges are employed.
[0053] The wide range of hydrocarbons produced in the reaction zone
will typically afford liquid phase products at the reaction zone
operating conditions. Therefore, the effluent stream of the
reaction zone will often be a mixed phase stream including liquid
and vapor phase products. The effluent stream of the reaction zone
may be cooled to effect the condensation of additional amounts of
hydrocarbons and passed into a vapor-liquid separation zone
separating the liquid and vapor phase products. The vapor phase
material may be passed into a second stage of cooling for recovery
of additional hydrocarbons. The liquid phase material from the
initial vapor-liquid separation zone, together with any liquid from
a subsequent separation zone, may be fed into a fractionation
column. Typically, a stripping column is employed first to remove
light hydrocarbons such as propane and butane. The remaining
hydrocarbons may be passed into a fractionation column where they
are separated by boiling point range into products such as naphtha,
kerosene and fuel oils. Hydrocarbons recovered from the reaction
zone and having a boiling point above that of the desired products
may be passed into conventional processing equipment such as a
hydrocracking zone in order to reduce their molecular weight. The
gas phase recovered from the reactor zone effluent stream after
hydrocarbon recovery may be partially recycled if it contains a
sufficient quantity of hydrogen and/or carbon monoxide.
[0054] Without further elaboration, it is believed that one skilled
in the art can, using the description herein, utilize the present
invention to its fullest extent. The following embodiments are to
be construed as illustrative, and not as constraining the scope of
the present invention in any way whatsoever.
EXAMPLES
General Procedure For Batch Tests
[0055] Each of the catalyst samples was treated with hydrogen prior
to use in the Fischer-Tropsch reaction. The catalyst sample was
placed in a small quartz crucible in a chamber and purged with 500
sccm (8.3.times.10.sup.-6 m.sup.3/s) nitrogen at room temperature
for 15 minutes. The sample was then heated under 100 sccm
(1.7.times.10.sup.-6 m.sup.3/s) hydrogen at 1.degree. C./minute to
100.degree. C. and held at 100.degree. C. for one hour. The
catalysts were then heated at 1.degree. C./minute to 400.degree. C.
and held at 400.degree. C. for four hours under 100 sccm
(1.7.times.10.sup.-6 m.sup.3/s) hydrogen. The samples were cooled
in hydrogen and purged with nitrogen before use.
[0056] A 2 mL pressure vessel was heated at either 225.degree. C.
under 1000 psig (6994 kPa) of H.sub.2:CO (2:1) and maintained at
that temperature and pressure for 1 hour. In a typical run, roughly
50 mg of the hydrogen catalyst and 1 mL of n-octane was added to
the vessel. After one hour, the reactor vessel was cooled in ice,
vented, and an internal standard of di-n-butylether was added. The
reaction product was analyzed on an HP6890 gas chromatograph.
Hydrocarbons in the range of C.sub.11-C.sub.40 were analyzed
relative to the internal standard. The lower hydrocarbons were not
analyzed since they are masked by the solvent and are also vented
as the pressure is reduced.
[0057] A C.sub.11.sup.+ Productivity (g C.sub.11.sup.+/hour/kg
catalyst) was calculated based on the integrated production of the
C.sub.11-C.sub.40 hydrocarbons per kg of catalyst per hour. The
logarithm of the weight fraction for each carbon number ln(Wn/n)
was plotted as the ordinate vs. number of carbon atoms in (Wn/n) as
the abscissa. From the slope, a value of alpha was obtained. Some
runs displayed a double alpha as shown in the tables. The results
of runs over a variety of catalysts at 225.degree. C. are shown in
Table 1.
Catalyst Preparation
[0058] The catalyst compositions are given in atomic ratios except
where otherwise noted.
Example 1
[0059] To a 150 mL petri dish, ruthenium (III) chloride (17.525 mL
of a 0.1151 M aqueous solution), cobalt (II) chloride (18.154 mL of
a 1.0 M aqueous solution) and colloidal alumina sol (4.321 mL,
4.668 M or 20 wt. %) were simultaneously combined. The pH of the
alumina sol was 4.0. The pH of the resultant mixture, after
addition of the reagents, was approximately 1.37. At that point the
colloid was destabilized to form a dark gel-like material. The
material was aged for five days before drying under vacuum at
150.degree. C. for 5 hours.
