U.S. patent application number 11/207232 was filed with the patent office on 2007-02-22 for methods of preparation of an olefin oligomerization catalyst.
Invention is credited to Ronald G. Abbott, Eduardo J. Baralt, Ronald D. Knudsen, Bruce E. Kreischer, Brooke L. Small.
Application Number | 20070043181 11/207232 |
Document ID | / |
Family ID | 37441298 |
Filed Date | 2007-02-22 |
United States Patent
Application |
20070043181 |
Kind Code |
A1 |
Knudsen; Ronald D. ; et
al. |
February 22, 2007 |
Methods of preparation of an olefin oligomerization catalyst
Abstract
A method of making an olefin oligomerization catalyst,
comprising contacting a chromium-containing compound, a
heteroatomic ligand, and a metal alkyl, wherein the
chromium-containing compound comprises less than about 5 weight
percent chromium oligomers. A method of making an olefin
oligomerization catalyst comprising a chromium-containing compound,
a nitrogen-containing compound, and a metal alkyl, the method
comprising adding a composition comprising the chromium-containing
compound to a composition comprising the metal alkyl. A method of
making an olefin oligomerization catalyst comprising a
chromium-containing compound, a nitrogen-containing compound, and a
metal alkyl, the method comprising abating all or a portion of
water, acidic protons, or both from a composition comprising the
chromium-containing compound, a composition comprising the
nitrogen-containing compound, or combinations thereof prior to or
during the preparation of the catalyst. Methods of oligomerizing
olefins by contacting such catalysts with an alpha olefin.
Inventors: |
Knudsen; Ronald D.;
(Bartlesville, OK) ; Abbott; Ronald G.; (Kingwood,
TX) ; Kreischer; Bruce E.; (Humble, TX) ;
Baralt; Eduardo J.; (Kingwood, TX) ; Small; Brooke
L.; (Kingwood, TX) |
Correspondence
Address: |
CHEVRON PHILLIPS CHEMICAL COMPANY
5700 GRANITE PARKWAY, SUITE 330
PLANO
TX
75024-6616
US
|
Family ID: |
37441298 |
Appl. No.: |
11/207232 |
Filed: |
August 19, 2005 |
Current U.S.
Class: |
526/104 |
Current CPC
Class: |
B01J 31/18 20130101;
B01J 31/2226 20130101; C07C 2527/125 20130101; B01J 31/04 20130101;
B01J 2231/20 20130101; B01J 31/128 20130101; C08F 4/69 20130101;
B01J 31/143 20130101; B01J 31/181 20130101; C08F 10/00 20130101;
C07C 2/32 20130101; C08F 10/00 20130101; B01J 31/4092 20130101;
B01J 2531/62 20130101; C07C 2531/22 20130101; Y02P 20/584
20151101 |
Class at
Publication: |
526/104 |
International
Class: |
C08F 4/24 20060101
C08F004/24 |
Claims
1. A method of making an olefin oligomerization catalyst,
comprising contacting a chromium-containing compound, a
heteroatomic ligand, and a metal alkyl, wherein the
chromium-containing compound comprises less than about 5 weight
percent chromium oligomers.
2. The method of claim 1 wherein the olefin oligomerization
catalyst further comprises a halide containing compound.
3. The method of claim 1 wherein the chromium-containing compound
comprises less than about 5 weight percent hydrated chromium
species.
4. The method of claim 1 wherein the chromium-containing compound
comprises less than about 50 weight percent free acid.
5. The method of 1 wherein the chromium-containing compound
comprises a chromium carboxylate.
6. The method of claim 5 wherein the chromium carboxylate comprises
chromium(III) 2-ethylhexanoate.
7. The method of claim 1 wherein the heteroatomic ligand comprises
a nitrogen-containing compound.
8. The method of claim 1 wherein the heteroatomic ligand comprises
a pyrrole-containing compound.
9. The method of claim 1 wherein a composition comprising the
chromium-containing compound is added to a composition comprising
the metal alkyl.
10. The method of claim 1 further comprising abating all or a
portion of water, acidic protons, or both from a composition
comprising the chromium-containing compound, a composition
comprising the heteroatomic ligand, or combinations thereof.
11. The method of claim 10 wherein the olefin oligomerization
catalyst further comprises a non metal halide containing compound
and the method further comprises abating all or a portion of water,
acidic protons, or both from the non metal halide containing
compound.
12. A method of oligomerizing olefins comprising contacting the
catalyst of claim 1 with an alpha olefin.
13. The method of claim 12 wherein the method of oligomerizing
olefins comprises trimerizing or tetramerizing ethylene.
14. A method of making an olefin oligomerization catalyst
comprising a chromium-containing compound, a nitrogen-containing
compound, and a metal alkyl, the method comprising adding a
composition comprising the chromium-containing compound to a
composition comprising the metal alkyl.
15. The method of claim 14 wherein the chromium-containing compound
comprises less than about 5 weight percent chromium oligomers.
16. A method of making an olefin oligomerization catalyst
comprising a chromium-containing compound, a nitrogen-containing
compound, and a metal alkyl, the method comprising abating all or a
portion of water, acidic protons, or both from a composition
comprising the chromium-containing compound, a composition
comprising the nitrogen-containing compound, or combinations
thereof prior to or during the preparation of the catalyst.
17. The method of claim 16 wherein the olefin oligomerization
catalyst further comprises a non metal halide containing compound
and the method further comprises abating all or a portion of water,
acidic protons, or both from the non metal halide containing
compound prior to or during the preparation of the catalyst.
18. The method of claim 16 wherein the chromium-containing compound
comprises less than about 5 weight percent chromium oligomers.
19. A method of making an olefin oligomerization catalyst
comprising a chromium-containing compound, a heteroatomic ligand, a
metal alkyl, the method comprising abating all or a portion of
water, acidic protons, or both from a composition comprising the
chromium-containing compound, a composition comprising the
heteroatomic ligand, or combinations thereof, and wherein the
heteroatomic ligand is described by the general formula
(R).sub.nA--B--C(R).sub.m wherein A and C are independently
selected from a group consisting of phosphorus arsenic, antimony,
oxygen, bismuth, sulfur, selenium, and nitrogen; B is a linking
group between A and C; each R is independently selected from any
homo or hetero hydrocarbyl group; and n and m are determined by the
respective valence and oxidation state of A and C.
20. The method of claim 19 wherein the olefin oligomerization
catalyst further comprises a non metal halide containing compound
and the method further comprises abating all or a portion of water,
acidic protons, or both from the non metal halide containing
compound prior to or during the preparation of the catalyst.
21. The method of claim 19 wherein the chromium-containing compound
comprises less than about 5 weight percent chromium oligomers.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The subject matter of the present application is related to
U.S. patent application Ser. Nos. 10/783,737 and 10/783,429, both
filed on Feb. 20, 2004 and entitled "Methods of Preparation of an
Olefin Oligomerization Catalyst," which are hereby incorporated
herein by reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to preparation of catalysts
for use in a process for producing an olefin oligomer. More
particularly, the present invention relates to preparing
oligomerization catalysts comprising a chromium-containing
compound, a nitrogen-containing compound, a metal alkyl, and an
optional halide-containing compound for use in a process for
producing an alpha-olefin oligomer comprising 1-hexene or 1-octene
from ethylene.
BACKGROUND OF THE INVENTION
[0003] Olefin oligomerization catalysts are known in the art, but
sometimes lack selectivity to a desired product and also have a low
product yield. Enhancements in preparation methods for
oligomerization catalysts to improve productivity and selectivity
to the desired product can reduce catalyst cost and improve
economics.
SUMMARY OF THE INVENTION
[0004] Disclosed herein is a method of making an olefin
oligomerization catalyst, comprising contacting a
chromium-containing compound, a heteroatomic ligand, and a metal
alkyl, wherein the chromium-containing compound comprises less than
about 5 weight percent chromium oligomers.
[0005] Further disclosed herein is method of making an olefin
oligomerization catalyst comprising a chromium-containing compound,
a nitrogen-containing compound, and a metal alkyl, the method
comprising adding a composition comprising the chromium-containing
compound to a composition comprising the metal alkyl.
[0006] Further disclosed herein is a method of making an olefin
oligomerization catalyst comprising a chromium-containing compound,
a nitrogen-containing compound, and a metal alkyl, the method
comprising abating all or a portion of water, acidic protons, or
both from a composition comprising the chromium-containing
compound, a composition comprising the nitrogen-containing
compound, or combinations thereof prior to or during the
preparation of the catalyst.
[0007] Further disclosed herein is a method of making an olefin
oligomerization catalyst comprising a chromium-containing compound,
a heteroatomic ligand, a metal alkyl, the method comprising abating
all or a portion of water, acidic protons, or both from a
composition comprising the chromium-containing compound, a
composition comprising the heteroatomic ligand, or combinations
thereof, and wherein the heteroatomic ligand is described by the
general formula (R).sub.nA--B--C(R).sub.m wherein A and C are
independently selected from a group consisting of phosphorus
arsenic, antimony, oxygen, bismuth, sulfur, selenium, and nitrogen;
B is a linking group between A and C; each R is independently
selected from any homo or hetero hydrocarbyl group; and n and m are
determined by the respective valence and oxidation state of A and
C.
[0008] Further disclosed herein are methods of oligomerizing
olefins by contacting such catalysts with an alpha olefin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIGS. 1A through 1D illustrate various embodiments of a
method of preparing an oligomerization catalyst comprising bulk
addition of catalyst components.
[0010] FIGS. 2A through 2D illustrate various embodiments of a
method for abating water in the preparing of an oligomerization
catalyst.
[0011] FIGS. 3A through 3B illustrate various embodiments of a
method for abating water in the preparing of an oligomerization
catalyst.
[0012] FIGS. 4A through 4E illustrate various embodiments of a
method of preparing an oligomerization catalyst comprising
simultaneous addition of catalyst components.
[0013] FIG. 5 is a graph of the average catalyst residence time
(i.e. catalyst age) versus the purity of hexene produced.
[0014] FIG. 6 is the spectra of chromium(III) 2-ethylhexanoate.
[0015] FIG. 7 is the spectra of chromium(III) 2-ethylhexanoate,
sample 17-1.
[0016] FIG. 8 is also the spectra of chromium(III)
2-ethylhexanoate, sample 17-2.
[0017] FIG. 9 is also the spectra of chromium(III)
2-ethylhexanoate, sample 17-3.
[0018] FIG. 10 is the spectra of chromium(III) 2-ethylhexanoate,
sample 17-4a.
[0019] FIG. 11 is the spectra of azeotroped chromium(III)
2-ethylhexanoate, sample 17-4b.
[0020] FIG. 12 is the spectra of azeotroped chromium(III)
2-ethylhexanoate, sample 17-4c.
[0021] FIG. 13 is the spectra heated of chromium(III)
2-ethylhexanoate, sample 17-4d.
[0022] FIG. 14 is the spectra of heated chromium(III)
2-ethylhexanoate, sample 17-4e.
[0023] FIG. 15 is the spectra of chromium(III) 2-ethylhexanoate
sample 17-4f used for oligomerization catalyst preparation.
DETAILED DESCRIPTION
[0024] The present invention relates to a method of making a
catalyst for use in oligomerizing an olefin. Generally, the
catalyst comprises a chromium-containing compound, a heteroatomic
ligand, a metal alkyl, an optional halide-containing compound and
an optional solvent. In an aspect, the method of making the
catalyst comprises adding a composition comprising the
chromium-containing compound to composition comprising the metal
alkyl. In an aspect, the method of making the catalyst comprises
abating all or a portion of water, acidic protons, or both from a
composition comprising the chromium-containing compound, a
composition comprising a non-metal halide-containing compound, a
composition comprising a solvent, or combinations thereof prior to
contact thereof with a composition comprising a metal
halide-containing compound. Additional aspects relating to the
method of making the catalyst are described herein. Additionally,
the applicable heteroatomic ligands are described herein and are
generally applicable to the method of making the catalyst. In
embodiments, the heteroatomic ligand is a nitrogen-containing
ligand.
[0025] The present invention also relates to a method of
oligomerizing an olefin utilizing the method of making the catalyst
as disclosed herein. In an aspect, the method of oligomerizing
olefin can be a method of trimerizing an olefin and/or
tetramerizing an olefin. In embodiments, the method of
oligomerizing an olefin utilizing is a method for trimerizing
ethylene; alternatively a method for tetramerizing ethylene. In an
embodiment, a method for trimerizing an olefin, e.g., ethylene to
1-hexene, is disclosed wherein the catalyst does not include the
optional halide-containing compound. Alternatively, a method for
trimerizing an olefin, e.g., ethylene to 1-hexene, is disclosed
wherein the catalyst does include the optional halide-containing
compound. In an embodiment, a method for tetramerizing an olefin,
e.g., ethylene to 1-octene, is disclosed wherein the catalyst does
not include the optional halide-containing compound. Alternatively,
a method for tetramerizing an olefin, e.g., ethylene to 1-octene,
is disclosed wherein the catalyst does include the optional
halide-containing compound. As used herein, the term optional
halide-containing compound is intended to cover embodiments where
the halide-containing compound is present as well as embodiments
where the halide-containing compound is not present.
[0026] The present invention also relates to aspects of a
chromium-containing compound utilized in the method of making the
catalyst disclosed herein and the method of oligomerizing an olefin
utilizing the method of making the catalyst disclosed herein. In
embodiments, the chromium-containing compound can comprise a
chromium carboxylate. In some embodiments, the chromium carboxylate
can be chromium(III) tris-2-ethylhexanoate. In an aspect, the
composition comprising a chromium-containing compound contains less
than 10 weight percent chromium oligomers based upon the total
weight of all chromium species within the composition the
chromium-containing compound. Other aspects of the
chromium-containing compound and the composition comprising the
chromium-containing compound are described herein. Additionally,
the aspects of the chromium containing compound are also applicable
to the chromium-containing compound utilized in the method of
making the catalyst and the method of oligomerizing an olefin.
[0027] As used herein, a catalyst component includes a
chromium-containing compound, a heteroatomic ligand, a metal alkyl,
an optional halide-containing compound, an optional solvent, or
combinations thereof. In an embodiment, a catalyst component
includes a chromium-containing compound, a nitrogen-containing
compound, a metal alkyl, an optional halide-containing compound, an
optional solvent, or combinations thereof. In the various
embodiments disclosed herein, contacting of catalyst components may
occur in one or more contact zones. A contact zone is a zone in
which the components are commingled and/or combined, and thereby
contacted. The contact zone may be disposed in a vessel, e.g. a
storage tank, tote, container, mixing vessel, reactor, etc.; a
length of pipe, e.g. a tee, inlet, injection port, or header for
combining component feed lines into a common line; or any other
suitable apparatus for bringing the components into contact. As
used herein, the terms contacted and combined refer to any addition
sequence, order, or concentration for contacting or combining two
or more catalyst components. The term added to refers to a first
catalyst component added, e.g., poured, into a second catalyst
component. Where a first catalyst component is added to a second
catalyst component, the initial concentration, or molar ratio, of
the first catalyst component compared to the second catalyst
component typically is relatively small and increases over the
duration of the addition. In some embodiments, contacting of
components may occur in one or more upstream contact zone(s) prior
to further contacting with other catalyst component(s) in one or
more downstream contact zone(s). Where a plurality of contact zones
are employed, contacting may occur simultaneously across the
contact zones, sequentially across the contact zones, or both, as
is suitable for a given embodiment. Contacting may be carried out
in a batch or continuous process, as is suitable for a given
embodiment.
[0028] In embodiments utilizing a vessel for contacting the
components, the components may be optionally mixed by a mixer
disposed in the vessel and the formed mixture may then be removed
for subsequent processing. In embodiments utilizing a tee or other
means for combing lines such as a header, an optional in-line mixer
may be placed in the commingled catalyst feed line to ensure that
adequate contacting of the combined components takes place, and the
mixture is thus formed as it passes through the commingled feed
line. Where a method of making a catalyst recites contact or
combination of catalyst components, such may be carried out by
contacting or combining all or a portion of such components in
various embodiments.
[0029] As used herein, a composition comprising a catalyst
component includes the catalyst component alone or in combination
with one or more additional compounds, solvents, or both. None,
some, or all of the contacting steps may be carried out in the
presence of a solvent (sometimes referred to as an optional
solvent), which may be introduced to a contact zone via inclusion
with one or more compositions comprising a catalyst component or
may be introduced separately to a contact zone, for example in a
solvent line or as an initial charge to a contact zone.
[0030] Disclosed herein is a method of making a catalyst comprising
a chromium-containing compound, a nitrogen-containing compound, a
metal alkyl, an optional halide-containing compound, and optionally
a solvent for use in oligomerizing an olefin, wherein a composition
comprising the chromium-containing compound is contacted in a
contact zone with a composition comprising the metal alkyl. In FIG.
1, four embodiments for contacting the composition comprising the
chromium-containing compound with the composition comprising the
metal alkyl in a contact zone are illustrated. FIGS. 1A through 1D
are included as illustrative representations of embodiments of the
present disclosure and do not limit the disclosure. For example,
FIGS. 1A-1D are described in the context of the use of a
pyrrole-containing compound as the nitrogen-containing compound,
but it should be understood that other nitrogen-containing
compounds as described herein may be used in the embodiments shown
in FIGS. 1A-1D or any other embodiments disclosed herein.
Furthermore, FIGS. 1A-1D are described in the context of the use of
a halide-containing compound, but it should be understood that in
alternative embodiments, the halide-containing compound may be
omitted from the embodiments shown in FIGS. 1A-1D or from any other
embodiments disclosed herein.
[0031] In an embodiment as illustrated in FIG. 1A, the composition
comprising the metal alkyl may be disposed in contact zone 115 and
the composition comprising the chromium-containing compound may be
contacted with or added to the composition comprising the metal
alkyl present in contact zone 115 via line 110. The final catalyst
composition may be recovered as a product via line 170. The
composition comprising the chromium-containing compound in line 110
may further comprise a pyrrole-containing compound, a non-metal
halide-containing compound, the solvent, or combinations thereof.
The composition comprising the chromium-containing compound may
also comprise an amount of non-halide metal alkyl to abate
undesired water, acidic protons, or both, as disclosed in more
detail herein. The final catalyst composition may be further dilute
with a solvent (which may not be identical to the catalyst
preparation solvent) prior to use in the oligomerization
reaction.
[0032] The composition comprising the metal alkyl present in
contact zone 115, may comprise the pyrrole-containing compound, the
halide-containing compound, the solvent, or combinations thereof.
The halide-containing compound may be a metal halide, non-metal
halide, or combinations thereof. The composition comprising the
metal alkyl may also comprise a metal alkyl halide, a non-halide
metal alkyl, a non-metal halide, a metal halide, or combinations
thereof. The metal alkyl halide in this and other embodiments may
comprise diethylaluminum chloride (DEAC) and the non-halide metal
alkyl may comprise triethyl aluminum (TEA). In an embodiment the
metal alkyl may be the halide-containing compound, e.g. DEAC is the
halide-containing compound and the metal alkyl.
[0033] In an embodiment as illustrated in FIG. 1B, a
pyrrole-chromium mixture may be formed in contact zone 225 by
contacting a composition comprising the pyrrole-containing compound
fed to contact zone 225 via line 220 and the composition comprising
the chromium-containing compound fed to contact zone 225 via line
210, which may occur about instantaneously or over a first period
of time of from about 1 minute to about 12 hours, alternatively
from about 1 minute to about 6 hours, alternatively from about 1
minute to about 3 hours, alternatively from about 1 hour to about 2
hours. Introduction of the composition comprising the
chromium-containing compound and the composition comprising the
pyrrole-containing compound to contact zone 225 may be sequential
(e.g. chromium followed by pyrrole or vice-versa) or simultaneous.
Once the pyrrole-chromium mixture has been contacted in contact
zone 225 the pyrrole-chromium mixture from contact zone 225 may be
contacted with or added to the composition comprising the metal
alkyl present in contact zone 215 via line 240, which may occur
about instantaneously or over a second period of time of from about
1 minute to about 12 hours, alternatively from about 1 minute to
about 6 hours, alternatively from about 1 minute to about 3 hours,
to form the final catalyst product in contact zone 215. The final
catalyst product may be withdrawn from contact zone 215 via line
270. The final catalyst composition may be further dilute with a
solvent (which may not be identical to the catalyst preparation
solvent) prior to use in the oligomerization reaction.
[0034] The composition comprising the pyrrole-containing compound
in line 220 and the composition comprising the chromium-containing
compound in line 210 may be contacted, e.g., over the first period
of time, at an about constant pyrrole to chromium (Py:Cr) molar
ratio or alternatively at a variable Py:Cr molar ratio to form the
pyrrole-chromium mixture in contact zone 225. The pyrrole-chromium
mixture in contact zone 225 may then be contacted with or added to,
e.g., over the second period of time, the metal alkyl present in
contact zone 215 via line 240, or alternatively already present in
contact zone 215, at an about constant Py:Cr molar ratio, for
example in the range of from about 1.0:1 to about 4.0:1.
Alternatively, the pyrrole-chromium mixture in contact zone 225 may
then be contacted with or added to, e.g., over the second period of
time, the metal alkyl present in contact zone 215 via line 240 at a
variable Py:Cr molar ratio. In an embodiment the variable Py:Cr
molar ratio is decreasing over the second period of time where a
decreasing Py:Cr molar ratio refers to a general decreasing trend
in the molar ratio from the start of the addition sequence to the
finish and occasional increases in the ratio within the overall
decreasing trend are acceptable. In an embodiment a decreasing
trend of the Py:Cr refers to the specific situation where the
ending Py:Cr ratio is less than the beginning Py:Cr ratio. In an
embodiment, an initial Py:Cr molar ratio at the start of the
addition may be greater than the final Py:Cr molar ratio of the
catalyst; and an ending Py:Cr molar ratio at the end of the
addition may be less than the final Py:Cr molar ratio of the
catalyst. In an embodiment, the final Py:Cr molar ratio of the
catalyst may be in a range of from about 1.0:1 to about 4.0:1; the
initial Py:Cr molar ratio may be greater than about 6:1,
alternatively greater than about 20:1, alternatively greater than
about 40:1, alternatively greater than about 60:1; and the ending
Py:Cr molar ratio may be greater than or equal to about 0,
alternatively greater than or equal to about 0.1:1, alternatively
greater than or equal to about 0.3:1, and alternatively greater
than or equal to about 0.6:1. In an embodiment, the initial Py:Cr
molar ratio is about twice the final Py:Cr molar ratio of the
catalyst during a first about one-half of the addition and the
ending Py:Cr molar ratio is about 0 during a second about one-half
of the addition, wherein the final Py:Cr molar ratio of the
catalyst is in a range of from about 1.0:1 to about 4.0:1.
Introduction of a pyrrole-containing compound and a
chromium-containing compound in a contact zone (e.g., formation of
a Py:Cr mixture) as disclosed in various embodiments may be carried
out as disclosed in this paragraph, including but not limited to
the embodiments shown in FIGS. 1D, 2C, 2D, 3B, and 4A-E.
[0035] The composition comprising the chromium-containing compound
in line 210 may comprise a non-metal halide-containing compound,
the solvent, or combinations thereof. The composition comprising
the pyrrole-containing compound in line 220 may comprise a
non-metal halide-containing compound, the solvent, or combinations
thereof. The composition comprising the chromium-containing
compound in line 210, the composition comprising the
pyrrole-containing compound in line 220, or both may also comprise
an amount of non-halide metal alkyl to abate undesired water,
acidic protons, or both as disclosed herein. Alternatively, the
non-halide metal alkyl may be contacted with or added to the
pyrrole-chromium mixture, for example in line 240 via line 230, in
contact zone 225 (not shown), or both, to abate undesired water,
acidic protons, or both. The composition comprising the metal alkyl
present in contact zone 215, may comprise the halide-containing
compound, the solvent, or combinations thereof. The composition
comprising the metal alkyl may also comprise a metal alkyl halide,
a non-halide metal alkyl, a metal halide, non-metal halide, or
combinations thereof.
[0036] In an embodiment as shown in FIG. 1C, a pyrrole-metal alkyl
mixture may be formed in contact zone 325 by contacting the
composition comprising the pyrrole-containing compound fed to
contact zone 325 via line 320 with the composition comprising the
metal alkyl fed to contact zone 325 via line 315 which may occur
about instantaneously or over a first period of time. Addition of
the composition comprising the pyrrole-containing compound and the
composition comprising the metal alkyl to contact zone 325 may be
sequential (e.g. pyrrole followed by metal alkyl or vice-versa) or
simultaneous. Once the pyrrole-metal alkyl mixture has been
contacted in contact zone 325 the pyrrole-metal alkyl mixture from
contact zone 325 may be disposed via line 360 in contact zone 335.
The composition comprising the chromium-containing compound may
then be contacted with or added to contact zone 335 via line 310,
which may occur about instantaneously or over a second period of
time. The composition comprising the chromium-containing compound
is thus contacted with or added to the pyrrole-metal alkyl mixture
present in contact zone 335, to form the final catalyst product in
contact zone 335. Addition of the composition comprising the
pyrrole-metal alkyl mixture and the composition comprising the
chromium-containing compound to contact zone 335 may be sequential
(e.g. pyrrole-metal alkyl followed by the chromium containing
compound or vice-versa) or simultaneous. The final catalyst product
may be withdrawn from contact zone 335 via line 370. The final
catalyst composition may be further diluted with a solvent (which
may not be identical to the catalyst preparation solvent) prior to
use in the oligomerization reaction.
[0037] Although the embodiment shown in FIG. 1C shows two contact
zones being used to perform the addition sequences, the addition
sequences could alternatively be performed in a single contact
zone, for example, in contact zone 325. In this embodiment, the
composition comprising the metal alkyl may first be placed in the
contact zone. In a second step the composition comprising the
pyrrole-containing compound may be contacted with or added to the
composition comprising the metal alkyl present in the contact zone
(or visa-versa) to adequately contact and form the pyrrole-metal
alkyl mixture. In a third step, the composition containing the
chromium-containing compound may be contacted with or added to the
pyrrole-metal alkyl mixture to form the final catalyst product.
[0038] The composition comprising the chromium-containing compound
in line 310 may comprise a non-metal halide-containing compound,
the solvent, or combinations thereof. The composition comprising
the pyrrole-containing compound in line 320 may comprise a
non-metal halide-containing compound, the solvent, or combinations
thereof. The composition comprising the chromium-containing
compound in line 310, the composition comprising the
pyrrole-containing compound in line 320, or both may comprise an
amount of non-halide metal alkyl to abate undesired water, acidic
protons, or both. The composition comprising the metal alkyl in
line 315, may comprise the halide-containing compound, the solvent,
or combinations thereof. The composition comprising the metal alkyl
may also comprise a metal alkyl halide, a non-halide metal alkyl, a
metal halide, non-metal halide, or combinations thereof.
