U.S. patent application number 09/730310 was filed with the patent office on 2001-12-06 for hydrocarbon hydrogenation catalyst and process.
This patent application is currently assigned to Phillips Petroleum Company. Invention is credited to Drake, Charles A., Wu, An-hsiang.
Application Number | 20010049332 09/730310 |
Document ID | / |
Family ID | 23617919 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010049332 |
Kind Code |
A1 |
Wu, An-hsiang ; et
al. |
December 6, 2001 |
Hydrocarbon hydrogenation catalyst and process
Abstract
A catalyst composition and process for preparing such catalyst
composition which can be useful in contacting a
hydrocarbon-containing fluid which contains a highly unsaturated
hydrocarbon such as 1,3-butadiene, in the presence of hydrogen,
with such catalyst composition in a hydrogenation zone under a
hydrogenation condition effective to hydrogenate such highly
unsaturated hydrocarbon to a less unsaturated hydrocarbon such as
n-butene is disclosed. Such process for preparing a catalyst
composition includes (1) combining a zeolite, a Group VIB metal,
and an inorganic support to form a modified zeolite; (2) calcining
such modified zeolite under a calcining condition to produce a
calcined, modified zeolite; and (3) contacting such calcined,
modified zeolite with a carburizing agent under a carburizing
condition to provide such catalyst composition.
Inventors: |
Wu, An-hsiang;
(Bartlesville, OK) ; Drake, Charles A.; (Nowata,
OK) |
Correspondence
Address: |
Richmond, Hitchcock, Fish & Dollar
P.O. Box 2443
Bartlesville
OK
74005
US
|
Assignee: |
Phillips Petroleum Company
Bartlesville
OK
|
Family ID: |
23617919 |
Appl. No.: |
09/730310 |
Filed: |
December 5, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09730310 |
Dec 5, 2000 |
|
|
|
09408824 |
Sep 29, 1999 |
|
|
|
6235954 |
|
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Current U.S.
Class: |
502/177 ;
423/439; 423/440; 502/523; 502/60 |
Current CPC
Class: |
B01J 29/076 20130101;
C10G 45/34 20130101; C07C 2529/076 20130101; C07C 5/03
20130101 |
Class at
Publication: |
502/177 ;
423/439; 423/440; 502/60; 502/523 |
International
Class: |
B01J 027/22; C01B
031/30 |
Claims
What is claimed is:
1. A process comprising contacting a hydrocarbon-containing fluid
which comprises a highly unsaturated hydrocarbon, in the presence
of hydrogen, with a catalyst composition in a hydrogenation zone
under a hydrogenation condition effective to hydrogenate said
highly unsaturated hydrocarbon to a less unsaturated hydrocarbon
wherein said catalyst composition is prepared by the steps
comprising: (1) combining a zeolite, a Group VIB metal, and an
inorganic support to form a modified zeolite; (2) calcining said
modified zeolite under a calcining condition to produce a calcined,
modified zeolite; and (3) contacting said calcined, modified
zeolite with a carburizing agent under a carburizing condition to
provide said catalyst composition.
2. A process according to claim 1 wherein said highly unsaturated
hydrocarbon is a diolefin.
3. A process according to claim 2 wherein said diolefin contains in
the range of from 3 carbon atoms per molecule to about 12 carbon
atoms per molecule.
4. A process according to claim 3 wherein said diolefin is selected
from the group consisting of propadiene, 1,2-butadiene,
1,3-butadiene, isoprene, 1,2-pentadiene, 1,3-pentadiene,
1,4-pentadiene, 1,2-hexadiene, 1,3-hexadiene, 1,4-hexadiene,
1,5-hexadiene, 2-methyl-1,2-pentadiene, 2,3-dimethyl-1,3-butadiene,
heptadienes, methylhexadienes, octadienes, methylheptadienes,
dimethylhexadienes, ethylhexadienes, trimethylpentadienes,
methyloctadienes, dimethylheptadienes, ethyloctadienes,
trimethylhexadienes, nonadienes, decadienes, undecadienes,
dodecadienes, cyclopentadienes, cyclohexadienes,
methylcyclopentadienes, cycloheptadienes, methylcyclohexadienes,
dimethylcyclopentadienes, ethylcyclopentadienes, dicyclopentadiene
(also known as tricyclo[5.2.1].sup.2,6deca-3,8-diene), and
combinations thereof.
5. A process according to claim 4 wherein said diolefin is selected
from the group consisting of propadiene, 1,2-butadiene,
1,3-butadiene, isoprene, 1,2-pentadiene, 1,3-pentadiene,
1,4-pentadiene, cyclopentadienes, dicyclopentadiene (also known as
tricyclo[5.2.1 ].sup.2,6deca-3,8-diene), and combinations
thereof.
6. A process according to claim 5 wherein said diolefin is selected
from the group consisting of 1,2-butadiene and 1,3-butadiene.
7. A process according to claim 6 wherein said diolefin is
1,3-butadiene.
8. A process according to claim 1 wherein said less unsaturated
hydrocarbon is selected from the group consisting of ethylene,
propylene, n-butenes, isobutylene, 1-pentene, 2-pentene,
methyl-1-butenes, methyl-2-butenes, 1-hexene, 2-hexene, 3-hexene,
methyl-1-pentenes, 2,3-dimethyl-1-butene, 1-heptene, 2-heptene,
3-heptene, methyl-1-hexenes, methyl-2-hexenes, methyl-3-hexenes,
dimethylpentenes, ethylpentenes, octenes, methylheptenes,
dimethylhexenes, ethylhexenes, nonenes, methyloctenes,
dimethylheptenes, ethylheptenes, trimethylhexenes, cyclopentene,
cyclohexene, methylcyclopentene, cycloheptene, methylcyclohexene,
dimethylcyclopentenes, ethylcyclopentenes, cyclooctenes,
methylcycloheptenes, dimethylcyclohexenes, ethylcyclohexenes,
trimethylcyclohexenes, methylcyclooctenes, dimethylcyclooctenes,
ethylcyclooctenes, and combinations thereof.
9. A process according to claim 8 wherein said less unsaturated
hydrocarbon comprises n-butenes.
10. A process according to claim 1 wherein said
hydrocarbon-containing fluid further comprises a monoolefin.
11. A process according to claim 10 wherein said monoolefin is
selected from the group consisting of ethylene, propylene,
n-butenes, isobutylene, 1-pentene, 2-pentene, methyl-1-butenes,
methyl-2-butenes, 1-hexene, 2-hexene, 3-hexene, methyl-1-pentenes,
2,3-dimethyl-1-butene, 1-heptene, 2-heptene, 3-heptene,
methyl-1-hexenes, methyl-2-hexenes, methyl-3-hexenes,
dimethylpentenes, ethylpentenes, octenes, methylheptenes,
dimethylhexenes, ethylhexenes, nonenes, methyloctenes,
dimethylheptenes, ethylheptenes, trimethylhexenes, cyclopentene,
cyclohexene, methylcyclopentene, cycloheptene, methylcyclohexene,
dimethylcyclopentenes, ethylcyclopentenes, cyclooctenes,
methylcycloheptenes, dimethylcyclohexenes, ethylcyclohexenes,
trimethylcyclohexenes, methylcyclooctenes, dimethylcyclooctenes,
ethylcyclooctenes, and combinations thereof.
12. A process according to claim 11 wherein said
hydrocarbon-containing fluid further comprises a saturated
hydrocarbon selected from the group consisting of methane, ethane,
propane, butane, methylpropane, methylbutane, dimethylbutane,
pentanes, hexanes, and combinations thereof.
13. A process according to claim 12 wherein said
hydrocarbon-containing fluid further comprises an aromatic
hydrocarbon selected from the group consisting of benzene, toluene,
ethylbenzene, styrene, xylenes, and combinations thereof.
14. A process according to claim 1 wherein said hydrogenation
condition comprises: the presence of hydrogen in an amount in the
range of from about 0.1 to about 1000 moles of said hydrogen
employed for each mole of said highly unsaturated hydrocarbon
present in said hydrocarbon-containing fluid. a temperature in the
range of from about 10.degree. C. to about 600.degree. C.; a
pressure in the range of from about 0 pounds per square inch gauge
(psig) to about 2000 psig; and a charge rate of said
hydrocarbon-containing fluid to said hydrogenation zone such as to
provide a gas hourly space velocity in the range of from about 1 to
about 30,000 liters of hydrocarbon-containing fluid per liter of
catalyst per hour (liter/liter/hour).
15. A process according to claim 14 wherein said hydrogenation zone
comprises a reactor vessel.
16. A process according to claim 1 wherein said combining of said
combining step (1) comprises mixing said zeolite, said Group VIB
metal, and said inorganic support to form a mixture and then
extruding said mixture to form said modified zeolite.
17. A process according to claim 16 wherein said mixing comprises
subjecting said zeolite, said Group VIB metal, and said inorganic
support to a mixing means to provide said mixture.
18. A process according to claim 17 wherein said mixing means is
selected from the group consisting of tumblers, stationary shells
or troughs, muller mixers, impact mixers, and combinations
thereof.
