U.S. patent application number 15/216742 was filed with the patent office on 2016-11-10 for system and method for catalyst preparation.
The applicant listed for this patent is Chevron Phillips Chemical Company LP. Invention is credited to Elizabeth A. Benham, Rebecca A. Gonzales, Albert P. Masino, Randy S. Muninger, Qing Yang.
Application Number | 20160325252 15/216742 |
Document ID | / |
Family ID | 49485833 |
Filed Date | 2016-11-10 |
United States Patent
Application |
20160325252 |
Kind Code |
A1 |
Benham; Elizabeth A. ; et
al. |
November 10, 2016 |
System and Method for Catalyst Preparation
Abstract
Techniques are provided for catalyst preparation. A system for
catalyst preparation may include an agitator disposed inside a
polymerization catalyst tank and configured to mix a polymerization
catalyst and a solvent to generate a polymerization catalyst
solution. The system may also include a heating system coupled to
the polymerization catalyst tank and configured to maintain a
temperature of the polymerization catalyst solution above a
threshold. The system may also include a precontactor configured to
receive feed streams comprising an activator and the polymerization
catalyst solution from the polymerization catalyst tank to generate
a catalyst complex. The system may also include a transfer line
configured to transfer the catalyst complex from an outlet of the
precontactor to a reactor.
Inventors: |
Benham; Elizabeth A.;
(Spring, TX) ; Masino; Albert P.; (Tulsa, OK)
; Yang; Qing; (Bartlesville, OK) ; Muninger; Randy
S.; (Dewey, OK) ; Gonzales; Rebecca A.;
(Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chevron Phillips Chemical Company LP |
The Woodlands |
TX |
US |
|
|
Family ID: |
49485833 |
Appl. No.: |
15/216742 |
Filed: |
July 22, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14340205 |
Jul 24, 2014 |
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15216742 |
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13655024 |
Oct 18, 2012 |
8821800 |
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14340205 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 4/008 20130101;
B01J 2219/0801 20130101; C08F 10/00 20130101; C08F 2500/05
20130101; B01J 19/123 20130101; C08F 4/00 20130101; B01J 4/02
20130101; B01J 2219/00182 20130101; B01J 19/1837 20130101; C08F
2500/08 20130101; B01J 14/00 20130101; C08F 2500/07 20130101; C08F
110/02 20130101; B01J 2219/00164 20130101; B01J 2219/00094
20130101; B01J 19/127 20130101; C08F 210/16 20130101; C08F 210/14
20130101; C08F 2/01 20130101; B01J 19/06 20130101; B01J 2204/002
20130101; C08F 2420/00 20130101; B01J 2219/00186 20130101 |
International
Class: |
B01J 4/02 20060101
B01J004/02; C08F 110/02 20060101 C08F110/02; B01J 19/12 20060101
B01J019/12; B01J 14/00 20060101 B01J014/00; B01J 19/06 20060101
B01J019/06 |
Claims
1-20. (canceled)
21. A method for controlling a polymerization reactor system, the
method comprising: (a) contacting a metallocene catalyst system
comprising a metallocene compound with an olefin monomer and an
optional olefin comonomer in a polymerization reactor within the
reactor system to produce a polyolefin; (b) determining a
concentration of the metallocene compound in a solution comprising
the metallocene compound, wherein the concentration is determined
by a method comprising the steps of: subjecting a sample of the
solution to a wavelength of light in an ultraviolet-visible
spectrometer; and measuring an absorbance of the sample and
correlating the absorbance to determine the concentration of the
metallocene compound in the solution; and (c) adjusting a flow rate
of the metallocene compound into the polymerization reactor when
the concentration of the metallocene compound in the solution has
reached a predetermined level.
22. The method of claim 21, wherein the solution comprising the
metallocene compound is a catalyst solution feed stream to a
precontactor vessel.
23. The method of claim 21, wherein the solution comprising the
metallocene compound is a metallocene catalyst system feed stream
to the polymerization reactor.
24. The method of claim 21, further comprising a step of filtering
prior to subjecting the sample of the solution to the wavelength of
light in the ultraviolet-visible spectrometer.
25. The method of claim 24, wherein: the metallocene catalyst
system is a heterogeneous catalyst system; and the sample of the
solution is prepared from a feed stream of the heterogeneous
catalyst system to the polymerization reactor.
26. The method of claim 21, wherein correlating the absorbance to
determine the concentration comprises a calibration curve.
27. The method of claim 21, wherein: the solution comprises the
metallocene compound and a solvent; and the wavelength of light is
selected to minimize absorbance by the solvent.
28. The method of claim 21, wherein: the solution comprising the
metallocene compound is a catalyst solution feed stream to a
precontactor vessel; and the flow rate of the metallocene compound
into the polymerization reactor is adjusted by adjusting a flow
rate of the feed stream to the precontactor vessel and/or by
adjusting a flow rate of the metallocene catalyst system exiting
the precontactor vessel and entering the polymerization
reactor.
29. The method of claim 21, wherein the metallocene catalyst system
comprises at least one metallocene compound, an activator, and a
co-catalyst.
30. The method of claim 28, wherein: the activator comprises a
chemically-treated solid oxide; and the co-catalyst comprises an
alkyl aluminum compound.
31. The method of claim 21, wherein the metallocene catalyst system
is contacted with ethylene and an olefin comonomer comprising
butene, 1-hexene, 1-octene, or a mixture thereof.
32. The method of claim 21, wherein the reactor system comprises a
fluidized bed reactor, a gas-phase reactor, a loop slurry reactor,
or any combination thereof.
33. A polymerization reactor system comprising: (A) a
polymerization reactor configured to contact a metallocene catalyst
system with an olefin monomer and an optional olefin comonomer to
produce a polyolefin; (B) a precontactor configured to contact a
metallocene compound, an activator, and a co-catalyst to form the
metallocene catalyst system; (C) an ultraviolet-visible
spectrometer system configured to determine a concentration of the
metallocene compound in a solution comprising the metallocene
compound present within the reactor system; and (D) a controller
configured to control a flow rate of the metallocene compound into
the polymerization reactor based on the concentration determined by
the ultraviolet-visible spectrometer system.