[0039] In an embodiment as shown in FIG. 1D, a composition
comprising the pyrrole-containing compound in line 420 and a
composition comprising the chromium-containing compound in line 410
may be simultaneously contacted with or added to, which may occur
about instantaneously or over a period of time, with a composition
comprising the metal alkyl present in contact zone 415, and a final
catalyst product may be withdrawn from contact zone 415 via line
470. The final catalyst composition may be further diluted with a
solvent (which may not be identical to the catalyst preparation
solvent) prior to use in the oligomerization reaction. The
composition comprising the chromium-containing compound and the
composition comprising the pyrrole-containing compound may be
contacted with or added to the composition comprising the metal
alkyl at Py:Cr molar ratios described previously.
[0040] The composition comprising the chromium-containing compound
in line 410 may comprise a non-metal halide-containing compound,
the solvent, or combinations thereof. The composition comprising
the pyrrole-containing compound in line 420 may comprise a
non-metal halide-containing compound, the solvent, or combinations
thereof. In the embodiment shown in FIG. 1D, the composition
comprising the metal alkyl in contact zone 415, may comprise the
halide-containing compound, the solvent, or combinations thereof,
each added to contact zone 415 through various input lines not
shown in FIG. 1D. The composition comprising the metal alkyl may
also comprise a metal alkyl halide, a non-halide metal alkyl, a
metal halide, non-metal halide, or combinations thereof. The
composition comprising the chromium-containing compound in line
410, the composition comprising the pyrrole-containing compound in
line 420, or both may comprise an amount of non-halide metal alkyl
to abate undesired water, acidic protons, or both.
[0041] Further disclosed herein is a method of making a catalyst
comprising abating all or a portion of water, acidic protons, or
both from a composition comprising the chromium-containing
compound, a composition comprising the nitrogen-containing
compound, a composition comprising the optional non-metal
halide-containing compound, a composition comprising the solvent,
or combinations thereof prior to contact thereof with a composition
comprising the metal halide-containing compound. Abating water,
acidic protons, or both may include neutralizing acidic protons;
physically removing water; physically removing acidic protons;
chemically binding or reacting free water such that the water is no
longer free; or combinations thereof. The amount of water, acid
protons, or both removed from the catalyst component may be
determined using known methods, for example infrared analysis to
determine water content.
[0042] In embodiments to prepare a catalyst, one or more of the
catalyst components may contain water, for example the composition
comprising the chromium-containing compound. Water may be present
in a catalyst compound, for example as a contaminant or as a
co-product produced during the preparation of the catalyst
compound. For example, water may be co-produced during preparation
of the chromium-containing compound, and such water may complex
with the chromium. Acidic protons may also be present, for example
carboxylic acid (e.g., ethylhexanoic acid) remaining from
production of the chromium-containing compound (e.g., chromium
tris(2-ethylhexanoate)). This free water as well as acid present in
the chromium source can subsequently react with a metal halide
present in the catalyst, for example the metal alkyl halide such as
DEAC, to form corrosive compounds, e.g. hydrogen halide compound
(e.g. hydrochloric acid). Such compounds may cause corrosion in
downstream equipment over time, in particular when heated, for
example in downstream fractionation facilities. Accordingly, it may
be desirable to abate water, acidic protons, or both, when making
the catalyst to prevent downstream formation of potentially
corrosive by-products. The presence of water may also reduce the
effectiveness of the metal alkyl.
[0043] Furthermore, in embodiments of a method of preparing a
catalyst, impurities in the catalyst components can participate in
unwanted side reactions leading to the formation of precipitates.
These precipitates may to lead to further unwanted reactions, for
example polymer formation in the oligomerization of ethylene to an
olefin composition comprising 1-hexene or 1-octene. Water may be an
initiator of the precipitation reactions and therefore may be
desirably abated from the catalyst components to improve
selectivity to 1-hexene or 1-octene. Abating water, acidic protons,
or both may also have beneficial impact on catalyst efficiency,
even where corrosive compounds are produced. For example, in an
embodiment, water is abated from one or more catalyst components by
contact thereof with a corrosive abatement compound such as a
halide-containing compound, which reacts with and abates the water.
Reactions of water with a corrosive abatement compound such as a
halide-containing compound may produce a corrosive compound, e.g.,
HCl, and such should be taken into account in the overall design of
the system. Examples of suitable halide-containing compounds for
reaction with water include a metal halide, a metal alkyl halide, a
non-halide metal alkyl and a metal halide, a non-metal halide, or
combinations thereof. The use of a halide-containing compound to
abate water may be used in place of or in addition to other water
abatement embodiments disclosed herein such as the use of a
non-halide metal alkyl to abate water.
[0044] In an embodiment, water, acidic protons, or both may be
abated by pre-contacting one or more catalyst components with a
non-corrosive abatement compound, which is a compound that does not
form a corrosive compound such as a hydrogen halide compound upon
contact with the water, acidic protons, or both. Non-corrosive
abatement compounds include, for example, a non-halide metal alkyl
such as TEA. Corrosive abatement compounds are compounds that can
form a corrosive compound upon contact with water, acidic protons
or both such as (i) a metal alkyl halide, (ii) a metal halide and a
metal alkyl, and (iii) a non-metal halide and a metal alkyl. The
corrosive abatement compounds also include any other combination of
compounds that form a corrosive compound upon contact with water,
acidic proton, or both.
[0045] In an embodiment, one or more catalyst components such as a
composition comprising the chromium-containing compound, a
composition comprising the nitrogen-containing compound, an
optional non-metal halide-containing compound, a solvent, or
combinations thereof, are contacted with a non-halide metal alkyl
to abate water, acidic protons, or both. The non-halide metal alkyl
can react with free water, acid protons, or both contained in the
catalyst component(s) when pre-contacted to abate water, acidic
protons, or both. The non-halide metal alkyl may be pre-mixed in a
contact zone with the one or more catalyst components. The pre-mix
may be made by either adding the non-halide metal alkyl to the
catalyst component(s) or vice versa, and in an embodiment, the
pre-mix may be made by adding the non-halide metal alkyl to the
catalyst component(s). These additions can be made in various
ratios as described below.
[0046] In an embodiment, the non-halide metal alkyl is added to or
contacted with a composition comprising the chromium-containing
compound. Given that the chromium may react with the non-halide
metal alkyl to form a gel, it may be desirable to maintain a low
concentration of non-halide metal alkyl by adding it to the
composition comprising the chromium-containing compound, so that
there may only be an amount available to react with the water and
acid. Conversely, with a high concentration of non-halide metal
alkyl, such as can occur when adding the composition comprising the
chromium-containing compound to the non-halide metal alkyl, more
non-halide metal alkyl would be available to react with the
chromium (and thereby form a gel) after the water and acid were
removed.
[0047] In each embodiment, the water or acid abating substance
(e.g., a non-halide metal alkyl) may be contacted with or added to
one or more catalyst components in an amount effective to abate
substantially all free/available water, acidic protons, or both
from some or all of the components contacted with the non-halide
metal alkyl. In an embodiment, the amount of non-halide metal alkyl
contacted with or added to such components is small relative to the
amount of the catalyst components to which it is being contacted
with or added to. In an embodiment, the portion of the non-halide
metal alkyl contacted with or added to a catalyst component(s) may
be less than or equal to about 30 weight percent of the catalyst
component(s) to which it is contacted with or added to;
alternatively less than about 20 weight percent of the catalyst
component(s) to which it is contacted with or added to;
alternatively less than about 10 weight percent of the catalyst
component(s) to which it is contacted with or added to;
alternatively less than about 5 weight percent of the catalyst
component(s) to which it is contacted with or added to. In an
embodiment, the portion of the non-halide metal alkyl contacted
with or added to a catalyst component(s) may be less than or equal
to about 120 mole percent of the catalyst component(s) to which it
is contacted with or added to; alternatively less than about 80
mole percent of the catalyst component(s) to which it is contacted
with or added to; alternatively less than about 40 mole percent of
the catalyst component(s) to which it is contacted with or added
to; alternatively less than about 20 mole percent of the catalyst
component(s) to which it is contacted with or added to. The
non-halide metal alkyl may be contacted with or added to a catalyst
component(s) in an amount such that the non-halide metal alkyl to
catalyst component(s) molar ratio may be less than about 1.5:1,
alternatively less than about 1.2:1, alternatively less than about
1:1. The non-halide metal alkyl may be contacted with or added to a
catalyst component(s) in a molar ratio sufficient to abate at least
about 25% of the water, acidic protons, or both associated with the
catalyst component(s) present in the pre-contacting contact zone;
alternatively at least about 90% of the water, acidic protons, or
both associated with the catalyst component(s) present in the
pre-contacting contact zone; alternatively at least about 100% of
the water, acidic protons, or both associated with the catalyst
component(s) present in the pre-contacting contact zone;
alternatively in an amount that may be at least about 10% in excess
of an amount sufficient to abate at least about 100% of the water,
acidic protons, or both associated with the catalyst component(s)
present in the pre-contacting contact zone; alternatively in an
amount that may be at least about 20% in excess of an amount
sufficient to abate at least about 100% of the water, acidic
protons, or both associated with the catalyst component(s) present
in the pre-contacting contact zone; alternatively in an amount that
may be at least about 30% in excess of an amount sufficient to
abate at least about 100% of the water, acidic protons, or both
associated with the catalyst component(s) present in the
pre-contacting contact zone; alternatively in an amount that may be
at least about 100% in excess of an amount sufficient to abate at
least about 100% of the water, acidic protons, or both associated
with the catalyst component(s) present in the pre-contacting
contact zone; or alternatively in an amount that may be at least
about 200% in excess of an amount sufficient to abate at least
about 100% of the water, acidic protons, or both associated with
the catalyst component(s) present in the pre-contacting contact
zone.
[0048] Upon abatement of water, acidic protons, or both from one or
more catalyst components, such abated catalyst components may be
stored until needed for preparation of a catalyst composition. Such
storage may or may not be in the presence of a solvent. The pre-mix
comprising a portion of non-halide metal alkyl and one or more
abated catalyst component(s) may then be contacted with the
remaining catalyst components including the metal alkyl halide to
form the final catalyst product. The remaining catalyst components
may also comprise additional non-halide metal alkyl to comprise the
total non-halide metal alkyl composition in the final catalyst. In
an embodiment, the additional non-halide metal alkyl may be the
same as that used in the pre-mix. Alternatively, the additional
non-halide metal alkyl may be different from that used in the
pre-mix.
[0049] FIGS. 2A-2D represent various embodiments for abating water,
acidic protons, or both in the composition comprising the
chromium-containing compound, the composition comprising the
nitrogen-containing compound, or both prior to contact with the
composition comprising a metal halide-containing compound. FIGS. 2A
through 2D are included as illustrative representations of
embodiments of the present disclosure and do not limit the
disclosure. For example, FIGS. 2A-2D are described in the context
of the use of a pyrrole-containing compound as the
nitrogen-containing compound, but it should be understood that
other nitrogen-containing compounds as described herein may be used
in the embodiments shown in FIGS. 2A-2D or any other embodiments
disclosed herein. Furthermore, FIGS. 2A-2D are described in the
context of the use of a halide-containing compound, but it should
be understood that in alternative embodiments, the
halide-containing compound may be omitted from the embodiments
shown in FIGS. 1A-1D or from any other embodiments disclosed
herein. Various embodiments for abating water, acidic protons, or
both may be combined to increase overall effectiveness.
[0050] The composition comprising a chromium-containing compound
may be contacted with the non-halide metal alkyl to form a mixture
prior to contacting the mixture with the remaining catalyst
components. In an embodiment shown in FIG. 2A a composition
containing the chromium-containing compound may be disposed in
contact zone 510, the placement of which may take place via input
line 505. The composition in contact zone 510 may optionally
contain solvent, other catalyst components, or combinations
thereof, provided that contact zone 510 does not comprise (i) a
metal alkyl halide, (ii) a metal halide and a metal alkyl, or (iii)
a non-metal halide and a metal alkyl. Non-halide metal alkyl,
optionally in solvent, may be added to the composition containing a
chromium-containing compound in contact zone 510 via line 530. The
non-halide metal alkyl may be added in an amount less than or equal
to about 30 weight percent of the composition containing the
chromium-containing compound to which it is added or in other
amounts as disclosed herein.
[0051] The resultant mixture in contact zone 510 may then be passed
from contact zone 510 via line 511 and optionally fed into a filter
512, comprising dry (free of any water) filter medium, for
filtering any precipitate that may have formed from the mixture.
The precipitate may be filtered and the filtrate may be passed via
line 513 into contact zone 515 for contacting with the remaining
catalyst components including a composition comprising the metal
alkyl, the pyrrole-containing compound, the halide-containing
compound (e.g., a metal halide or non-metal halide), the solvent,
any remaining non-halide metal alkyl, metal alkyl halide, or
combinations thereof, which may be placed into contact zone 515 via
various input lines not shown in FIG. 2A. A catalyst product may
then be withdrawn from contact zone 515 via line 570. Where
filtering is omitted, the remaining catalyst components may be
alternatively contacted in contact zone 510.
[0052] The composition comprising a pyrrole-containing compound may
be contacted with the non-halide metal alkyl to form a mixture
prior to contacting the mixture with the remaining catalyst
components. In an embodiment shown in FIG. 2B a composition
comprising a pyrrole-containing compound may be disposed in contact
zone 620 via input line 607. The composition in contact zone 620
may optionally contain solvent, other catalyst components, or
combinations thereof, provided that contact zone 620 does not
comprise (i) a metal alkyl halide, (ii) a metal halide and a metal
alkyl, or (iii) a non-metal halide and a metal alkyl. Non-halide
metal alkyl, which may be in solvent, may be added to the
composition containing a nitrogen-containing compound in contact
zone 620 via line 630. The non-halide metal alkyl may be added in
an amount less than or equal to about 10 weight percent of the
composition containing the pyrrole-containing compound to which it
is added or in other amounts as disclosed herein.
[0053] The resultant mixture in contact zone 620 may then be passed
from contact zone 620 via line 621 and optionally filtered (not
shown) to remove any precipitate that may have formed in the
mixture. The resultant mixture may then be fed into contact zone
615 for contacting with the remaining catalyst components including
a composition comprising the metal alkyl, the chromium-containing
compound, the halide-containing compound (e.g., a metal halide or
non-metal halide), the solvent, any remaining non-halide metal
alkyl, metal alkyl halide, or combinations thereof, which may be
placed into contact zone 615 via various input lines not shown in
FIG. 2B. A catalyst product may then be withdrawn from contact zone
615 via line 670. Where filtering is omitted, the remaining
catalyst components may be alternatively contacted in contact zone
620 via various input lines not shown in FIG. 2B.
[0054] The composition comprising the chromium containing compound
may be contacted with the composition comprising pyrrole-containing
compound to form a mixture prior to contacting the mixture with the
non-halide metal alkyl. In an embodiment as illustrated in FIG. 2C,
a pyrrole-chromium mixture may be formed in contact zone 725 by
contacting a composition comprising the pyrrole-containing compound
fed to contact zone 725 via line 720 and the composition comprising
the chromium-containing compound fed to contact zone 725 via line
710, which may occur about instantaneously or over a first period
of time. Feeding of the composition comprising the
chromium-containing compound and the composition comprising the
pyrrole-containing compound to contact zone 725 may be sequential
(e.g. chromium followed by pyrrole or vice-versa) or simultaneous
and at constant or varying Py:Cr ratios as disclosed previously.
Once the pyrrole-chromium mixture has been contacted in contact
zone 725 the pyrrole-chromium mixture from contact zone 725 may be
placed in contact zone 731 via line 740. The pyrrole-chromium
mixture may optionally contain solvent, other catalyst components,
or combinations thereof, but does not comprise (i) a metal alkyl
halide, (ii) a metal halide and a metal alkyl, or (iii) a non-metal
halide and a metal alkyl. Non-halide metal alkyl, which may be in
solvent, may be added to the pyrrole-chromium mixture in contact
zone 731 via line 730. The non-halide metal alkyl may be added in
an amount less than or equal to about 10 weight percent of the
pyrrole-chromium mixture to which it is added or in other amounts
as disclosed herein. Although not shown in FIG. 2C, contact zone
725 and contact zone 731 may be the same contact zone providing
that the addition sequence as described above remains the same.
[0055] The resultant mixture in contact zone 731 may then be passed
from contact zone 731 via line 732 and may optionally be filtered
(not shown) to remove any precipitate that may have formed in the
mixture. The mixture may be fed into contact zone 715 for
contacting with the remaining catalyst components including a
composition comprising the metal alkyl, the halide-containing
compound (e.g., a metal halide or non-metal halide), the solvent,
any remaining non-halide metal alkyl, metal alkyl halide, or
combinations thereof, which may be placed into contact zone 715 via
various input lines not shown in FIG. 2C. A catalyst product may
then be withdrawn from contact zone 715 via line 770 and may
optionally be filtered in a filter (not shown). Where filtering is
omitted, remaining catalyst components may be alternatively
contacted in contact zone 725 or 731.
[0056] The composition comprising a chromium-containing compound
may be contacted with the non-halide metal alkyl to form a first
mixture; the composition comprising a pyrrole-containing compound
may be contacted with the non-halide metal alkyl to form a second
mixture; and the first and second mixtures may be contacted with
the remaining catalyst components. In an embodiment shown in FIG.
2D a composition containing a chromium-containing compound may be
disposed in contact zone 810, the placement of which takes place
via input line 805. The composition in contact zone 810 may
optionally contain solvent, other catalyst components, or
combinations thereof, but contact zone 810 does not comprise (i) a
metal alkyl halide, (ii) a metal halide and a metal alkyl, or (iii)
a non-metal halide and a metal alkyl. Non-halide metal alkyl, which
may be in solvent, may be added to the composition containing a
chromium-containing compound in contact zone 810 via line 830
forming a first mixture. The non-halide metal alkyl may be added in
an amount less than or equal to about 10 weight percent of the
composition containing the chromium-containing compound to which it
is added or in other amounts as disclosed herein.
[0057] A second mixture can be formed in contact zone 820. The
composition comprising a pyrrole-containing compound may be
disposed in contact zone 820, the placement of which takes place
via input line 807. The composition comprising a pyrrole-containing
compound in contact zone 820 may optionally contain solvent, other
catalyst components, or combinations thereof, but does not comprise
(i) a metal alkyl halide, (ii) a metal halide and a metal alkyl, or
(iii) a non-metal halide and a metal alkyl. Non-halide metal alkyl,
which may be in solvent, may be added to the composition containing
a pyrrole-containing compound in contact zone 820 via line 831
forming the second mixture. The non-halide metal alkyl may be added
in an amount less than or equal to about 10 weight percent of the
composition containing the nitrogen-containing compound to which it
is added or in other amounts as disclosed herein.
[0058] The first mixture, second mixture, or both may optionally be
filtered (not shown) to remove any precipitate that may have formed
in the mixtures. Optionally, either the first, second, or both
mixtures may be stored. The first and second mixtures may then be
fed into contact zone 815 via lines 811 and 821, respectively for
contacting with the remaining catalyst components including the
composition comprising metal halide. Alternatively, although not
shown in FIG. 2D the first and second mixtures may be contacted
separately in another contact zone prior to being fed via a
commingled feed line into contact zone 815, and such commingled
feed line may be optionally filtered to remove any precipitate that
may have formed. Contact zone 815 initially may be comprised of a
composition comprising the metal alkyl, a halide-containing
compound (e.g., a metal halide or non-metal halide), a solvent, the
remaining non-halide metal alkyl, metal alkyl halide, or
combinations thereof, all of which have been placed into contact
zone 815 via various input lines not shown in FIG. 2D. A catalyst
product may then be withdrawn from contact zone 815 via line 870
and optionally filtered (filter not shown). In alternative
embodiments, remaining catalyst components may be contacted in
contact zone 810 or 820.
[0059] The addition of the composition comprising the
pyrrole-containing compound and the composition comprising the
chromium-containing compound as shown in FIGS. 2C and 2D may be
made in constant or varying Py:Cr ratios as disclosed
previously.
[0060] Water may be removed from the chromium-containing compound
prior to contact with the metal halide-containing compound
according to various water abatement embodiment disclosed herein.
In an embodiment, the chromium-containing catalyst feedstock may be
contacted with an azeotropic solvent such as an aromatic compound,
paraffin solvent, chlorinated solvent, other solvent, or mixture of
solvents capable of forming an azeotrope with water. The azeotropic
solvent, the chromium-containing compound, and any water present
form a solution and the solution may be subjected to an azeotropic
distillation to remove the water, wherein the solvent-water
azeotrope is a lower boiling component. Optionally, the solvent
used to remove water by azeotropic distillation may be recovered
after the azeotropic distillation. In an embodiment, the azeotropic
solvent used to remove water using azeotropic distillation may
comprise ethylbenzene, benzene, meta-xylene, ortho-xylene,
para-xylene, mixed xylenes, toluene, octane, nonane, heptane,
hexane, mixed hexanes, cyclohexane, carbon tetrachloride,
chloroform, dichloromethane, 1,1,2 trichloroethane, or combinations
thereof. The amount of water removed from a catalyst component by
various abatement methods may be monitored using known analytical
methods such as infrared analysis.
[0061] In an embodiment shown in FIG. 3A a composition containing a
chromium-containing compound may be disposed in contact zone 910,
the placement of which takes place via an input line 905. The
composition in contact zone 910 may optionally contain solvent,
other catalyst components, or combinations thereof, but contact
zone 910 does not comprise (i) a metal alkyl halide, (ii) a metal
halide and a metal alkyl, or (iii) a non-metal halide and a metal
alkyl. An azeotropic solvent, e.g., a composition comprising an
aromatic compound such as ethylbenzene, may be added to the
composition containing a chromium-containing compound in contact
zone 910 via line 902 or directly added to separator 900. The
azeotropic solvent may be added in an amount effective to form an
azeotropic solution with the chromium-containing compound. In an
embodiment, the azeotropic solvent may be added in an amount from
about 0.5 to about 1000 times the weight of the composition
containing the chromium-containing compound to which it is added,
alternatively from about 0.5 to about 500 times the weight,
alternatively from about 0.5 to about 100 times the weight,
alternatively from about 0.5 to about 50 times the weight,
alternatively from about 0.5 to about 25 times the weight,
alternatively from about 0.5 to about 15 times the weight. The
resultant azeotropic solution in contact zone 910 may then be
passed from contact zone 910 via line 911 and fed into a separator
900 for the azeotropic distillation of the solution to remove the
water. Operating temperature of separator 900 will depend on the
azeotropic solvent used and the pressure maintained on the
separator. The water may be removed from separator 900 through
overhead line 912, optionally the aromatic compound recovered, and
the remaining abated components may be fed via line 913 into
contact zone 915 for contacting with the remaining catalyst
components including the composition comprising the metal alkyl,
the nitrogen-containing compound (e.g the pyrrole-containing
compound or any other nitrogen-containing compound described
herein), the halide-containing compound (e.g., a metal halide or
non-metal halide), the catalyst solvent, any remaining non-halide
metal alkyl, metal alkyl halide, or combinations thereof, which may
be placed into contact zone 915 via various input lines not shown
in FIG. 3A. A catalyst product may then be withdrawn from contact
zone 915 via line 970 and optionally filtered (not shown).
Alternatively the water abated material comprising the
chromium-containing compound may be stored prior to contact with
the remaining catalyst components. Optionally, the abated
components from line 913 may be subjected to further water
abatement as described herein, for example contact with a
non-halide metal alkyl, adsorbent, or both prior to contact with
the remaining catalyst components.
[0062] In an embodiment, one or more catalyst components other than
(i) a metal alkyl halide, (ii) a metal halide and a metal alkyl, or
(iii) a non-metal halide and a metal alkyl, for example the
composition comprising the chromium-containing compound, the
composition comprising the nitrogen-containing compound, the
non-metal halide-containing compound, the solvent, or combinations
thereof are contacted with an adsorbent to abate water. The
contacting may occur prior to contacting with (i) a metal alkyl
halide, (ii) a metal halide and a metal alkyl, or (iii) a non-metal
halide and a metal alkyl. In some embodiments, contacting the
chromium-containing compound with the nitrogen-containing compound
may enhance the solubility of the chromium-containing compound in a
solvent (e.g. ethylbenzene) as well as reduce the solution
viscosity. Thus, the reduced viscosity and more soluble solution
may enhance the suitability of the solution to water abatement by
means of passing it through an adsorbent such as molecular sieves,
to remove all or a portion of any water present. In an embodiment,
the nitrogen-containing compound added may constitute substantially
all or only a portion of the nitrogen-containing compound required
to make the catalyst composition. Other known means for reducing
viscosity, enhancing solubility, or both may be employed such that
a catalyst component becomes suitable for contact with an adsorbent
to remove water.
[0063] Adsorption as used herein refers to the separation operation
in which one component of a gas or liquid mixture is selectively
retained in the pores of a resinous or microcrystalline solid. A
gas or liquid mixture contacts a solid (the adsorbent) and a
mixture component (the adsorbate, which is typically water) adheres
to the surface of the solid. In an embodiment, an adsorbent may be
used to abate water by adding the adsorbent to catalyst
component(s) in a vessel and mixing thoroughly for adequate
contacting of the adsorbent with the catalyst component(s). The
mixture may then be allowed to stand and after a period of time,
the adsorbent settles to the bottom of the vessel. Separation can
be completed by decanting or filtration (e.g., suction filtration).
Alternatively, water may be abated by passing the catalyst
component(s) through a fixed adsorption bed comprised of an
adsorbent, allowing the mixture adequate contact time for the
adsorbate to sufficiently adhere to the adsorbent, and then
removing the abated catalyst component(s) from the adsorption bed.
The adsorbent may then be replaced or regenerated for the next use.
The original adsorption capacity of the saturated bed may be
recovered by any suitable regeneration method, for example, thermal
regeneration, regeneration by pressure swing, or regeneration by
purging.
[0064] In the embodiments, any suitable adsorbent may be used.
Examples of suitable adsorbents include 3-Angstrom molecular
sieves, 5-Angstrom molecular sieves, 13X molecular sieves, alumina,
silica, or combinations thereof. 3-Angstrom (3A) and 5-Angstrom
(5A) refers to the size of the molecule the material can adsorb,
for example, the 3A molecular sieve can adsorb molecules less than
3 angstrom and the 5A molecular sieve can adsorb molecules less
than 5 angstrom. Molecular sieves are crystalline structures not
unlike sponges on a molecular scale. They have a solid framework
defining large internal cavities where molecules can be adsorbed.