19. A process according to claim 18 wherein said mixing means
comprises a muller mixer.
20. A process according to claim 16 wherein said extruding
comprises subjecting said mixture to an extruding means to provide
an extruded mixture.
21. A process according to claim 20 wherein said extruding means is
selected from the group consisting of screw extruders, auger
extruders, auger-type extruders, and combinations thereof.
22. A process according to claim 21 wherein said extruding means
comprises a screw extruder.
23. A process according to claim 1 wherein said catalyst
composition comprises said zeolite in an amount in the range of
from about 1 weight percent said zeolite based on the total weight
of said catalyst composition to about 95 weight percent, said
catalyst composition comprises said Group VIB metal in an amount in
the range of from about 1 weight percent said Group VIB metal based
on the total weight of said catalyst composition to about 95 weight
percent, and said catalyst composition comprises said inorganic
support in an amount in the range of from about 1 weight percent
said inorganic support based on the total weight of said catalyst
composition to about 90 weight percent.
24. A process according to claim 1 wherein said calcining condition
comprises: a temperature in the range of from about 100.degree. C.
to about 1500.degree. C.; a time period in the range of from about
1 hour to about 30 hours; and a pressure in the range of from about
7 pounds per square inch absolute (psia) to about 750 psia.
25. A process according to claim 1 wherein said carburizing agent
comprises a hydrocarbon.
26. A process according to claim 25 wherein said hydrocarbon
contains in the range of from about 1 carbon atom per molecule to
about 20 carbon atoms per molecule.
27. A process according to claim 26 wherein said hydrocarbon is
selected from the group consisting of methane, ethane, propane,
butanes, isobutane, pentanes, hexanes, heptanes, octanes, nonanes,
benzene, toluene, and combinations thereof.
28. A process according to claim 27 wherein said hydrocarbon is
methane.
29. A process according to claim 1 wherein said carburizing
condition comprises: the presence of hydrogen delivered at a
hydrogen flow rate in the range of from about 200 mL/min to about
1200 mL/min; a temperature in the range of from about 150.degree.
C. to about 1500.degree. C.; a time period in the range of from
about 1 hour to about 40 hours; and said carburizing agent is
delivered at a flow rate in the range of from about 25 mL/min to
about 500 mL/min.
30. A process according to claim 1 wherein said zeolite is selected
from the group consisting of beta zeolite, zeolite X, zeolite Y,
zeolite L, and combinations thereof.
31. A process according to claim 30 wherein said zeolite is zeolite
L.
32. A process according to claim 1 wherein said group VIB metal is
selected from the group consisting of chromium, molybdenum,
tungsten, and combinations thereof.
33. A process according to claim 32 wherein said group VIB metal is
molybdenum.
34. A process according to claim 33 wherein said molybdenum is
present in a molybdenum compound selected from the group consisting
of molybdenum chloride, molybdenum acetate, molybdenum fluoride,
molybdenum hexacarbonyl, molybdenum sulfide, sodium molybdates,
potassium molybdates, molybdenum oxychloride, molybdenum sulfide,
ammonium tetrathiomolybdate, ammonium molybdate, ammonium
dimolybdate, ammonium heptamolybdate, molybdenum oxides, and
combinations thereof.
35. A process according to claim 34 wherein said molybdenum
compound is molybdenum oxide.
36. A process according to claim 1 wherein said inorganic support
is selected from the group consisting of silica, alumina, titanium
dioxide, zirconia, spinel, and combinations thereof.
37. A process according to claim 36 wherein said inorganic support
is an alumina selected from the group consisting of alpha alumina,
beta alumina, delta alumina, eta alumina, gamma alumina, and
combinations thereof.
38. A process for preparing a catalyst composition useful in
contacting a hydrocarbon-containing fluid which comprises a highly
unsaturated hydrocarbon, in the presence of hydrogen, with said
catalyst composition in a hydrogenation zone under a hydrogenation
condition effective to hydrogenate said highly unsaturated
hydrocarbon to a less unsaturated hydrocarbon wherein said process
for preparing said catalyst composition comprises: (1) combining a
zeolite, a Group VIB metal, and an inorganic support to form a
modified zeolite; (2) calcining said modified zeolite under a
calcining condition to produce a calcined, modified zeolite; and
(3) contacting said calcined, modified zeolite with a carburizing
agent under a carburizing condition to provide said catalyst
composition.
39. A process according to claim 38 wherein said combining of said
combining step (1) comprises mixing said zeolite, said Group VIB
metal, and said inorganic support to form a mixture and then
extruding said mixture to form said modified zeolite.
40. A process according to claim 39 wherein said mixing comprises
subjecting said zeolite, said Group VIB metal, and said inorganic
support to a mixing means to provide said mixture.
41. A process according to claim 40 wherein said mixing means is
selected from the group consisting of tumblers, stationary shells
or troughs, muller mixers, impact mixers, and combinations
thereof.
42. A process according to claim 41 wherein said mixing means
comprises a muller mixer.
43. A process according to claim 39 wherein said extruding
comprises subjecting said mixture to an extruding means to provide
an extruded mixture.
44. A process according to claim 43 wherein said extruding means is
selected from the group consisting of screw extruders, auger
extruders, auger-type extruders, and combinations thereof.
45. A process according to claim 44 wherein said extruding means
comprises a screw extruder.
46. A process according to claim 38 wherein said catalyst
composition comprises said zeolite in an amount in the range of
from about 1 weight percent said zeolite based on the total weight
of said catalyst composition to about 95 weight percent, said
catalyst composition comprises said Group VIB metal in an amount in
the range of from about 1 weight percent said Group VIB metal based
on the total weight of said catalyst composition to about 95 weight
percent, and said catalyst composition comprises said inorganic
support in an amount in the range of from about 1 weight percent
said inorganic support based on the total weight of said catalyst
composition to about 90 weight percent.
47. A process according to claim 38 wherein said calcining
condition comprises: a temperature in the range of from about
100.degree. C. to about 1500.degree. C.; a time period in the range
of from about 1 hour to about 30 hours; and a pressure in the range
of from about 7 pounds per square inch absolute (psia) to about 750
psia.
48. A process according to claim 38 wherein said carburizing agent
comprises a hydrocarbon.
49. A process according to claim 48 wherein said hydrocarbon
contains in the range of from about 1 carbon atom per molecule to
about 20 carbon atoms per molecule.
50. A process according to claim 49 wherein said hydrocarbon is
selected from the group consisting of methane, ethane, propane,
butanes, isobutane, pentanes, hexanes, heptanes, octanes, nonanes,
benzene, toluene, and combinations thereof.
51. A process according to claim 50 wherein said hydrocarbon is
methane.
52. A process according to claim 38 wherein said carburizing
condition comprises: the presence of hydrogen delivered at a
hydrogen flow rate in the range of from about 200 mL/min to about
1200 mL/min; a temperature in the range of from about 150.degree.
C. to about 1500.degree. C.; a time period in the range of from
about 1 hour to about 40 hours; and said carburizing agent is
delivered at a flow rate in the range of from about 25 mL/min to
about 500 mL/min.
53. A process according to claim 38 wherein said zeolite is
selected from the group consisting of beta zeolite, zeolite X,
zeolite Y, zeolite L, and combinations thereof.
54. A process according to claim 53 wherein said zeolite is zeolite
L.
55. A process according to claim 38 wherein said group VIB metal is
selected from the group consisting of chromium, molybdenum,
tungsten, and combinations thereof.
56. A process according to claim 55 wherein said group VIB metal is
molybdenum.
57. A process according to claim 56 wherein said molybdenum is
present in a molybdenum compound selected from the group consisting
of molybdenum chloride, molybdenum acetate, molybdenum fluoride,
molybdenum hexacarbonyl, molybdenum sulfide, sodium molybdates,
potassium molybdates, molybdenum oxychloride, molybdenum sulfide,
ammonium tetrathiomolybdate, ammonium molybdate, ammonium
dimolybdate, ammonium heptamolybdate, molybdenum oxides, and
combinations thereof.
58. A process according to claim 57 wherein said molybdenum
compound is molybdenum oxide.
59. A process according to claim 38 wherein said inorganic support
is selected from the group consisting of silica, alumina, titanium
dioxide, spinel, and combinations thereof.
60. A process according to claim 59 wherein said inorganic support
is an alumina selected from the group consisting of alpha alumina,
beta alumina, delta alumina, eta alumina, gamma alumina, and
combinations thereof.
61. A composition prepared according to claim 38.
62. A composition prepared according to claim 39.
63. A composition prepared according to claim 40.
64. A composition prepared according to claim 41.
65. A composition prepared according to claim 42.
66. A composition prepared according to claim 43.
67. A composition prepared according to claim 44.
68. A composition prepared according to claim 45.
69. A composition prepared according to claim 46.
70. A composition prepared according to claim 47.
71. A composition prepared according to claim 48.
72. A composition prepared according to claim 49.
73. A composition prepared according to claim 50.
74. A composition prepared according to claim 51.
75. A composition prepared according to claim 52.
76. A composition prepared according to claim 53.
77. A composition prepared according to claim 54.
78. A composition prepared according to claim 55.
79. A compositon prepared according to claim 56.
80. A composition prepared according to claim 57.
81. A composition prepared according to claim 58.
82. A composition prepared according to claim 59.
83. A composition prepared according to claim 60.
84. A catalyst composition comprising a modified zeolite comprising
a zeolite, a Group VIB metal, and an inorganic support wherein said
modified zeolite has been calcined under a calcining condition and
contacted with a carburizing agent under a carburizing condition to
thereby provide a carburized, calcined, modified zeolite.