[0060] The final xerogel had a nominal composition of Ru (0.05)/Co
(0.45)/Al (0.5).
Example 2
[0061] To a 150 mL petri dish, ruthenium (III) chloride (17.357 mL
of a 0.1151 M aqueous solution), cobalt (II) chloride hexahydrate
(COCl.sub.2*6H.sub.2O, 17.960 mL of a 1.0 M aqueous solution) and
colloidal alumina sol (4.280 mL, 4.668 M or 20 wt. %) were
simultaneously combined. In a second step, 0.404 mL of a 1.0 M
cesium chloride solution was added. The colloid was destabilized to
form a dark red gel-like material. The material was aged for five
days before drying under vacuum at 150.degree. C. for 5 hours.
[0062] The final xerogel had a nominal composition Ru (0.0495)/Co
(0.445)/Cs (0.01)/Al (0.495).
Example 3
[0063] To a 150 mL petri dish, ruthenium (III) chloride (16.641 mL
of a 0.1151 M aqueous solution), cobalt (II) chloride hexahydrate
(CoCl.sub.2.6H.sub.2O, 17.239 mL of a 1.0 M aqueous solution) and
colloidal alumina sol (4.103 mL, 4.668 M or 20 wt. %) were
simultaneously combined. In a second step, 2.016 mL of a 1 M
aqueous lithium nitrate (LiNO.sub.3) solution were added. The
colloid was destabilized to form a dark red gel-like material. The
material was aged for five days before drying under vacuum at
150.degree. C. for 5 hours.
[0064] The final xerogel had a nominal composition of Ru
(0.0475)/Co (0.4275)/Li (0.05)/Al (0.475).
Example 4
[0065] To a 150 mL petri dish, ruthenium (III) chloride (16.641 mL
of a 0.1151 M aqueous solution), cobalt (II) chloride hexahydrate
(COCl.sub.2.6H.sub.2O, 17.239 mL of a 1.0 M aqueous solution) and
colloidal alumina sol (4.103 mL, 4.668 M or 20 wt. %) were
simultaneously combined. In a second step, 2.016 mL of a 1 M
aqueous solution of rubidium nitrate were added. The colloid was
destabilized to form a dark red gel-like material. The material was
aged for five days before drying under vacuum at 150.degree. C. for
5 hours.
[0066] The final xerogel had a nominal composition of Ru
(0.0475)/Co (0.4275)/Rb (0.05)/Al (0.475).
Example 5
[0067] To a 150 mL petri dish, ruthenium (III) chloride (17.072 mL
of a 0.1151 M aqueous solution), cobalt (II) chloride hexahydrate
(COCl.sub.2.6H.sub.2O, 17.685 mL of a 1.0 M aqueous solution) and
colloidal alumina sol (4.209 mL, 4.668 M or 20 wt. %) were
simultaneously combined. In a second step, 1.034 mL of a 2.0 M
aqueous sodium chloride solution were added. The colloid was
destabilized to form a dark red gel-like material. The material was
aged for five days before drying under vacuum at 150.degree. C. for
5 hours.
[0068] The final xerogel had a nominal composition Ru (0.0475)/Co
(0.4275)/Na (0.05)/Al (0.475).
Example 6
[0069] To a 150 mL petri dish, ruthenium (III) chloride (17.072 mL
of a 0.1151 M aqueous solution), cobalt (II) chloride hexahydrate
(CoCl.sub.2.6H.sub.2O, 17.685 mL of a 1.0 M aqueous solution) and
colloidal alumina sol (4.209 mL, 4.668 M or 20 wt. %) were
simultaneously combined. In a second step, 1.034 mL of 2.0 M
aqueous potassium chloride (KCl) solution were added. The colloid
was destabilized to form a red gel-like material. The material was
aged for five days before drying under vacuum at 150.degree. C. for
5 hours.
[0070] The final xerogel had a nominal composition of Ru
(0.0475)/Co (0.4275)/K (0.05)/Al (0.475).
Example 7
[0071] To a 150mL petri dish, ruthenium (III) chloride (16.641 mL
of a 0.1151 M aqueous solution), cobalt (II) chloride hexahydrate
(CoCl.sub.2.6H.sub.2O, 17.239 mL of a 1.0 M aqueous solution) and
colloidal alumina sol (4.103 mL, 4.668 M or 20 wt. %) were
simultaneously combined. In a second step, 2.016 mL of 1.0 M
aqueous cesium chloride solution were added. The colloid was
destabilized to form a red gel-like material. The material was aged
for five days before drying under vacuum at 150.degree. C. for 5
hours.