34. The reactor system of claim 33, wherein the ultraviolet-visible
spectrometer system further comprises a filter for filtering a
sample of the solution comprising the metallocene compound prior to
analysis.
35. The reactor system of claim 33, wherein the reactor system
comprises one or more polymerization reactors selected
independently from a fluidized bed reactor, a gas-phase reactor, or
a loop slurry reactor.
36. The reactor system of claim 33, wherein the controller is
configured to control the flow rate of the metallocene compound
into the polymerization reactor continuously based on the
concentration determined by the ultraviolet-visible spectrometer
system.
37. The reactor system of claim 33, wherein: the solution
comprising the metallocene compound is a catalyst solution feed
stream to the precontactor; and the controller controls the flow
rate of the metallocene compound into the polymerization reactor by
adjusting a flow rate of the catalyst solution feed stream to the
precontactor and/or by adjusting a flow rate of the metallocene
catalyst system exiting the precontactor and entering the
polymerization reactor.
38. The reactor system of claim 33, wherein the reactor system
comprises a loop slurry reactor.
39. The reactor system of claim 33, wherein the ultraviolet-visible
spectrometer system is further configured to determine the
concentration of the metallocene compound using a calibration
curve.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 14/016,648, entitled "System and Method for Catalyst
Preparation" filed on Oct. 18, 2012, which is incorporated by
reference herein in its entirety.
BACKGROUND
[0002] The present disclosure relates generally to catalyst
preparation, and more particularly, to preparation of metallocene
catalysts.
[0003] This section is intended to introduce the reader to aspects
of art that may be related to aspects of the present disclosure,
which are described and/or claimed below. This discussion is
believed to be helpful in providing the reader with background
information to facilitate a better understanding of the various
aspects of the present disclosure. Accordingly, it should be
understood that these statements are to be read in this light and
not as admissions of prior art.
[0004] Catalysts can be employed to facilitate the formation of
products through chemical reactions. It is often desirable to
prepare the catalyst in a certain way to achieve desired properties
of the catalyst and/or the products. For example, in certain
polymerization manufacturing facilities, the catalyst is prepared
off-site by a vendor and is then shipped to the polymerization
reaction facility. At the vendor facility, the catalyst may be
dissolved in a solvent to form a catalyst solution, which may be
used by the polymerization manufacturing facility directly or with
some additional processing or handling. However, the concentration
of the catalyst in the solvent may be limited by the solubility of
the catalyst in the solvent. In other words, attempting to dissolve
greater amounts of the catalyst in the solution may cause
precipitation of the catalyst out of solution, which may be
undesirable. In addition, the solubility of the catalyst in the
solvent may be affected by temperature. For example, the solubility
of the catalyst may decrease at low temperatures. Thus, the
concentration of the catalyst in the solvent may be less than
desirable, thereby resulting in feeding the catalyst solution at
high flow rates. In addition, it is now recognized that issues with
catalyst concentration in the solvent may necessitate increased
sizes of storage tanks, transfer lines, pumps, and other equipment
associated with handling the catalyst solution to facilitate
managing the high flow rates of the catalyst solution. This may add
to both capital and operating expenditures of the polymerization
manufacturing facility. Further, it is now recognized that the
costs and other considerations associated with transporting
catalyst solution may be greater than those associated with the
transportation of only the catalyst.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Advantages of the present disclosure may become apparent
upon reading the following detailed description and upon reference
to the drawings in which:
[0006] FIG. 1 is a block diagram of an embodiment of a polyolefin
manufacturing system with a catalyst preparation system in
accordance with present embodiments;
[0007] FIG. 2 is a schematic flow diagram of an embodiment of a
catalyst preparation system that may be employed in the polyolefin
manufacturing system of FIG. 1, in accordance with present
embodiments;
[0008] FIG. 3 is a schematic flow diagram of an embodiment of a
catalyst preparation system with more than one catalyst tank that
may be employed in the polyolefin manufacturing system of FIG. 1,
in accordance with present embodiments;
[0009] FIG. 4 is a schematic flow diagram of an embodiment of a
catalyst preparation system with more than one catalyst mix/run
tank that may be employed in the polyolefin manufacturing system of
FIG. 1, in accordance with present embodiments;
[0010] FIG. 5 is a schematic flow diagram of an embodiment of a
catalyst preparation system with separate mix and run catalyst
tanks that may be employed in the polyolefin manufacturing system
of FIG. 1, in accordance with present embodiments; and
[0011] FIG. 6 is a flow chart depicting a method for preparing
catalyst in accordance with present embodiments.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0012] One or more specific embodiments of the present disclosure
will be described below. In an effort to provide a concise
description of these embodiments, not all features of an actual
implementation are described in the specification. It should be
appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation-specific decisions must be made to achieve the
developers' specific goals, such as compliance with system-related
and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure.
[0013] The present disclosure is directed to techniques for
catalyst solution preparation. More specifically, the present
disclosure is directed to techniques for catalyst solution
preparation by an on-site catalyst preparation system. As used
herein, the term "on-site" refers to being on the same location
and/or integral with a polymerization manufacturing facility and
any adjacent associated manufacturing facilities. The
polymerization manufacturing facility may produce various polymers
in a variety of different reactors, such as, but not limited to,
fluidized bed reactors, gas-phase reactors, loop slurry reactors,
or any combination thereof. Such reactor systems may be modeled
using a continuous ideal stirred tank reactor (CISTR) model.
[0014] Reactors of a polymerization manufacturing facility may
receive a monomer, a diluent, and a catalyst complex prepared by a
catalyst preparation system in accordance with present embodiments
to produce polymers. In certain embodiments, a polymerization
catalyst tank of the catalyst preparation system mixes a
polymerization catalyst and a solvent using an agitator to generate
a polymerization catalyst solution. A heating system coupled to
polymerization catalyst tank may help maintain a temperature of the
polymerization catalyst solution above a threshold. For example,
the threshold may be determined to help prevent precipitation of
the polymerization catalyst out of the polymerization catalyst
solution. A precontactor of the catalyst preparation system may
then receive a cocatalyst, an activator, and the polymerization
catalyst solution from the polymerization catalyst tank to generate
the catalyst complex. The precontactor may also include a heating
system. A transfer line may be used to transfer the catalyst
complex from the precontactor to the reactors of the polymerization
manufacturing facility.