These cavities are interconnected by pore openings through which
molecules can pass. Because of their crystalline nature, the pores
and cavities are the same size, and depending on the size of the
openings, they can adsorb molecules readily, slowly, or not at all,
thus functioning as molecular sieves--adsorbing molecules of
certain sizes while rejecting larger ones.
[0065] In an embodiment wherein the nitrogen-containing compound is
a pyrrole-containing compound as illustrated in FIG. 3B, a
pyrrole-chromium mixture may be formed in contact zone 1025 by
contacting a composition comprising the pyrrole-containing compound
fed to contact zone 1025 via line 1020 and the composition
comprising the chromium-containing compound fed to contact zone
1025 via line 1010, which may occur about instantaneously or over a
first period of time. Feeding of the chromium-containing
composition and the pyrrole-containing composition to contact zone
1025 may be sequential (e.g. chromium followed by pyrrole or
vice-versa) or simultaneous and at constant or varying Py:Cr ratios
as disclosed previously. Once the pyrrole-chromium mixture has been
contacted in contact zone 1025 the pyrrole-chromium mixture from
contact zone 1025 may be passed to contact zone 1000 via line 1040.
The pyrrole-chromium mixture may optionally contain solvent, other
catalyst components, e.g. a non-metal halide, or combinations
thereof, but does not comprise (i) a metal alkyl halide, (ii) a
metal halide and a metal alkyl, or (iii) a non-metal halide and a
metal alkyl. The pyrrole-chromium mixture is contacted with an
adsorbent disposed in contact zone 1000. Contact zone 1000 may be a
fixed adsorption bed as described in a previous embodiment, sized
accordingly to the volumes of materials being adsorbed. The
pyrrole-chromium mixture may be passed through the adsorption bed
comprised of an adsorbent, e.g. 3A molecular sieve, allowing for
the adsorption process to occur over a second period of time to
adsorb essentially all of the free water from the pyrrole-chromium
mixture. Contact with the adsorbent in contact zone 1000 may be
carried out according to various known methods. One skilled in the
art will understood that other nitrogen-containing compounds as
described herein may be used in the embodiments shown in FIGS.
3B.
[0066] The water abated mixture in contact zone 1000 may then be
passed from contact zone 1000 via line 1018 and contacted with the
remaining catalyst components in contact zone 1015 including the
composition comprising the metal alkyl, a halide-containing
compound (e.g., a metal halide or non-metal halide), the solvent,
any remaining non-halide metal alkyl, metal alkyl halide, or
combinations thereof, which may be placed into contact zone 1015
via various input lines not shown in FIG. 3B. A catalyst product
may then be withdrawn from contact zone 1015 via line 1070 and
optionally filtered (not shown). Alternatively the water abated
material comprising the chromium-containing compound may be stored
prior to contact with the remaining catalyst components.
Optionally, the water abated compounds from contact zone 1000 may
be subjected to further water abatement as described herein, for
example contact with a non-halide metal alkyl, azeotropic
distillation, or both prior to contact with the remaining catalyst
components.
[0067] Embodiments for abating water, acidic protons, or both as
disclosed herein, for example the embodiments shown in FIGS. 2A-2D
and 3A-3B, may be applied alone or in combination to other
processes and catalyst compositions known in the art, for example,
water, acidic protons, or both may be abated from the catalyst
compositions or components disclosed in reference U.S. Pat. No.
6,133,495, U.S. application Ser. No. 2002/0035029, WO 01/83447, WO
03/053890, WO 03/053891, WO 04/056477, WO 04/056478, WO 04/056479,
and WO 04/056480, each of which is incorporated herein in its
entirety. Likewise, embodiments for preparing catalysts, for
example embodiments shown in FIGS. 1A-1D and 4A-4E, may be applied
alone or in combination to other processes and catalyst
compositions known in the art, for example those set forth in U.S.
Pat. No. 6,133,495, 2002/0035029, WO 01/83447, WO 03/053890, WO
03/053891, WO 04/056477, WO 04/056478, WO 04/056479, and WO
04/056480. When applying the water abatement and catalyst
preparation embodiments to these catalyst compositions or
components disclosed in reference U.S. Pat. No. 6,133,495,
2002/0035029, WO 01/83447, WO 03/053890, WO 03/053891, WO
04/056477, WO 04/056478, WO 04/056479, and WO 04/056480, the
appropriate substitutions and adjustment should be made for
components that have a similar function; e.g. substitution of the
heteroatomic ligands of U.S. Pat. No. 6,133,495, 2002/0035029, WO
01/83447, WO 03/053890, WO 03/053891, WO 04/056477, WO 04/056478,
WO 04/056479, and WO 04/056480 for the nitrogen-containing compound
disclosed herein and adjustments of the ligand:Cr (e.g.,
pyrrole:chromium) molar ratios to account for the number of
equivalents of ligand(s) per mole of the ligand. Furthermore,
catalyst compositions or components disclosed in reference U.S.
Pat. No. 6,133,495, U.S. application Ser. No. 2002/0035029, WO
01/83447, WO 03/053890, WO 03/053891, WO 04/056477, WO 04/056478,
WO 04/05477, WO 04/056478, WO 04/056479, and WO 04/056480 may be
combined with other catalyst compositions or components as set
forth herein to make various final catalysts according to various
embodiments described herein, and water may be abated from any one
or more of such compositions or components by any one or more
abatement method disclosed herein.
[0068] In an embodiment, water, acidic protons, or both may be
abated from the catalyst composition for producing an alpha-olefin
oligomer disclosed in U.S. Pat. No. 6,133,495. In an embodiment,
the nitrogen-containing compound as described herein is replaced
with a pyrrole ring-containing compound as described in U.S. Pat.
No. 6,133,495. A chromium-based catalyst is prepared by bringing a
pyrrole ring-containing compound, an alkyl aluminum compound, and a
halogen-containing compound into contact with each other in a
hydrocarbon solvent, halogenated hydrocarbon solvent or mixture
thereof, and then bringing the mixed resultant solution into
contact with the chromium compound, wherein water, acidic protons,
or both are abated from the catalyst or a component thereof prior
to or during preparation of the catalyst. In an embodiment, the
chromium-based catalyst is prepared by bringing the chromium
compound, the pyrrole ring-containing compound, the alkyl aluminum
compound, and the halogen-containing compound into contact with
each other in a hydrocarbon solvent, halogenated hydrocarbon
solvent or mixture thereof in the absence of alpha-olefin under
such a condition that the concentration of the chromium compound in
the resultant mixed solution is about 1.times.10.sup.-7 to 1
mol/liter, alternatively about 1.times.10.sup.-5 to
3.times.10.sup.-2 mol/liter, alternatively adjusted to not more
than about 8.times.10.sup.-3 mol/liter, alternatively, not more
than about 0.416 mg Cr/mL, wherein water, acidic protons, or both
are abated from the catalyst or a component thereof prior to or
during preparation of the catalyst. In an embodiment, water, acidic
protons, or both are abated from a catalyst component comprising a
pyrrole derivative represented by the general formula (I): ##STR1##
wherein R.sup.1 to R.sup.4 are a hydrogen atom or a linear or
branched hydrocarbon group having 1 to 20 carbon atoms, in which
R.sup.3 and R.sup.4 may integrally form a ring; X is a halogen
atom; M is an element selected from the group consisting of those
belonging to 3-Group, 4-Group, 6-Group (exclusive of chromium),
13-Group, 14-Group and 15-Group of the Periodic Table; m and n are
numbers satisfying the relationships of 1.ltoreq.m.ltoreq.6,
0.ltoreq.n.ltoreq.5 and 2.ltoreq.m+n.ltoreq.6 with the proviso that
the sum of m and n is identical to the valence of the element M; n
represents the number of Rs; and R is a hydrogen atom or a linear
or branched hydrocarbon group having 1 to 20 carbon atoms and when
n is not less than 2, and Rs may be the same or different.
[0069] In an embodiment, water, acidic protons, or both may be
abated from the catalyst composition disclosed in U.S. patent Ser.
No. 2002/0035029. In an embodiment, the nitrogen-containing
compound as described herein is replaced with a neutral
multidentate ligand as described in 2002/0035029. In an embodiment,
a catalyst for oligomerization of ethylene comprises:
[0070] (i) an organometallic complex having a neutral multidentate
ligand having a tripod structure, represented by the following
formula (1): AMQ.sub.n (1) wherein A may be a neutral multidentate
ligand having a tripod structure, M may be a transition metal atom
of group 3 to group 10 of the periodic table, each Q may be
independently selected from the group consisting of a hydrogen
atom, a halogen atom, a straight chain or branched alkyl group
having 1 to 10 carbon atoms which may have a substituent, an aryl
group having 6 to 10 carbon atoms which may have a substituent, and
n is an integer equal to a formal oxidation valence of M, and
[0071] (ii) an alkylaluminoxane; [0072] said neutral multidentate
ligand A in formula (1) being a tridentate ligand represented by
the following formula (2) or formula (3): ##STR2## wherein j, k and
m independently represent an integer of 0 to 6, each D.sup.1
independently represents a divalent hydrocarbon group which may
have a substituent, each L.sup.1 independently represents a
substituent containing an element of group 14, 15, 16 or 17 of the
periodic table, with the proviso that all of the three L.sup.1s are
not concurrently a substituent containing an element of group 14 or
17, G.sup.1 represents a carbon or silicon atom, and R.sup.1
represents a hydrogen atom, an alkyl group having 1 to 10 carbon
atoms which may have a substituent, or an aryl group having 6 to 10
carbon atoms which may have a substituent; ##STR3## wherein a, b
and c independently represent an integer of 0 to 6; u represents an
integer of 0 or 1; each D.sup.2 independently represents a divalent
hydrocarbon group which may have a substituent; each L.sup.2
independently represents a substituent containing an element of
group 14, 15, 16 or 17 of the periodic table, with the proviso that
all of the three L.sup.2s are not concurrently a substituent
containing an element of group 14 or 17, G.sup.2 represents a
nitrogen or phosphorus atom when u is 0, or a phosphorus atom when
u is 1, and R.sup.2 represents an oxygen or sulfur atom. Water,
acidic protons, or both may be abated from the catalyst or a
component thereof prior to or during preparation of the
catalyst.
[0073] In an embodiment, a catalyst for the oligomerization of
ethylene comprises: [0074] (i) an organometallic complex having a
neutral multidentate ligand having a tripod structure, represented
by the following formula (1): AMQ.sub.n (1) wherein A is a neutral
multidentate ligand having a tripod structure, M is a transition
metal atom of group 3 to group 10 of the periodic table, each Q is
independently selected from the group consisting of a hydrogen
atom, a halogen atom, a straight chain or branched alkyl group
having 1 to 10 carbon atoms which may have a substituent, an aryl
group having 6 to 10 carbon atoms which may have a substituent, and
n is an integer equal to a formal oxidation valence of M, and
[0075] (ii) an alkylaluminoxane, and [0076] (iii) a halogenated
inorganic compound; said neutral multidentate ligand A in formula
(1) being a tridentate ligand represented by the following formula
(2) or formula (3): ##STR4## wherein j, k and m independently
represent an integer of 0 to 6, each D.sup.1 independently
represents a divalent hydrocarbon group which may have a
substituent, each L.sup.1 independently represents a substituent
containing an element of group 14, 15, 16 or 17 of the periodic
table, with the proviso that all of the three L.sup.1s are not
concurrently a substituent containing an element of group 14 or 17,
G.sup.1 represents a carbon or silicon atom, and R.sup.1 represents
a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which
may have a substituent, or an aryl group having 6 to 10 carbon
atoms which may have a substituent; ##STR5## wherein a, b and c
independently represent an integer of 0 to 6; u represents an
integer of 0 or 1; each D.sup.2 independently represents a divalent
hydrocarbon group which may have a substituent; each L.sup.2
independently represents a substituent containing an element of
group 14, 15, 16 or 17 of the periodic table, with the proviso that
all of the three L.sup.2s are not concurrently a substituent
containing an element of group 14 or 17, G.sup.2 represents a
nitrogen or phosphorus atom when u is 0, or a phosphorus atom when
u is 1, and R.sup.2 represents an oxygen or sulfur atom. Water,
acidic protons, or both may be abated from the catalyst or a
component thereof prior to or during preparation of the
catalyst.
[0077] In an embodiment, a catalyst for the oligomerization of
ethylene comprises:
[0078] (i) an organometallic complex having a neutral multidentate
ligand having a tripod structure, represented by the following
formula (1): AMG.sub.n (1) wherein A is a neutral multidentate
ligand having a tripod structure, M is a transition metal atom of
group 3 to group 10 of the periodic table, each Q is independently
selected from the group consisting of a hydrogen atom, a halogen
atom, a straight chain or branched alkyl group having 1 to 10
carbon atoms which may have a substituent, an aryl group having 6
to 10 carbon atoms which may have a substituent, and n is an
integer equal to a formal oxidation valence of M,
[0079] (ii) an alkylaluminoxane,
[0080] (iii) a halogenated inorganic compound, and
[0081] (iv) an alkyl group-containing compound represented by the
following formula (4): R.sub.pEJ.sub.q (4) wherein p and q are
numbers satisfying the formulae: 0.ltoreq.p.ltoreq.3 and
0.ltoreq.q.ltoreq.3, provided that (P+q) is in the range of 1 to 3,
E represents an atom, other than a hydrogen atom, of group 1, 2, 3,
11, 12 or 13 of the periodic table, each R independently represents
an alkyl group having 1 to 10 carbon atoms, and each J
independently represents a hydrogen atom, an alkoxide group having
1 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms,
an aryl group having 6 to 10 carbon atoms or a halogen atom; said
neutral multidentate ligand A in formula (1) being a tridentate
ligand represented by the following formula (2) or formula (3):
##STR6## wherein j, k and m independently represent an integer of 0
to 6, each D1 independently represents a divalent hydrocarbon group
which may have a substituent, each L1 independently represents a
substituent containing an element of group 14, 15, 16 or 17 of the
periodic table, with the proviso that all of the three L1s are not
concurrently a substituent containing an element of group 14 or 17,
G.sup.1 represents a carbon or silicon atom, and R.sup.1 represents
a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which
may have a substituent, or an aryl group having 6 to 10 carbon
atoms which may have a substituent; ##STR7## wherein a, b and c
independently represent an integer of 0 to 6; u represents an
integer of 0 or 1; each D.sup.2 independently represents a divalent
hydrocarbon group which may have a substituent; each L.sup.2
independently represents a substituent containing an element of
group 14, 15, 16 or 17 of the periodic table, with the proviso that
all of the three L.sup.2s are not concurrently a substituent
containing an element of group 14 or 17, G.sup.2 represents a
nitrogen or phosphorus atom when u is 0, or a phosphorus atom when
u is 1, and R.sup.2 represents an oxygen or sulfur atom. Water,
acidic protons, or both may be abated from the catalyst or a
component thereof prior to or during preparation of the
catalyst.
[0082] In an embodiment, a catalyst for the oligomerization of
ethylene comprises:
[0083] (i) an organometallic complex having a neutral multidentate
ligand having a tripod structure, represented by the following
formula (1): AMQ.sub.n (1) wherein A is a neutral multidentate
ligand having a tripod structure, M is a transition metal atom of
group 3 to group 10 of the periodic table, each Q is independently
selected from the group consisting of a hydrogen atom, a halogen
atom, a straight chain or branched alkyl group having 1 to 10
carbon atoms which may have a substituent, an aryl group having 6
to 10 carbon atoms which may have a substituent, and n is an
integer equal to a formal oxidation valence of M,
[0084] (ii) an alkylaluminoxane, and
[0085] (iii) an alkyl group-containing compound represented by the
following formula (4): R.sub.pEJ.sub.q (4) wherein p and q are
numbers satisfying the formulae: 0.ltoreq.p.ltoreq.3 and
0.ltoreq.q.ltoreq.3, provided that (P+q) is in the range of 1 to 3,
E represents an atom, other than a hydrogen atom, of group 1, 2, 3,
11, 12 or 13 of the periodic table, each R independently represents
an alkyl group having 1 to 10 carbon atoms, and each J
independently represents a hydrogen atom, an alkoxide group having
1 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms,
an aryl group having 6 to 10 carbon atoms or a halogen atom; said
neutral multidentate ligand A in formula (1) being a tridentate
ligand represented by the following formula (2) or formula (3):
##STR8## wherein j, k and m independently represent an integer of 0
to 6, each D.sup.1 independently represents a divalent hydrocarbon
group which may have a substituent, each L.sup.1 independently
represents a substituent containing an element of group 14, 15, 16
or 17 of the periodic table, with the proviso that all of the three
L.sup.1s are not concurrently a substituent containing an element
of group 14 or 17, G.sup.1 represents a carbon or silicon atom, and
R.sup.1 represents a hydrogen atom, an alkyl group having 1 to 10
carbon atoms which may have a substituent, or an aryl group having
6 to 10 carbon atoms which may have a substituent; ##STR9## wherein
a, b and c independently represent an integer of 0 to 6; u
represents an integer of 0 or 1; each D.sup.2 independently
represents a divalent hydrocarbon group which may have a
substituent; each L.sup.2 independently represents a substituent
containing an element of group 14, 15, 16 or 17 of the periodic
table, with the proviso that all of the three L.sup.2s are not
concurrently a substituent containing an element of group 14 or 17,
G.sup.2 represents a nitrogen or phosphorus atom when u is 0, or a
phosphorus atom when u is 1, and R.sup.2 represents an oxygen or
sulfur atom. Water, acidic protons, or both may be abated from the
catalyst or a component thereof prior to or during preparation of
the catalyst.
[0086] In an embodiment, a catalyst for oligomerization of ethylene
comprises:
[0087] (i) an organometallic complex having a neutral multidentate
ligand having a tripod structure, represented by the following
formula (1): AMQ.sub.n (1) wherein A is a neutral multidentate
ligand having a tripod structure, M is a transition metal atom of
group 3 to group 10 of the periodic table, each Q is independently
selected from the group consisting of a hydrogen atom, a halogen
atom, a straight chain or branched alkyl group having 1 to 10
carbon atoms which may have a substituent, an aryl group having 6
to 10 carbon atoms which may have a substituent, and n is an
integer equal to a formal oxidation valence of M, [0088] (ii) an
alkylaluminoxane, and [0089] (iii) at least one compound selected
from the group consisting of an amine compound and an amide
compound; said neutral multidentate ligand A in formula (1) being a
tridentate ligand represented by the following formula (2) or
formula (3): ##STR10## wherein j, k and m independently represent
an integer of 0 to 6, each D.sup.1 independently represents a
divalent hydrocarbon group which may have a substituent, each
L.sup.1 independently represents a substituent containing an
element of group 14, 15, 16 or 17 of the periodic table, with the
proviso that all of the three L.sup.1 s are not concurrently a
substituent containing an element of group 14 or 17, G.sup.1
represents a carbon or silicon atom, and R.sup.1 represents a
hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may
have a substituent, or an aryl group having 6 to 10 carbon atoms
which may have a substituent; ##STR11## wherein a, b and c
independently represent an integer of 0 to 6; u represents an
integer of 0 or 1; each D.sup.2 independently represents a divalent
hydrocarbon group which may have a substituent; each L.sup.2
independently represents a substituent containing an element of
group 14, 15, 16 or 17 of the periodic table, with the proviso that
all of the three L.sup.2s are not concurrently a substituent
containing an element of group 14 or 17, G.sup.2 represents a
nitrogen or phosphorus atom when u is 0, or a phosphorus atom when
u is 1, and R.sup.2 represents an oxygen or sulfur atom. Water,
acidic protons, or both may be abated from the catalyst or a
component thereof prior to or during preparation of the
catalyst.
[0090] In an embodiment, a catalyst for the oligomerization of
ethylene comprises:
[0091] (i) an organometallic complex having a neutral multidentate
ligand having a tripod structure, represented by the following
formula (1): AMQ.sub.n (1) wherein A is a neutral multidentate
ligand having a tripod structure, M is a transition metal atom of
group 3 to group 10 of the periodic table, each Q is independently
selected from the group consisting of a hydrogen atom, a halogen
atom, a straight chain or branched alkyl group having 1 to 10
carbon atoms which may have a substituent, an aryl group having 6
to 10 carbon atoms which may have a substituent, and n is an
integer equal to a formal oxidation valence of M, [0092] (ii) an
alkylaluminoxane, [0093] (iii) at least one compound selected from
the group consisting of an amine compound and an amide compound,
and [0094] (iv) an alkyl group-containing compound represented by
the following formula (4): R.sub.pEJ.sub.q (4) wherein p and q are
numbers satisfying the formulae: 0.ltoreq.p.ltoreq.3 and
0.ltoreq.q.ltoreq.3, provided that (P+q) is in the range of 1 to 3,
E represents an atom, other than a hydrogen atom, of group 1, 2, 3,
11, 12 or 13 of the periodic table, each R independently represents
an alkyl group having 1 to 10 carbon atoms, and each J
independently represents a hydrogen atom, an alkoxide group having
1 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms,
an aryl group having 6 to 10 carbon atoms or a halogen atom; said
neutral multidentate ligand A in formula (1) being a tridentate
ligand represented by the following formula (2) or formula (3):
##STR12## wherein j, k and m independently represent an integer of
0 to 6, each D.sup.1 independently represents a divalent
hydrocarbon group which may have a substituent, each L.sup.1
independently represents a substituent containing an element of
group 14, 15, 16 or 17 of the periodic table, with the proviso that
all of the three L.sup.1s are not concurrently a substituent
containing an element of group 14 or 17, G.sup.1 represents a
carbon or silicon atom, and R.sup.1 represents a hydrogen atom, an
alkyl group having 1 to 10 carbon atoms which may have a
substituent, or an aryl group having 6 to 10 carbon atoms which may
have a substituent; ##STR13## wherein a, b and c independently
represent an integer of 0 to 6; u represents an integer of 0 or 1;
each D.sup.2 independently represents a divalent hydrocarbon group
which may have a substituent; each L.sup.2 independently represents
a substituent containing an element of group 14, 15, 16 or 17 of
the periodic table, with the proviso that all of the three L.sup.2s
are not concurrently a substituent containing an element of group
14 or 17, G.sup.2 represents a nitrogen or phosphorus atom when u
is 0, or a phosphorus atom when u is 1, and R.sup.2 represents an
oxygen or sulfur atom. Water, acidic protons, or both may be abated
from the catalyst or a component thereof prior to or during
preparation of the catalyst.
[0095] In an embodiment, an olefin oligomerization catalyst system
incorporates a halogen source into a pyrrole ligand as disclosed in
WO 01/83447, and water, acidic protons, or both may be abated from
the catalyst system or a component thereof prior to or during
preparation of the catalyst. In an embodiment, the
nitrogen-containing compound as described herein is replaced with a
halopyrrole ligand as described in WO 01/83447. In an embodiment,
water, acidic protons, or both are abated from a catalyst component
comprising a halopyrrole ligand. The catalyst system may comprise a
chromium source, a metal alkyl, and the halopyrrole ligand and may
be utilized for oligomerizing ethylene to an olefin composition
comprising 1-hexene or 1-octene.
[0096] In an embodiment, an olefin oligomerization catalyst system
incorporates a mixed heteroatomic ligand with at least three
heteroatoms, of which at least one heteroatom is sulfur and at
least 2 heteroatoms are not the same, as disclosed in WO 03/053890
and water, acidic protons, or both may be abated from the catalyst
system or a component thereof prior to or during preparation of the
catalyst. In an embodiment, the nitrogen-containing compound as
described herein is replaced with a heteroatomic ligand as
described in WO 03/053890. In an embodiment, water, acidic protons,
or both are abated from the catalyst system or a catalyst component
comprising a multidentate mixed heteroatomic ligand, which includes
at least three heteroatoms of which at least one is a sulfur atom.
The catalyst system may comprise a chromium source, a metal alkyl,
an aluminoxane, and the multidentate mixed heteroatomic ligand and
may be utilized for oligomerizing ethylene to an olefin composition
comprising 1-hexene or 1-octene.
[0097] In an embodiment, water, acidic protons, or both may be
abated from the ligand and the ligand may be comprised of the
following ligand types:
[0098] (a) R.sup.1A(R.sup.2BR.sup.3)(R.sup.4CR.sup.5) wherein
R.sup.1, R.sup.3 and R.sup.5 may be hydrogen or independently be
selected from the groups consisting of alkyl, aryl, aryloxy,
halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl,
carbonylamino, dialkylamino, or derivatives thereof, or aryl
substituted with any of these substituents; R.sup.2 and R.sup.4 may
be the same or different and are C.sub.1 to about C.sub.15
hydrocarbyls; A is nitrogen or phosphorous; and B and C are sulfur;
and
[0099] (b) R.sup.1A(R.sup.2BR.sup.3R.sup.4)(R.sup.5CR.sup.6)
wherein R.sup.1, R3.sup.1, R.sup.4, and R.sup.6 may be hydrogen or
independently be selected from the groups consisting of alkyl,
aryl, aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy,
aminocarbonyl, carbonylamino, dialkylamino, or derivatives thereof,
or aryl substituted with any of these substituents; R.sup.2 and
R.sup.5 may be the same or different and are C.sub.1 to about
C.sub.15 hydrocarbyls; A and B are individually nitrogen or
phosphorous; and C is sulfur; and
[0100] (c) A(R.sup.1BR.sup.2R.sup.3)(R.sup.4CR.sup.5) wherein
R.sup.2, R.sup.3, and R.sup.5 may be hydrogen or independently be
selected from the groups consisting of alkyl, aryl, aryloxy,
halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl,
carbonylamino, dialkylamino, or derivatives thereof, or aryl
substituted with any of these substituents; R.sup.1 and R.sup.4 may
be the same or different and are C.sub.1 to about C.sub.15
hydrocarbyls; B is nitrogen or phosphorous; and A and C are sulfur;
and
[0101] (d) A(R.sup.1BR.sup.2R.sup.3)(R.sup.4CR.sup.5R.sup.6)
wherein R.sup.2, R.sup.3, R.sup.5, and R.sup.6 may be hydrogen or
independently be selected from the groups consisting of alkyl,
aryl, aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy,
aminocarbonyl, carbonylamino, dialkylamino, or derivatives thereof,
or aryl substituted with any of these substituents; R.sup.1 and
R.sup.4 may be the same or different and are C.sub.1 to about
C.sub.15 hydrocarbyls; B and C are individually nitrogen or
phosphorous; and A is sulfur.