85. A catalyst composition according to claim 84 wherein said
modified zeolite is a mixture comprising said zeolite, said Group
VIB metal, and said inorganic support.
86. A catalyst composition according to claim 85 wherein said
modified zeolite is an extruded mixture comprising said zeolite,
said Group VIB metal, and said inorganic support.
87. A catalyst composition according to claim 84 wherein said
catalyst composition comprises said zeolite in an amount in the
range of from about 1 weight percent said zeolite based on the
total weight of said catalyst composition to about 95 weight
percent, said catalyst composition comprises said Group VIB metal
in an amount in the range of from about 1 weight percent said Group
VIB metal based on the total weight of said catalyst composition to
about 95 weight percent, and said catalyst composition comprises
said inorganic support in an amount in the range of from about 1
weight percent said inorganic support based on the total weight of
said catalyst composition to about 90 weight percent.
88. A process according to claim 84 wherein said zeolite is
selected from the group consisting of beta zeolite, zeolite X,
zeolite Y, zeolite L, and combinations thereof.
89. A process according to claim 88 wherein said zeolite is zeolite
L.
90. A process according to claim 84 wherein said group VIB metal is
selected from the group consisting of chromium, molybdenum,
tungsten, and combinations thereof.
91. A process according to claim 90 wherein said group VIB metal is
molybdenum.
92. A process according to claim 84 wherein said inorganic support
is an alumina selected from the group consisting of alpha alumina,
beta alumina, delta alumina, eta alumina, gamma alumina, and
combinations thereof.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a catalyst composition, the
preparation of a catalyst composition, and to a process of using a
catalyst composition for hydrogenating a highly unsaturated
hydrocarbon.
[0002] It is well known to one skilled in the art that an
unsaturated hydrocarbon can be produced by a thermal cracking
process. For example, a fluid stream containing a saturated
hydrocarbon such as, for example, ethane, propane, butane, pentane,
naphtha, or combinations thereof can be fed into a thermal (or
pyrolytic) cracking furnace. Within the furnace, the saturated
hydrocarbon is converted to a less unsaturated hydrocarbon such as,
for example, ethylene and propylene. Less unsaturated hydrocarbons
are an important class of chemicals that find a variety of
industrial uses. For example, ethylene and propylene can be used as
a monomer or comonomer for producing polyolefins. Other uses of
less unsaturated hydrocarbons are well known to one skilled in the
art.
[0003] However, a less unsaturated hydrocarbon produced by a
thermal cracking process generally contains an appreciable amount
of highly unsaturated hydrocarbons such as less desirable
alkyne(s), diolefin(s), polyene(s), or combinations thereof. For
example, ethylene produced by thermal cracking of ethane is
generally contaminated with some acetylene which must be
selectively hydrogenated to ethylene, but not to ethane, in a
hydrogenation reaction. Similarly, in a thermal cracking process
for producing a butene, butynes and butadienes are generally
co-produced which must be selectively hydrogenated to a butene, but
not further hydrogenated to a butane.
[0004] These highly unsaturated hydrocarbons described above are
undesirable for several reasons. Generally, these highly
unsaturated hydrocarbons are highly reactive and tend to polymerize
by forming gums if they are left in the product stream. Also, these
undesirable products can have an effect on further processes, such
as alkylation. Thus, these highly unsaturated hydrocarbons are
preferably removed. A preferred process for removing such
undesirable highly unsaturated hydrocarbons is a selective
hydrogenation process. This process not only minimizes the loss of
desired less unsaturated hydrocarbons, but can also help to avoid a
"runaway" reaction which is difficult to control in front-end and
total-cracked-gas processes thereby increasing the selectivity by
which desired products, as opposed to undesired products, are
produced.
[0005] Catalysts comprising palladium and an inorganic support are
known catalysts for the hydrogenation of highly unsaturated
hydrocarbons such as alkynes and/or diolefins. Sulfided catalysts
comprising a metal selected from the group consisting of
molybdenum, cobalt, and nickel and combinations thereof have also
been used as hydrogenation catalysts. However, these catalysts can
be expensive to prepare and can have the potential to introduce
sulfur contaminants which can poison and deactivate catalysts used
in hydrogenation processes.
[0006] As such, development of a catalyst which is cost-efficient
and easier to prepare than known catalysts and processes therewith
in the selective hydrogenation of a highly unsaturated hydrocarbon
such as a diolefin to a less unsaturated hydrocarbon such as a
monoolefin in which selectivity is improved and unnecessary
introduction of contaminants is avoided would be a significant
contribution to the art and to the economy.
SUMMARY OF THE INVENTION
[0007] It is an object of this invention to provide a catalyst
composition which can be useful as a catalyst in the selective
hydrogenation of a highly unsaturated hydrocarbon such as a
diolefin to a less unsaturated hydrocarbon such as a
monoolefin.
[0008] It is another object of this invention to provide a process
for producing such catalyst composition which can be useful as a
catalyst in the selective hydrogenation of a highly unsaturated
hydrocarbon such as a diolefin to a less unsaturated hydrocarbon
such as a monoolefin.
[0009] It is another object of this invention to employ such
catalyst composition in a process for selectively hydrogenating a
highly unsaturated hydrocarbon such as a diolefin to a less
unsaturated hydrocarbon such as a monoolefin.
[0010] Advantages of this invention include a catalyst composition
which avoids unnecessary introduction of contaminants which can
poison and deactivate catalysts used in hydrogenation processes.
Another advantage of this invention is that the process of making
such catalyst is cost-efficient and easier to prepare than known
catalysts. Yet another advantage of this invention is an increased
or enhanced selectivity to a desired product such as a less
unsaturated hydrocarbon.
[0011] The present invention is directed to a catalyst composition
which comprises a carburized, calcined, modified zeolite having
incorporated therein a metal of Group VIB of the Periodic Table of
the Elements (i.e., a Group VIB metal) such as chromium,
molybdenum, tungsten and combinations thereof. The composition also
comprises an inorganic support. The inorganic support can be
selected from the group consisting of silica, alumina, titanium
dioxide, zirconia, a spinel such as zinc aluminate, zinc titanate,
magnesium aluminate, calcium aluminate, and the like and
combinations thereof.
[0012] The present invention is also directed to a process for
producing a catalyst composition which can be useful as a catalyst
in the selective hydrogenation of a highly unsaturated hydrocarbon
such as a diolefin to a lower unsaturated hydrocarbon such as a
monoolefin. The process can comprise: (1) combining a zeolite, a
metal of Group VIB of the Periodic Table of the Elements (i.e., a
Group VIB metal), and an inorganic support to form a modified
zeolite; (2) calcining such modified zeolite under a calcining
condition to produce a calcined, modified zeolite; and (3)
contacting such calcined, modified zeolite with a carburizing agent
under a carburizing condition to provide a carburized, calcined,
modified zeolite.
[0013] The present invention is also directed to a process which
can be used to employ a catalyst composition of this invention in
the selective hydrogenation of a highly unsaturated hydrocarbon
such as a diolefin to a less unsaturated hydrocarbon such as a
monoolefin. The process can comprise contacting a
hydrocarbon-containing fluid, which comprises a highly unsaturated
hydrocarbon, in the presence of hydrogen with a catalyst
composition in a hydrogenation zone under a hydrogenation condition
effective to selectively hydrogenate a highly unsaturated
hydrocarbon to a less unsaturated hydrocarbon. The catalyst
composition can be a catalyst composition of the present
invention.
[0014] Other objects and advantages of the invention will be
apparent from the detailed description of the invention and the
appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0015] As used in the present invention, the term "hydrocarbon"
generally refers to, unless otherwise indicated, one or more
hydrocarbons, saturated or unsaturated, having in the range of from
about 1 carbon atom per molecule to about 50 carbon atoms per
molecule, preferably in the range of from about 2 carbon atoms per
molecule to about 40 carbon atoms per molecule, more preferably in
the range of from about 2 carbon atoms per molecule to about 30
carbon atoms per molecule and, most preferably, in the range of
from about 2 carbon atoms per molecule to about 20 carbon atoms per
molecule. Preferably, a hydrocarbon is a saturated hydrocarbon, a
mixture of saturated hydrocarbons, or a mixture of saturated
hydrocarbons and less unsaturated hydrocarbons. Also, as used in
the present invention, the term "fluid" denotes gas, liquid, vapor,
or combinations thereof.
[0016] The term "saturated hydrocarbon" refers to any hydrocarbon
which does not contain any carbon-to-carbon double bonds or
carbon-to-carbon triple bonds. Examples of saturated hydrocarbons
include, but are not limited to, ethane, propane, butanes, hexanes,
octanes, decanes, naphtha, and the like and combinations
thereof.