[0015] By preparing the polymerization catalyst solution on-site,
the polymerization catalyst may be shipped to the polymerization
manufacturing facility from the vendor in solid form (e.g., a dry
powder), thereby simplifying and reducing costs associated with the
transportation of the polymerization catalyst. Further, the solvent
used to dissolve polymerization catalyst may be selected to be
particularly compatible and/or desirable for use in the reactors of
the polymerization manufacturing facility. For example, in certain
embodiments, the solvent may be a material already being fed to the
reactor, such as a comonomer. In addition, by heating the
polymerization catalyst solution in the catalyst preparation
system, the concentration of the polymerization catalyst may be
greater than that of catalyst solutions shipped to the
polymerization manufacturing facility by vendors. Thus, the storage
tanks and other equipment associated with the polymerization
catalyst solution may be smaller and less expensive than equipment
associated with vendor-supplied catalyst solutions. In addition,
the frequency of preparing batches of catalyst solution may be
reduced. Further, use of high-concentration catalyst solution may
improve the control of the polymerization reaction. For example,
the ratio of high-molecular weight polymer to low-molecular weight
polymer may be facilitated by using high-concentration catalyst
solution.
[0016] FIG. 1 depicts an embodiment of a manufacturing system 10
that employs catalysts to produce a polymer product through
chemical reactions. In particular, FIG. 1 is a schematic
representation of a manufacturing process for producing
polyolefins, such as polyethylene homopolymer, copolymer, and/or
terpolymer, among others. Although the catalyst preparation
techniques described herein are generally described with respect to
polyolefin production, the techniques can be applied to any
chemical reactor system that can be modeled using a continuous
ideal stirred tank reactor model. For example, the catalyst
preparation techniques can be applied to other types of polymer
production.
[0017] As shown in FIG. 1, the manufacturing system 10 includes a
reactor system 12, which receives various feedstocks, such as a
catalyst complex 14, a monomer 16, and/or a diluent 18. The
catalyst complex 14 and its preparation are described in detail
below. The monomer 16 may include one or more monomers and/or
comonomers, such as, but not limited to, ethylene, propylene,
butene, hexene, octene, decene, and so forth. The diluent 18 may
include one or more diluents, such as, but not limited to, an inert
hydrocarbon that is liquid at reaction conditions, such as
isobutane, propane, n-butane, n-pentane, i-pentane, neopentane,
n-hexane, n-heptane, cyclohexane, cyclopentane, methylcyclopentane,
or ethylcyclohexane, among others. In certain embodiments, the
diluent 18 may be employed to suspend catalyst particles and
polymer particles within the reactor vessels of the reactor system
12. In further embodiments, the reactor system 12 may also receive
other materials, such as, but not limited to, chain transfer agents
(e.g. hydrogen), catalysts, co-catalysts, and other additives.
[0018] The reactor system 12 can include one or more polymerization
reactors, such as liquid-phase reactors, gas-phase reactors, or a
combination thereof. Multiple reactors may be arranged in series,
in parallel, or in any other suitable combination or configuration.
Within the polymerization reactors, the monomer 16 (e.g., one or
more monomers and/or comonomers) may be polymerized to form a
product containing polymer particles 20, typically called fluff or
granules. According to certain embodiments, the monomer 16 may
include 1-olefins having up to 10 carbon atoms per molecule and
typically no branching nearer the double bond than the 4-position.
For example, the monomer 16 may include monomers and comonomers
such as ethylene, propylene, butene, 1-pentene, 1-hexene, 1-octene,
1-decene, or any combination thereof. The polymer particles 20 may
possess one or more melt, physical, rheological, and/or mechanical
properties of interest, such as density, melt index (MI), melt flow
rate (MFR), copolymer or comonomer content, modulus, and
crystallinity. The reaction conditions, such as temperature,
pressure, flow rate, mechanical agitation, product takeoff,
component concentrations, polymer production rate, and so forth,
may be selected to achieve the desired properties of the polymer
particles 20.
[0019] Product effluent, which includes the formed polymer
particles 20, as well as non-polymer components, such as the
diluent 18, unreacted monomer 16, and residual catalyst, exits the
reactor system 12 and enters various systems, such as a product
recovery system, an extrusion system, and/or a loadout system, to
produce extruded polymer pellets. Examples of polymer pellets that
may be produced by the manufacturing system 10 include, but are not
limited to, low density polyethylene (LDPE), linear low density
polyethylene (LLDPE), medium density polyethylene (MDPE), high
density polyethylene (HDPE), and enhanced polyethylene such as
bimodal grades. The various types and grades of polyethylene
pellets may be marketed, for example, under the brand names
Marlex.RTM. polyethylene or MarFlex.RTM. polyethylene of
Chevron-Phillips Chemical Company, LP, of The Woodlands, Tex.,
USA.
[0020] The produced polymer (e.g., polyethylene) pellets can be
used in the manufacture of a variety of products, components,
household items and other items, including adhesives (e.g.,
hot-melt adhesive applications), electrical wire and cable,
agricultural films, shrink film, stretch film, food packaging
films, flexible food packaging, milk containers, frozen-food
packaging, trash and can liners, grocery bags, heavy-duty sacks,
plastic bottles, safety equipment, coatings, toys, and an array of
containers and plastic products. Further, the products and
components formed from the polymer pellets may be further processed
and assembled prior to distribution and sale to the consumer. For
example, the polymer pellets are generally subjected to further
processing, such as blow molding, injection molding, rotational
molding, blown film, cast film, extrusion (e.g., sheet extrusion,
pipe and corrugated extrusion, coating/lamination extrusion, etc.),
and so on.