[0102] In an embodiment the ligand may comprise
bis(2-ethylsulfanyl-ethyl)-amine,
bis-(2-methylsulfanyl-ethyl)-amine,
bis-(2butylsulfanyl-ethyl)-amine,
bis-(2-decylsulfanyl-ethyl)-amine,
bis-(2butylsulfanyl-ethyl)-amine,
bis-(2-decylsulfanyl-ethyl)-amine, bis-(ethylsulfanylmethyl)-amine,
bis-(2-ethylsulfanyl-phenyl)-amine,
bis-(2-ethylsulfanyl-ethyl)phosphine,
bis-(2-ethylsulfanyl-ethyl)-ethylphosphine,
bis-(2-ethylsulfanylethyl)-phenylphosphine,
N-methylbis-(2-ethylsulfanyl-ethyl)-amine,
(2ethylsulfanyl-ethyl)(3-ethylsulfanyl-propyl)-amine,
(2-ethylsulfanyl-ethyl)(2diethylphosphino-ethyl)-amine,
(2-ethylsulfanyl-ethyl)(2-diethylphosphinoethyl)-sulfide,
(2-ethylsulfanyl-ethyl)(2-diethylamino-ethyl)-amine and
(ethylsulfanyl-ethyl)(2-diethylamino-ethyl)-sulfide,
(2-ethylsulfanyl-ethyl)(2diethylphosphino-ethyl)-phosphine,
(2-ethylsulfanyl-ethyl)(2-diethylaminoethyl)-ethylphosphine,
bis-(2-diethylphosphino-ethyl)-sulfide,
bis-(2diethylamino-ethyl)-sulfide,
(2-diethylphosphino-ethyl)(2-diethylamino-ethyl)sulfide and
derivatives thereof, wherein water, acidic protons, or both may be
abated from the ligand.
[0103] In an embodiment, an olefin oligomerization catalyst system
incorporates a mixed heteroatomic ligand with at least three
heteroatoms, of which at least heteroatom is nitrogen and at least
two heteroatoms are not the same, as disclosed in WO 03/053891, and
water, acidic protons, or both may be abated from the catalyst
system or a component thereof prior to or during preparation of the
catalyst. In an embodiment, the nitrogen-containing compound as
described herein is replaced with a mixed heteroatomic ligand as
described in WO 03/053891. In an embodiment, the ligand may be a
multidentate mixed heteroatomic ligand for an oligomerization of
olefins catalyst, which ligand includes at least three heteroatoms.
At least one heteroatom may be nitrogen and at least two
heteroatoms may not be the same. The ligand may contain, in
addition to nitrogen, at least one phosphorous heteroatom. In an
embodiment, the ligand may be selected such that none of the
non-carbon based heteroatoms are directly bonded to any of the
other non-carbon based heteroatoms. In an embodiment, the ligand
may not include a sulfur heteroatom. In an embodiment, water,
acidic protons, or both may be abated from a ligand having the
structure R.sup.1A(R.sup.2BR.sup.3R.sup.4)(R.sup.5CR.sup.6R.sup.7)
wherein R.sup.1, R.sup.3, R.sup.4, R.sup.6 and R.sup.7 may be
hydrogen or independently be selected from the groups consisting of
alkyl, aryl, aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy,
alkoxy, aminocarbonyl, carbonylamino, dialkylamino, or derivatives
thereof, or aryl substituted with any of these substituents;
R.sup.2 and R.sup.5 are the same or different and are C.sub.1 to
about C.sub.15 hydrocarbyls; and at least A, B or C is nitrogen
with the remainder of A, B and C being individually nitrogen or
phosphorous.
[0104] In an embodiment the ligand may comprise
bis-(2-diethylphosphino-ethyl)-amine,
bis-(diethylphosphino-methyl)-amine,
bis-(2-diethylphosphino-phenyl)-amine,
N-methylbis-(2-diethylphosphino-ethyl)-amine,
bis-(2-diphenylphosphino-ethyl)-amine,
(2-diethylphosphino-ethyl)(3-diethylphosphino-propyl)-amine,
bis-(2- dicyclohexylphosphino-ethyl)-amine,
N-benzylbis-(2-diethylphosphino-ethyl)-amine,
N-methyl-(2-diethylphosphino-ethyl)(3-diethylphosphino-propyl)-amine,
(2-diethylphosphinoethyl)(2-diethylamino-ethyl)-amine,
N-methyl-(2-diethylphosphino-ethyl)(2-diethylamino-ethyl)-amine and
bis-(2-diethylamino-ethyl)ethylphosphine. A suitable multidentate
mixed heteroatomic ligand is bis-(2-diethylphosphino-ethyl)-amine
and derivatives thereof, wherein water, acidic protons, or both may
be abated from the ligand.
[0105] In an embodiment, an olefin oligomerization catalyst system
incorporates a heteroatomic ligand, as disclosed in WO 04/056477,
WO 04/056478, WO 04/056479 or WO 04/056480, and water, acidic
protons, or both may be abated from the catalyst system or a
component thereof prior to or during preparation of the catalyst.
In an embodiment, the nitrogen-containing compound as described
herein is replaced with a heteroatomic ligand as described in WO
04/056477, WO 04/056478, WO 04/056479 or WO 04/056480. In an
embodiment, water, acidic protons or both may be abated from any
heteroatomic ligand described in WO 04/056477, WO 04/056478, WO
04/056479 or WO 04/056480.
[0106] In an aspect, the heteroatomic ligand can be described by
the formula (R).sub.nA--B--C(R).sub.m wherein A and C are
independently selected from a group which comprises phosphorus
arsenic, antimony, oxygen, bismuth, sulfur, selenium, and nitrogen,
and B is a linking group between A and C, and R is independently
selected from any homo or hetero hydrocarbyl group and n and m is
determined by the respective valence and oxidation state of A
and/or C. In embodiments, A and/or C may be a potential electron
donor for coordination with the transition metal. An electron donor
is defined as that entity that donates electrons used in chemical,
including dative covalent, bond, formation. In some embodiments, at
least one R group is substituted with a polar substituent.
[0107] In an aspect, the heteroatomic ligand can be described by
the formula (R.sup.1)(R.sup.2)A--B--C(R.sup.3)(R.sup.4) where A and
C are independently selected from a group which comprises
phosphorus, arsenic, antimony, bismuth and nitrogen and B is a
linking group between A and C. In embodiments, R.sup.1, R.sup.2,
R.sup.3 and R.sup.4 can independently be hydrocarbyl, substituted
hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl
groups. In some embodiments, R.sup.1, R.sup.2, R.sup.3 and R.sup.4
can be non-aromatic and aromatic, including heteroaromatic. In
other embodiments, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can
independently be substituted aromatic or substituted heteroaromatic
groups. In further embodiments, R.sup.1, R.sup.2, R.sup.3 and
R.sup.4 can independently be linked to one or more of each other or
to the linking group B to form a cyclic structure together with A
and C, A and B or B and C. In an aspect, the substituents on
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be polar; alternatively,
non-polar; alternatively, electron donating; or alternatively, not
electron donating. In embodiments, a non-electron donating
substituents can be non-polar. In embodiments, a polar substituent
can be electron donating.
[0108] IUPAC defines non-polar as an entity without a permanent
electric dipole moment. Suitable non-polar substituents may be a
methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl,
pentyl, hexyl, cyclopentyl, 2-methylcyclohexyl, cyclohexyl,
cylopentadienyl, phenyl, bi-phenyl, naphthyl, tolyl, xylyl,
mesityl, ethenyl, propenyl and benzyl group, or the like. Polar is
defined by IUPAC as an entity with a permanent electron dipole
moment. Any polar substituents on R.sup.1, R.sup.2, R.sup.3, and
R.sup.4 may be electron donating. Examples of polar substituents
include without limitation methoxy, ethoxy, isopropoxy,
C.sub.3-C.sub.20 alkoxy, phenoxy, pentafluorophenoxy,
trimethylsiloxy, dimethylamino, methylsulfanyl, tosyl,
methoxymethyl, methylthiomethyl, 1,3-oxazolyl, methoxymethoxy,
hydroxyl, amino, phosphino, arsino, stibino, sulfate, nitro and the
like.
[0109] In embodiments, A and/or C may be independently oxidized by
S, Se, N or O where the valence of A and/or C allows for such
oxidation. In other embodiments, A and C may be independently
phosphorus or phosphorus oxidised by S or Se or N or O.
[0110] In an aspect, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can
independently be hydrocarbyl, substituted hydrocarbyl,
heterohydrocarbyl or substituted heterohydrocarbyl groups where any
substituents are non-electron donating; alternatively, substituted
aromatic or substituted heteroaromatic groups containing
non-electron donating substituents on the atom adjacent to the atom
bound to A or C; or alternatively, substituted aromatic or
substituted hetero-aromatic groups containing non-polar
substituents on the atom adjacent to the atom bound to A or C. In
some embodiments, two or more of R.sup.1, R.sup.2, R.sup.3 and
R.sup.4 can be aromatic or heteroaromatic containing at least one
non-electronic donating substituent on the atom adjacent to the
atom bound to A or C. In other embodiments, R.sup.1, R.sup.2,
R.sup.3 and R.sup.4 can be aromatic or heteroaromatic containing at
least one non-polar substituent on the atom adjacent to the atom
bound to A or C. In other embodiments, R.sup.1, R.sup.2, R.sup.3
and R.sup.4 can independently be aromatic or substituted aromatic
groups where the substituent on the atom adjacent to the atom bound
to A or C is non-electron donating; or alternatively, aromatic or
substituted aromatic groups where the substituent on the atom
adjacent to the atom bound to A or C is not a polar group. In
further embodiments, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be
aromatic or heteroaromatic and each of R.sup.1, R.sup.2, R.sup.3
and R.sup.4 can be substituted on at least one of the atoms
adjacent to the atom bound to A or C by a non- electron donating
group; or alternatively, aromatic or hetero aromatic and each of
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be substituted on at
least one of the atoms adjacent to the atom bound to A or C by a
non- polar group.
[0111] In an aspect, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are
independently selected from non-aromatic and aromatic, including
heteroaromatic, groups where at least one of R.sup.1, R.sup.2,
R.sup.3 and R.sup.4 is substituted with a polar group. In some
embodiments, up to four of R.sup.1, R.sup.2, R.sup.3 and R.sup.4
can have substituents on the atom adjacent to the atom bound to A
or C. In embodiments when at least one of R.sup.1, R.sup.2, R.sup.3
and R.sup.4 is substituted with a polar group, each of R.sup.1,
R.sup.2, R.sup.3 and R.sup.4 can be aromatic, including
heteroaromatic, but not all of R.sup.1, R.sup.2, R.sup.3 and
R.sup.4, if the all are aromatic, are substituted on the atom
adjacent to the atom bound to A or C. In some embodiments when at
least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is substituted
with a polar group, not more than two of R.sup.1, R.sup.2, R.sup.3
and R.sup.4, if they are aromatic, can have substituent on the atom
adjacent to the atom bound to A or C. In other embodiments, any
polar substituents on R.sup.1, R.sup.2, R.sup.3 and R.sup.4 if they
are aromatic, may not be on the atom adjacent to the atom bound to
A or C. In yet other embodiments, at least one of R.sup.1, R.sup.2,
R.sup.3 and R.sup.4, if aromatic, can be substituted with a polar
substituent on the 2.sup.nd or further atom from the atom bound to
A or C.
[0112] In an aspect, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are
independently non-aromatic or aromatic, including heteroaromatic,
groups. In embodiments, one or more of R.sup.1, R.sup.2, R.sup.3
and R.sup.4 may be not electron donating. In some embodiments,
R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can independently be non
aromatic or aromatic, including hetero aromatic, groups and not all
the groups R.sup.1, R.sup.2, R.sup.3 and R.sup.4, if aromatic, have
a substituent on the atom adjacent to the atom bound to A or C. In
other embodiments, each non electron donating substituent on one or
more of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be non-polar. In
embodiments, each R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be
independently selected from the group comprising a benzyl, phenyl,
tolyl, xylyl, mesityl, biphenyl, naphthyl, anthracenyl, methoxy,
ethoxy, phenoxy, tolyloxy, dimethylamino, diethylamino,
methylethylamino, thiophenyl, pyridyl, thioethyl, thiophenoxy,
trimethylsilyl, dimethylhydrazyl, methyl, ethyl, ethenyl, propyl,
butyl, propenyl, propynyl, cyclopentyl, cyclohexyl, ferrocenyl and
tetrahydrofuranyl group. Alternatively, each R.sup.1, R.sup.2,
R.sup.3 and R.sup.4 can be independently selected from a group
comprising a phenyl, tolyl, biphenyl, naphthyl, thiophenyl and
ethyl group.
[0113] In some embodiments, R.sup.1, R.sup.2, R.sup.3 and R.sup.4
can be independently selected from a group comprising a methyl,
ethyl, ethylenyl, propyl, propenyl, propynyl, butyl, cyclohexyl,
2-methylcyclohexyl, 2-ethylcyclohexyl, 2-isopropylcyclohexyl,
benzyl, phenyl, tolyl, xylyl, o-methylphenyl, o-ethylphenyl,
o-isopropylphenyl, o-t-butylphenyl, cumyl, mesityl, biphenyl,
naphthyl, anthracenyl, methoxy, ethoxy, phenoxy, tolyloxy,
dimethylamino, thiomethyl, thiophenyl, trimethylsilyl,
dimethylhydrazyl group; alternatively a benzyl, phenyl, tolyl,
xylyl, mesityl, biphenyl, naphthyl, anthracenyl, methoxy, ethoxy,
phenoxy, tolyloxy, dimethylamino, diethylamino, methylethylamino,
thiophenyl, pyridyl, thioethyl, thiophenoxy, trimethylsilyl,
dimethylhydrazyl, methyl, ethyl, ethenyl, propyl, butyl, propenyl,
propynyl, cyclopentyl, cyclohexyl, ferrocenyl and tetrahydrofuranyl
group; or alternatively, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can
independently be selected from a group comprising a phenyl, tolyl,
biphenyl, naphthyl, thiophenyl and ethyl group.
[0114] B may be selected from any one of a group comprising:
organic linking groups comprising a hydrocarbyl, substituted
hydrocarbyl, heterohydrocarbyl and a substituted heterohydrocarbyl;
inorganic linking groups comprising single atom links; ionic links;
and a group comprising methylene, dimethylmethylene, 1,2-ethane,
1,2-phenylene, 1,2-propane, 1,2-catechol, 1,2-dimethylhydrazine,
--B(R.sup.5)--, --Si(R.sup.5).sub.2--, --P(R.sup.5)-- and
--N(R.sup.5)-- where R.sup.5 is hydrogen, a hydrocarbyl or
substituted hydrocarbyl, a substituted heteroatom or a halogen.
Alternatively, B may be --N(R.sup.5)-- and R.sup.5 is a hydrocarbyl
or a substituted hydrocarbyl group.
[0115] R.sup.5 may be hydrogen or may be selected from the groups
consisting of alkyl, substituted alkyl, aryl, substituted aryl,
aryloxy, substituted aryloxy, halogen, nitro, alkoxycarbonyl,
carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino,
silyl groups or derivatives thereof, and aryl substituted with any
of these substituents. Alternatively, R.sup.5 may be an isopropyl,
a 1-cyclohexyl-ethyl, a 2-methyl-cyclohexyl or a 2-octyl group. B
may be selected to be a single atom spacer. A single atom linking
spacer is defined as a substituted or non-substituted atom that is
bound directly to A and C. A and/or C may be independently oxidized
by S, Se, N or O. A and C may be independently phosphorus or
phosphorus oxidized by S or Se or N or O.
[0116] In another embodiment, any of the groups in the ligand
R.sup.1, R.sup.2, R.sup.3, R.sup.4 or R.sup.5 may include any
cyclic heteroatomic group such as
cyclopentadienyl-dimethylsilyl-t-butyl group or a cyclic homoatomic
group such as cyclopentadienyl, indenyl or fluorene group.
[0117] The ligand may also contain multiple
(R).sub.nA--B--C(R).sub.m units. Not limiting examples of such
ligands include dendrimeric ligands as well as ligands where the
individual units are coupled either via one or more of the R groups
or via the linking group B. In non-limiting embodiments, the
dendrimeric lingands can include
1,2-di-(N(P(o-ethylphenyl).sub.2).sub.2)-benzene,
1,4-di-(N(P(o-ethylphenyl).sub.2).sub.2)-benzene,
N(CH.sub.2CH.sub.2N(P(o-ethylphenyl).sub.2).sub.2).sub.3 and
1,4-di-(P(o-ethylphenyl)-N(methyl)P(o-ethylphenyl).sub.2)-benzene;
alternatively, 1,2-di-(N(P(4-methoxyphenyl).sub.2).sub.2)-benzene,
1,4-di-(N(P(4-methoxyphenyl).sub.2).sub.2)-benzene,
N(CH.sub.2CH.sub.2N(P(4-methoxyphenyl).sub.2).sub.2).sub.3 and
1,4-di-(P(4-methoxyphenyl)N(methyl)P(4-methoxy-phenyl).sub.2)-benzene,
1,2-di (N(P(phenyl).sub.2).sub.2)-benzene,
1,4-di-(N(P(phenyl).sub.2).sub.2)-benzene,
N(CH.sub.2CH.sub.2N(P(phenyl).sub.2).sub.2).sub.3 and
1,4-di-(P(phenyl)N(methyl)P(phenyl).sub.2)-benzene; alternatively,
1,2-di-(N(P(4-methoxyphenyl).sub.2).sub.2)-benzene,
1,4-di-(N(P(4-methoxyphenyl).sub.2).sub.2)-benzene,
N(CH.sub.2CH.sub.2N(P(4-methoxyphenyl).sub.2).sub.2).sub.3 and
1,4-di-(P(4-methoxyphenyl)N(methyl)P(4-methoxy-phenyl).sub.2)-benzene;
or alternatively, 1,2-di (N(P(phenyl).sub.2)2)-benzene,
1,4-di-(N(P(phenyl).sub.2).sub.2)-benzene,
N(CH.sub.2CH.sub.2N(P(phenyl).sub.2).sub.2).sub.3 and
1,4-di-(P(phenyl)N(methyl)P(phenyl).sub.2)-benzene.
[0118] The ligands can be prepared using procedures known to one
skilled in the art and procedures disclosed in published
literature.
[0119] In non-limiting embodiments, the ligands can include
(o-ethylphenyl).sup.2PN(methyl)P(o-ethylphenyl).sub.2,
(o-isopropylphenyl).sub.2PN(methyl)P(o-isopropylphenyl).sub.2,
(o-methylphenyl).sub.2PN(methyl)P(o-methylphenyl).sub.2
(o-ethylphenyl).sub.2PN(methyl)P(o-ethylphenyl)(phenyl),
(o-ethylphenyl).sub.2PN(isopropyl)P(o-ethylphenyl).sub.2,
(o-isopropyl).sub.2PN(isopropyl)P(o-isopropyl).sub.2,
(o-methyl).sub.2PN(isopropyl)P(o-methyl).sub.2,
(o-t-butylphenyl).sub.2PN(methyl)P(o-t-butylphenyl).sub.2,
(o-t-butylphenyl).sub.2PN(isopropyl)P(o-t-butylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(pentyl)P(o-ethylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(phenyl)P(o-ethylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(p-methoxyphenyl)P(o-ethylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(benzyl)P(o-ethylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(1-cyclohexylethyl)P(o-ethylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(2-methylcyclohexyl)P(o-ethylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(cyclohexyl)P(o-ethylphenyl).sub.2,
(o-ethylphenyl).sub.2PN(allyl)P(o-ethylphenyl).sub.2,
(3-ethyl-2-thiophenyl).sub.2PN(methyl)P(3-ethyl-2-thiophenyl).sub.2,
(2-ethyl-3-thiophenyl).sub.2PN(methyl)P(2-ethyl-3-thiophenyl).sub.2
and
(2-ethyl4-pyridyl).sub.2PN(methyl)P(2-ethyl4-pyridyl).sub.2.
[0120] In other non-limiting embodiments, the ligands can include
(3-methoxyphenyl).sub.2PN(methyl)P(3-methoxyphenyl).sub.2,
(4-methoxyphenyl).sub.2PN(methyl)P(4-methoxyphenyl).sub.2,
(3-methoxyphenyl).sub.2PN(isopropyl)-P(3-methoxyphenyl).sub.2,
(4-methoxyphenyl).sub.2PN(isopropyl)P(4-methoxyphenyl).sub.2,
(4-methoxyphenyl).sub.2PN(2-ethylhexyl)P(4-methoxyphenyl).sub.2,
(3-methoxyphenyl)(phenyl)PN(methyl)P(phenyl).sub.2 and
(4-methoxyphenyl)-(phenyl)PN(methyl)P(phenyl).sub.2,
(3-methoxyphenyl)(phenyl)PN(methyl)P(3-methoxyphenyl)(phenyl),
(4-methoxyphenyl)(phenyl)PN(methyl)-P(4-methoxyphenyl)(phenyl),
(3-methoxyphenyl).sub.2PN(methyl)P-(phenyl).sub.2 and
(4-methoxyphenyl).sub.2PN-(methyl)P(phenyl).sub.2,
(4-methoxyphenyl).sub.2PN(1-cyclohexylethyl)P(4-methoxyphenyl).sub.2,
(4-methoxy-phenyl).sub.2PN(2-methylcyclohexyl)P(4-methoxyphenyl).sub.2,
(4-methoxyphenyl).sub.2PN(decyl)P(4-methoxyphenyl).sub.2,
(4-methoxyphenyl).sub.2PN(pentyl)P(4-methoxyphenyl).sub.2,
(4-methoxyphenyl).sub.2PN(benzyl)P(4-methoxyphenyl).sub.2,
(4-methoxyphenyl).sub.2PN(phenyl)P(4-methoxyphenyl).sub.2,
(4-fluorophenyl).sub.2PN(methyl)P(4-fluorophenyl).sub.2,
(2-fluorophenyl).sub.2PN(methyl)P(2-fluorophenyl).sub.2,
(4-dimethyl-aminophenyl).sub.2PN(methyl)P(4-dimethylamino-phenyl).sub.2,
(4-methoxyphenyl).sub.2PN(allyl)P(4-methoxyphenyl).sub.2,
(phenyl).sub.2PN(isopropyl)P(2-methoxyphenyl).sub.2,
(4-(4-methoxyphenyl)-phenyl).sub.2PN(isopropyl)P(4-(4-methoxyphenyl)-phen-
yl).sub.2 and (4
methoxyphenyl)-(phenyl)PN(isopropyl)P(phenyl).sub.2.
[0121] In yet other non-limiting embodiments, the ligands can
include (phenyl).sub.2PN(methyl)P(phenyl).sub.2,
(phenyl).sub.2PN(pentyl)P(phenyl).sub.2
(phenyl).sub.2PN(phenyl)P(phenyl).sub.2,
(phenyl).sub.2PN(p-methoxyphenyl)P(phenyl).sub.2,
(phenyl).sub.2PN(p-t-butylphenyl)P(phenyl).sub.2,
(phenyl).sub.2PN((CH.sub.2).sub.3-N-morpholine)P(phenyl).sub.2,
(phenyl).sub.2PN-(Si(CH.sub.3).sub.3)P(phenyl).sub.2,
(((phenyl).sub.2P).sub.2NCH.sub.2CH.sub.2)N,
(ethyl).sub.2PN(methyl)P(ethyl).sub.2,
(ethyl).sub.2PN(isopropyl)-P(phenyl).sub.2,
(ethyl)(phenyl)PN(methyl)P(ethyl)(phenyl),
(ethyl)(phenyl)PN(isopropyl)P(phenyl).sub.2,
(phenyl).sub.2P(.dbd.Se)N(isopropyl)P(phenyl).sub.2,
(phenyl).sub.2PCH.sub.2CH.sub.2P(phenyl).sub.2,
(o-ethylphenyl)(phenyl)-PN(isopropyl)P(phenyl).sub.2,
(o-methylphenyl).sub.2PN(isopropyl)P(o-methylphenyl)(phenyl),
(phenyl).sub.2PN(benzyl)-P(phenyl).sub.2,
(phenyl).sub.2PN(1-cyclohexyl-ethyl)P(phenyl).sub.2,
(phenyl).sub.2PN[CH.sub.2CH.sub.2CH.sub.2Si(OMe.sub.3)]P(phenyl).sub.2,
(phenyl).sub.2PN(cyclohexyl)P(phenyl).sub.2,
(phenyl).sub.2PN(2-methylcyclohexyl)P(phenyl).sub.2,
(phenyl).sub.2PN(allyl)-P(phenyl).sub.2,
(2-naphthyl).sub.2PN(methyl)P(2-naphthyl).sub.2,
(p-biphenyl).sub.2PN(methyl)P(p-biphenyl).sub.2,
(p-methylphenyl).sub.2PN(methyl)P(p-methylphenyl).sub.2,
(2-thiophenyl).sub.2PN(methyl)P(2-thiophenyl).sub.2,
(phenyl).sub.2PN(methyl)-N(methyl)P(phenyl).sub.2,
(m-methylphenyl).sub.2PN(methyl)P(m-methylphenyl).sub.2,
(phenyl).sub.2PN(isopropyl)P(phenyl).sub.2, and
(phenyl).sub.2P(.dbd.S) N(isopropyl)P(phenyl).sub.2.
[0122] In an aspect, the catalyst comprising the heteroatomic
ligand described by the formula
(R.sup.1)(R.sup.2)A--B--C(R.sup.3)(R.sup.4) can oligomerize
ethylene to olefin composition comprising 1-hexene, 1-octene, or
mixtures thereof. In other embodiments, the heteroatomic ligand
described by the formula (R')(R.sup.2)A--B--C(R.sup.3)(R.sup.4) can
trimerize ethylene to 1-hexene; alternatively, tetramerize ethylene
to 1-octene; or alternatively, trimerize and tetramerize ethylene
to mixtures of 1-hexene and 1-octene.
[0123] The heteroatomic ligand can be modified to be attached to a
polymer chain so that the resulting heteroatomic coordination
complex of the transition metal is soluble at elevated
temperatures, but becomes insoluble at 25.degree. C. This approach
would enable the recovery of the complex from the reaction mixture
for reuse and has been used for other catalyst as described by D.
E. Bergbreiter et al., J. Am. Chem. Soc., 1987, 109, 177-179. In a
similar vein these transition metal complexes can also be
immobilized by binding the heteroatomic ligands to silica, silica
gel, polysiloxane or alumina or the like backbone as, for example,
demonstrated by C. Yuanyin et al., Chinese J. React Pol, 1992,
1(2), 152-159 for immobilizing platinum complexes.