[0017] The term "highly unsaturated hydrocarbon" refers to a
hydrocarbon having a carbon-to-carbon triple bond or two or more
carbon-to-carbon double bonds. Examples of highly unsaturated
hydrocarbons include, but are not limited to, aromatic compounds
such as benzene and naphthalene; alkynes such as acetylene, propyne
(also referred to as methylacetylene), and butynes; diolefins such
as propadiene, butadienes, pentadienes (including isoprene),
hexadienes, octadienes, and decadienes; and the like and
combinations thereof.
[0018] The term "less unsaturated hydrocarbon" refers to a
hydrocarbon in which a carbon-to-carbon triple bond in a highly
unsaturated hydrocarbon is hydrogenated to a carbon-to-carbon
double bond, or a hydrocarbon in which the number of
carbon-to-carbon double bonds is one less, or at least one less,
than that in a highly unsaturated hydrocarbon, or a hydrocarbon
having at least one carbon-to-carbon double bond. Examples of less
unsaturated hydrocarbons include, but are not limited to,
monoolefins such as ethylene, propylene, butenes, pentenes,
hexenes, octenes, decenes, and the like and combinations
thereof.
[0019] The term "hydrogenation process" refers to a process which
hydrogenates a highly unsaturated hydrocarbon such as an alkyne or
a diolefin to a less unsaturated hydrocarbon such as a monoolefin
or a saturated hydrocarbon such as an alkane. The term "selective"
refers to such hydrogenation process in which a highly unsaturated
hydrocarbon such as an alkyne or a diolefin is hydrogenated to a
less unsaturated hydrocarbon such as a monoolefin without further
hydrogenating such less unsaturated hydrocarbon to a saturated
hydrocarbon such as an alkane. Thus, for example, when a highly
unsaturated hydrocarbon is converted to a less unsaturated
hydrocarbon without further hydrogenating such a less unsaturated
hydrocarbon to a saturated hydrocarbon, the hydrogenation process
is "more selective" than when such highly unsaturated hydrocarbon
is hydrogenated to a less unsaturated hydrocarbon and then further
hydrogenated to a saturated hydrocarbon.
[0020] The term "n-butenes" refers to 1-butenes, cis-2-butenes, and
trans-2-butenes.
[0021] According to the present invention, a catalyst composition
which can be useful as a catalyst in the selective hydrogenation of
a highly unsaturated hydrocarbon such as a diolefin to a less
unsaturated hydrocarbon such as a monoolefin is provided. The
composition can comprise a carburized, calcined, modified zeolite
wherein the modified zeolite comprises a zeolite, a Group VIB metal
selected from the group consisting of chromium, molybdenum,
tungsten, and combinations thereof, and an inorganic support.
Examples of suitable inorganic supports include, but are not
limited to, silica, alumina, titanium dioxide, zirconia, a spinel
such as zinc aluminate, zinc titanate, magnesium aluminate, calcium
aluminate, and the like and combinations thereof. The presently
preferred inorganic support is an alumina selected from the group
consisting of alpha alumina, beta alumina, delta alumina, eta
alumina, gamma alumina, and the like and combinations thereof. The
more preferred inorganic support is gamma alumina. The composition
can also comprise a carburized, calcined, modified zeolite wherein
the modified zeolite is a mixture or an extruded mixture comprising
a zeolite, a Group VIB metal, and an inorganic support.
[0022] Any commercially available zeolite can be employed in the
present invention as long as such zeolite is effective in
selectively hydrogenating a highly unsaturated hydrocarbon to a
less unsaturated hydrocarbon when used according to the present
invention. The presently preferred zeolites are beta zeolite,
zeolite X, zeolite Y, zeolite L, and the like and combinations
thereof. The more preferred zeolite is zeolite L.
[0023] Generally, the catalyst composition can comprise a metal of
Group VIB of the Periodic Table of the Elements (i.e., a Group VIB
metal) in any weight percent so long as such weight percent is
effective in selectively hydrogenating a highly unsaturated
hydrocarbon such as a diolefin to a less unsaturated hydrocarbon
such as a monoolefin. The catalyst composition comprises a Group
VIB metal in the range of from about 1 weight percent Group VIB
metal based on the total weight of the catalyst composition to
about 95 weight percent Group VIB metal, preferably in the range of
from about 5 weight percent Group VIB metal to about 80 weight
percent Group VIB metal and, more preferably, in the range of from
about 10 weight percent Group VIB metal to about 60 weight percent
Group VIB metal.
[0024] Generally, the catalyst composition can comprise a zeolite
in any weight percent so long as such weight percent is effective
in selectively hydrogenating a highly unsaturated hydrocarbon such
as a diolefin to a less unsaturated hydrocarbon such as a
monoolefin. The catalyst composition comprises a zeolite in the
range of from about 1 weight percent zeolite based on the total
weight of the catalyst composition to about 95 weight percent
zeolite, preferably in the range of from about 5 weight percent
zeolite to about 80 weight percent zeolite and, more preferably, in
the range of from about 10 weight percent zeolite to about 60
weight percent zeolite.
[0025] Generally, the catalyst composition can comprise an
inorganic support in any weight percent so long as such weight
percent is effective in selectively hydrogenating a highly
unsaturated hydrocarbon such as a diolefin to a less unsaturated
hydrocarbon such as a monoolefin. The catalyst composition
comprises an inorganic support in the range of from about 1 weight
percent inorganic support based on the total weight of the catalyst
composition to about 90 weight percent inorganic support,
preferably in the range of from about 5 weight percent inorganic
support to about 80 weight percent inorganic support and, more
preferably, in the range of from about 10 weight percent inorganic
support to about 60 weight percent inorganic support.
[0026] Generally, the catalyst composition can comprise carbon in
any weight percent so long as such weight percent is effective in
selectively hydrogenating a highly unsaturated hydrocarbon such as
a diolefin to a less unsaturated hydrocarbon such as a monoolefin.
The catalyst composition comprises carbon in the range of from
about 0.1 weight percent carbon based on the total weight of the
catalyst composition to about 90 weight percent carbon, preferably
in the range of from about 0.5 weight percent carbon to about 60
weight percent carbon and, more preferably, in the range of from
about 1 weight percent carbon to about 50 weight percent
carbon.
[0027] Any metal of Group VIB of the Periodic Table of the Elements
(i.e., a Group VIB metal) such as chromium, molybdenum, tungsten,
and the like and combinations thereof can be employed in the
present invention. The presently preferred Group VIB metal is
molybdenum. Preferably, when preparing a catalyst composition
disclosed herein, such Group VIB metal is present in a Group VIB
metal-containing compound. Preferably, such Group VIB metal or
Group VIB metal-containing compound is selected such that it can be
combined with, or incorporated therein or thereon, a zeolite, or a
zeolite and an inorganic support, of the present invention. And,
preferably, such Group VIB metal or Group VIB metal-containing
compound is selected so that, as compared to use of a zeolite only,
or zeolite and inorganic support only, it is more effective in a
catalyst composition of the present invention in selectively
hydrogenating a highly unsaturated hydrocarbon such as a diolefin
to a less unsaturated hydrocarbon such as a monoolefin.
[0028] Generally, any molybdenum compound which, when combined with
a zeolite, or a zeolite and an inorganic support, according to the
present invention, is effective in selectively hydrogenating a
highly unsaturated hydrocarbon such as a diolefin to a less
unsaturated hydrocarbon such as a monoolefin can be used in the
present invention. Examples of suitable molybdenum compounds
include, but are not limited to, molybdenum chloride, molybdenum
acetate, molybdenum fluoride, molybdenum hexacarbonyl, molybdenum
sulfide, sodium molybdates, potassium molybdates, molybdenum
oxychloride, molybdenum sulfide, ammonium tetrathiomolybdate,
ammonium molybdate, ammonium dimolybdate, ammonium heptamolybdate,
molybdenum oxides, and the like and combinations thereof. The
molybdenum can have any suitable oxidation state such as 2, 3, 4,
5, and 6. The presently preferred molydenum compound is molybdenum
oxide.
[0029] Generally, any tungsten compound which, when combined with a
zeolite, or a zeolite and an inorganic support, according to the
present invention, is effective in selectively hydrogenating a
highly unsaturated hydrocarbon such as a diolefin to a less
unsaturated hydrocarbon such as a monoolefin can be used in the
present invention. Examples of suitable tungsten compounds include,
but are not limited to, tungsten hexachloride, tungsten
tetrachloride, tungsten pentachloride, tungsten hexabromide,
tungsten tetrabromide, tungsten pentabromide, tungsten
hexafluoride, tungsten tetrafluoride, tungsten pentafluoride,
tungsten hexacarbonyl, tungsten oxychloride, tungsten hexasulfide,
tungsten tetrasulfide, tungsten oxide, tungsten pentasulfide,
ammonium metatungstate, sodium metatungstate, potassium
metatungstate, tungstic acid and the like and combinations thereof.
The presently preferred tungsten compound is tungsten oxide.