[0021] Returning to FIG. 1, the catalyst complex 14 may be prepared
by combining a catalyst solution 22, a cocatalyst 24, and activator
26. Examples of the cocatalyst 24 include, but are not limited to,
organometallic compounds, such as triisobutylaluminum,
triethylaluminum or tri-ethyl boron, alkyl aluminum compounds,
methyl aluminoxane, and so forth. Examples of the activator 26
include, but are not limited to, solid super acids and
chemically-treated solid oxides. In one embodiment, the solid oxide
can have a surface area of from about 100 to about 1000 m.sup.2/g.
In yet another embodiment, the solid oxide can have a surface area
of from about 200 to about 800 m.sup.2/g. In still another
embodiment, the solid oxide can have a surface area of from about
250 to about 600 m.sup.2/g.
[0022] When the activator 26 is a chemically-treated solid oxide,
it can include a solid inorganic oxide that includes oxygen and one
or more elements selected from Group 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, or 15 of the periodic table, or that includes
oxygen and one or more elements selected from the lanthanide or
actinide elements (See: Hawley's Condensed Chemical Dictionary,
11.sup.th Ed., John Wiley & Sons, 1995; Cotton, F. A.,
Wilkinson, G., Murillo, C. A., and Bochmann, M., Advanced Inorganic
Chemistry, 6.sup.th Ed., Wiley-Interscience, 1999). For example,
the inorganic oxide can include oxygen and an element, or elements,
selected from Al, B, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, La, Mn, Mo,
Ni, Sb, Si, Sn, Sr, Th, Ti, V, W, P, Y, Zn, and Zr.
[0023] Suitable examples of solid oxide materials or compounds that
can be used to form the chemically-treated solid oxide used as the
activator 26 can include, but are not limited to, Al.sub.2O.sub.3,
B.sub.2O.sub.3, BeO, Bi.sub.2O.sub.3, CdO, Co.sub.3O.sub.4,
Cr.sub.2O.sub.3, CuO, Fe.sub.2O.sub.3, Ga.sub.2O.sub.3,
La.sub.2O.sub.3, Mn.sub.2O.sub.3, MoO.sub.3, NiO, P.sub.2O.sub.5,
Sb.sub.2O.sub.5, SiO.sub.2, SnO.sub.2, SrO, ThO.sub.2, TiO.sub.2,
V.sub.2O.sub.5, WO.sub.3, Y.sub.2O.sub.3, ZnO, ZrO.sub.2, and the
like, including mixed oxides thereof, coatings of one oxide with
another, and combinations thereof. For example, the solid oxide can
comprise silica, alumina, silica-alumina, silica-coated alumina,
aluminum phosphate, aluminophosphate, heteropolytungstate, titania,
zirconia, magnesia, boria, zinc oxide, mixed oxides thereof, or any
combination thereof.
[0024] Returning to FIG. 1, the catalyst solution 22 may be
prepared by combining a catalyst 28 and a solvent 30. Specifically,
the catalyst 28 may be dissolved in the solvent 30. In one
embodiment, the catalyst 28 may essentially be a solid material.
Examples of the catalyst 28 include, but are not limited to,
metallocene catalysts, Ziegler-Natta catalysts, chromium-based
catalysts, vanadium-based catalysts, nickel-based catalysts, or a
combination thereof, among others. Examples of chromium-based
catalysts include, but are not limited to, chrome, chromocene,
chrome titanium, chrome silica, chrome with aluminum phosphate, and
so forth. Examples of the solvent 30 include, but are not limited
to, comonomers, such as those listed above, 1-hexene, cyclohexane,
heptane, an alkene, an alkane, a cycloalkene, a cycloalkane, or any
combination thereof. In a certain embodiment, the solvent 30 is
1-hexene and excludes toluene. Use of 1-hexene may be more
desirable than toluene because 1-hexene has fewer environmental
concerns than toluene. In addition, 1-hexene is used (i.e.,
chemically consumed or reacted) during polymerization and thus,
would appear as a residual in the polymer particles 20 in smaller
quantities than toluene, which is not used during polymerization.
Certain catalysts 28 may be less soluble in 1-hexene than toluene.
Thus, the heating of the catalyst solution 22, as described in
detail below, may facilitate use of 1-hexene instead of toluene and
help prevent precipitation of the catalyst 28.
[0025] FIG. 2 depicts an embodiment of a catalyst preparation
system 40 that may be used to prepare the catalyst complex 14 fed
to the reactor system 12. Specifically, the catalyst preparation
system 40 may include a catalyst tank 42 to store the catalyst 28.
In one embodiment, a catalyst control valve 44 may be used as a
transfer means to control the transfer of the catalyst 28 from the
catalyst tank 42 to a catalyst mix/run tank 46. Other catalyst
transfer means can also be employed either with or without a
catalyst control valve 44. For example, the catalyst 28 may be
pressured (e.g., via the use of nitrogen), pumped, conveyed, or
otherwise transported to the catalyst mix/run tank 46. The catalyst
preparation system 40 may also include a solvent tank 48 to store
the solvent 30. In one embodiment, a solvent control valve 50 may
be used to control the transfer of the solvent 30 to the catalyst
mix/run tank 46. Other solvent transfer means can also be used
either with or without a solvent control valve 50. For example, the
solvent 30 may be pressured from the solvent tank 48 or in certain
embodiments, a pump may be used to transfer the solvent 30 from the
solvent tank 48. Indeed, in some embodiments, a pump may replace or
cooperate with the solvent control valve 50.
[0026] As shown in FIG. 2, the catalyst mix/run tank 46 includes an
agitator 52 that is powered by a motor 54. The agitator 52 may be
used to dissolve and/or mix the catalyst 28 and the solvent 30 in
the catalyst mix/run tank 46. Thus, the agitator 52 may help speed
the mixing of the catalyst 28 and the solvent 30 and/or improve the
consistency of the catalyst solution 22. In certain embodiments,
the catalyst mix/run tank 46 may include a heating system 56 to
heat the catalyst solution 22. Examples of the heating system 56
include, but are not limited to, a heated tempered water jacket, a
heated tempered water coil, an electrical clamp-on jacket, or any
other suitable heating system. By heating the catalyst solution 22
with the heating system 56, greater concentrations of catalyst 28
may be achieved without resulting in precipitation of the catalyst
28. In addition, the heating system 56 may be used whenever both
the catalyst 28 and the solvent 30 are present at the same time to
help prevent precipitation of the catalyst 28 at low temperatures.