[0124] In an embodiment using a pyrrole-containing compound, a
nitrogen-containing compound may be contacted with the metal alkyl
prior to contacting the metal alkyl with the chromium-containing
compound, the pyrrole-containing compound, the optional
halide-containing compound, the solvent, or combinations thereof,
to make a catalyst for use in oligomerizing an olefin. Typically,
preparation of catalyst can result in undesirable reaction products
of metal alkyls, e.g., aluminum alkyls, with water impurities.
Water present in the catalyst components at the time they are added
to the metal alkyl compound may be a source of precipitates that
can lead to polymer formation in the oligomerization reaction. Such
precipitates may be abated by the addition of a nitrogen compound
to the metal alkyl, thereby enhancing the solubility of the
undesirable reaction products and preventing them from
precipitating out, and further minimizing polymer production in the
oligomerization reaction.
[0125] The nitrogen-containing compound may be comprised of amines,
pyrroles, pyridines, substituted pyrroles such as indoles, di and
tri nitrogen heterocycles, or combinations thereof. In an
embodiment, the nitrogen-compound may be 2,5-dimethylpyrrole, which
in this case the nitrogen compound can serve in two different
functions: one, in the formation of the active site in the catalyst
system; and two, in preventing the precipitation of the product of
the water and metal alkyl reaction (as a solubility enhancer). In
an embodiment, the nitrogen-containing compound is tributyl amine.
In an embodiment, the final catalyst product is comprised of from
about 0.01 to about 10 moles nitrogen per mole metal; alternatively
the final catalyst product is comprised of from about 0.05 to about
5 moles nitrogen to mole metal; or alternatively the final catalyst
product is comprised of from about 0.1 to about 0.5 moles nitrogen
to mole metal.
[0126] In an embodiment for making a catalyst comprising a
chromium-containing compound, a nitrogen-containing compound, a
metal alkyl, an optional halide-containing compound, and optionally
a solvent for use in oligomerizing an olefin, the
chromium-containing compound, the nitrogen-containing compound, and
the metal alkyl may be simultaneously contacted. In an embodiment
the simultaneous contact of the catalyst components occur via
addition to a single contact zone. The simultaneous contacting may
occur over a period of time of from about 1 minute to about 12
hours; alternatively from about 1 minute to about 6 hours; or
alternatively from about 1 minute to about 3 hours. In an
embodiment, the simultaneous contacting may occur over a period of
less than or equal to about 120 minutes to form a catalyst product.
In an embodiment, one or more of the catalyst components may be fed
to the contact zone at mass flow rates of from about 0.1 Kg/hr to
about 500 Kgs/hr, alternatively from about 5 Kg/hr to about 250
Kgs/hr; alternatively from about 10 Kg/hr to about 150 Kgs/hr;
alternatively from about 0.1 Kg/hr to about 100 Kgs/hr;
alternatively from about 0.1 Kg/hr to 50 Kgs/hr; alternatively from
about 0.5 Kg/hr to 25 Kgs/hr; or alternatively from about 1.0 Kg/hr
to 10 Kgs/hr. Such mass flow rates may also be employed with other
embodiments described herein. In an embodiment, the simultaneous
contacting is performed in a continuous process (wherein the period
of time may be an extended period of time), or alternatively in a
batch process. In an embodiment, the metal alkyl may be in a
solution comprising a non-metal halide and a metal alkyl, a metal
alkyl halide, a metal halide and a metal alkyl, or combinations
thereof. In an embodiment, the halide-containing compound may also
be simultaneously contacted with the chromium-containing compound,
the nitrogen-containing compound, and the metal alkyl, for example
by simultaneous addition to the hydrocarbon solvent.
[0127] In an embodiment as shown in FIG. 4A, the composition
comprising the chromium-containing compound may be fed into contact
zone 1100 via line 1110, the composition comprising the
nitrogen-containing compound may be fed into contact zone 1100 via
line 1120, the composition comprising the metal alkyl may be fed
into contact zone 1100 via line 1115, and the composition
comprising the optional halide-containing compound may be fed into
contact zone 1100 via line 1180, all compositions being fed into
contact zone 1100 simultaneously over a period of time. In an
embodiment as shown in FIG. 4B, the composition comprising the
chromium-containing compound may be fed into contact zone 1100 via
line 1110, the composition comprising the nitrogen-containing
compound may be fed into contact zone 1100 via line 1120, the
compositions comprising the metal alkyl and the optional
halide-containing compound may be pre-contacted and fed into
contact zone 1100 via line 1117, the final compositions being fed
into contact zone 1100 simultaneously over a period of time. In an
embodiment as shown in FIG. 4C, the compositions comprising the
chromium-containing compound and the nitrogen-containing compound
may be pre-contacted and fed into contact zone 1100 via line 1122,
the composition comprising the metal alkyl may be fed into contact
zone 1100 via line 1115, and the compositions comprising the
optional halide-containing compound may be fed into contact zone
1100 via line 1180, the final compositions being fed into contact
zone 1100 simultaneously over a period of time. In an embodiment as
shown in FIG. 4D, the compositions comprising the
chromium-containing compound and the nitrogen-containing compound
may be pre-contacted and fed into contact zone 1100 via line 1122
and the compositions comprising the metal alkyl and the optional
halide-containing compound may be pre-contacted and fed into
contact zone 1100 via line 1117, the final compositions being fed
into contact zone 1100 simultaneously over a period of time. In the
embodiments shown in FIGS. 4A-4D, a hydrocarbon solvent may be
placed in contact zone 1100 before, after, or concurrently with
addition of the various catalyst components. Contact zone 1100 may
comprise a single vessel, for example a storage tank, tote,
container, mixing vessel, etc. A catalyst product may be withdrawn
from contact zone 1100 via line 1170 and optionally filtered
(filter not shown). In the embodiments shown in FIGS. 4A-4D, the
addition of the composition comprising the nitrogen-containing
compound (e.g. the pyrrole-containing compound or any other
nitrogen containing ligand described herein) and the composition
comprising the chromium-containing compound may be made in constant
or varying Py:Cr ratios as disclosed previously. Additionally, the
water, acidic protons, or both abatement embodiments set forth in
FIGS. 2A-2D and 3A-3B may be combined with the simultaneous
addition embodiments of FIGS. 4A 4D.
[0128] In an embodiment for making a catalyst comprising a
chromium-containing compound, a nitrogen-containing compound, a
metal alkyl, an optional halide-containing compound, and optionally
a solvent for use in oligomerizing an olefin, the compositions
comprising the chromium-containing compound, the
nitrogen-containing compound, the metal alkyl, the optional
halide-containing compound, or combinations thereof may be
contacted with a previously prepared oligomerization catalyst
composition. The previously prepared oligomerization catalyst
solution may comprise the same or different chromium-containing
compound, nitrogen-containing compound, metal alkyl, and optional
halide-containing compound. The optional halide-containing compound
may comprise a metal halide, a metal alkyl halide, or combinations
thereof.
[0129] Any of the embodiments disclosed herein for making catalysts
may be carried out wherein the new catalyst may be prepared in one
or more contact zones comprising existing, previously prepared
active catalyst. For example, in the embodiments shown in FIGS.
4A-D, contact zone 1100 may be a holding tank for active catalyst
to be fed to an oligomerization reactor and be comprised of
previously prepared oligomerization catalyst. The various catalyst
compounds in lines 1110, 1115, 1117, 1120, 1122, and 1180 may be
simultaneously combined with the previously prepared
oligomerization catalyst composition in contact zone 1100.
[0130] In an embodiment as shown in FIG. 4E, contact zone 1200 may
be a holding tank for active catalyst to be fed to an
oligomerization reactor and comprises previously made
oligomerization catalyst. The chromium-containing compound in line
1210 may be combined with a hydrocarbon solvent in line 1250
forming a first solution in contact zone 1225. The
nitrogen-containing compound in line 1220, the metal alkyl in line
1215, and the optional halide-containing compound in line 1280 may
be combined with the hydrocarbon solvent in line 1251 forming a
second solution in contact zone 1235. The hydrocarbon solvent in
line 1250 may be the same or different hydrocarbon solvent in line
1251. The first solution in contact zone 1225 and the second
solution in contact zone 1235 may then be contacted (e.g.,
simultaneously or sequentially, including a plurality of iterative
addition sequences) with the previously made oligomerization
catalyst composition in contact zone 1200 via lines 1216 and 1218,
respectively, to make the new catalyst composition. Optionally, a
mixer may be disposed in contact zone 1200 to thoroughly mix the
new and existing catalyst components. Again, the contacting of the
composition comprising the nitrogen-containing compound (e.g. the
pyrrole-containing compound or any other nitrogen containing ligand
described herein) and the composition comprising the
chromium-containing compound may be made in constant or varying
Py:Cr ratios as disclosed previously. Additionally, the water,
acidic protons, or both abatement embodiments set forth in FIGS.
2A-2D and 3A-3B may be combined with the simultaneous addition
embodiment of FIG. 4E.
[0131] Contacting of the catalyst components can be done under any
conditions sufficient to thoroughly contact the components.
Typically, contacting is performed in an inert atmosphere, such as,
for example, nitrogen and/or argon. The reaction temperature for
the disclosed methods of making a catalyst for use in oligomerizing
an olefin can be any temperature. For ease of operation, ambient
temperature may be employed. In order to effectuate a more
efficient reaction, temperatures which maintain the reaction
mixture in a liquid state are desirable. In an embodiment, reaction
temperature is maintained at less than about 120.degree. C.;
alternatively less than about 100.degree. C.; alternatively less
than about 75.degree. C.; alternatively less than about 50.degree.
C.; or alternatively less than about 25.degree. C. when contacting
the compositions comprising the chromium-containing compound, the
nitrogen-containing compound, the metal alkyl, the optional
halide-containing compound, or combinations thereof to make the
catalyst. The preparation of the catalyst system at a low
temperature may increase catalyst activity and reduce levels of
undesirable co-product polymer.
[0132] The reaction pressure for the disclosed methods of making a
catalyst for use in oligomerizing an olefin can be any pressure
that does not adversely effect the reaction. Generally, pressures
within the range of from about atmospheric pressure to about three
atmospheres are acceptable. For ease of operation atmospheric
pressure may be employed.
[0133] The reaction time for the disclosed methods of making a
catalyst for use in oligomerizing an olefin can be any amount of
time that can react substantially all reactants (i.e., catalyst
components). Depending on the reactants, as well as the reaction
temperature and pressure, reaction time can vary. Usually, times of
less than about 1 day can be sufficient, for example from about 1
minute to about 12 hours. In an embodiment, reaction time is from
about 1 minute to about 6 hours, alternatively from about 1 minute
to about 3 hours. Longer times usually provide no additional
benefit and shorter times may not allow sufficient time for
complete reaction.
[0134] The resultant olefin oligomerization catalyst system
prepared as described above in any of the embodiments can be
collected and kept under a dry, inert atmosphere to maintain
chemical stability and reactivity. In an embodiment, it may be
desirable to contact the catalyst with the olefin within about 1000
hours of preparation of the catalyst; alternatively the catalyst
may be contacted with the olefin within about 800 hours of
preparation of the catalyst; alternatively the catalyst may be
contacted with the olefin within about 600 hours of preparation of
the catalyst; alternatively the catalyst may be contacted with the
olefin within about 400 hours of preparation of the catalyst; or
alternatively the catalyst may be contacted with the olefin within
about 200 hours of preparation of the catalyst. In an embodiment,
the olefin oligomerization catalyst comprising the
chromium-containing compound, the nitrogen-containing compound, the
metal alkyl, the optional halide-containing compound, and
optionally the solvent may product a product (e.g., hexane) having
a purity of at least 99.4 at a time within about 200 hours after
preparation of the catalyst; alternatively the product may have a
purity of at least about 99.3 at a time within about 400 hours
after preparation of the catalyst; alternatively the product may
have a purity of at least about 99.1 at a time within about
600_hours after preparation of the catalyst; alternatively the
product may have a purity of at least about 98.8 at a time within
about 800 hours after preparation of the catalyst; or alternatively
the product may have a purity of less than about 98.8 at a time
greater than about 900 hours after preparation catalyst.
[0135] The chromium-containing compound may be one or more organic
or inorganic chromium compounds, with a chromium oxidation state of
from about 0 to about 6. As used in this disclosure, chromium metal
may be included in this definition of a chromium compound.
Generally, the chromium-containing compound will have a formula of
CrX.sub.n, wherein X can be the same or different and can be any
organic or inorganic radical, and n may be an integer from 0 to 6.
Suitable organic radicals can have from about 1 to about 20 carbon
atoms per radical, and are selected from alkyl, alkoxy, ester,
ketone, amino radicals, or combinations thereof. The organic
radicals can be straight-chained or branched, cyclic or acyclic,
aromatic or aliphatic, and can be made of mixed aliphatic,
aromatic, and/or cycloaliphatic groups. Suitable inorganic radicals
include, but are not limited to halides, sulfates, oxides, or
combinations thereof.
[0136] The chromium-containing compound may be a chromium(II)
compound, chromium(III) compound, or combinations thereof. Suitable
chromium(II) compounds include, but are not limited to, chromous
fluoride, chromous chloride, chromous bromide, chromous iodide,
chromium(II) bis(2-ethylhexanoate), chromium(II) acetate,
chromium(II) butyrate, chromium(II) neopentanoate, chromium(II)
laurate, chromium(II) stearate, chromium(II) oxalate, chromium(II)
benzoate, chromium(II) pyrrolide(s), or combinations thereof.
Suitable chromium(III) compounds include, but are not limited to,
chromium carboxylates, chromium naphthenates, chromium halides,
chromium pyrrolides, chromium benzoates, chromium dionates, or
combinations thereof. Specific chromium(III) compounds include, but
are not limited to, chromium(III) trichloride tris-tetrahydrofuran
complex, (benzene)-tricarbonyl chromium(III), chromium(III)
2,2,6,6-tetramethylheptanedionate, chromium(III) naphthenate,
chromium(III) chloride, chromic bromide, chromic chloride, chromic
fluoride, chromium(III) hexacarbonyl, chromium(III)
acetylacetonate, chromium(III) pyrrolide(s), or combinations
thereof.
[0137] In an embodiment, the chromium-containing compound is a
chromium(III) carboxylate. Without limitation, examples of
chromium(III) carboxylates include chromium(III) isooctanoate,
chromium(III) tris(2-ethylhexanoate), chromium(III)
oxy-2-ethylhexanoate, chromium(III) dichloroethylhexanoate,
chromium(III) acetate, chromium(III) butyrate, chromium(III)
neopentanoate, chromium(III) laurate, chromium(III) stearate,
chromium(III) oxalate, chromium(III) benzoate, chromium(III)
octanoate, chromium(III) propionate, or combinations thereof. In
some embodiments, the chromium-containing compound can be
chromium(III) tris(2-ethylhexanoate).
[0138] A typical chromium carboxylate preparation may contain a
mixture of compounds, referred to generally as the chromium
carboxylate preparation mixture and referred to more specifically
as the Cr-mix when the chromium carboxylate is chromium(III)
2-ethylhexanoate. Compounds in the preparation mixture may include
the desired chromium carboxylate, denoted hereafter as
Cr(COOR).sub.x, a hydrated chromium species, denoted hereafter as
Cr(H.sub.2O).sub.x, chromium oligomers, denoted hereafter as
Cr.sub.x, free water and free acid. In an embodiment, the weight
percent chromium in the preparation mixture ranges from about 10.3
wt % to 12.8 wt %; alternatively from 10.4 wt % to 11.8 wt %;
alternatively from 10.5 wt % to 11.2 wt % based on the total weight
of the preparation mixture. In such an embodiment, the chromium
content may be decreased to within the wt. % ranges disclosed.
Methods for decreasing the chromium content such as ligand
titration and heating are known to one of ordinary skill in the
art. The wt % chromium is relative to the carboxyl group used.
[0139] The hydrated chromium species, Cr(H.sub.2O).sub.x, include
any species having water complexed to the chromium atom, for
example including but not limited to hydrated chromium
carboxylates. The chromium oligomers, Cr.sub.x, include any
chromium containing species containing more than one chromium atom
per chromium-containing species. The chromium oligomer and hydrated
chromium species can have a negative impact upon catalyst
performance in the oligomerization of ethylene to 1-hexene or
1-octene. Thus, the presence of the chromium oligomers and hydrated
chromium species should be controlled to achieve the desired
catalytic performance in the oligomerization of ethylene to
1-hexene or 1-octene.
[0140] Herein the weight percent chromium carboxylate refers to the
amount of the desired Cr(COOR).sub.x based on the total amount of
chromium-containing species in the mixture as indicated by equation
1: wt . .times. % .times. .times. Cr .times. .times. .times.
carboxylate = wt . .times. Cr .times. .times. .times. carboxylate
wt . .times. Cr .times. .times. species ( 1 ) ##EQU1## where
.SIGMA. wt. Cr species includes all chromium containing species
present in the composition including chromium oligomer, hydrated
chromium species, and the desired chromium carboxylate. In
embodiments, the wt. % chromium carboxylate can be greater than 90
wt. %; alternatively greater than 92.5 weight percent;
alternatively, greater than 95 wt. %; alternatively, greater than
97.5 weight percent; or alternatively, greater than 99.0 weight
percent.
[0141] In an embodiment, the monomeric chromium content and the
residual (excess) radicals are optimized. This value is designated
by the ratio moles Cr:((moles ligand.times.number of coordination
equivalents of the ligand/mole of ligand)/Cr oxidation number). In
an embodiment the ratio moles Cr:((moles ligand.times.number of
coordination equivalents of the ligand/mole of ligand)/Cr oxidation
number) is from about 0.9:1 to about 1.1:1, alternatively from
about 0.94:1 to about 1.08:1, alternatively from about 0.97:1 to
about 1.05:1.
[0142] In an embodiment the chromium carboxylate is chromium(III)
2-ethylhexanoate, which may also be referred to as Cr(EH).sub.3.
During the manufacture of chromium(III) 2-ethylhexanoate a mixture
of compounds may be obtained, which includes the desired
Cr(EH).sub.3, hydrated chromium species, free and coordinated
2-ethylhexanoic acid, chromium oligomers and free water. Hereafter,
the chromium(III) 2-ethylhexanoate mixture will be referred to as
Cr-mix.
[0143] In an embodiment, the oligomerization catalyst produced
using the Cr-mix disclosed herein provides a selective catalyst
with a high conversion rate. Without wishing to be limited by
theory, the relationship between the components of the Cr-mix and
catalyst selectivity, purity, conversion and productivity may be
described by Table 1A: TABLE-US-00001 TABLE 1A Selectivity Purity
C.sub.2 conversion Productivity chromium oligomers - - + hydrated
chromium + - - species Free acid - -
[0144] In Table 1A, the impact of the particular species in the
Cr-mix on catalyst selectivity, purity, conversion and productivity
are indicated as a positive effect (improved performance) by a plus
sign (+) or a negative effect (decreased performance) by a minus
sign (-). In Table 1 A, selectivity to 1-hexene relates to the
selectivity of the catalyst in producing 1 -hexene versus all
olefin oligomer produced and purity relates to the production of
1-hexene versus all C.sub.6 product produced. Table 1A indicates
that the presence of chromium oligomers in the Cr-mix may have a
positive impact on conversion while negatively affecting
selectivity and purity. In contrast, the presence of hydrated
chromium species may have a positive impact on selectivity while
negatively impacting conversion and productivity. Finally, the
presence of free acid in the Cr-mix may negatively impact
selectivity and productivity. Without wishing to be limited by
theory, a Cr-mix having reduced quantities of chromium oligomers,
hydrated chromium species and free acid amounts in the ranges
disclosed herein may produce an oligomerization catalyst having
increased selectivity, purity, conversion and productivity when
compared to a catalyst produced with a Cr-mix having those
components in amounts outside of the disclosed ranges.
[0145] In an embodiment, the amount of chromium oligomers present
in the chromium carboxylate preparation mixture (e.g. Cr-mix) can
be less than about 5 wt. %; alternatively, less than about 2.5 wt.
%; alternatively; less that about 1.0 wt. %; or alternatively, less
than 0.5 wt. % based on the total weight of chromium in the
compound. Generally, the chromium carboxylate is soluble in
methanol while the chromium oligomers are insoluble in methanol.
Thus, one can determine the quantity of chromium oligomers by,
placing a known quantity of chromium preparation in methanol,
filtering the solution to collect the chromium oligomers, drying
the chromium oligomers and calculating the weight percentage of
chromium oligomers in based upon the total quantity of chromium
species in the chromium carboxylate preparation. In an aspect, the
chromium carboxylate preparation is a chromium(III)
tris-2-ethylhexanote preparation (i.e., Cr-mix) and the chromium
carboxylate is chromium(III) tris-2-ethylhexanote.
[0146] In an embodiment, the amount of hydrated chromium species
present in the chromium carboxylate preparation (e.g., the Cr-mix)
is less than about 5 wt. %; alternatively, less than to about 2.5
wt. %; alternatively; less than about 1 wt. %; alternatively, less
than 0.5 wt. %; or alternatively, less than 0.25 weight percent. In
an embodiment, the amount of hydrated chromium is determined via an
acetone solubility test, wherein hydrated chromium(III)
carboxylates are not soluble in acetone while non-hydrated
chromium(III) carboxylates are freely soluble in acetone.
Alternatively, the amount of hydrated chromium may be determined
via UV-Vis, wherein there is a color difference between the
hydrated and non hydrated chromium(III) carboxylates. The amount of
hydrated chromium species present in the chromium carboxylate
preparation may be adjusted by methods known to one of ordinary
skill in the art, for example titration.
[0147] In an embodiment, the amount of free acid in the chromium
carboxylate preparation (e.g., the Cr-mix) is below 50 wt. %;
alternatively below 30 wt. %; alternatively below 20 wt. %;
alternatively, less than 10 wt. %. The amount of free acid may be
adjusted to the disclosed ranges by the acid abatement methods
disclosed herein. Alternatively, the amount of free acid may be
adjusted to the disclosed ranges by any method suitable for the
adjustment of free acid chemically compatible with the compounds
described. Such methods are known to one of ordinary skill in the
art.
[0148] In an embodiment, the particulates, insoluble in hexane, in
the chromium carboxylate preparation (e.g., the Cr-mix) are below 1
weight percent; alternatively below 0.5 wt. % ; alternatively below
0.2 wt. %. The amount of particles present in the Cr-mix may be
adjusted by methods known to one of ordinary skill in the art, for
example filtration.
[0149] In an embodiment, the water content in the chromium
carboxylate preparation (e.g., the Cr-mix) is below 1 wt. %;
alternatively below 0.5 wt. %; alternatively below 0.2 wt. %.
Alternatively, the water content is less than or equal to 1000
ppmw. The water content in Cr-mix may be determined by any suitable
analytical method for the determination of water content. Such
methods for determination of water content are known to one of
ordinary skill in the art and include techniques such as Karl
Fischer and infrared analysis. In an embodiment, the water content
in Cr-mix may be reduced further through the use of water abatement
techniques such as molecular sieves or azeotropic distillation or
metal alkyl addition as described previously.
[0150] In an embodiment, the nitrogen-containing ligand coordinates
the chromium in the chromium-containing compound thus forming a
Cr-N bond that is at least a portion of the active site of the
oligomerization catalyst. Without limitation, examples of such
nitrogen-containing ligands have been disclosed herein and include
pyrrole and pyrrole-containing compounds, the pyrrole
ring-containing compounds and pyrrole derivatives disclosed in U.S.
Patent No. 6,133,495, the neutral multidentate ligands disclosed in
U.S. Pat. No. 2002/0035029, a pyrrole ligand as disclosed in WO
01/83447, a mixed heteroatomic ligand as disclosed in WO 03/053890
or WO 03/053891 or a heteroatomic ligand as disclosed in WO
04/056477, WO 04/056478, WO 04/056479 or WO 04/056480.
[0151] In an embodiment, the nitrogen-containing compound is a
pyrrole-containing compound. The pyrrole-containing compound can be
any pyrrole-containing compound that will react with a chromium
salt to form a chromium pyrrolide complex. The pyrrole-containing
compound includes hydrogen pyrrolide, e.g., pyrrole
(C.sub.4H.sub.5N), derivatives of pyrrole, as well as metal
pyrrolide complexes, alkali metal pyrrolides, salts of alkali metal
pyrrolides, or combinations thereof. A pyrrolide (or a pyrrole) can
be any compound comprising a 5-membered, nitrogen-containing
heterocycle, such as pyrrole, derivatives of pyrrole, substituted
pyrrole, and mixtures thereof. Broadly, the pyrrole-containing
compound can be pyrrole, any heteroleptic or homoleptic metal
complex or salt containing a pyrrolide radical or ligand, or
combinations thereof.
[0152] Generally, the pyrrole-containing compound will have from
about 4 to about 20 carbon atoms per molecule. Pyrrolides (or
pyrroles) include hydrogen pyrrolide (pyrrole), derivatives of
pyrrole, substituted pyrrolides (or pyrroles), lithium pyrrolide,
sodium pyrrolide, potassium pyrrolide, cesium pyrrolide, the salts
of substituted pyrrolides, or combinations thereof. Examples of
substituted pyrrolides (or pyrroles) include, but are not limited
to, pyrrole-2-carboxylic acid, 2-acetylpyrrole,
pyrrole-2-carboxaldehyde, tetrahydroindole, 2,5-dimethylpyrrole,
2,4-dimethyl-3-ethylpyrrole, 3-acetyl-2,4-dimethylpyrrole,
ethyl-2,4-dimethyl-5-(ethoxycarbonyl)-3-pyrrole-propionate,
ethyl-3,5-dimethyl-2-pyrrole-carboxylate
[0153] In an embodiment the pyrrole-containing compound is
2,5-dimethylpyrrole. The content of 2,5-dimethylpyrrole is greater
than 98 weight percent; alternatively greater than 99.0 weight
percent; alternatively greater than 99.5 weight percent. The water
content of the pyrrole containing compound is below 1 weight
percent; alternatively below 0.5 weight percent; alternatively
below 0.01 weight percent. The color of the pyrrole containing
compound (Platinum-Cobalt Number) is below 200; alternatively below
120; alternatively below 80.