[0030] Generally, any chromium compound which, when combined with a
zeolite, or a zeolite and an inorganic support, according to the
present invention, is effective in selectively hydrogenating a
highly unsaturated hydrocarbon such as a diolefin to a less
unsaturated hydrocarbon such as a monoolefin can be used in the
present invention. Examples of suitable chromium compounds include,
but are not limited to, chromium acetate, chromium acetylacetonate,
chromium chloride, chromium fluoride, chromium nitrate, hydrated
chromium nitrate, chromium nitrate nonahydrate, chromium nitride,
chromium oxide, chromium perchlorate, chromium potassium sulfate,
chromium sulfate, chromium telluride, and the like and combinations
thereof. The presently preferred chromium compound is chromium
oxide.
[0031] The catalyst composition can be in any physical form and
dimension so long as such physical form and dimension is effective
in selectively hydrogenating a highly unsaturated hydrocarbon such
as a diolefin to a less unsaturated hydrocarbon such as a
monoolefin. Generally, the catalyst composition can be
characterized by characteristics such as shape, particle size, and
surface area. The catalyst composition can have any suitable shape
such as spherical, cylindrical, trilobal, and the like and
combinations thereof. The catalyst composition can have a particle
size generally in the range of from about 1 millimeter (mm) to
about 10 mm, preferably in the range of from about 2 mm to about 8
mm. Generally, the catalyst composition can have a surface area, as
measured by the BET method (Brunauer, Emmett and Teller method)
employing N.sub.2 in the range of from about 0.6 m.sup.2/g to about
200 m.sup.2/g, preferably in the range of from about 1 m.sup.2/g to
about 100 m.sup.2/g.
[0032] According to the present invention, any suitable inorganic
support can be used so long as the catalyst composition can
selectively hydrogenate a highly unsaturated hydrocarbon such as a
diolefin to a less unsaturated hydrocarbon such as a monoolefin.
Examples of suitable inorganic supports include, but are not
limited to, silica, alumina, titanium dioxide, zirconia, a spinel
such as zinc aluminate, zinc titanate, magnesium aluminate, calcium
aluminate, and the like and combinations thereof. The presently
preferred inorganic support is an alumina selected from the group
consisting of alpha alumina, beta alumina, delta alumina, eta
alumina, gamma alumina, and the like and combinations thereof. The
more preferred inorganic support is gamma alumina.
[0033] According to the present invention, a process for producing
a catalyst composition which can be useful as a catalyst
composition in the hydrogenation of a highly unsaturated
hydrocarbon such as a diolefin to a less unsaturated hydrocarbon
such as a monoolefin is provided. The catalyst composition can be
prepared by any suitable, effective method or manner which results
in a catalyst composition comprising a zeolite, a Group VIB metal,
and an inorganic support wherein such catalyst composition has been
calcined and carburized, and can also be prepared by any method or
manner which results in the catalyst composition being effective in
the selective hydrogenation of a highly unsaturated hydrocarbon to
a less unsaturated hydrocarbon.
[0034] The process of preparing the catalyst composition can
comprise (1) combining a zeolite, a Group VIB metal, and an
inorganic support to form a modified zeolite; (2) calcining such
modified zeolite under a calcining condition to produce a calcined,
modified zeolite; and (3) contacting such calcined, modified
zeolite with a carburizing agent under a carburizing condition to
provide a catalyst composition. Generally, the combining of a
zeolite, a Group VIB metal, and an inorganic support can be
conducted in any suitable manner and in any suitable order which
results in a modified zeolite which can then be calcined and
carburized to produce a catalyst composition of the present
invention. Generally, the amounts of a zeolite, a Group VIB metal,
and an inorganic support used are such that when such zeolite,
Group VIB metal, and inorganic support are combined, calcined, and
carburized according to the present invention, a catalyst
composition is produced having weight percents of zeolite, Group
VIB metal, and inorganic support as disclosed hereinabove.
[0035] Any method or manner known to one skilled in the art for
carrying out the combining of the combining step (1) to form a
modified zeolite can be employed in this invention. Generally, the
combining step can be any effective method to provide a modified
zeolite so long as such modified zeolite can be calcined and
carburized to produce a catalyst composition which is effective in
selectively hydrogenating a highly unsaturated hydrocarbon such as
a diolefin to a less unsaturated hydrocarbon such as a monoolefin.
The term "modified zeolite" refers to a composition containing a
zeolite, a Group VIB metal, and an inorganic support which can then
be calcined and carburized according to the present invention to
thereby provide the catalyst composition of the present invention.
For example, the term "modified zeolite" can refer to a mixture of
a zeolite, a Group VIB metal, and an inorganic support, an extruded
mixture of a zeolite, a Group VIB metal, and an inorganic support,
or a dried extruded mixture of a zeolite, a Group VIB metal, and an
inorganic support.
[0036] For example, combining a zeolite, a Group VIB metal, and an
inorganic support can comprise physically mixing or blending a
Group VIB metal or Group VIB metal-containing compound with a
zeolite and an inorganic support by stirring, extrusion, blending,
kneading, and the like and combinations thereof. Also for example,
a Group VIB metal or Group VIB metal-containing compound can be
combined with a zeolite and an inorganic support by extrusion. The
presently preferred technique for combining a zeolite, a Group VIB
metal, and an inorganic support to thereby provide a modified
zeolite which can be calcined and carburized to thereby provide a
catalyst composition of the present invention is by physical mixing
such zeolite in powder form, a Group VIB metal or Group VIB
metal-containing compound in powder form, and an inorganic support
in powder form to thereby provide a mixture which is then
extruded.
[0037] Generally, any suitable means for mixing a zeolite, a Group
VIB metal, and an inorganic support can be employed. Examples of
suitable mixing means for use in preparing a mixture of a zeolite,
a Group VIB metal, and an inorganic support of the inventive method
are described in detail in Perry's Chemical Engineers' Handbook,
Sixth Edition, published by McGraw-Hill, Inc., copyright 1984, at
pages 21-3 through 21-10, which pages are incorporated herein by
reference. Thus, examples of suitable mixing means can include, but
are not limited to, devices such as tumblers, stationary shells or
troughs, muller mixers, which are either batch type or continuous
type, impact mixers, and the like. It is preferred to use a muller
mixer in the physical mixing of a zeolite, a Group VIB metal, and
an inorganic support. A liquid such as, but not limited to, water,
may be used in the mixing of a zeolite, a Group VIB metal, and an
inorganic support to thereby provide a mixture.
[0038] The mixture of a zeolite, a Group VIB metal, and an
inorganic support can then be formed or shaped, preferably
extruded. Any suitable means known to those skilled in the art for
forming or shaping, preferably extruding, the mixture of a zeolite,
a Group VIB metal, and an inorganic support can be used to achieve
the desired formed or shaped mixture, preferably an extruded
mixture (i.e., extrudate). A liquid such as, but not limited to,
water, may be used in forming or shaping, preferably extruding, the
mixture of a zeolite, a Group VIB metal, and an inorganic support
to thereby provide a formed or shaped, preferably extruded,
mixture.
[0039] Generally, any suitable extruding means for extruding can be
used to provide an extruded mixture of a zeolite, a Group VIB
metal, and an inorganic support. Examples of suitable extruding
means are described in detail in Perry's Chemical Engineers'
Handbook, Sixth Edition, published by McGraw Hill, Inc., copyright
1984, at pages 8-60 through 8-72, which pages are incorporated
herein by reference. Thus, examples of suitable extruding means
include, but are not limited to, such devices as screw extruders
(also known as auger extruders or auger-type extruders) and the
like and combinations thereof. It is presently preferred to use a
screw extruder in the extruding of a mixture of a zeolite, a Group
VIB metal, and an inorganic support.
[0040] The mixture, preferably an extruded mixture of a zeolite, a
Group VIB metal, and an inorganic support can be subjected to a
drying condition in an atmosphere of air or inert gas (such as, but
not limited to, nitrogen, hydrogen, argon, and the like and
combinations thereof) by any method(s) or manner known to one
skilled in the art. Such drying condition includes a temperature in
the range of from about 200.degree. C. to about 1200.degree. C.,
preferably a temperature in the range of from about 400.degree. C.
to about 1000.degree. C. and, most preferably, a temperature in the
range of from about 500.degree. C. to about 900.degree. C. Such
drying condition also includes a pressure in the range of from
about 7 pounds per square inch absolute (psia) upwardly to about
750 psia, preferably a pressure in the range of about 14 psia
upwardly to about 450 psia and, most preferably, a pressure in the
range of from about atmospheric pressure (i.e, about 14.7 psia)
upwardly to about 25 psia. The drying of the mixture can also be
carried out under vacuum conditions. Such drying condition also
includes a time period in the range of from about 0.5 hour to about
40 hours, preferably in the range of from about 1 hour to about 30
hours and, most preferably, in the range of from about 1.5 hours to
about 20 hours. The rate of drying the mixture is controlled so as
to avoid surges of water vapor and splattering.