A transfer line 58 may be used to transfer the catalyst solution 22
from the catalyst mix/run tank 46. The transfer line 58 may include
a piping heating system 60, such as, but not limited to, a heated
tempered water jacket, electrical tracing, or any other suitable
heating system, which may be used to maintain a temperature of the
catalyst solution 22 above a threshold as the catalyst solution 22
travels through the transfer line 58. A catalyst solution pump 62
may be coupled to the transfer line 58 and used to transfer the
catalyst solution 22 from the catalyst mix/run tank 46. In
addition, the transfer line 58 may include a catalyst solution
control valve 64 to control the transfer of the catalyst solution
22 from the catalyst mix/run tank 46 to a precontactor 66 either
with or without a catalyst solution pump 62.
[0027] In addition to the catalyst solution 22 from the catalyst
mix/run tank 46, the precontactor 66 may receive the cocatalyst 24
from a cocatalyst tank 68 via a cocatalyst pump 70. In other
embodiments, the cocatalyst 24 may be pressured to the precontactor
66 or otherwise transferred. In further embodiments, the cocatalyst
24 may be transferred directly from the cocatalyst tank 68 to one
or more reactors in the reactor system 12, bypassing the
precontactor 66. An activator tank 72 may store the activator 26
before being transferred to the precontactor 66 via pressuring, a
pump, or the like. The precontactor 66 includes a precontactor
agitator 74 powered by a precontactor motor 76. The precontactor
agitator 74 may be used to thoroughly mix the catalyst solution 22
with the cocatalyst 24 and the activator 26. The precontactor 66
may also include a precontactor heating system 78 to heat the
catalyst complex 14 in the precontactor 66. The precontactor
heating system 78 may be similar to the heating system 56 for the
catalyst mix/run tank 46 described above. In one embodiment, the
precontactor heating system 78 may be used only during preparation
of the catalyst complex 14 and then shut off afterwards. A
precontactor transfer line 80 may be used to transfer the catalyst
complex 14 from the precontactor 66. In certain embodiments, one or
more precontactor pumps 82 may be used to transfer the catalyst
complex 14 from the precontactor 66 to one or more reactors in the
reactor system 12.
[0028] Regardless of the specific catalyst 28 used, operating
conditions within the catalyst preparation system 40 may be
controlled to produce the catalyst complex 14 with desired
properties. For example, a control system 90 can be employed to
control operating conditions within the manufacturing system 10,
such as the catalyst preparation system 40. For example, the
control system 90 may be employed to adjust the flow rates,
temperatures, and/or other properties of the catalyst 28, solvent
30, catalyst solution 22, cocatalyst 24, activator 26, and/or
catalyst complex 14. Further, the control system 90 may be employed
to transition from feeding one type of catalyst complex 14 to the
reactor system 12 to feeding another type of catalyst complex 14 to
the reactor system 12. Moreover, the control system 90 may be
employed to monitor and/or adjust operating conditions within the
manufacturing system 10, such as temperatures, pressures, the
reaction rate, and the solids concentrations, among others.
According to certain embodiments, the control system 90 may receive
input signals 92 from sensors (such as, temperature sensors,
pressure sensors, and/or flow transducers, among others) within the
manufacturing system 10 that are indicative of operating conditions
and may then generate control signals 102 to adjust operating
conditions of the manufacturing system 10.
[0029] Specifically, as shown in FIG. 2, the control system 90 may
receive input signals 92 from various sensors disposed within the
catalyst preparation system 40, such as, but not limited to, a
catalyst mix/run tank temperature sensor 94, a catalyst mix/run
tank concentration sensor 96, a precontactor temperature sensor 98,
a catalyst complex flow sensor 100, and so forth. In other
embodiments, the control system 90 may receive input signals 92
from other sensors disposed in the catalyst preparation system 40
and/or the manufacturing system 10. Based on the input signals 92,
the control system 90 may transmit control signals 102 to various
devices and equipment disposed in the catalyst preparation system
40, such as, but not limited to, any catalyst transfer means, the
catalyst control valve 44, any solvent transfer means, the solvent
control valve 50, the catalyst mix/run tank motor 54, the catalyst
mix/run tank heating system 56, the transfer pipe heating system
60, the catalyst solution transfer pump 62, the catalyst solution
control valve 64, the cocatalyst pump 70, the precontactor motor
76, the precontactor pump 82, the precontactor heating system 78,
and so forth.
[0030] In certain embodiments, the input signal 92 received by the
control system 90 may be indicative of a demand for the catalyst 28
in the catalyst mix/run tank 46. For example, the input signal 92
may be indicative of a concentration of the catalyst 28 in the
catalyst solution 22 that is lower than a setpoint and may be
transmitted by the catalyst mix/run tank concentration sensor 96.
In response, the control system 90 may activate an output, such as
an actuator for the catalyst control valve 44, to supply the
catalyst 28 to the catalyst mix/run tank 46 and/or other catalyst
transfer means. The control system 90 may receive an additional
input signal 92 indicative of a demand for the catalyst solution 22
in the precontactor 66. For example, the input signal 92 may be
indicative of a concentration of the catalyst 28 in the catalyst
complex 14 or the level of the catalyst complex 14 in the
precontactor 66 that is below a setpoint. In response, the control
system 90 may activate an output, such as an actuator for the
catalyst solution pump 62 and/or the catalyst solution control
valve 64, to supply the catalyst solution 22 to the precontactor
66. In other embodiments, the control system 90 may receive an
additional input signal 92 indicative of a demand for the catalyst
complex 14 in the reactor system 12. For example, the input signal
92 may be indicative of a flow rate of the catalyst complex 14 to
the reactor system 12 that is below a setpoint and may be
transmitted by the catalyst complex flow sensor 100. In response,
the control system 90 may activate an output, such as an actuator
for the precontactor pump 82, to supply more catalyst complex 14 to
the reactor system 12. In further embodiments, the control system
90 may receive an additional input signal 92 indicative of a
temperature of the catalyst solution 22 in the catalyst mix/run
tank 46. For example, the input signal 92 may be transmitted by the
catalyst mix/run tank temperature sensor 94 and indicate that the
temperature of the catalyst solution 22 is below a setpoint. In
response, the control system 90 may activate an output, such as an
actuator for the heating system 56, to supply additional heat to
the catalyst mix/run tank 46. The control system 90 may operate in
a similar manner to supply heat to the precontactor 66 based on
data acquired via an input signal 92 from the precontactor
temperature sensor 98.