[0154] In an embodiment, the pyrrole-containing compound used in an
oligomerization catalyst system comprises a dimeric pyrrole
compound, for example one or more compounds represented by the
following general structures: ##STR14## wherein, each
R.sup.1-R.sup.6 may independently be H, or a C.sub.1-C.sub.20
aromatic group, or any two vicinal to each other, taken together
with the carbon atom to which they are bonded may form an aromatic
or non-aromatic ring. Y is a structural bridge having 1 to 20
carbon atoms and may include linear, branched, or cyclic paraffinic
or aromatic or contain cyclic paraffinic or aromatic structures and
may include hetero atoms such as oxygen or sulfur in the form of
linear, branched, or cyclic ether, silyl, sulfide, sulfone,
sulfoxide functionality.
[0155] In an embodiment shown as Structure (I), R.sup.1, R.sup.3,
R.sup.4, and R.sup.6 are methyl group, R.sup.2 and R.sup.5 are
hydrogens, and Y.dbd.(CH.sub.2).sub.n wherein n=1-10. In an
embodiment shown as Structure (II), R.sup.1 and R.sup.6 are methyl
groups, R.sup.2-R.sup.5 are hydrogens, and Y.dbd.(CH.sub.2)n
wherein n=1-10. In an embodiment shown as Structure (III), R.sup.1,
R.sup.3, and R.sup.5 are methyl groups, R.sup.2, R.sup.4, and
R.sup.6 are hydrogen, and Y.dbd.(CH.sub.2).sub.n wherein
n=1-10.
[0156] Use of the dimeric pyrroles may produce a catalyst system
with activity and selectivity to a desired oligomerized product,
such as, for example comprising 1-hexene or1-octene_as well as low
polymer production.
[0157] The metal alkyl, sometimes referred to as an activating
compound, may be a heteroleptic or homoleptic metal alkyl compound
of any of the metals aluminum, boron, lithium, magnesium, or zinc.
The metal alkyl may be a metal alkyl halide such as DEAC; a
non-halide metal alkyl such as TEA; or combinations thereof. One or
more metal alkyls can be used. The ligand(s) on the metal can be
aliphatic, aromatic, or combinations thereof. For example, the
ligand(s) may be any saturated or unsaturated aliphatic radical.
The metal alkyl may be a compound that can be considered both a
Lewis acid and a metal alkyl. As used in this disclosure, a Lewis
acid may be defined as any compound that may be an electron
acceptor. Activating compounds which are both a metal alkyl and a
Lewis acid include alkylaluminum compounds, alkylmagnesium,
alkylzinc, alkyllithium compounds, or combinations thereof. The
metal alkyl can have any number of carbon atoms. However, due to
commercial availability and ease of use, the metal alkyl will
usually comprise less than about 70 carbon atoms per metal alkyl
molecule and alternatively less than about 20 carbon atoms per
molecule. In an embodiment, the metal alkyls are non-hydrolyzed,
i.e., not pre-contacted with water, such as alkylaluminum
compounds, derivatives of alkylaluminum compounds, halogenated
alkylaluminum compounds, and mixtures thereof for improved product
selectivity, as well as improved catalyst system reactivity,
activity, productivity, or combinations thereof. In an embodiment
the metal alkyl may be non-halide metal alkyl, a metal alkyl
halide, a non-hydrolyzed alkylaluminum compound, a hydrolyzed
alkylalumimum compound, or combinations thereof.
[0158] Suitable non-halide metal alkyls include, but are not
limited to, alkylaluminum compounds, alkyl boron compounds,
alklymagnesium compounds, alkylzinc compounds, alkyllithium
compounds, or combinations thereof. Suitable non-halide metal
alkyls include, but are not limited to, n-butyllithium,
s-butyllithium, t-butyllithium, diethylmagnesium, dibutylmagnesium,
diethylzinc, triethylaluminum, trimethylaluminum,
tripropylaluminum, tributylaluminum, triisobutylaluminum,
tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum ethoxide,
diethylaluminum phenoxide, and mixtures thereof. Suitable metal
alkyl halide compounds include, but are not limited to,
ethylaluminum dichloride, diethylaluminum chloride, diethylaluminum
bromide, diethylaluminum sesquichloride, diisobutylaluminum
chloride, ethylaluminum sesquichloride, diethylaluminum bromide,
diethylaluminum iodide, ethylaluminumethoxychloride, and mixtures
thereof. In an embodiment, the alkylaluminum compound may be
triethylaluminum.
[0159] When a oligomerization catalyst system may be the desired
product, the metal alkyl may be at least one non-hydrolyzed
alkylaluminum compound, expressed by the general formulae
AlR.sub.3, AlR.sub.2X, AlRX.sub.2, AlR.sub.2OR, AlRXOR,
Al.sub.2R.sub.3X.sub.3, or combinations thereof, wherein R may be
an alkyl group and X may be a halogen atom. Suitable compounds
include, but are not limited to, trimethylaluminum,
triethylaluminum, tripropylaluminum, tri-n-butylaluminum,
tri-iso-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum,
diethylaluminumchloride, diethylaluminumbromide,
diethylaluminumethoxide, diethylaluminum phenoxide,
ethylaluminumethoxychloride, ethylaluminum dichloride,
diethylaluminum chloride, diethylaluminum bromide, ethylaluminum
sesquichloride, or combinations thereof. In an embodiment, the
activating compound for an oligomerization catalyst system may be a
trialkylaluminum compound, AlR.sub.3, for example triethylaluminum.
Additionally, hydrolyzed alkylaluminum compounds, aluminoxanes, may
be used. Aluminoxanes can be prepared as known in the art by
reacting water or water containing materials with trialkylaluminium
compounds. Suitable aluminoxanes are prepared from
trialkylaluminium compounds such as trimethylaluminium,
triethylaluminium, tripropylaluminium, tributylaluminium,
trlisobutylaluminium, trihexylaluminium or the like, and mixtures
thereof. Mixtures of different aluminoxanes may also be used.
Suitable hydrolyzed alkylaluminum compounds include, but are not
limited to methylaluminoxane, modified methylaluminoxane, and
ethylaluminoxanes, and mixtures thereof.
[0160] The olefin oligomerization catalyst systems can further
comprise a catalyst support. A supported chromium catalyst system
can be prepared with any support useful to support a chromium
catalyst. Suitable catalyst supports include, but are not limited
to, zeolites, inorganic oxides, either alone or in combination,
phosphated inorganic oxides, and mixtures thereof, for example
silica, silica-alumina, alumina, fluorided alumina, silated
alumina, thoria, aluminophosphate, aluminum phosphate, phosphated
silica, phosphated alumina, silica-titania, coprecipitated
silica/titania, fluorided/silated alumina, and mixtures thereof. In
an embodiment, the catalyst support is aluminophosphate.
[0161] The solvent may be a hydrocarbon solvent, a halogenated
hydrocarbon solvent, or combinations thereof, usually having not
more than 30 carbon atoms. Specific examples of the solvents may
include aliphatic and alicyclic saturated hydrocarbons such as
isobutane, pentane, n-hexane, hexanes, cyclohexane, n-heptane or
n-octane, aliphatic and alicyclic unsaturated hydrocarbons such as
2-hexene, cyclohexene or cyclo-octene, aromatic hydrocarbons such
as toluene, benzene or xylenes, othro-xylene, meta-xylene,
paraxylene, chlorobenzene, halogenated hydrocarbons such as carbon
tetrachloride, chloroform, methylene chloride or chlorobenzene or
dichlorobenzene, or the like. In an embodiment, the hydrocarbon
solvent may be an aromatic or a halogenated aromatic compound
having between about 6 to about 20 carbon atoms; a saturated or
unsaturated hydrocarbon having from about 3 to about 14 carbon
atoms; a halogenated saturated hydrocarbon having from about 1 to
about 9 carbon atoms; or combinations thereof. The solvent may be a
hydrocarbon such as cyclohexane, isobutane, n-hexane, hexanes,
n-heptane, heptanes, pentane, or mixtures thereof. In an
embodiment, the solvent is ethylbenzene. In an embodiment the
solvent is tetradecene. In an embodiment, alpha-olefins may be used
as the solvent, for example 1-hexene. In an embodiment, the solvent
may comprise normal and/or isomeric mixtures of butene, hexene,
octene, decene, dodecene, tetradecene, or combinations thereof.
[0162] In an embodiment, the hydrocarbon compound used as a solvent
can be any combination of one or more aromatic or aliphatic
unsaturated hydrocarbon compounds. While not wishing to be bound by
theory, it may be believed that an unsaturated hydrocarbon compound
acts as more than a solvent, and can be a reactant, a stabilizing
component, or both, either during, subsequent, or both, to
formation of an inventive catalyst system. Suitable unsaturated
hydrocarbon compounds can be any unsaturated hydrocarbon compound
that can solubilize the catalyst system. In an embodiment, aromatic
compounds having from about 6 to about 20 carbon atoms per molecule
as a solvent there can be used in combination with any unsaturated
aliphatic hydrocarbon comprising less than about 20 carbon atoms
per molecule. Specific unsaturated aliphatic compounds include
ethylene, 1-hexene, 1,3-butadiene, and mixtures thereof. In an
embodiment, the unsaturated aliphatic hydrocarbon compound may be
ethylene, which may be both a solvent and a reactant. Specific
unsaturated aromatic hydrocarbon compounds include, but are not
limited to, toluene, benzene, ortho-xylene, metaxylene,
para-xylene, ethylbenzene, xylene, mesitylene, hexamethylbenzene,
and mixtures thereof.
[0163] The optional halide-containing compound can be any compound
containing a halogen, for example organohalides (including those
listed as suitable solvents); non-organohalides; metal halides
(including metal alkyl halides such as those previously described
and non-alkyl metal halides such as tin tetrachloride and magnesium
chloride); non-metal halides; or combinations thereof. Suitable
compounds include, but are not limited to, compounds with a general
formula of R.sub.,X.sub.n, wherein R can be any organic radical,
inorganic radical, or both, X can be a halide, selected from
fluoride, chloride, bromide, iodide, or combinations thereof, and m
and n each are numbers greater than 0. Where R is an organic
radical, R may have from about 1 to about 70 carbon atoms per
radical, alternatively from 1 to 20 carbon atoms per radical, for
best compatibility and catalyst system activity. Where R is an
inorganic radical, R may be selected from aluminum, silicon,
germanium, hydrogen, boron, lithium, tin, gallium, indium, lead,
and mixtures thereof. In an embodiment, the halide-containing
compound is a chloride-containing compound such as DEAC or
organochlorides. Specific organo halides compounds include, but are
not limited to, methylene chloride, chloroform, benzylchloride
chlorobenzene, carbon tetrachloride, chloroethane,
1,1-dichloroethane, 1,2-dichloroethane, tetrachloroethane,
hexachloroethane, 1,4-di-bromobutane, 1-bromobutane, aryl chloride,
carbon tetrabromide, bromoform, bromobenzene, iodomethane,
di-iodomethane, hexafluorobenzene trichloro-acetone,
hexachloro-acetone, hexachloro-cyclohexane,
1,3,5-trichloro-benzene, hexachloro-benzene, trityl chloride, or
mixtures thereof. Specific non-alkyl metal halides include but are
not limited to silicon tetrachloride, tin (II) chloride, tin (IV)
chloride, germanium tetrachloride, boron trichloride, scandium
chloride, yttrium chloride, lanthanum chloride, titanium
tetrachloride, zirconium tetrachloride, hafnium tetrachloride,
aluminum chloride, gallium chloride, silicon tetrachloride, tin
tetrachloride, phosphorus trichloride, antimony trichloride,
trityl-hexachloro-antimonate, antimony pentachloride, bismuth
trichloride, boron tribromide, silicon tetrabromide, , aluminum
fluoride, molybdenum pentachloride, tungsten hexachloride, aluminum
tribromide, aluminum trichloride, or combinations thereof. Specific
metal alkyl halide compounds include, diethyl aluminum chloride,
ethyl aluminum sesquichloride, ethyl aluminum dichloride, mixture
of non-halide metal alkyls and metal halides,
trimethyl-chlorosilane, tributyl tin chloride, dibutyl tin
dichloride, or combinations thereof.
[0164] Furthermore, the chromium-containing compound, the metal
alkyl, or solvent can contain and provide a halide to the reaction
mixture. For example, the halide source may be an alkylaluminum
halide and may be used in conjunction with alkylaluminum compounds.
Suitable alkylaluminum halides include, but are not limited to,
diisobutylaluminum chloride, diethylaluminum chloride,
ethylaluminum sesquichloride, ethylaluminum dichloride,
diethylaluminum bromide, diethylaluminum iodide, and mixtures
thereof.
[0165] The amount of each reactant used to prepare an
oligomerization catalyst system can be any amount sufficient that,
when combined to form the catalyst system, oligomerization occurs
upon contact with one or more olefins. Generally, a molar excess of
the metal alkyl is used. In an embodiment in which the
nitrogen-containing compound is a pyrrole, expressed as a molar
ratio, in terms of moles of nitrogen (N) in the pyrrole compound to
moles of metal (M) in the metal alkyl, usually less than a 1:150
molar ratio is used. In an embodiment, the metal (M) is aluminum.
In an embodiment, the N:M molar ratio is from about 1:1 to about
1:50, alternatively from about 1:1 to about 1:20, or alternatively
from about 1:1 to about 1:10. Generally, the amount of metal
alkyl/pyrrole solution used is determined based on the moles of
chromium. In an embodiment, expressed as a molar ratio, in terms of
moles of chromium (Cr) to moles of nitrogen (N) in the pyrrole
compound to moles of metal (M) in the metal alky, i.e., Cr:N:M, the
ratio of the chromium containing compound to the pyrrole-containing
compound is at least about 1:15 and the ratio of the chromium
containing compound to metal alkyl is at least about 1:150 such
that Cr:N:M is at least about 1:15:150. In an embodiment, the
Cr:N:M molar ratio is within a range of about 3:3:3 (also expressed
as about 1:1:1) to about 1:3:100; alternatively, the Cr:N:M molar
ratio is within a range of 1:3:9 to 1:3:21. In an embodiment, to
prepare an oligomerization catalyst system, about one mole of
chromium, as the element chromium (Cr), can be contacted with about
1 to about 50 moles of pyrrole-containing compound and about 1 to
about 75 moles of aluminum, as the element, optionally in an excess
of unsaturated hydrocarbon. The halide source may be present in an
amount from about 1 to about 75 moles of halide, as the element. In
an embodiment, about 1 mole of chromium, calculated as the element
chromium (Cr), can be contacted with about 1 to about 15 moles of
pyrrole-containing compound; about 5 to about 40 moles of aluminum,
calculated as the element aluminum (Al); and about 1 to about 30
moles of the halide-containing compound, calculated as elemental
halide (X); in an excess of unsaturated hydrocarbon. In an
embodiment, about one mole of chromium, as the element (Cr), may be
contacted with two to four moles of pyrrole-containing compound; 10
to 25 moles of aluminum, as the element (Al); and 2 to 15 moles of
halide, as an element (X); in an excess of unsaturated
hydrocarbon.
[0166] The ratio of pyrrole to chromium (Py:Cr) in the final
catalyst composition recovered as product from the various
embodiments disclosed herein is referred to as the final Py:Cr
molar ratio. The final Py:Cr molar ratio of the catalyst may be in
a range of from about 1.0:1 to about 4.0:1; alternatively from
about 1.5:1 to about 3.7:1; alternatively from about 1.5:1 to about
2.5:1; alternatively from about 2.0:1 to about 3.7:1; alternatively
from about 2.5:1 to about 3.5:1; or alternatively from about 2.9:1
to about 3.1:1.
[0167] The catalyst synthesis prepared in a hydrocarbon solvent may
be referred to as a catalyst system solution. The resultant
catalyst system, prior to introduction to any of the reactant, may
have a chromium concentration of about less than about 50 mg Cr/ml
catalyst system solution, for example from about 0.005g Cr/mL
catalyst system solution to about 25 mg Cr/ml catalyst system
solution, alternatively from about 0.1 mg Cr/ml catalyst system
solution to about 25 mg Cr/ml catalyst system solution,
alternatively from about 0.5 mg Cr/ml catalyst system solution to
about 15 mg Cr/ml catalyst system solution, or alternatively from
about 1 mg Cr/ml catalyst system solution to about 15 mg Cr/ml
catalyst system solution
[0168] Catalysts prepared in accordance with the present disclosure
may be used for the oligomerization of olefins, for example,
alpha-olefins. The oligomerization of olefins may be conducted by
any suitable oligomerization methods. In an embodiment, an
oligomerization catalyst is contacted with one or more olefins in a
reaction zone under suitable reaction conditions (e.g.,
temperature, pressure, etc.) to oligomerize the olefins. Linear or
branched alpha-olefins having 2 to 30 carbon atoms can be used as
the olefins raw material. Specific examples of the alpha-olefins
may include ethylene, propylene, 1-butene, 1-hexene, 1-octene,
3-methyl-1-butene, 4-methyl-1-pentene or the like. When ethylene is
used as the alpha-olefin, it is possible to produce an olefin
composition comprising 1-hexene as a trimer or 1-octene as a
tetramer of ethylene with a high yield and a high selectivity.
[0169] In the description above, like parts are marked throughout
the specification and drawings with the same reference numerals,
respectively. The drawing figures are not necessarily to scale.
Certain features of the invention may be shown exaggerated in scale
or in somewhat schematic form and some details of conventional
elements may not be shown in the interest of clarity and
conciseness. The present disclosure is susceptible to embodiments
of different forms. There are shown in the drawings, and herein are
described in detail, specific embodiments of the present disclosure
with the understanding that the present disclosure is to be
considered an exemplification of the principles of the invention,
and is not intended to limit the invention to that illustrated and
described herein. It is to be fully recognized that the different
teachings of the embodiments discussed above may be employed
separately or in any suitable combination to produce desired
results. Specifically, the present disclosure for a method of
making a catalyst by contacting of catalyst components should not
be limited by any of the various embodiments described. Various
embodiments set forth in the figures may be combined. For example,
the water, acidic protons, or both abatement embodiments set forth
in FIGS. 2A-2D and 3A-3B may be combined with the bulk addition
embodiments of FIGS. 1A-1D or the simultaneous addition embodiments
of FIGS. 4A-4E. Additionally, various embodiments for abating water
may be combined in any desired number and sequence, for example
azeotropic distillation followed by contact with a non-halide metal
alkyl (e.g., TEA), contact with an adsorbent, or both in any order;
contact with a non-metal halide followed by contact with an
adsorbent (or vice-versa); azeotropic distillation before, after,
or between contact with a non-metal halide followed by contact with
an adsorbent; etc. The water, acidic protons, or both abatement,
bulk addition, and simultaneous addition embodiments may be
integrated in any desired and operable number and sequence in other
embodiments. The method disclosed herein is for making an
oligomerization catalyst that may be useful in any suitable
reaction such that the reaction is an oligomerization reaction. In
an embodiment, the method of the present disclosure is for a
oligomerization catalyst for use in a trimerization reaction
producing 1-hexene from ethylene or the tetramerization reaction to
produce 1-octene and the detailed description above may be focused
on these embodiments but with the understanding that the present
invention may have broader applications.
EXAMPLES
[0170] Preparation of an oligomerization catalyst having been
generally described, the following examples are given as particular
embodiments of the catalyst disclosed and to demonstrate the
practice and advantages thereof. It is understood that the examples
are given by way of illustration and are not intended to limit the
specification or the claims to follow in any manner.
[0171] Various embodiments for preparing the oligomerization
catalyst are shown in examples 1 through 14. In example 1,
selective 1-hexene catalyst is prepared at various temperatures and
chromium concentrations. In example 2, selective 1-hexene catalyst
is prepared by simultaneous addition of chromium/ethylbenzene and
TEA/DEAC/pyrrole/ethylbenzene to the heel of previously prepared
catalyst. In example 3, selective 1-hexene catalyst is prepared by
using a pyrrole:chromium ratio of 6:1 for the first half of the
chromium/pyrrole addition and a pyrrole:chromium ratio of 0 during
the second half of the chromium/pyrrole addition. In example 4,
selective 1-hexene catalyst is prepared by simultaneous addition of
all catalyst components. In example 5, chromium compounds
containing various amounts of water and chromium oligomers are used
in the preparation of the selective 1 -hexene catalyst. In example
6, selective 1-hexane catalyst is prepared by separate but
simultaneous addition of the pyrrole and chromium components to a
solution of TEA and DEAC. In example 7, selective 1-hexene catalyst
is improved when a small amount of TEA is added to the chromium
component and water, acidic protons, or both are abated. In example
8, water, acidic protons, or both are abated in the preparation of
the selective 1-hexene catalyst by contacting a small amount of TEA
with the chromium/pyrrole solution. In example 9, preparation of
the selective 1-hexene catalyst is made by varying the
pyrrole:chromium ratio during the addition to TEA/DEAC.
[0172] In example 10, preparation of the selective 1-hexene
catalyst is made using high initial pyrrole:chromium contact ratios
when contacted with TEA/DEAC. In example 11, preparation of the
selective 1-hexene catalyst is made using simultaneous separate
addition of catalyst components to the heel of previously prepared
catalyst. In example 12, preparation of the selective 1-hexene
catalyst is made with the addition of a nitrogen compound to the
alkylaluminum compound to solubilize products resulting from the
reaction of water and aluminum alkyls. In example 13, water is
abated when the pyrrole and chromium components are contacted to
reduce the chromium component's viscosity, facilitating water
removal using molecular sieves. In example 14, water is abated by
azeotropic distillation to remove the water from the chromium
catalyst component. In example 15, the impact of the catalyst age
on 1-hexene purity is described. Several of the above examples also
include the embodiment for the addition of chromium and/or pyrrole
to the alkyl aluminums.
[0173] In the examples below, catalyst was prepared using one of
two apparatus set-ups. One set-up is a lab scale set-up for
preparing catalyst in small quantities, for example 100 ml, which
are typically used for screening purposes. The other set-up is a
pilot plant scale set-up typically designed for preparing larger
quantities of catalyst, for example 3.5 gallons, which would be
suitable for use in a pilot plant.
[0174] The lab scale set-up prepares catalyst in a dry box in which
the atmosphere inside the box is controlled with an inert gas
blanket to keep it free of oxygen and moisture, which may be
detrimental to the catalyst components, the prepared catalysts, or
both. All lab scale catalyst preparation procedures described in
the examples below are performed in glassware in a dry box. Once
the catalyst is prepared it is diluted with cyclohexane to the
concentration desired for oligomerization reactor tests. The
diluted catalyst solution is then transferred into a 300 cc metal
cylinder to provide the means for transport of the catalyst to an
oligomerization reactor under protected atmosphere. Note that any
transfer of components via syringes described in the examples below
is done in the dry box.
[0175] The pilot plant scale set-up prepares catalyst under a
nitrogen blanket to control the atmosphere, keeping it free of
oxygen and moisture. All pilot plant scale catalyst preparation
procedures described in the examples below are performed in a 5
gallon reactor comprising a Hastelloy.RTM. autoclave. Once the
catalyst is prepared it is filtered into a 5-10 gallon metal
cylinder. About 150 grams of the prepared catalyst is then
transferred from the large cylinder into a smaller, 300 cc, metal
cylinder and transported to an inert gas blanketed dry box as
described above. The prepared catalyst is transferred into
glassware and is diluted with cyclohexane to the desired
concentration for testing in the oligomerization reactor. The
diluted catalyst solution is then transferred into a 300 cc metal
cylinder and transported to an oligomerization reactor.
[0176] In the examples below, the prepared catalyst is tested in
either a batch or a continuous oligomerization reactor. The batch
oligomerization reactor is a 1 liter autoclave that is sealed and
is under a nitrogen blanket. It has a magnetic stirring device to
stir the contents of the sealed container. Prepared catalyst
solution transported to the oligomerization reactor in the 75 cc
metal cylinder. Solvent, e.g., cyclohexane, is charged to the
oligomerization reactor, and the catalyst is transferred to the
reactor by connecting the cylinder to the reactor and pressurizing
the cylinder with ethylene, which conveys the catalyst into the
reactor. The oligomerization reactor is pressurized with 650 psig
of ethylene and 50 psig of hydrogen, and is operated at a
temperature of about 115.degree. C.
[0177] In some of the examples below, a continuous oligomerization
reactor is used to test the prepared catalyst. The continuous
oligomerization is performed by controlling of all the feeds to the
reactor by using separate controls for each feed component.
Hydrogen is fed to the reactor at a rate of about 0.5 L/hr, and
ethylene is fed to the reactor at a rate of about 497 g/hr. The
reactor is either a 1 liter or a 1 gallon autoclave, depending on
the desired residence time in the reactor. Reaction temperature is
about 115.degree. C., and pressure is about 800 psig.
[0178] Online samples of production from the continuous
oligomerization reactor were collected via liquid sampling valves
(manufactured by Valco) and fed to an online gas chromatograph
(GC), a Hewlett Packard 6890, for analysis. The production samples
were analyzed by the GC for the amount of ethylene, hexene, and
C.sub.6 isomers and higher oligomers. From this information the
selectivity, purity, and conversion was calculated. Selectivity
(1-C.sub.6=) refers to the weight percent of ethylene converted
into 1-hexene. Purity (1-C.sub.6=/C.sub.6) refers to the weight
percent of 1-hexene in the total of all C.sub.6 isomers. Conversion
(C.sub.2=) refers to the weight percent of ethylene has been
converted to oligomer product (e.g., hexene or decenes, etc.).
Productivity refers how much 1-hexene the catalyst produced, and
relates to the amount of catalyst used. Productivity is quantified
in units of grams of 1-hexene per gram of chromium (g 1-C.sub.6=/g
Cr). In the batch processes, productivity is evaluated over a 30
minute time frame. Other evaluations made on the product include
reactor polymer (Rx Polymer) and total polymer. At the end of each
day, the reactor was opened and cleaned. Any polymer inside the
reactor was collected, allowed to dry, and then weighed. This
amount was then extrapolated to a commercial sized processing unit
of 100,000,000 pounds/year and reported as reactor polymer,
quantified in pounds per hour expected in a 100,000,000 pound per
year plant (Lb/Hr 100MM/yr Plant). A filter comprising a stainless
steel pad placed downstream of the reactor was also removed, dried
and weighed at the end of each day for amounts of polymer. This
amount of polymer was then scaled up to a 100,000,000 pounds/year
plant and added to the reactor polymer amount for reporting the
total polymer, quantified in pounds per hour expected in a
100,000,000 pound per year plant (Lb/Hr 100MM/yr Plant).
[0179] To determine the presence of water of hydration in some of
the samples an infrared analysis was done using standard IR
apparatus. The IR band for the complexed water, e.g., about 1450
cm.sup.-1, of hydration is near the band for chromium oligomers,
making it difficult to distinguish the two. Therefore, in some
cases a methanol solution test for precipitation of chromium
oligomers was performed to help in evaluating the online samples to
determine the presence of water of hydration.