[0072] The final xerogel had a nominal composition of Ru
(0.0475)/Co (0.4275)/K (0.05)/Al (0.475).
Example 8
[0073] An aqueous solution of ruthenium (III) chloride (4.951 mL,
0.1151 M), an aqueous solution of cobalt (II) chloride (22.793 mL,
1 M), tetraethylorthosilicate (11.248 mL) and 0.72 mL of colloidal
alumina sol (20 wt. %) were combined in a 150 mL petri dish under
an inert atmosphere. In a second step, aqueous HCl (0.288 mL, 1.0
M) was added with swirling. The final pH of the mixture was 1.51. A
red homogeneous, clear gel formed after several hours. The material
was aged for four days, and dried under vacuum at 120.degree. C.
for 5 hours.
[0074] The final xerogel had a nominal composition of Ru (0.01)/Co
(0.4)/Al (0.059)/Si (0.531).
Example 9
[0075] An aqueous solution of ruthenium (III) chloride (5.202 mL,
0.1151 M), an aqueous solution of cobalt (II) chloride (23.950 mL,
1 M), tetraethylorthosilicate (60 volume % solution in absolute
ethanol, 1.313 mL) and 6.811 mL of colloidal alumina sol (4.668 M
or 20 wt. %) were combined in a 150 mL petri dish under an inert
atmosphere. In a second step, aqueous HCl (2.724 mL, 1.0 M) was
added with swirling. The final pH of the mixture was 1.00. A
red-brown 1.0 M aqueous nickel chloride hexahydrate
(NiCl.sub.2.6H.sub.2O) was added with swirling. The final pH of the
mixture was 1.32. A red-brown homogeneous, clear gel formed. The
material was aged for four days, and dried under vacuum at
120.degree. C. for 5 hours.
[0076] The final xerogel had a nominal composition of Ru (0.05)/Ni
(0.1)/Ce (0.425)/Al (0.425).
Example 13
[0077] An aqueous solution of ruthenium (III) chloride (3.00 mL,
0.1151 M), 20.701 mL of colloidal cerium oxide (1.4177 M), 6.287 mL
of colloidal alumina sol (4.668 M or 20 wt. %), and 10.013 mL of
1.0 M aqueous cobalt chloride hexahydrate solution
(CoCl.sub.2.6H.sub.2O) were combined in a 150 mL petri dish under
an inert atmosphere. The final pH of the mixture was 1.97. A dark
gel-like material formed. The material was aged for four days, and
dried under vacuum at 120.degree. C. for 5 hours.
[0078] The final xerogel had a nominal composition of Ru (0.005)/Co
(0.145)/Ce (0.425)/Al (0.425).
Example 14
[0079] An aqueous solution of ruthenium (III) chloride (18.78 mL,
0.1151 M), 12.960 mL of colloidal cerium oxide (1.4177 M), 3.936 mL
of colloidal alumina sol (4.668 M or 20 wt. %), and 2.162 mL of 1.0
M aqueous cobalt chloride hexahydrate solution
(CoCl.sub.2.6H.sub.2O) were combined in a 150 mL petri dish under
an inert atmosphere. In a second step, 2.162 mL of 1 M aqueous
nickel chloride solution (NiCl.sub.2.6H.sub.2O) were added. The
final pH of the mixture was 1.34. A gel-like material formed. The
material was aged for four days, and dried under vacuum at
120.degree. C. for 5 hours.
[0080] The final xerogel had a nominal composition of Ru (0.05)/Co
(0.050/Ni (0.05)/Ce (0.425)/Al (0.425).
Example 15
[0081] An aqueous solution of ruthenium (III) chloride (15.5394 mL,
0.1151 M), 6.330 mL of colloidal cerium oxide (1.4177 M) and 1.922
mL of colloidal alumina sol (4.668 M or 20 wt. %) were combined in
a 150 mL petri dish under an inert atmosphere. In a second step,
16.154 mL of a 1 M aqueous nickel chloride solution
(NiCl.sub.2.6H.sub.2O) were added. The final pH of the mixture was
1.34. A gel-like material formed. The material was aged for four
days, and dried under vacuum at 120.degree. C. for 5 hours.