[0031] According to certain embodiments, the control system 90 may
be a Distributed Control System (DCS). The control system 90 may
include one or more automation controllers, microprocessors,
instruction set processors, graphics processors, analog to digital
converters, interface boards, and/or related chip sets. Further,
the control system 90 may cooperate with storage that stores
executable code, data, and instructions for the control system 90.
For example, the storage may store non-transitory machine-readable
code for maintaining a temperature of the catalyst solution 22
above a threshold based on measured process variables. The storage
may include volatile memory, such as random access memory, and/or
non-volatile memory, such as read only memory, flash memory, a hard
drive, or any other suitable optical, magnetic, or solid-state
computer readable media, as well as a combination thereof. The
control system 90 may also include a display and a user interface.
According to certain embodiments, the display and the user
interface may be part of an operator workstation. The display may
display a variety of information about the manufacturing system 10.
For example, the display may display graphs, trends, mass balances,
energy balances, process data, such as measured process variables,
and/or predictive data, among others that facilitate user
monitoring and control of the manufacturing system 10.
[0032] According to certain embodiments, the display may display
screens of the user interface that facilitate entry of user inputs.
For example, a user may enter desired operating parameters (e.g.,
setpoints) or adjustments that should be made to the manufacturing
system 10. In certain embodiments, a user may review an essentially
instantaneous reaction rate or trend shown on the display and may
enter a desired catalyst feed rate value or catalyst feed rate
adjustment. In another example, a user may adjust the temperature
of the reactor system 12 or one or more of the feed rates through
the user interface. However, in other embodiments, at least some of
the operating conditions may be adjusted automatically by the
control system 90. For example, in certain embodiments, the control
system 90 may automatically adjust the flow rate of catalyst 28 to
the catalyst mix/run tank 46 based on a measured concentration of
the catalyst 28 in the catalyst solution 22.
[0033] In certain embodiments, the control system 90 may be used to
maintain a temperature of the catalyst solution 22 and/or the
catalyst complex 14 above a threshold. The threshold may be
selected to help prevent precipitation of the catalyst 28 out of
the catalyst solution 22 and/or the catalyst complex 14. In certain
embodiments, the threshold may be between approximately 40 degrees
Celsius to approximately 50 degrees Celsius. In one embodiment, the
threshold may be approximately 45 degrees Celsius. A not-to-exceed
temperature threshold, such as approximately 60 degrees Celsius or
approximately 65 degrees Celsius, may be selected based on the
particular catalyst 28 used to avoid degradation of the catalyst
28. In one embodiment, the threshold may be between approximately
40 degrees Celsius and approximately 65 degrees Celsius. The
catalyst mix/run tank temperature sensor 94 may indicate a
temperature of the catalyst solution 22 and the precontactor
temperature sensor 98 may indicate a temperature of the catalyst
complex 14. Based on the input signals 92 received from the
temperature sensors 96 and/or 98, the control system 90 may send
control signals 102 to the catalyst mix/run tank heating system 56
and/or the precontactor heating system 78 to maintain the
temperatures of the catalyst solution 22 and/or the catalyst
complex 14, respectively, above the threshold.
[0034] In other embodiments, the control system 90 may be used to
maintain a concentration of the catalyst 28 in the catalyst
solution 22 and/or the catalyst complex 14 above a threshold. The
threshold may be selected to help provide a desired amount of the
catalyst 28 to reach the reactor system 12. In certain embodiments,
the catalyst concentration threshold may be above approximately
0.40 weight percent in the solvent 30. This concentration threshold
may be greater than the concentration of catalyst solution 22
provided by off-site vendors because off-site vendors may be
limited by transportation issues. Thus, present embodiments may
enable the size of the catalyst mix/run tank 46 and associated
equipment and lines to be reduced relative to traditional
operations. In a certain embodiment, the catalyst concentration
threshold may be approximately 0.47 weight percent in the solvent
30. The catalyst mix/run tank concentration sensor 96 may provide
the input signal 92 to the control system 90 indicative of the
concentration of the catalyst 28 in the catalyst solution 22. In
response to the input signal 92 from the catalyst mix/run tank
concentration sensor 96, the control system 90 may transmit the
control signal 102 to the catalyst control valve 44 and/or the
solvent control valve 50 to maintain the concentration of the
catalyst 28 in the catalyst solution 22 above the threshold. For
example, the control signal 102 may open the catalyst control valve
44 and/or close the solvent control valve 50 if the indicated
concentration of the catalyst 28 in the catalyst solution 22 is
below the threshold. Similarly, the control system 90 may close the
catalyst control valve 44 and/or open the solvent control valve 50
if the concentration of the catalyst 28 in the catalyst solution 22
is above the threshold. In a similar manner, the control system 90
may be used to adjust one or more of the catalyst solution transfer
pump 62, catalyst solution control valve 64, and/or cocatalyst pump
70 to adjust or maintain the concentration of the catalyst 28 in
the catalyst complex 14 in the precontactor 66. In such
embodiments, the precontactor 66 may include a concentration sensor
similar to the catalyst mix/run tank concentration sensor 96 to
provide the input signal 92 to the control system 90. Further, the
control system 90 may transmit control signals 102 to the
precontactor pump 82 to adjust or maintain a flow rate of the
catalyst complex 14 to the reactor system 12. In other embodiments,
the control system 90 may also be used to control the catalyst
mix/run tank motor 54 and/or the precontactor motor 76.