[0041] The modified zeolite, preferably a mixture of a zeolite, a
Group VIB metal, and an inorganic support, more preferably an
extruded mixture, most preferably a dried extruded mixture, can
then be calcined under a calcining condition by any method(s) or
manner known to one skilled in the art to give a calcined, modified
zeolite. Generally, such calcining condition is such as to suitably
provide a calcined, modified zeolite which can be carburized
according to the present invention to produce a catalyst
composition which is effective in selectively hydrogenating a
highly unsaturated hydrocarbon such as a diolefin to a less
unsaturated hydrocarbon such as a monoolefin. Preferably, the
modified zeolite is calcined in air.
[0042] Generally, such calcining condition includes a temperature
in the range of from about 100.degree. C. to about 1500.degree. C.,
preferably in the range of from about 200.degree. C. to about
800.degree. C. and, most preferably, in the range of from about
250.degree. C. to about 700.degree. C. Such calcining condition
also includes a pressure in the range of from about 7 pounds per
square inch absolute (psia) to about 750 psia, preferably in the
range of from about atmospheric pressure (i.e., about 14.7 psia) to
about 450 psia and, most preferably, in the range of from about
atmospheric pressure to about 150 psia. Such calcining condition
also includes a time period in the range of from about 1 hour to
about 30 hours, preferably in the range of from about 2 hours to
about 20 hours and, most preferably, in the range of from about 3
hours to about 15 hours.
[0043] The calcined, modified zeolite can then be contacted with a
carburizing agent under a carburizing condition by any method(s) or
manner known to one skilled in the art to thereby provide a
catalyst composition of the present invention.
[0044] Generally, any aliphatic hydrocarbon, straight-chained
hydrocarbon, branch-chained hydrocarbon, or aromatic hydrocarbon,
non-substituted or substituted, can be used as the carburizing
agent. However, it is preferred that the hydrocarbon contains in
the range of from about 1 carbon atom per molecule to about 20
carbon atoms per molecule, preferably in the range of from about 1
carbon atom per molecule to about 15 carbon atoms per molecule and,
most preferably, in the range of from about 1 carbon atom per
molecule to about 10 carbon atoms per molecule. Examples of a
suitable hydrocarbon for use as a carburizing agent in the present
invention include, but are not limited to, methane, ethane,
propane, butanes, isobutane, pentanes, hexanes, heptanes, octanes,
nonanes, benzene, toluene, and the like and combinations thereof.
The presently preferred hydrocarbon for use as a carburizing agent
in the present invention is methane. The quantity of hydrocarbon
required for use as a carburizing agent is a quantity that can
result in a carburized, calcined, modified zeolite or a catalyst
composition of the present invention having a weight percent of
carbon as disclosed hereinabove. The quantity of carbon which is
incorporated with the catalyst composition of the present invention
can be determined by any means known to one skilled in the art such
as, for example, thermal gravimetric analysis.
[0045] Generally, such carburizing condition is such as to suitably
provide a catalyst composition which is effective in selectively
hydrogenating a highly unsaturated hydrocarbon such as a diolefin
to a less unsaturated hydrocarbon such as a monoolefin. The
carburizing condition for contacting the calcined, modified zeolite
with a carburizing agent includes a temperature in the range of
from about 150.degree. C. to about 1500.degree. C., preferably in
the range of from about 200.degree. C. to about 1200.degree. C.
and, most preferably, in the range of from about 275.degree. C. to
about 1000.degree. C. Such carburizing condition also includes a
pressure that can accommodate the temperature ranges, preferably
about atmospheric pressure (i.e., about 14.7 pounds per square
inch), and a time period in the range of from about 1 hour to about
40 hours, preferably in the range of from about 1 hour to about 20
hours and, most preferably, in the range of from about 1.5 hours to
about 15 hours. The carburizing agent is delivered at a flow rate
generally in the range of from about 25 milliliters per minute
(mL/min) to about 500 mL/min, preferably in the range from about 50
mL/min to about 400 mL/min and, most preferably, in the range of
from about 75 mL/min to about 300 mL/min.
[0046] Preferably, the carburizing is carried out in the presence
of a gas that is inert to the contacting of the calcined, modified
zeolite and carburizing agent, such as hydrogen, helium, argon,
nitrogen, and combinations thereof. The presently preferred inert
gas is hydrogen delivered at a hydrogen flow rate in the range of
from about 200 mL/min to about 1200 mL/min, preferably at a
hydrogen flow rate in the range of from about 250 mL/min to about
1000 mL/min and, most preferably, at a hydrogen flow rate in the
range of from about 300 mL/min to about 800 mL/min.
[0047] According to the present invention, a process for
selectively hydrogenating a highly unsaturated hydrocarbon such as
a diolefin to a less unsaturated hydrocarbon such as a monoolefin
is provided. The process can comprise contacting a
hydrocarbon-containing fluid which comprises one or more highly
unsaturated hydrocarbons such as an alkyne(s) and/or diolefin(s)
with the catalyst composition disclosed herein in the presence of
hydrogen in a hydrogenation zone under a hydrogenation condition to
selectively hydrogenate such one or more highly unsaturated
hydrocarbons to a less unsaturated hydrocarbon such as
monoolefin.
[0048] Hydrogen can be present either in the hydrocarbon-containing
fluid or in a hydrogen-containing fluid which is mixed with the
hydrocarbon-containing fluid before contacting with the catalyst
composition disclosed herein. If a hydrogen-containing fluid is
used, it can be a substantially pure hydrogen or any fluid
containing a sufficient concentration of hydrogen to effect the
hydrogenation disclosed herein. It can also contain other gases
such as, for example, nitrogen, methane, carbon monoxide, carbon
dioxide, steam, or combinations thereof so long as the
hydrogen-containing fluid contains a sufficient concentration of
hydrogen to effect the hydrogenation disclosed herein.
[0049] Optionally, the catalyst composition can be first treated,
prior to the hydrogenation disclosed herein, with a
hydrogen-containing fluid to activate the catalyst composition.
Such reductive, or activation, treatment can be carried out at a
temperature generally in the range of from about 20.degree. C. to
about 500.degree. C., preferably in the range of from about
30.degree. C. to about 450.degree. C. and, most preferably, in the
range of from 30.degree. C. to 400.degree. C. for a time period in
the range of from about 1 minute to about 30 hours, preferably in
the range of from about 0.5 hour to about 25 hours and, most
preferably, in the range of from 1 hour to 20 hours at a pressure
generally in the range of from about 1 pound per square inch
absolute to about 1000 pounds per square inch absolute (psia),
preferably in the range of from about 14.7 psia to about 500 psia
and, most preferably, in the range of from 14.7 psia to 200 psia.
When this optional reductive treatment is not carried out, the
hydrogen gas present in the reaction medium accomplishes this
reduction during the initial phase of the hydrogenation process(es)
of this invention.
[0050] The highly unsaturated hydrocarbon(s) is generally present
in the hydrocarbon-containing fluid as an impurity generally at a
level found in typical commercial feed streams. The highly
unsaturated hydrocarbon(s) is generally present in the
hydrocarbon-containing fluid in the range of from about 1 part by
weight highly unsaturated hydrocarbon(s) per billion parts by
weight hydrocarbon-containing fluid (i.e., about 1 ppb) to about
50,000 parts by weight highly unsaturated hydrocarbon(s) per
million parts by weight hydrocarbon-containing fluid (i.e., about
50,000 ppm), typically at a level in the range of from about 10 ppb
to about 40,000 ppm and, most typically, at a level in the range of
from about 100 ppb to about 30,000 ppm.
[0051] The hydrocarbon-containing fluid of the selective
hydrogenation process of this invention can also comprise one or
more less unsaturated hydrocarbon(s) such as a monoolefin(s), one
or more saturated hydrocarbon(s) such as an alkane(s), and one or
more aromatic hydrocarbons such as benzene, toluene, ethylbenzene,
styrene, xylenes, and combinations thereof. These additional
hydrocarbons can be present in the hydrocarbon-containing fluid at
a level in the range of from about 0.001 weight percent to about
99.999 weight percent.
[0052] Examples of suitable alkynes include, but are not limited
to, acetylene, propyne (also referred to as methylacetylene),
1-butyne, 2-butyne, 1-pentyne, 2-pentyne, 3-methyl-1-butyne,
1-hexyne, 1-heptyne, 1-octyne, 1-nonyne, 1-decyne, and the like and
combinations thereof. The presently preferred alkynes are acetylene
and propyne.
[0053] The alkynes are primarily hydrogenated to the corresponding
alkenes. For example, acetylene is primarily hydrogenated to
ethylene; propyne is primarily hydrogenated to propylene; and the
butynes are primarily hydrogenated to the corresponding butenes
(e.g., n-butenes).
[0054] Examples of suitable diolefins include those containing in
the range of from 3 carbon atoms per molecule to about 12 carbon
atoms per molecule. Examples of suitable diolefins include, but are
not limited to, propadiene, 1,2-butadiene, 1,3-butadiene, isoprene,
1,2-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 1,2-hexadiene,
1,3-hexadiene, 1,4-hexadiene, 1,5-hexadiene,
2-methyl-1,2-pentadiene, 2,3-dimethyl-1,3-butadiene, heptadienes,
methylhexadienes, octadienes, methylheptadienes,
dimethylhexadienes, ethylhexadienes, trimethylpentadienes,
methyloctadienes, dimethylheptadienes, ethyloctadienes,
trimethylhexadienes, nonadienes, decadienes, undecadienes,
dodecadienes, cyclopentadienes, cyclohexadienes,
methylcyclopentadienes, cycloheptadienes, methylcyclohexadienes,
dimethylcyclopentadienes, ethylcyclopentadienes, dicyclopentadiene
(also known as tricyclo[5.2.1].sup.2,6deca-3,8-diene), and the like
and combinations thereof.