Example 1
[0180] Catalyst 1-8
[0181] Catalyst was prepared by adding 14.1 lbs of dry,
nitrogen-purged toluene to a 5 gallon reactor. To the toluene was
added 630.9 g chromium(III) 2-ethylhexanoate dissolved in 750 mL
toluene followed by a 300 mL toluene rinse. 2,5-Dimethylpyrrole
(388.9 mL) was added to the chromium solution in the reactor. The
reactor was purged with nitrogen and brought to a temperature of
25.degree. C. A mixture of 1,600 g neat triethylaluminum (TEA) and
1,229 g neat diethylaluminum chloride (DEAC) was then added to the
reactor followed by 0.2 lbs of toluene rinse. The temperature
increased 18.degree. C. and was returned to 25.degree. C. with
cooling. The contents of the reactor stood overnight and were then
filtered, using a filter comprising a combination of a metal
screen, filter paper, glass wool, diatomaceous earth, and another
layer of glass wool. Additional catalysts were prepared in which
the temperature and chromium concentration of the catalyst
preparations were varied. The catalysts were tested for
productivity in a 1 gallon continuous reactor and the results are
shown in Table 1B. TABLE-US-00002 TABLE 1B Con- Temp centration
Productivity Rx Polymer Catalyst (.degree. C.) (mg Cr/mL) (g
1-C6=/g Cr) (Lb/Hr 100 MM/yr Plant) Ratio Cr/pyrrole/TEA/DEAC
(1/3/11/8) 1 25 1 43,183 0.001 2 75 1 40,010 0.083 3 25 5 45,769
0.005 4 75 5 44,599 0.000 Ratio Cr/pyrrole/TEA/DEAC (1/1.8/6.5/5) 5
25 1 41,961 0.015 6 75 1 38,008 0.005 7 25 5 43,373 0.016 8 75 5
27,127 0.906
[0182] The examples show that catalyst productivity increased with
a reduction in catalyst preparation temperature. Additionally, the
examples show the best catalyst productivity was observed in
catalyst 3 and catalyst 7 with 45,769 g 1-C6=/g Cr and 43,373g
1-C6=/g Cr, respectively, when prepared at low temperature
(25.degree. C.) and high chromium concentration (5 mg Cr/mL). Low
reactor polymer was also observed under the best productivity
conditions.
Example 2
[0183] Catalyst 9-10
[0184] An ethylbenzene solution containing 2.3 g chromium(III)
2-ethylhexanoate and 8.13 g ethylbenzene was prepared. A separate
solution containing 6.05 g neat triethylaluminum (TEA), 4.63 g neat
diethylaluminum chloride (DEAC), 1.37 g 2,5-dimethylpyrrole and
22.6 g ethylbenzene was also prepared. These two solutions were
added to 30.98 g of active catalyst over a 40 minute period such
that the addition time for both solutions started and ended at the
same time. The catalyst was tested in a 1 L continuous reactor and
the average results of two test runs are shown in Table 2 as
Catalyst 10. The average of two test runs of a standard catalyst
preparation is shown in Table 2 as Catalyst 9. TABLE-US-00003 TABLE
2 Select- Total ivity Purity Productivity Rx Polymer Polymer
Catalyst (1-C.sub.6=) (1-C.sub.6=) (g 1-C.sub.6=/g Cr) (Lb/Hr 100
MM/yr Plant) 9 89.3% 98.8% 82,575 0.00 13.33 10 89.1% 98.7% 82,989
0.00 7.18
[0185] The examples show that an acceptable catalyst can be
prepared. The examples further indicate that a fewer number of
tanks may be required to prepare catalyst.
Example 3
[0186] Catalyst 11
[0187] A solution was prepared by mixing 12.10 g neat
triethylaluminum (TEA), 9.38 g neat diethylaluminum chloride (DEAC)
and 20.02 g ethylbenzene. Two aliquots were added to this solution.
The first contained 2.3 g chromium(III) 2-ethylhexanoate, 1.14 g
ethylbenzene and 2.74 g 2,5-dimethylpyrrole. The second contained
2.3 g chromium(III) 2-ethylhexanoate and 1.14 g ethylbenzene.
Ethylbenzene was added to obtain a total volume of 100 mL. The
catalyst prepared by this method was tested in a 1 L continuous
reactor. The average results of three test runs are shown in Table
3. TABLE-US-00004 TABLE 3 Selectivity Purity Catalyst Productivity
Catalyst (1-C.sub.6=) (1-C.sub.6=/C.sub.6) (g 1-C.sub.6=/g Cr) 11
91.2% 99.2% 80,759
[0188] The example shows high selectivity (91.2%), high purity
(99.2%), and good catalyst productivity (80,759 g 1-C.sub.6=/g Cr)
for the catalyst preparation.
Example 4
[0189] Catalyst 12
[0190] Ethylbenzene (10.67 g) was added to a dry 100 mL volumetric
flask. Individual chemicals were added to each of four separate 20
mL syringes. The chemicals added were 4.76 g chromium(III)
2-ethylhexanoate dissolved in 2.38 g ethylbenzene, 12.06 g neat
triethylaluminum (TEA), 9.26 g neat diethylaluminum chloride (DEAC)
and 2.74 g 2,5-dimethylpyrrole. To each of these syringes was added
sufficient ethylbenzene to provide a total volume of 19-20 mL. The
needles of the syringes were added to the 100 mL volumetric flask
and the syringes emptied into the flask simultaneously at the same
rate over 30 minutes. After the additions were complete,
ethylbenzene was added to the flask to obtain a total volume of 100
mL. The catalyst (1 mL) prepared by this method was tested in a 1 L
batch reactor at 116.degree. C. and 680 psig. The results of this
test are shown in Table 4. TABLE-US-00005 TABLE 4 Selectivity
Purity Catalyst Productivity Catalyst (1-C.sub.6=)
(1-C.sub.6=/C.sub.6) (g 1-C.sub.6=/g Cr) 12 92.0% 98.7% 34,325
Example 5
[0191] Catalyst 13-15
[0192] Catalyst was prepared by adding 15.85 g ethylbenzene to a
dry 100 mL volumetric flask. To this flask was added 12.09 g neat
triethylaluminum (TEA), 9.26 g neat diethylaluminum chloride (DEAC)
and 2.74 g 2,5-dimethylpyrrole. To this mixture was added 4.76 g
chromium(III) 2-ethylhexanoate dissolved in 2.38 g ethylbenzene.
The volume was brought to 100 mL with ethylbenzene. Different
preparations of chromium(III) 2-ethylhexanoate were used to prepare
the catalysts 13-15. In catalyst 13 the chromium content of the
chromium(III) 2-ethylhexanoate was 10.5%. Infrared analysis and a
methanol solubility test indicated that some water of hydration was
present but no chromium oligomers. In catalyst 14 the chromium
content was 10.9% and infrared analysis and methanol solubility
indicated that neither water of hydration nor chromium oligomers
were present. In catalyst 15 the analysis indicated the presence of
chromium oligomers. The catalysts prepared were tested for activity
in the continuous reactor (1 L) and the average results for two
test runs of each preparation are shown in Table 5. TABLE-US-00006
TABLE 5 Selectivity Purity Conversion Catalyst Productivity
Catalyst (1-C.sub.6=) (1-C.sub.6=/C.sub.6) (C.sub.2=) (g
1-C.sub.6=/g Cr) 13 90.3% 99.1% 79.0% 83,642 14 88.7% 99.1% 84.5%
87,882 15 87.4% 98.1% 86.4% 88,460
[0193] The examples show that the best combination of purity and
productivity are obtained when the water of hydration and chromium
oligomers are not contained in the chromium(III) 2-ethylhexanoate
in significant amounts.
Example 6
[0194] Catalyst 16
[0195] Ethylbenzene (20.01 g) was added to a dry 125 mL Erlenmeyer
flask equipped with a magnetic stirrer. To the ethylbenzene was
added 12.07 g neat triethylaluminum and 9.27 g neat diethylaluminum
chloride. Into a 10 mL syringe was added 4.61 g chromium(III)
2-ethylhexanoate dissolved in 2.28 g ethylbenzene. Into a separate
10 mL syringe was added 2.73 g 2,5-dimethylpyrrole and 3.38 g
ethylbenzene. Both of the syringes had an approximate volume of 7.5
mL. The syringe needles were put into opposite sides of the
Erlenmeyer flask containing the diluted aluminum alkyls and the
contents were added simultaneously over 30 minutes. After the
addition was complete, the contents were transferred to a 100 mL
volumetric flask and diluted to about 103 mL with ethylbenzene.
This catalyst was tested in a continuous 1 L reactor and the
results (average of three test runs) are shown in Table 6.
TABLE-US-00007 TABLE 6 Selectivity Purity Conversion Catalyst
Productivity Catalyst (1-C.sub.6=) (1-C.sub.6=/C.sub.6) (C.sub.2=)
(g 1-C.sub.6=/g Cr) 16 93.0% 98.9% 66.6% 72,691
Example 7
[0196] Catalyst 17
[0197] Neat triethylaluminum (TEA, 0.27 g) was added to 30.01 g of
ethylbenzene. This solution was added slowly to 4.62 g
chromium(III) 2-ethylhexanoate dissolved in 2.27 g ethylbenzene.
This is an amount of TEA sufficient to react with water and excess
acid present in the chromium(III) 2-ethylhexanoate. The chromium
solution, after reaction with TEA, was added, over 50 minutes, to a
solution containing TEA (11.81 g), diethylaluminum chloride (DEAC,
9.27 g), 2,5-dimethylpyrrole (2.75 g) and ethylbenzene (25.01 g).
Ethylbenzene was subsequently added to provide a total volume of
100 mL.
[0198] Catalyst 18
[0199] A comparison catalyst was prepared by adding 30.02 g of
ethylbenzene to 4.62 g chromium(III) 2-ethylhexanoate dissolved in
2.27 g ethylbenzene. The chromium solution was added, over 50
minutes, to a solution containing TEA (12.08 g), diethylaluminum
chloride (DEAC, 9.28 g), 2,5-dimethylpyrrole (2.74 g) and
ethylbenzene (25.00 g). Ethylbenzene was subsequently added to
provide a total volume of 100 mL.
[0200] These catalysts were tested for productivity in a 1 L
continuous reactor. The average of two separate runs for each
catalyst is shown in Table 7. TABLE-US-00008 TABLE 7 Selectivity
Purity Conversion Catalyst Productivity Catalyst (1-C.sub.6=)
(1-C.sub.6=/C.sub.6) (C.sub.2=) (g 1-C.sub.6=/g Cr) 17 90.0% 98.8%
88.3% 93,129 18 89.1% 98.8% 82.7% 86,306
[0201] The addition of TEA to a chromium(III) 2-ethylhexanoate
solution provided a catalyst with increased activity. It will also
reduce corrosion in equipment after the catalyst has been
inactivated. The example further provides an example of TEA
addition to chromium to abate water, acidic protons, or both.
Example 8
[0202] Catalyst 19
[0203] Neat triethylaluminum (TEA, 0.43 g) was added to 2.01 g of
ethylbenzene. This solution was added slowly to 4.62 g
chromium(III) 2-ethylhexanoate in 27.27 g ethylbenzene. This is a
small excess of the amount of TEA sufficient to react with water
and excess acid present in the chromium(III) 2-ethylhexanoate. To
this chromium/TEA solution was added 2.73 g of 2,5-dimethylpyrrole.
The chromium/TEA/dimethylpyrrole solution, was added, over 30-40
minutes, to a solution containing TEA (11.62 g), diethylaluminum
chloride (DEAC, 9.25 g) and ethylbenzene (15.00 g). Ethylbenzene
was then added to provide a total volume of 100 mL.
[0204] Catalyst 20
[0205] A comparison catalyst was prepared by adding 2.74 g
2,5-dimethylpyrrole to 4.61 g chromium(III) 2-ethylhexanoate
dissolved in 2.27 g ethylbenzene. An immediate reduction in the
viscosity of the chromium solution was observed. This chromium
solution was added, over 30-40 minutes, to a solution containing
TEA (12.08 g), diethylaluminum chloride (DEAC, 9.27 g) and
ethylbenzene (20.00 g). Ethylbenzene was then added to provide a
total volume of 100 mL.
[0206] These catalyst preparations were tested for productivity in
a 1 L continuous reactor. The average of three separate test runs
for each catalyst is shown in Table 8. TABLE-US-00009 TABLE 8
Selectivity Purity Conversion Catalyst Productivity Catalyst
(1-C.sub.6=) (1-C.sub.6=/C.sub.6) (C.sub.2=) (g 1-C.sub.6=/g Cr) 19
92.0% 98.9% 74.4% 80,252 20 92.5% 99.1% 71.8% 77,877
[0207] The addition of TEA provided a catalyst with increased
activity. It can also reduce corrosion in downstream equipment
after the catalyst is inactivated.
Example 9
[0208] Several catalysts, catalysts 21-23 were prepared in which
the molar ratio of the 2,5-dimethylpyrrole/chromium was varied
during the addition to the solution of aluminum alkyls.
[0209] Catalyst 21
[0210] A chromium solution of 4.61 g chromium(III) 2-ethylhexanoate
dissolved in 2.27 g ethylbenzene was divided into four equal
portions of 1.72 g each. To each of these portions was added a
different amount of 2,5-dimethylpyrrole. To the first was added
1.52 g 2,5-dimethylpyrrole, to the second 0.84 g, to the third 0.27
g and to the fourth 0.12 g. The chromium/2,5-dimethylpyrrole
portions were then added sequentially to a solution containing
12.07 g neat triethylaluminum (TEA), 9.29 g neat diethylaluminum
chloride (DEAC) and 20.01 g ethylbenzene. The total addition time
was approximately 50 minutes. The resulting catalyst solution was
diluted to 100 mL with ethylbenzene. The results from testing of
this catalyst, in a 1 L continuous reactor, are shown as Catalyst
21 in Table 9 below. The results shown are the average of four
separate test runs.
[0211] Catalyst 22
[0212] A chromium solution of 4.61 g chromium(III) 2-ethylhexanoate
dissolved in 2.27 g ethylbenzene was divided into four portions. To
each of these portions was added a different amount of
2,5-dimethylpyrrole and a similar amount of ethylbenzene. The first
portion contained 0.69 g chromium solution, 1.50 g
2,5-dimethylpyrrole and 7.51 g ethylbenzene. The second contained
1.38 g chromium solution, 0.81 g 2,5-dimethylpyrrole and 7.52 g
ethylbenzene. The third portion contained 2.06 g chromium solution,
0.27 g 2,5-dimethylpyrrole and 7.50 g ethylbenzene. The fourth
portion contained 2.75 g chromium solution, 0.16 g
2,5-dimethylpyrrole and 7.51 g ethylbenzene. The
chromium/2,5-dimethylpyrrole/ethylbenzene portions were then added
sequentially to a solution containing 12.07 g neat triethylaluminum
(TEA), 9.27 g neat diethylaluminum chloride (DEAC) and 25.01 g
ethylbenzene. The total addition time was approximately 60 minutes.
The resulting catalyst solution was then diluted to 100 mL with
ethylbenzene. The results from testing of this catalyst, in a 1 L
continuous reactor, are shown as Catalyst 22 in Table 9 below. The
results shown are the average of two separate test runs.
[0213] Catalyst 23
[0214] A chromium solution of 4.61 g chromium(III) 2-ethylhexanoate
dissolved in 2.27 g ethylbenzene was divided into four portions. To
each of these portions was added a different amount of
2,5-dimethylpyrrole and a similar amount of ethylbenzene. The first
portion contained 0.35 g chromium solution, 1.53 g
2,5-dimethylpyrrole and 7.51 g ethylbenzene. The second contained
0.69 g chromium solution, 0.81 g 2,5-dimethylpyrrole and 7.49 g
ethylbenzene. The third portion contained 2.06 g chromium solution,
0.27 g 2,5-dimethylpyrrole and 7.51 g ethylbenzene. The fourth
portion contained 3.77 g chromium solution, 0.15 g
2,5-dimethylpyrrole and 7.50 g ethylbenzene. The
chromium/2,5-dimethylpyrrole/ethylbenzene portions were then added
sequentially to a solution containing 12.09 g neat triethylaluminum
(TEA), 9.26 g neat diethylaluminum chloride (DEAC) and 25.02 g
ethylbenzene. The total addition time was approximately 60 minutes.
The resulting catalyst solution was then diluted to 100 mL with
ethylbenzene. The results from testing of this catalyst, in a 1 L
continuous reactor, are shown as Catalyst 23 in Table 9 below. The
results shown are the average of two separate test runs.
Example 10
[0215] Catalyst 24
[0216] To a dry, nitrogen purged 5 gallon reactor was added 14.6
lbs of dry, nitrogen purged ethylbenzene. The reactor was purged
with nitrogen and a mixture consisting of 1,592 g neat
triethylaluminum (TEA) and 1,238 g neat diethylaluminum chloride
(DEAC) was added to the reactor. The aluminum alkyl mix vessel was
rinsed with 0.2 lbs of ethylbenzene and this rinse was added to the
reactor. A chromium solution was prepared by adding 700 mL of
ethylbenzene to 630.9 g chromium(III) 2-ethylhexanoate. The mixture
was stirred until solution was obtained and was transferred to a 1
gallon cylinder followed by a 75 mL ethylbenzene rinse. The
cylinder, containing the chromium solution, was pressured and
depressured several times with nitrogen.
Chromium/2,5-dimethylpyrrole (DMP) mixtures were added to the
reactor in four batches from a chromium/DMP mix tank. For the first
batch 65 g of chromium and 233 mL DMP were added to the mix tank
and then this mixture was added to the reactor in 31-52 g
increments with stirring and cooling so the temperature did not
exceed 22.degree. C. For the second batch 130 g of chromium and 97
mL DMP were added to the mix tank and then this mixture was added
to the reactor in 48-58 g increments with stirring and cooling so
the temperature did not exceed 22.degree. C. For the third batch
326 g of chromium and 39 mL DMP were added to the mix tank and then
this mixture was added to the reactor in 48-54 g increments with
stirring and cooling so the temperature did not exceed 22.degree.
C. For the fourth batch 789 g of chromium and 20 mL DMP were added
to the mix tank and then this mixture was added to the reactor in
100-130 g increments with stirring and cooling so the temperature
did not exceed 24.degree. C. Ethylbenzene (1 lb) was added to the
chromium solution cylinder and used to rinse the chromium/DMP mix
tank. The ethylbenzene rinse was then added to the reactor. The
reactor was stirred for an additional 30 minutes. After standing
overnight the catalyst solution was filtered, using a filter as
described above. The catalyst solution was tested for activity in a
1 L continuous reactor. The results are shown as Catalyst 24 in
Table 9 below. The results shown are the average of two separate
test runs.
Example 11
[0217] Catalyst 25
[0218] To a dry, nitrogen purged 5 gallon reactor was added 14.0
lbs of dry, nitrogen purged ethylbenzene. The reactor was purged
with nitrogen and a mixture consisting of 1,283 g neat
triethylaluminum (TEA) and 990 g neat diethylaluminum chloride
(DEAC) was added to the reactor. The aluminum alkyl mix vessel was
rinsed with 0.2 lbs of ethylbenzene and this rinse was added to the
reactor. A chromium solution was prepared by adding 700 mL of
ethylbenzene to 630.9 g chromium(III) 2-ethylhexanoate. The mixture
was stirred until solution was obtained and was transferred to a 1
gallon cylinder followed by a 75 mL ethylbenzene rinse. The
cylinder, containing the chromium solution, was pressured and
depressured several times with nitrogen.
Chromium/2,5-dimethylpyrrole (DMP) mixtures were added to the
reactor in four batches from a chromium/DMP mix tank. For the first
batch 52 g of chromium and 187 mL DMP were added to the mix tank
and then this mixture was added to the reactor in 20-52 g
increments with stirring and cooling so the temperature did not
exceed 21.degree. C. For the second batch 104 g of chromium and 78
mL DMP were added to the mix tank and then this mixture was added
to the reactor in 40-50 g increments with stirring and cooling so
the temperature did not exceed 22.degree. C. For the third batch
261 g of chromium and 31 mL DMP were added to the mix tank and then
this mixture was added to the reactor in 90-101 g increments with
stirring and cooling so the temperature did not exceed 23.degree.
C. For the fourth batch 625 g of chromium and 16 mL DMP were added
to the mix tank and then this mixture was added to the reactor in
30-108 g increments with stirring and cooling so the temperature
did not exceed 23.degree. C.
[0219] To the TEA/DEAC mix vessel was added 327 g neat TEA and 256
g neat DEAC. To the chromium/DMP mix tank was added 261 g of the
chromium solution. To a separate cylinder connected to the reactor
was added 78 mL of DMP. The reactor pressure was increased with
nitrogen and the valves connecting each of the above cylinders to
the reactor were opened. Reducing the reactor pressure transferred
the contents of each of these vessels simultaneously to the reactor
while the reactor was being stirred and cooled. An increase of
1.degree. C. (20.degree. C. to 21.degree. C.) was observed in the
reactor temperature upon addition of the catalyst components.
[0220] Ethylbenzene (0.4 lb) was added to the chromium solution
cylinder and used to rinse the chromium/DMP mix tank. The
ethylbenzene rinse was then added to the reactor. Ethylbenzene (0.5
lb) was added to the DMP cylinder. This rinse of the DMP cylinder
was added to the reactor. Ethylbenzene (0.2 lb) was added to the
aluminum alkyl mix vessel and then pressured into the reactor. The
reactor was stirred for an additional 30 minutes. After standing
overnight the catalyst solution was filtered, using a filter as
described above. The catalyst solution was tested for activity in a
1 L continuous reactor. The results are shown as Catalyst 25 in
Table 9. The results shown are the average of three separate test
runs. TABLE-US-00010 TABLE 9 Selectivity Purity Conversion Catalyst
Productivity Catalyst (1-C.sub.6=) (1-C.sub.6=/C.sub.6) (C.sub.2=)
(g 1-C.sub.6=/g Cr) 21 92.6% 98.8% 75.1% 81,432 22 91.2% 99.1%
77.6% 82,927 23 90.5% 99.1% 79.7% 84,536 24 91.0% 99.2% 87.5%
93,397 25 90.9% 99.0% 86.6% 92,297
[0221] Catalysts 21-24 show that varying the chromium to pyrrole
ratio in a decreasing manner produces a catalyst has increased
selectivity, product purity, and productivity. Catalyst 25
demonstrates the separate simultaneous addition of catalyst
components to a heel of active catalyst.
Example 12
[0222] Two catalysts were prepared, catalyst 26 and catalyst 27,
with the addition of a nitrogen compound to the alkylaluminum
compound to solubilize products resulting from the reaction of
water and aluminum alkyls.
[0223] Catalyst 26
[0224] To a dry 100 mL volumetric flask was added 25.01 g
ethylbenzene, 12.07 g neat triethylaluminum (TEA) and 9.27 g neat
diethylaluminum chloride (DEAC) and 0.34 g tributylamine. To this
was added a solution containing 4.61 g chromium(III)
2-ethylhexanoate, 2.27 g ethylbenzene and 2.74 g
2,5-dimethylpyrrole. Ethylbenzene was then added to provide a total
volume of 100 mL. Upon standing overnight no film was observed in
the neck of the flask and no precipitate was observed. When the
amine was not added to the catalyst preparation a film was observed
upon standing overnight. A film was observed in the neck of the
flask after standing for an additional 24 hours. This catalyst was
tested for activity in a 1 L continuous reactor. The results of two
separate test runs are shown in Table 10 below as Catalyst 26.
[0225] Catalyst 27
[0226] To a dry 100 mL volumetric flask was added 25.01 g
ethylbenzene, 12.07 g neat triethylaluminum (TEA) and 9.27 g neat
diethylaluminum chloride (DEAC) and 0.34 g tributylamine. To this
was added a solution containing 4.61 g chromium(III)
2-ethylhexanoate, 2.27 g ethylbenzene, 2.74 g 2,5-dimethylpyrrole
and 1.06 g tributylamine. Ethylbenzene was then added to provide a
total volume of 100 mL. Upon standing overnight no film was
observed in the neck of the flask and no precipitate was observed.
When the amine was not added to the catalyst preparation a film was
observed upon standing overnight. A film was observed in the neck
of the flask after standing for an additional 24 hours. This
catalyst was tested for activity in a 1 L continuous reactor. The
results of two separate test runs are shown in Table 10 as Catalyst
27. TABLE-US-00011 TABLE 10 Selectivity Purity Conversion Catalyst
Productivity Catalyst (1-C.sub.6=) (1-C.sub.6=/C.sub.6) (C.sub.2=)
(g 1-C.sub.6=/g Cr) 26 93.0% 99.2% 70.4% 76,697 27 92.8% 99.2%
69.5% 75,574
[0227] The example shows that the addition of an amine to the
alkylaluminum compounds inhibits formation of detrimental
precipitation from the catalyst solution.
Example 13
[0228] Catalyst 28
[0229] Chromium(III) 2-ethylhexanoate (18.44 g) dissolved in 9.1 g
ethylbenzene produces a viscous solution. When 2,5-dimethylpyrrole
(10.96 g) was added to this viscous solution a much thinner
solution results. This thinner solution is much more adaptable to
water removal by molecular sieves. Activated 3A molecular sieves
(15.05 g) were added to the chromium/pyrrole/ethylbenzene solution
and allowed to stand with periodic shaking for 22 days before
catalyst preparation. A solution was prepared in a 100 mL
volumetric flask consisting of ethylbenzene (25.00 g), neat
triethylaluminum (12.07 g) and neat diethylaluminum chloride (9.26
g). To this aluminum alkyl solution was added 9.62 g of the dried
chromium/pyrrole/ethylbenzene solution and the resulting catalyst
was diluted to 100 mL with additional ethylbenzene. After standing
overnight a film was observed in the neck of the flask but no
precipitate was observed in the flask. This catalyst was tested in
a 1 L continuous reactor and an average of two separate test runs
is shown in Table 11 as Catalyst 28. A control using undried
chromium/pyrrole/ethylbenzene solution was made at the same time.