[0035] The concentration sensor 96 shown in FIG. 2 may use various
techniques, such as spectrophotometry, to determine the
concentration of the catalyst 28 in the catalyst solution 22. In
one embodiment, the concentration sensor 96 may be an
ultraviolet-visible photometric analyzer (i.e., a UV-Vis analyzer),
which may utilize the Beer-Lambert law to determine the
concentration of the catalyst 28. Specifically, the UV-Vis analyzer
may pass a wavelength of light through the catalyst solution 22 and
measure the absorbance of the light at the selected wavelength. The
measured absorbance may then be compared to a calibration curve to
determine the concentration of the catalyst 28. The specific
wavelength of light may be selected to have little or no absorption
by the solvent 30, thereby reducing errors in the determined
concentration. Thus, the absorbance of light at the selected
wavelength may be essentially a function of the concentration of
the catalyst 28 in the catalyst solution 22. The UV-Vis analyzer
may used in various ways, such as, but not limited to, providing a
continuous on-line indication of the concentration of the catalyst
28 in the catalyst solution 22 and/or the catalyst complex 14,
analyzing batches of the catalyst solution 28 and/or the catalyst
complex 14, and so forth. In certain embodiments, the catalyst
solution 22 may include particles or other particulate matter that
may affect the spectrophotometric analysis. Thus, in certain
embodiments, the UV-Vis analyzer may include a filter or similar
device to remove particles and/or other matter from the catalyst
solution 22. In addition, in other embodiments, a measurement cell
of the UV-Vis analyzer may be flushed on a regular basis, e.g.,
daily, to reduce buildup of material that may affect the accuracy
of the measurement. In further embodiments, other techniques may be
used to determine the concentration of the catalyst 28 in the
catalyst solution 22.
[0036] FIG. 3 depicts an embodiment of the catalyst preparation
system 40 that can be employed in the manufacturing system 10 shown
in FIG. 1. In particular, FIG. 3 depicts a system that uses two
catalysts. For example, a first catalyst tank 120 may be used to
store a first catalyst 122 and a first catalyst control valve 124
may be used to control the flow of the first catalyst 122 to the
catalyst mix/run tank 46. The catalyst preparation system 40 may
also include a second catalyst tank 126 to store a second catalyst
128 and a second catalyst control valve 130 may be used to flow the
second catalyst 128 to the catalyst mix/run tank 46. The use of the
first and second catalysts 122 and 128 may facilitate production of
polymer particles 20 with certain desired characteristics compared
to polymer particles 20 produced using a single catalyst. In other
respects, the catalyst preparation system 40 shown in FIG. 3 is
similar to the system 40 shown in FIG. 2.
[0037] FIG. 4 depicts an embodiment of the catalyst preparation
system 40 with two catalyst mix/run tanks Specifically, a first
catalyst control valve 136 may control the flow rate of the
catalyst 28 to a first catalyst mix/run tank 140 and a first
solvent control valve 138 may control the flow rate of the solvent
30 to the first catalyst mix/run tank 140. The first catalyst
mix/run tank 140 may include a first agitator 142 driven by a first
motor 144 and may be heated using a first heating system 146. In
addition, the first catalyst mix/run tank 140 may include a first
temperature sensor 148 and a first concentration sensor 149.
Similarly, a second catalyst control valve 145 may control the flow
rate of the catalyst 28 to a second catalyst mix/run tank 150 and a
second solvent control valve 147 may control the flow rate of the
solvent 30 to the second catalyst mix/run tank 150. The second
catalyst mix/run tank 150 may include a second agitator 152 driven
by a second motor 154, a second heating system 156, a second
temperature sensor 158, and a second concentration sensor 160. The
catalyst solution 122 from the first catalyst mix/run tank 140 may
be transferred to the precontactor 66 through a first transfer line
162 and the catalyst solution 22 from the second catalyst mix/run
tank 150 may be transferred via a second transfer line 164. The
first and second catalyst mix/run tanks 140 and 150 may be used as
online spares for one another. For example, the first catalyst
mix/run tank 140 may be used to supply the catalyst solution 22 to
the precontactor 66 until the first catalyst mix/run tank 140 is
approximately empty, below a minimum level threshold, or otherwise
out-of-service. At that point, the second catalyst mix/run tank 150
may be used to supply the catalyst solution 22 to the precontactor
66 while the first catalyst mix/run tank 140 is unavailable.
Similarly, when the second catalyst mix/run tank 150 is
approximately empty, below a minimum level threshold, or otherwise
out-of-service, the first catalyst mix/run tank 140 may be used to
supply the catalyst solution 22 to the precontactor 66. In other
respects, the catalyst preparation system 40 shown in FIG. 4 is
similar to the system 40 shown in FIG. 2.
[0038] FIG. 5 depicts an embodiment of the catalyst preparation
system 40 including separate mix and run tanks Specifically, the
catalyst preparation system 40 includes a catalyst mix tank 180
that includes a catalyst mix agitator 182 driven by catalyst mix
motor 184. The catalyst mix tank 180 may include a catalyst mix
heating system 186, a catalyst mix concentration sensor 187, and a
catalyst mix temperature sensor 188. A catalyst mix pump 191 may be
used to transfer the catalyst solution 22 from the catalyst mix
tank 180 to a catalyst run tank 190 via catalyst mix transfer line
189. The catalyst run tank 190 may include a catalyst run agitator
192 driven by catalyst run motor 194, a catalyst run heating system
196, a catalyst run concentration sensor 197, and a catalyst run
temperature sensor 198. A catalyst run transfer line 200 may be
used to transfer the catalyst solution 22 from the catalyst run
tank 190 to the precontactor 66. As shown in FIG. 5, the catalyst
mix tank 180 may be used to prepare the catalyst solution 22 and
the catalyst run tank 190 may be used to supply the catalyst
solution 22 to the precontactor 66. When the catalyst run tank 190
is approximately empty or below a minimal level threshold, the
catalyst solution 22 from the catalyst mix tank 180 may be used to
refill the catalyst run tank 190. Additional catalyst solution 22
may then be prepared in the catalyst tank 180 to be transferred
later to the catalyst run tank 190. In other respects, the catalyst
preparation system 40 shown in FIG. 5 is similar to the system 40
shown in FIG. 2.