[0055] Presently preferred diolefins are propadiene, 1,2-butadiene,
1,3-butadiene, isoprene, 1,2-pentadiene, 1,3-pentadiene,
1,4-pentadiene, cyclopentadienes (such as 1,3-cyclopentadiene),
dicyclopentadiene (also known as
tricyclo[5.2.1].sup.2,6deca-3,8-diene), and combinations thereof.
These diolefins are preferably selectively hydrogenated to their
corresponding monoolefins containing the same number of carbon
atoms per molecule as the diolefins. For example, propadiene is
selectively hydrogenated to propylene; 1,2-butadiene and
1,3-butadiene are selectively hydrogenated to n-butenes;
1,3-pentadiene and 1,4-pentadiene are selectively hydrogenated to
1-pentene and 2-pentene; isoprene is selectively hydrogenated to
methyl-1-pentene and methyl-2-pentene; and 1,3-cyclopentadiene is
selectively hydrogenated to cyclopentene. The more presently
preferred diolefin is 1,3-butadiene.
[0056] Examples of suitable monoolefins include, but are not
limited to, ethylene, propylene, n-butenes (also referred to as
normal butenes which include 1-butenes, cis-2-butenes, and
trans-2-butenes), isobutylene, 1-pentene, 2-pentene,
methyl-1-butene (such as 2-methyl-1-butene), methyl-2-butene (such
as 2-methyl-2-butene), 1-hexene, 2-hexene, 3-hexene,
methyl-1-pentene, 2,3-dimethyl-1-butene, 1-heptene, 2-heptene,
3-heptene, methyl-1-hexene, methyl-2-hexene, methyl-3-hexene,
dimethylpentenes, ethylpentenes, octenes, methylheptenes,
dimethylhexenes, ethylhexenes, nonenes, methyloctenes,
dimethylheptenes, ethylheptenes, trimethylhexenes, cyclopentenes,
cyclohexenes, methylcyclopentenes, cycloheptenes,
methylcyclohexenes, dimethylcyclopentenes, ethylcyclopentenes,
cyclooctenes, methylcycloheptenes, dimethylcyclohexenes,
ethylcyclohexenes, trimethylcyclohexenes, methylcyclooctenes,
dimethylcyclooctenes, ethylcyclooctenes, and the like and
combinations thereof.
[0057] Examples of suitable saturated hydrocarbons include, but are
not limited to, methane, ethane, propane, butanes, methylpropanes,
methylbutanes, dimethylbutanes, pentanes, hexanes, and the like and
combinations thereof.
[0058] Examples of suitable aromatic hydrocarbons include, but are
not limited to, benzene, toluene, ethylene, styrene, xylenes, and
the like and combinations thereof.
[0059] Furthermore, the hydrocarbon-containing fluid can contain in
the range of from about 0.001 weight percent hydrogen to about 20
weight percent hydrogen, and up to 10,000 parts per million by
volume (ppmv) of carbon monoxide.
[0060] It is within the scope of this invention to have additional
compounds (such as water, alcohols, ethers, aldehydes, ketones,
carboxylic acids, esters and other oxygenated compounds) present in
the hydrocarbon-containing fluid, as long as such additional
compounds do not significantly interfere with the selective
hydrogenation process of a highly unsaturated hydrocarbon to a less
unsaturated hydrocarbon as described herein.
[0061] In a preferred embodiment of the present invention, the
hydrocarbon-containing fluid contains 1,3-butadiene and essentially
no other hydrocarbons. In other words, the hydrocarbon-containing
fluid is a 1,3-butadiene stream. Preferably, the 1,3-butadiene is
selectively hydrogenated to n-butenes (i.e., normal butenes which
include 1-butenes, cis-2-butenes, and trans-2-butenes) without
further hydrogenating such n-butenes to butane.
[0062] The selective hydrogenation process(es) of this invention is
generally carried out by contacting a hydrocarbon-containing fluid
comprising at least one highly unsaturated hydrocarbon, in the
presence of hydrogen, with a catalyst composition of this invention
under a hydrogenation condition. The hydrocarbon-containing fluid
can be contacted by any suitable manner with a catalyst composition
described herein which is contained within a hydrogenation zone.
Such hydrogenation zone can comprise, for example, a reactor
vessel.
[0063] The contacting step, of contacting the
hydrocarbon-containing fluid with a catalyst composition disclosed
herein, can be operated as a batch process step or, preferably, as
a continuous process step. In the latter operation, a solid or
fixed catalyst bed or a moving catalyst bed or a fluidized catalyst
bed can be employed. Preferably, a fixed catalyst bed is employed.
Any of these operational modes have advantages and disadvantages,
and those skilled in the art can select the one most suitable for a
particular hydrocarbon-containing fluid and catalyst
composition.
[0064] The contacting step is preferably carried out within a
hydrogenation zone, wherein is contained a catalyst composition
disclosed herein, and under a hydrogenation condition that suitably
promotes the selective hydrogenation of a highly unsaturated
hydrocarbon to a less unsaturated hydrocarbon as described herein.
Such hydrogenation condition should be such as to avoid significant
hydrogenation of a less unsaturated hydrocarbon(s) being initially
present in the hydrocarbon-containing fluid to a saturated
hydrocarbon(s) such as an alkane(s) or cycloalkane(s).
[0065] Generally, such hydrogenation process comprises the presence
of hydrogen, preferably hydrogen gas, in an amount in the range of
from about 0.1 mole of hydrogen employed for each mole of highly
unsaturated hydrocarbon present in the hydrocarbon-containing fluid
to about 1000 moles of hydrogen employed for each mole of highly
unsaturated hydrocarbon present in the hydrocarbon-containing
fluid, preferably in the range of from about 0.5 mole to about 500
moles of hydrogen employed for each mole of highly unsaturated
hydrocarbon present in the hydrocarbon-containing fluid and, most
preferably, in the range of from about 0.7 mole to about 200 moles
of hydrogen employed for each mole of highly unsaturated
hydrocarbon present in the hydrocarbon-containing fluid.
[0066] Generally, such hydrogenation condition comprises a
temperature and a pressure necessary for the selective
hydrogenation process of this invention depending largely upon the
activity of the catalyst composition, the hydrocarbon-containing
fluid composition, and the desired extent of hydrogenation.
Generally, such temperature is in the range of from about
10.degree. C. to about 600.degree. C., preferably in the range of
from about 20.degree. C. to about 500.degree. C. and, most
preferably, in the range of from 30.degree. C. to 450.degree. C. A
suitable pressure is generally in the range of from about 0 pounds
per square inch gauge (psig) to about 2000 psig, preferably in the
range of from about 0 psig to about 1500 psig and, most preferably,
in the range of from about 0 psig to about 1000 psig.
[0067] Such hydrogenation condition further comprises the flow rate
at which the hydrocarbon-containing fluid is charged (i.e., the
charge rate of hydrocarbon-containing fluid) to the hydrogenation
zone. The flow rate is such as to provide a gas hourly space
velocity ("GHSV") generally exceeding 1 liter/liter/hour. The term
"gas hourly space velocity", as used herein, shall mean the
numerical ratio of the rate at which a hydrocarbon-containing fluid
is charged to the hydrogenation zone in liters per hour at standard
condition of temperature and pressure ("STP") divided by the liters
of catalyst composition contained in the hydrogenation zone to
which the hydrocarbon-containing fluid is charged. Typically, the
gas hourly space velocity of the hydrocarbon-containing fluid will
be in the range of from about 1 to about 30,000 liters of
hydrocarbon-containing fluid per liter of catalyst per hour
(liter/liter/hour), preferably in the range of from about 2 to
about 20,000 liter/liter/hour and, most preferably, in the range of
from about 3 to about 10,000 liter/liter/hour.
[0068] If it is desired to regenerate the catalyst composition of
this invention after prolonged use in the selective hydrogenation
process(es) described herein, the regeneration can be accomplished
by calcining the catalyst composition in an oxidizing atmosphere
such as in air at a temperature that does not exceed about
700.degree. C. to bum off carbonaceous and sulfur deposits.
[0069] The following examples are presented to further illustrate
this invention and are not to be construed as unduly limiting the
scope of this invention.
EXAMPLE I
[0070] This example illustrates the preparation of various
molybdenum-containing catalysts to be used in a selective
hydrogenation process.
[0071] Catalyst A (Control)
[0072] A 15.0 gram quantity of molybdenum oxide (MoO.sub.3) in
powder form was combined with 25.0 grams of a commercially
available alumina (Al.sub.2O.sub.3) support in powder form (such
alumina support had been provided by United Catalyst Inc. (UCI),
Louisville, Ky. under the product designation of "CATAPAL D") by
physically mixing the MoO.sub.3 and the CATAPAL D. The mixture was
then extruded to provide an extrudate having a diameter of
{fraction (1/16)} inch (i.e., a {fraction (1/16)} inch extrudate).