After standing overnight a film was observed in the neck of the
flask and a precipitate was also observed. This catalyst was tested
in a 1 L continuous reactor and an average of two separate test
runs is shown in Table 11 as Catalyst 29. TABLE-US-00012 TABLE 11
Selectivity Purity Conversion Catalyst Productivity Catalyst
(1-C.sub.6=) (1-C.sub.6=/C.sub.6) (C.sub.2=) (g 1-C.sub.6=/g Cr) 28
93.2% 99.4% 76.0% 83,056 29 94.3% 99.3% 64.5% 71,312
[0230] In addition to the improved catalyst productivity as shown,
reduced downstream corrosion could be obtained using the dried
catalyst components.
Example 14
[0231] Catalyst 30-31
[0232] Chromium(III) 2-ethylhexanoate (222.10 g) was added to a
round bottom flask equipped with a Dean-Stark tube. Ethylbenzene
(147.39 g) was added and the flask was heated to reflux the
contents. Reflux was continued until water no longer accumulated in
the Dean-Stark tube. Ethylbenzene and water (27.13 g) were
discarded from the Dean-Stark tube. This chromium solution was used
to make catalyst by adding it to a 100 mL volumetric flask
containing ethylbenzene (16.73 g), neat triethylaluminum (12.28 g),
neat diethylaluminum chloride (9.26 g) and 2,5-dimethylpyrrole
(2.74 g). Ethylbenzene was subsequently added to dilute the
catalyst to a 100 mL volume. This catalyst was tested in a 1 L
continuous reactor. The results of the test (two catalyst
preparations and three separate test runs) are shown in Table 12 as
Catalyst 30. A control catalyst prepared similarly but with
chromium(III) 2-ethylhexanoate that had not been azeotrope dried
was used. The results of testing the undried preparation are shown
as Catalyst 31 in Table 12. TABLE-US-00013 TABLE 12 Selectivity
Purity Conversion Catalyst Productivity Catalyst (1-C.sub.6=)
(1-C.sub.6=/C.sub.6) (C.sub.2=) (g 1-C.sub.6=/g Cr) 30 89.4% 98.7%
81.5% 84,462 31 88.5% 98.8% 82.3% 85,400
[0233] The example shows that drying the chromium component by
azeotropic distillation prepares an effective catalyst and also
will reduce equipment corrosion.
Example 15
[0234] An ethylene trimerization catalyst composition was prepared
using methods known to those skilled in the art, placed in the
catalyst feed tank (under inert conditions) of a continuous
1-hexene production process, and aged for approximately 900 hours.
The continuous 1-hexene production process was then started using
the aged catalyst in the feed tank for the trimerization of
ethylene to 1-hexene. Periodically, additional fresh ethylene
trimerization catalyst was prepared and added to the catalyst used
in the continuous 1-hexene production process. The average age of
the ethylene oligomerization catalyst composition periodically
calculated to determine the average time the catalyst had resided
in the catalyst feed tank based upon the average catalyst
composition in the catalyst feed tank. Throughout the continuous
1-hexene production process, samples of the continuous 1-hexene
production process product we removed and analyzed for 1-hexene
content. FIG. 5 shows the impact of the average catalyst residence
time (i.e. catalyst age) on the purity of the hexene production
produced by the continuous 1-hexene production process. FIG. 5
indicates that the purity of the 1-hexene product is negatively
impacted by increasing age of the ethylene trimerization
catalyst.
[0235] During the manufacture of chromium(III) 2-ethylhexanoate,
also denoted as Cr(EH).sub.3, a mixture of compounds is obtained.
These compounds include the desired Cr(EH).sub.3, hydrated chromium
species, free and coordinated 2-ethylhexanoic acid, chromium
oligomers and free water. In examples 16-27 the chemical
composition of Cr(EH).sub.3 and its effect on the oligomerization
activity of the catalyst were investigated. Cr(EH).sub.3
preparation is presented in Example 16. The impact of production
variables in Cr(EH).sub.3 preparation on oligomerization catalyst
activity is investigated in Example 17 while in Example 18 the
effect of chromium concentration and free acid addition on catalyst
activity was determined. In Example 19, the effect of hydrated
chromium species and chromium oligomers on catalyst activity was
determined while the effect of water content on the catalyst
activity was investigated in Example 20. The chemical composition
of Cr(EH).sub.3 provided by a second supplier was investigated
using infrared analysis in Example 21. This material was further
subjected to water abatement protocols as described in Examples 22
and 23. Infrared analysis of Cr(EH).sub.3 from Supplier A was
recorded in the absence of solvent with heating is presented in
Example 24. Finally, the methodology for preparation of a 1-hexene
catalyst is presented in Example 25 while testing of these
catalysts in a batch trimerization or continuous trimerization run
is detailed in Examples 26 and 27 respectively.
Example 16
[0236] A sample of chromium(III) 2-ethylhexanoate was prepared by
dissolving 60.02 g (1.5 moles) of sodium hydroxide in 249.13 g of
distilled water. 2-Ethylhexanoic acid (238.57 g, 1.65 moles) was
added with stirring to form sodium 2-ethylhexanoate. In a separate
container, 100.00 g (0.25 mole) of chromium nitrate nonahydrate
(Alfa Aesar, 98.5%) was dissolved in 250 ml of distilled water. The
chromium nitrate solution was slowly added to the sodium
2-ethylhexanoate solution with good stirring (stirring became
difficult towards the end of the addition). When the addition was
complete, 250 mL of hexanes (Fischer, H303-4) were added and
stirring was continued for 15 minutes. The layers were separated
and the hexane layer (and a 60 mL hexane wash) containing the
chromium(III) 2-ethylhexanoate was washed with 100 mL 5% sodium
hydroxide solution two times, water (100 mL), 10% sodium carbonate
solution (100 mL) and finally with distilled water (100 mL) two
times. Additional hexane was added and the hexane solution was then
dried over anhydrous magnesium sulfate. The mixture was filtered
with a Buchner funnel and a water aspirator. Frequent changes of
the filter paper were required. The reduced pressure of a water
aspirator removed most of the hexane. Additional hexane was added
and the resulting solution was slowly added to 250 mL of acetone. A
blue granular solid was filtered from the acetone and air dried to
yield trihydrated chromium(III) 2-ethylhexanoate. The infrared
spectrum of a dilute ethylbenzene solution of this blue solid
showed a strong absorption at 1540 cm.sup.-1 and no absorption
peaks at either 1600 or 1700 cm.sup.-1 (FIG. 6).
Example 17
[0237] The effect of chromium concentration and free acid addition
on catalyst activity was determined using three lots of
Cr(EH).sub.3 prepared in the laboratory. Lot 1 contained 11.5 wt %
chromium. Lot 2 contained 10.5 wt % and was the same as Lot 1 but
the chromium concentration was adjusted by the addition of
2-ethylhexanoic acid. Lot 3 contained 10.5 wt % chromium and had
been chemically dried with acetic anhydride to remove water.
Catalysts were prepared from each of these lots and the catalysts
were evaluated in the continuous reactor as described in Example
27. Catalyst preparations A and B differ in the ratios of the
catalyst components. Both types of catalysts were prepared from
these samples and tested. Low reactor chromium concentrations were
used to magnify any differences. The results of the continuous
reactor tests are shown in Table 13. TABLE-US-00014 TABLE 13 Effect
of Excess Acid and Drying Agent in the Chromium Component 1-Hexene
1-Hexene Catalyst Productivity Catalyst Lot (% Selectivity) (%
Purity) (g 1-Hexene/g Cr) Catalyst A.sup.a 1 96.1 99.3 59,500 2
94.7 99.2 44,500 3 96.1 99.3 58,900 Catalyst B.sup.b 1 96.5 99.3
88,700 2 95.9 na.sup.c 23,500 3 95.2 99.0 97,900 .sup.aMole ratio
Cr/DMP/TEA/DEAC is 1/1.8/6.5/5, 2.0 ppm Cr in reactor. .sup.bMole
ratio Cr/DMP/TEA/DEAC is 1/3/11/8, 1.5 ppm Cr in reactor. .sup.cNot
available as low productivity dropped amount of internal hexenes
below detection limits.
The results demonstrate the detrimental effect of increased acid as
seen in the lower catalyst productivity for Lot 2.
Example 18
[0238] Three samples (17-1, 17-2, and 17-3) of chromium(III)
2-ethylhexanoate were prepared from a chromium(III)
2-ethylhexanoate stock solution. The three samples were taken from
the chromium(III) 2-ethylhexanoate stock solution at different
heating and stripping times. These samples contain a mixture of
compounds and are denoted herein as Cr-mix. These different
compositions of Cr-mix were used to prepare oligomerization
catalysts as described in Example 25. In Sample 17-1 the chromium
content of the Cr-mix was 10.5 wt %. The infrared spectrum of
chromium(III) 2-ethylhexanoate sample 17-1 showed absorption peaks
at 1540 and 1600 cm.sup.-1 (FIG. 7). The absorption at 1600
cm.sup.-1 Cr(EH).sub.3 was attributed to the nonhydrated
Cr(EH).sub.3 while the 1540 cm.sup.-1 absorption is expected for
both the hydrated Cr(EH).sub.3 and chromium oligomers. In order to
estimate the amount of chromium oligomers in the mixture, a
methanol solubility test was performed. The methanol solubility
test can help in ascertaining the amount of chromium oligomers
present, as they are insoluble in methanol. A compound that has
greater than 90% of the material dissolve methanol (i.e. a small
amount of precipitate) has a low chromium oligomer content. The
methanol solubility test showed little precipitate. In sample 17-2
the chromium content of the Cr(EH).sub.3 was 10.9 wt %. The
infrared spectrum of chromium(III) 2-ethylhexanoate sample 17-2
showed strong absorption at 1600 cm.sup.-1 with only a small peak
at 1540 cm.sup.-1 (FIG. 8). The methanol solubility test showed
little precipitate. In sample 17-3 the chromium concentration was
12.7 wt %. The infrared spectrum of chromium(III) 2-ethylhexanoate
sample 17-3 showed absorption peaks at 1540 and 1600 cm.sup.-1
(FIG. 9). The methanol solubility test showed a large amount of
precipitate. The oligomerization catalysts prepared using these
chromium sources were tested in the continuous reactor as described
in Example 27. The results (Table 14) demonstrate the effect of
chromium oligomers and hydrated species in the chromium(III)
2-ethylhexanoate.
Example 19
[0239] The effect of hydrated chromium species and chromium
oligomers on catalyst activity was determined. The hydrated
chromium species and chromium oligomer amounts vary with the
chromium preparation conditions. In order to investigate the
effects of the chromium preparation variations, samples from a
single Cr(EH).sub.3 preparation that differed in the time of
heating and vacuum stripping were obtained. The three different
samples of Cr(EH).sub.3 were used to prepare selective 1-hexene
catalysts as described in Example 25. The amounts of hydrated
chromium species and chromium oligomers were estimated by a
combination of infrared analysis and methanol solubility. Both the
hydrated chromium species and chromium oligomers show infrared
absorption at 1540 cm.sup.-1 but the hydrated chromium species is
soluble in the methanol test while chromium oligomers form
precipitates. The rational for the infrared absorption peak
assignments is described in Example 24.
[0240] The chromium concentration in sample 17-1 was 10.5 wt %.
This preparation has the shortest heating and vacuum stripping
time. Infrared analysis of chromium(III) 2-ethylhexanoate sample
17-1 (FIG. 7) and solubility in the methanol test indicated that
some hydrated chromium species were present but only small amounts
of chromium oligomers were present. In sample 17-2 additional
heating and vacuum stripping resulted in a chromium concentration
of 10.9 wt %. Infrared analysis of chromium(III) 2-ethylhexanoate
sample 17-2 (FIG. 8) and methanol solubility tests indicated that
only small amounts of either hydrated chromium species or chromium
oligomers were present. In sample 17-3 the heating and vacuum
stripping time was extended and a chromium concentration of 12.7 wt
% was obtained. This sample would represent a high chromium
concentration. Infrared analysis of chromium(III) 2-ethylhexanoate
sample 17-3 (FIG. 9) indicated the presence of either hydrated
chromium species or chromium oligomers (1540 cm.sup.-1). Since
hydrated chromium species were not present in the earlier sample
(sample 17-2), chromium oligomers were presumed to be present. A
sizeable precipitate in the methanol solubility test confirmed the
presence of chromium oligomers. The catalysts prepared were tested
for activity in the continuous reactor (as described in Example 27)
and the average results of two reactor runs for each preparation
are shown in Table 14. TABLE-US-00015 TABLE 14 Effect of Hydrated
Chromium Species and Chromium Oligomers in Catalyst Preparation %
Conversion % Selectivity % Purity Productivity Sample Wt % Cr
(1-C.sub.6=) (1-C.sub.6=/C.sub.6) (C.sub.2=) (g 1-C.sub.6=/g Cr)
17-1 10.5 90.3 99.10 79.0 83,642 17-2 10.9 88.7 99.09 84.5 87,882
17-3 12.7 87.4 98.07 86.4 88,460
[0241] The results demonstrate that longer heating and vacuum
stripping times resulted in higher chromium concentrations, lower
hydrated chromium species, lower acid concentration and greatly
increased viscosity. Table 14 shows that the best combination of
product purity and catalyst productivity is obtained when hydrated
chromium species and chromium oligomers are minimized in the
chromium(III) 2-ethylhexanoate.
Example 20
[0242] The effect of water content in the chromium compound on
catalyst activity was determined. An ethylbenzene azeotrope was
formed in order to remove water from the Cr(EH).sub.3. The binary
azeotrope of water with ethylbenzene actually contains a higher
mole fraction of water (0.744) than the binary azeotrope of either
benzene (0.295) or toluene (0.444). A base material on hand for 7
years, chromium(III) 2-ethylhexanoate (222.10 g), was added to a
round bottom flask equipped with a Dean-Stark tube. Ethylbenzene
(147.39 g) was added and the flask was heated to reflux the
contents. Reflux was continued until water no longer accumulated in
the Dean-Stark tube. A total 2.6 mL of water was collected in the
Dean-Stark tube. Water analysis according to Karl Fisher titration
ASTM E 1064-04a showed 96 ppm water to be present in the final
Cr(EH).sub.3 ethylbenzene solution. This chromium solution was used
to make catalyst as described in Example 25. Testing of a catalyst
prepared from the dried Cr(EH).sub.3 was done in the continuous
reactor (as described in Example 27) and showed similar
productivity and 1-hexene purity to the standard catalyst. The
results demonstrated that water could be removed from Cr(EH).sub.3
by azeotropic distillation.
[0243] A second set of samples of Cr(EH).sub.3 in ethylbenzene were
prepared for testing, and low moisture levels (500-700 ppm water)
were observed. These low moisture levels were attributed to the
ethylbenzene water azeotrope.
Example 21
[0244] Infrared analysis was used to characterize a second
Cr(EH).sub.3 sample (chromium(III) 2-ethylhexanoate Sample 17-4a).
The sample was a blue-violet solid powder containing 14.6 wt %
chromium.
[0245] This material was found to be much less soluble in
ethylbenzene than the Cr(EH).sub.3 material described in example
17. Solubility and color indicated that this material contained
hydrated chromium species. The presence of hydrated chromium
species in chromium(III) 2-ethylhexanoate sample 17-4a was also
consistent with the infrared analysis that showed a large peak at
1540 cm.sup.-1 and only a very small (trace) peak at 1600 cm.sup.-1
(FIG. 10). There was no significant absorption peak at 1700
cm.sup.-1 indicating the low amount of free 2-ethylhexanoic
acid.
Example 22
[0246] The blue violet solid described in Example 21, chromium(III)
2-ethylhexanoate Sample 17-4a, was azeotroped with ethylbenzene to
see if the water of hydration could be removed in this manner.
Heating 30.03 g of this material in 75.2 g ethylbenzene formed a
gel that was difficult to handle. The gel had to be transferred
twice to larger flasks. In the end a total of 367.7 g of
ethylbenzene was added. Very little water was collected in the Dean
Stark tube after a lengthy reflux time. Part of this water may have
come from contact with the atmosphere during the difficult
transfers to larger flasks. The color of the solution remained
blue. At this low Cr(EH).sub.3 concentration there is some
interference in the infrared spectrum (FIG. 11--chromium(III)
2-ethylhexanoate Sample 17-4b) in the 1600 cm.sup.-1 peak with the
ethylbenzene absorption peak at 1605 cm.sup.-1. Color, solubility
and the infrared analysis are consistent with the presence of
hydrated chromium species remaining after attempted removal of the
water of hydration by azeotroping. When 2-ethylhexanoic acid was
added to this solution, water was observed accumulating in the
Dean-Stark tube and the solution turned a green color. The infrared
spectrum (FIG. 12--chromium(III) 2-ethylhexanoate Sample 17-4c)
shows the peak at 1600 cm.sup.-1 becoming much larger than the peak
at 1540 cm.sup.-1. The color change, water accumulation and the
shift in the infrared peaks are consistent with the removal of
water from hydrated chromium species. A peak at 1700 cm.sup.-1 was
observed indicating the presence of free 2-ethylhexanoic acid.
Example 23
[0247] The effect of acid addition on water abatement for the blue
violet solid Cr(EH).sub.3 Sample 17-4a was investigated.
2-Ethylhexanoic acid (3 g, 0.021 moles) from Aldrich was added to
the solid blue-violet Cr(EH).sub.3 Sample 17-4a (3 g, ca. 0.006
moles) in a 50 mL Erlenmeyer flask, this constituted a 3.5 molar
excess of 2-ethylhexanoic acid. Some liquid acid remained after the
solid was wet. A solution was not obtained. The mixture was heated
to 192.degree. C. for 2 hours without the presence of a solvent.
The color changed to deep green. After cooling a green semisolid
was obtained. When ethylbenzene was added to the green semisolid
the solubility of the Cr(EH).sub.3 was greatly increased. The
infrared spectrum (FIG. 13) of the resulting semisolid
(chromium(III) 2-ethylhexanoate Sample 17-4d), dissolved in
ethylbenzene, showed a strong absorption at 1600 cm.sup.-1 with
only a small absorption at 1540 cm.sup.-1. The color change,
solubility and infrared analysis demonstrate the conversion of
hydrated chromium species to the non-hydrated form by heating with
acid.
[0248] To confirm the infrared absorption peak assignments,
additional experiments were performed. A sample of trihydrated
Cr(EH).sub.3 was prepared in the laboratory from chromium nitrate
and sodium 2-ethylhexanoate in aqueous solution (Example 16). A
blue solid material with low solubility in ethylbenzene was
obtained. Infrared analysis (FIG. 6) showed a large absorption peak
at 1540 cm.sup.-1. There was no significant absorption peak at 1600
cm.sup.-1 (ethylbenzene subtracted spectrum) and no significant
free acid peak at 1700 cm.sup.-1.
Example 24
[0249] A 10.5 wt % Cr(EH).sub.3 described in Example 19 was heated,
without solvent to determine what changes in the infrared spectrum
would be observed. The sample of the 10.5 wt % Cr(EH).sub.3 was
heated to 200-240.degree. C. for 2-3 hours to make chromium(III)
2-ethylhexanoate Sample 17-4e. No additional 2-ethylhexanoic acid
was added. The infrared spectrum of an ethylbenzene solution of the
resulting semisolid (chromium(III) 2-ethylhexanoate Sample 17-4e )
showed the absorption peak at 1540 cm.sup.-1 was larger than the
peak at 1600 cm.sup.-1 (FIG. 14).
[0250] Since this heating did not involve additional acid, an
increase in chromium oligomers was expected. Comparison of the
infrared spectrum of the heated material with that of the starting
Cr(EH).sub.3 (chromium(III) 2-ethylhexanoate Sample 17-4f--FIG. 15)
shows the absorption peak at 1540 cm.sup.-1 increases to become
larger than the peak at 1600 cm.sup.-1. This is the reverse
absorption intensity of the unheated Cr(EH).sub.3. An absorption
peak at 1540 cm.sup.-1 is consistent with the presence of chromium
oligomers as was indicated in the extended heating and vacuum
stripping samples (FIG. 9) discussed earlier. In summary the
infrared absorption peak at 1540 cm.sup.-1 can be attributed to
both hydrated chromium species and chromium oligomers. The methanol
solubility test can help in ascertaining the amount of chromium
oligomers present, as they are insoluble in methanol. The
absorption peak at 1600 cm.sup.-1 is attributed to the unhydrated
Cr(EH).sub.3 and the absorption peak at 1700 cm.sup.-1 is due to
the free acid carbonyl.
Example 25
[0251] A typical catalyst preparation as used in the Examples is
given here. The catalyst preparation was done in a drybox under an
inert gas atmosphere. Dry, degassed ethylbenzene (20.01 g) was
added to a weighed, dry 100 mL volumetric flask (dried overnight in
a glass oven). To this flask was added 12.08 g neat
triethylaluminum and 9.26 g neat diethylaluminum chloride. The
contents were mixed and allowed to stand for 15 minutes. Then
2,5-dimethylpyrrole (2.76 g) was carefully added down the side of
the flask. The contents were mixed (gas evolution was observed) and
the weight loss was determined after 30 minutes to be 0.60 g. To
this mixture sufficient Cr(EH).sub.3 diluted in ethylbenzene (6.89
g; 7.27 wt % Cr) was added to supply 500 mg chromium metal. When
neat Cr(EH).sub.3 was used the ethylbenzene dilution was done the
day before the catalyst preparation to allow time for the
Cr(EH).sub.3 to dissolve in the ethylbenzene. The chromium solution
was added over about 40 minutes. The weight loss was determined 30
minutes after the end of chromium addition and was 1.05 g. The
volume was brought to 100 mL by the addition of 39.14 g of
ethylbenzene. There was a total of 61.43 g of ethylbenzene added
including the ethylbenzene included in the chromium. The net weight
of the catalyst was 88.49 g. After standing overnight the solution
obtained a reddish orange color. The catalyst had a concentration
of 5 mg Cr/mL and was active as prepared.
Example 26
[0252] Batch reactor trimerization runs were conducted as indicated
in various Examples. Trimerization runs were carried out in a 1
Liter stainless steel autoclave reactor equipped with a magna drive
stirrer and a bottom valve. The temperature was controlled at the
desired set point by an internal steam/water cooling coil. A
typical run was carried out using the following procedure. The
reactor was purged with nitrogen at 100.degree. C. for at least 15
minutes to remove moisture, oxygen and other volatile impurities.
During this time 2-3 mL of 2-ethyl-1-hexanol was added to the line
between the reactor bottom valve and the product cylinder. The
catalyst (1 mL) was diluted to 25 mL with dry, nitrogen purged
cyclohexane and the amount of diluted catalyst was weighed and
added to a 50 mL stainless steel cylinder in the drybox. A measured
amount of cyclohexane (225 mL) was added to the reactor and the
catalyst charged into the line to the reactor. The catalyst was
then washed into the reactor with another measured amount of
cyclohexane (225 mL). The weight of the measured amount of
cyclohexane had been previously determined by weighing several
charges. The reactor was then allowed to come to the desired
operating temperature (115.degree. C.) within about 5 minutes. Care
was taken during the addition of the components to add minimum
nitrogen pressure to the reactor. Hydrogen (a delta of 50 psig) was
then added. The reactor was then pressurized with ethylene to the
desired pressure (650-800 psig) and ethylene was fed on demand at
the desired pressure for 30 minutes. The reactor stirrer was
stopped and the contents of the reactor were then charged to the
product cylinder through the bottom valve. The product cylinder was
weighed to determine the weight gain from the reaction. The
consumption of ethylene was determined from the ethylene flow meter
and verified by the increase in the weight of the reactor contents.
A sample of the contents of the product cylinder was sent to the GC
through a liquid sampling valve.
Example 27
[0253] Continuous reactor trimerization runs were conducted as
indicated in various Examples. The continuous ethylene
trimerization runs were carried out in a 1 Liter stirred autoclave
reactor. In a typical run, cyclohexane solvent was first charged to
the reactor. A 3 mL aliquot of 1.9 M TEA was then added to the
reactor to remove any residual moisture and the reactor was heated
to 115.degree. C. (solvent was pumped through the system while the
reactor was being heated). The catalyst feed pump was then started
and the catalyst was added to the reactor for 30 minutes at double
its normal rate. The catalyst feed rate was then reduced to normal
and ethylene and hydrogen were added to the solvent feed at the
desired feed rates. Separate control systems were provided for each
individual feed to the reactor. Standard catalyst preparations
(Cr/DMP/TEA/DEAC mole ratios of 1/3/11/8) were used for these
tests. The run was carried out continuously for six hours.
[0254] The product stream was monitored by on-line GC samples on an
hourly basis and readings of pressure and temperature were recorded
every 30 minutes. The catalyst feed rate was also checked every 30
minutes. The reactor was run liquid full on back pressure control.
2-Ethyl-1-hexanol was added to the reactor product stream
immediately after the reactor and the reactor product then passed
through a cooled filter (1 Liter autoclave packed with stainless
steel sponge) before being sent to a product tank. At the end of
the run the ethylene, hydrogen and catalyst feeds were shut off.
The reactor was flushed with solvent for 30 minutes and allowed to
cool. The contents of the reactor were then blown into the product
tank, the reactor depressurized and disassembled for cleaning. Any
polymer formed in the reactor was collected, dried and weighed. The
polymer filter material was also collected, dried and weighed. The
filter system was cleaned and new, weighed filter material put in
place for the next run.
[0255] While preferred embodiments of the invention have been shown
and described, modifications thereof can be made by one skilled in
the art without departing from the spirit and teachings of the
invention. The embodiments described herein are exemplary only, and
are not intended to be limiting. Many variations and modifications
of the invention disclosed herein are possible and are within the
scope of the invention. Where numerical ranges or limitations are
expressly stated, such express ranges or limitations should be
understood to include iterative ranges or limitations of like
magnitude falling within the expressly stated ranges or limitations
(e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater
than 0.10 includes 0.11, 0.12, 0.13, etc.). Use of the term
"optionally" with respect to any element of a claim is intended to
mean that the subject element is required, or alternatively, is not
required. Both alternatives are intended to be within the scope of
the claim. Use of broader terms such as comprises, includes,
having, etc. should be understood to provide support for narrower
terms such as consisting of, consisting essentially of, comprised
substantially of, etc.
[0256] Accordingly, the scope of protection is not limited by the
description set out above but is only limited by the claims which
follow, that scope including all equivalents of the subject matter
of the claims. Each and every claim is incorporated into the
specification as an embodiment of the present invention. Thus, the
claims are a further description and are an addition to the
preferred embodiments of the present invention. The discussion of a
reference in the Description of Related Art is not an admission
that it is prior art to the present invention, especially any
reference that may have a publication date after the priority date
of this application. The disclosures of all patents, patent
applications, and publications cited herein are hereby incorporated
by reference, to the extent that they provide exemplary, procedural
or other details supplementary to those set forth herein.
* * * * *