[0082] The final xerogel had a nominal composition of Ru (0.05)/Ni
(0.45)/Ce (0.25)/Al (0.25).
Example 16
[0083] An aqueous solution of ruthenium (III) chloride (14.046 mL,
0.1151 M), 11.404 mL of colloidal cerium oxide (1.4177 M) and
14.550 mL of 1.0 M aqueous cobalt chloride hexahydrate solution
(CoCl.sub.2.6H.sub.2O) were combined in a 150 mL petri dish under
an inert atmosphere. The final pH of the mixture was 1.51. A
gel-like material formed. The material was aged for four days, and
dried under vacuum at 120.degree. C. for 5 hours.
[0084] The final xerogel had a nominal composition of Ru (0.05)/Co
(0.45)/Ce (0.5).
1TABLE 1 (225.degree. C.) Ex. C.sub.11.sup.+ No. Catalyst
Productivity Alpha 1 Ru (0.05)/Co (0.45)/Al (0.5) 368 0.88 2 Ru
(0.0495)/Co (0.445)/Cs (0.01)/ 153 0.8 Al (0.495) 3 Ru (0.0475)/Co
(0.4275)/Li (0.05)/ 208 0.78 Al (0.475) 4 Ru (0.0475)/Co
(0.4275)/Rb (0.05)/ 260 0.8 Al (0.475) 5 Ru (0.0475)/Co (0.4275)/Na
(0.05)/ 256 0.77 Al (0.475) 6 Ru (0.0475)/Co (0.4275)/K (0.05)/ 166
0.76 Al (0.475) 7 Ru (0.0475)/Co (0.4275)/Cs (0.05)/ 159 0.81 Al
(0.475) 8 Ru (0.01)/Co (0.4)/Al (0.059)/Si (0.531) 110 0.78/0.92 9
Ru (0.01)/Co (0.4)/Al (0.531)/Si (0.059) 88 0.79/0.89 10 Ru
(0.01)/Co (0.4)/Zr (0.059)/ 69 0.77/0.89 Al (0.531) 11 Ru (0.05)/Ce
(0.425)/Al (0.425) 53 0.78/0.9 12 Ru (0.05)/Ni (0.1)/Ce (0.425)/ 6
0.76/0.9 Al (0.475) 13 Ru (0.005)/Co (0.145)/Ce (0.425)/ 11 0.81 Al
(0.475) 14 Ru (0.05)/Co (0.050/Ni (0.05)/ 13 0.83 Ce (0.425)/Al
(0.425) 15 Ru (0.05)/Ni (0.45)/Ce (0.25)/Al (0.25) 11 0.77 16 Ru
(0.05)/Co (0.45)/Ce (0.5) 115 0.81
[0085] While a preferred embodiment of the present invention has
been shown and described, it will be understood that variations can
be made to the preferred embodiment without departing from the
scope of, and which are equivalent to, the present invention. For
example, the structure and composition of the catalyst can be
modified and the process steps can be varied.
[0086] The complete disclosures of all patents, patent documents,
and publications cited herein are incorporated by reference in
their entirety. U.S. patent application Ser. No. ______, entitled
Fischer-Tropsch Processes Using Xerogel and Aerogel Catalysts, and
U.S. patent application Ser. No. ______, entitled Fischer-Tropsch
Processes Using Catalysts on Mesoporous Supports, both filed
concurrently herewith on Aug. 18, 1999, are hereby incorporated
herein by reference in their entirety.
[0087] U.S. patent application No. 09/314,921, entitled
Fischer-Tropsch Processes and Catalysts Using Fluorided Supports,
filed May 19, 1999, U.S. patent application No. 09/314,920,
entitled Fischer-Tropsch Processes and Catalysts Using Fluorided
Alumina Supports, filed May 19, 1999, and U.S. patent application
No. 09/314,811, entitled Fischer-Tropsch Processes and Catalysts
With Promoters, filed May 19, 1999, are hereby incorporated herein
by reference in their entirety.
[0088] The foregoing detailed description and examples have been
given for clarity of understanding only. No unnecessary limitations
are to be understood therefrom. The invention is not limited to the
exact details shown and described, for variations obvious to one
skilled in the art will be included within the invention by the
claims.
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