The molybdenum-and-alumina extrudate was then calcined in air at
538.degree. C. for 6 hours to produce 30.8 grams of Control
Catalyst A. Control Catalyst A contained 30.8 weight percent
molybdenum (Mo).
[0073] Catalyst B (Control)
[0074] A 22.4 gram quantity of the above-described Control Catalyst
A was heated, in a gas mixture of methane (CH.sub.4) and hydrogen
(H.sub.2) at a hydrocarbon (methane, CH.sub.4) flow rate of 150
mL/min and a hydrogen (H.sub.2) flow rate of 600 mL/min, from a
temperature of 400.degree. C. to 705.degree. C. over a time period
of 5 hours followed by heating at 700.degree. C. for 2 hours to
provide 21.0 grams of Control Catalyst B. Control Catalyst B
contained 66 weight percent molybdenum carbide (Mo.sub.2C). X-ray
data confirmed that the molybdenum carbide had a hexagonal
structure and a crystalline domain size of 8 angstoms. The
"crystalline domain size" was determined from the line broadening
of the X-ray diffraction profile.
[0075] Catalyst C (Invention)
[0076] A 5.0 gram quantity of molybdenum oxide (MoO.sub.3) in
powder form was combined with 12.0 grams of a commercially
available alumina (Al.sub.2O.sub.3) support in powder form (such
alumina support had been provided by United Catalyst Inc. (UCI),
Louisville, Kentucky under the product designation of "CATAPAL D")
and 1.0 gram of commercially available zeolite L in powder form
(such zeolite L had been provided by CU Chemie Uetikon AG,
Switzerland, under the product designation "K-LTL ZEOCAT") by
physically mixing the MoO.sub.3, CATAPAL D, and zeolite L. The
mixture was then extruded to provide an extrudate having a diameter
of {fraction (1/16)} inch (i.e., a {fraction (1/16)} inch
extrudate). The molybdenum-alumina-zeolite extrudate was then
calcined in air at 538.degree. C. for 6 hours to produce 21.5 grams
of a modified zeolite. A 20.3 gram quantity of such modified
zeolite was then heated, in a gas mixture of methane (CH.sub.4) and
hydrogen (H.sub.2) at a hydrocarbon (methane, CH.sub.4) flow rate
of 150 mL/min and a hydrogen (H.sub.2) flow rate of 600 mL/min,
from a temperature of 400.degree. C. to 705.degree. C. over a time
period of 5 hours followed by heating at 700.degree. C. for 2 hours
to provide 19.0 grams of Invention Catalyst C. Invention Catalyst C
contained 70 weight percent molybdenum carbide (Mo.sub.2C). X-ray
data confirmed that the molybdenum carbide had a hexagonal
structure and a crystalline domain size of 7 angstoms. The
"crystalline domain size" was determined from the line broadening
of the X-ray diffraction profile.
EXAMPLE II
[0077] This example illustrates the performance of the catalysts
described hereinabove in Example I in a selective hydrogenation
process.
[0078] A 3.4 gram quantity of Control Catalyst A (the runs were
repeated using a 3.3 gram quantity of Control Catalyst B and a 2.7
gram quantity of Invention Catalyst C) was placed in a stainless
steel reactor tube having a 0.62 inch inner diameter and a length
of about 18 inches. The catalyst (resided in the middle of the
reactor, both ends of the reactor were packed with 6 mL of 3 mm
glass beads) was reduced at about 380.degree. C. for about 1 hour
under hydrogen gas flowing at 12 liters per hour at 0 pounds per
square inch gauge (psig). Thereafter, while maintaining a hydrogen
gas flow rate of 6 liters per hour (L/hr) at 0 psig, a
hydrocarbon-containing fluid containing 1,3-butadiene having a
density of 2.204 gram per milliliter (g/mL) and a molecular weight
of 54.07 was continuously introduced into the reactor at a rate of
about 6.0 L/hr (resulting in a weight hourly space velocity
("WHSV") of about 4 to 5 hour.sup.-1). The hydrogen gas flow rate
was such as to maintain a hydrogen to highly unsaturated
hydrocarbon (1,3-butadiene) (H2:HC) mole ratio of about 1. The
reactor was then heated to a reaction temperature of about
370.degree. C. over about an 8-hour time period for Control
Catalyst A and Invention Catalyst C. A reaction temperature of
300.degree. C. was used for Control Catalyst B because at
300.degree. C. all 1,3-butadiene present in the
hydrocarbon-containing fluid had been converted. The formed
reaction product exited the reactor tube and passed through several
ice-cooled traps. The liquid portion remained in these traps and
was weighed, whereas the volume of the gaseous portion which exited
the traps was measured in a "wet test meter". Liquid and gaseous
product samples (collected at hourly intervals) were analyzed by
means of a gas chromatograph. Results of test runs for Catalysts A,
B, and C are summarized in Table I. All test data were obtained
after about 7 hours on stream.
[0079] Various n-butenes selectivities for each of the
above-described catalysts are shown below in Table I. The term
"1,3-butadiene weight percent conversion" refers to the weight
percent of the feed (1,3-butadiene) which was hydrogenated to a
hydrocarbon other than 1,3-butadiene. The term "n-butenes (or
.SIGMA.C.sub.4.dbd.) selectivity" refers to the mole percent of
feed (1,3-butadiene) which was hydrogenated to the desired
n-butenes (1-butenes, cis-2-butenes, and trans-2-butenes). The
n-butenes selectivity value is representative of the amount of
desired n-butenes (1-butenes, cis-2-butenes, and trans-2-butenes)
contained in the process effluent as opposed to undesired product,
i.e., butane. Thus, a higher value for n-butenes selectivity
indicated that less butane was produced and that the catalyst was
more selective or had a better selectivity to n-butenes.
1TABLE I n-butenes Time on 1,3-BD (or .SIGMA.C.sub.4=) Catalyst
Stream Temp wt % mole % Catalyst Preparation (hr) (.degree. C.)
conversion.sup.d selectivity.sup.e Catalyst A MoO.sub.3 + 7.14 371
48.9 78.4 (Control).sup.a alumina (Calcined) Catalyst B MoO.sub.3 +
7.00 301 100.0 13.8 (Control).sup.b alumina (Calcined and
Carburized) Catalyst C MoO.sub.3 + 7.15 376 96.2 98.0
(Invention).sup.c alumina + zeolite L (Calcined and Carburized)
.sup.aCatalyst A (Control) MoO.sub.3 was combined with alumina and
then calcined. .sup.bCatalyst B (Control) MoO.sub.3 was combined
with alumina and then calcined and carburized. .sup.cCatalyst C
(Invention) MoO.sub.3 was combined with alumina and a zeolite L and
then calcined and carburized. .sup.d1,3-BD wt % conversion
represents the weight percent of the feed (1,3-butadiene) that was
hydrogenated. .sup.en-butenes (or .SIGMA.C.sub.4=) mole %
selectivity represents the mole percent of 1,3-butadiene which was
converted to the desired n-butenes (1-butenes, cis-2-butenes, and
trans-2-butenes) contained in the process effluent as opposed to
undesired product such as butane.
[0080] Test data in Table I clearly show that Invention Catalyst C
produced less undesirable product, i.e., butane, than Control
Catalysts A and B. In other words, Invention Catalyst C had better
selectivity to n-butenes than Control Catalysts A or B. For
example, at a 1,3-butadiene conversion of 96.2 weight percent,
Invention Catalyst C was already at 98.0 mole percent selectivity
to n-butenes whereas Control Catalyst B, after 100.0 weight percent
of the 1,3-butadiene was converted, produced a mere 13.8 mole
percent selectivity to n-butenes. In addition, Control Catalyst A
exhibited a better mole percent selectivity to n-butenes (78.4)
than Control Catalyst B, but only converted 48.9 weight percent of
the 1,3-butadiene. The data demonstrate that Invention Catalyst C
is clearly superior in attaining a high weight percent conversion
of 1,3-butadiene (96.2) while attaining a very high mole percent
selectivity to n-butenes (98.0).
[0081] The performance of Invention Catalyst C, as compared to
Control Catalysts A and B, is superior in hydrogenating a highly
unsaturated hydrocarbon such as 1,3-butadiene to a less unsaturated
hydrocarbon such as n-butenes (1-butenes, cis-2-butenes, and
trans-2-butenes) without further hydrogenating to a saturated
hydrocarbon such as butane. The improvement in catalyst performance
is believed to be due to the novel process of using a catalyst
composition prepared by combining a zeolite, a Group VIB metal, and
an inorganic support to provide a modified zeolite which is then
calcined and carburized.
[0082] The results shown in the above examples clearly demonstrate
that the present invention is well adapted to carry out the objects
and attain the ends and advantages mentioned as well as those
inherent therein.
[0083] Reasonable variations, modifications, and adaptations can be
made within the scope of the disclosure and the appended claims
without departing from the scope of this invention.
* * * * *