[0039] FIG. 6 depicts a method 210 for preparing the catalyst
complex 14. The method 210 may begin by mixing the catalyst 28 and
the solvent 30 in the catalyst mix/run tank 46 to generate the
catalyst solution 22 (block 212). For example, the control system
90 may activate the catalyst mix/run tank agitator 52 to mix the
contents of the catalyst mix/run tank 46 to generate the catalyst
solution 22. The catalyst solution 22 may also be prepared, for
example, in the first catalyst mix/run tank 140, the second
catalyst mix/run tank 150, or the catalyst mix tank 180. The method
210 may then continue by heating the catalyst solution 22 to
maintain a temperature of the catalyst solution 22 above a
threshold (block 214). For example, the control system 90 may be
used to control the heat provided to the catalyst solution 22 via
the catalyst mix/run tank heating system 56 based on the
temperature sensed by the catalyst mix/run tank temperature sensor
94. In other embodiments, the control system 90 may be used to
maintain the temperature of the catalyst solution 22 above the
threshold in, for example, the first catalyst mix/run tank 140, the
second catalyst mix/run tank 150, the catalyst mix tank 180, or the
catalyst run tank 190. The method 210 may then continue by mixing
the heated catalyst solution 22 with the cocatalyst 24 and the
activator 26 in the precontactor 66 to generate the catalyst
complex 14 (block 216). For example, the control system 90 may use
the precontactor agitator 74 to mix the contents of the
precontactor 66 to generate the catalyst complex 14.
[0040] The method 210 may then continue by heating the catalyst
complex 14 to maintain a temperature above a threshold (block 218).
For example, the control system 90 may use the precontactor heating
system 78 to maintain the temperature of the catalyst complex 14
above the threshold as determined by the precontactor temperature
sensor 98. The method may then continue by transferring the heated
catalyst complex 14 to the reactor system 12 (block 220). In
certain embodiments, the control system 90 may be used to control
the precontactor pump 82 to adjust the flow rate of the catalyst
complex to the reactor system 12 as measured by the catalyst
complex flow sensor 100.
ADDITIONAL DESCRIPTION
[0041] Systems and methods for catalyst preparation have been
described. The following clauses are offered as further description
of the disclosure.
Embodiment 1
[0042] A system, comprising: an agitator disposed inside a
polymerization catalyst tank and configured to mix or dissolve at
least a portion or all of a polymerization catalyst and a solvent
to generate a polymerization catalyst solution; a heating system
coupled to the polymerization catalyst tank and configured to
maintain a temperature of the polymerization catalyst solution
above a threshold; a precontactor configured to receive feed
streams comprising an activator and the polymerization catalyst
solution from the polymerization catalyst tank to generate a
catalyst complex; and a transfer line configured to transfer the
catalyst complex from an outlet of the precontactor to a
reactor.
Embodiment 2
[0043] The system of embodiment 1, wherein the precontactor
comprises: a second agitator disposed inside the precontactor and
configured to mix the activator and polymerization catalyst
solution; and a second heating system coupled to the precontactor
and configured to maintain a temperature of the catalyst complex
above a second threshold.
Embodiment 3
[0044] The system defined in any preceding embodiment, comprising
the reactor configured to polymerize monomer into polymer solids in
the presence of the catalyst complex.
Embodiment 4
[0045] The system defined in any preceding embodiment, comprising a
plurality of reactors configured to polymerize monomer into polymer
solids in the presence of the catalyst complex.
Embodiment 5
[0046] The system defined in any preceding embodiment, wherein the
plurality of reactors are operated in a series configuration or in
a parallel configuration.
Embodiment 6
[0047] The system defined in any preceding embodiment, wherein the
polymerization catalyst comprises a metallocene catalyst.
Embodiment 7
[0048] The system defined in any preceding embodiment, wherein the
solvent comprises a comonomer.
Embodiment 8
[0049] The system defined in any preceding embodiment, wherein the
comonomer comprises 1-hexene.
Embodiment 9
[0050] The system defined in any preceding embodiment, wherein the
feed streams comprise a cocatalyst.
Embodiment 10
[0051] The system defined in any preceding embodiment, wherein the
cocatalyst comprises triisobutylaluminum, triethylaluminum, or any
combination thereof.
Embodiment 11
[0052] The system defined in any preceding embodiment, wherein the
activator comprises a solid super acid.
Embodiment 12
[0053] The system defined in any preceding embodiment, wherein the
heating system is configured to heat a second transfer line
configured to transfer the polymerization catalyst solution from
the polymerization catalyst tank to the precontactor.
Embodiment 13
[0054] The system defined in any preceding embodiment, comprising a
sensor configured to provide an indication of a concentration of
the polymerization catalyst in the polymerization catalyst
solution.
Embodiment 14
[0055] A method, comprising: making a polymerization catalyst
solution by dissolving a polymerization catalyst with one or more
solvents in a heated polymerization catalyst tank; making a
polymerization catalyst complex by combining at least a portion of
the polymerization catalyst solution with an activator in a
precontactor; and transferring the polymerization catalyst complex
from the precontactor to a reactor.
Embodiment 15
[0056] The method or system defined in any preceding embodiment,
comprising combining a cocatalyst with the polymerization catalyst
solution and the activator in the precontactor.
Embodiment 16
[0057] The method or system defined in any preceding embodiment,
comprising heating the polymerization catalyst complex in the
precontactor.
Embodiment 17
[0058] The method or system defined in any preceding embodiment,
comprising maintaining the polymerization catalyst solution in the
polymerization catalyst tank at a temperature between approximately
40 degrees Celsius to 50 degrees Celsius.
Embodiment 18
[0059] The method or system defined in any preceding embodiment,
comprising polymerizing a monomer in the presence of the catalyst
complex to produce polymer solids in the reactor.
Embodiment 19
[0060] The method or system defined in any preceding embodiment,
comprising measuring a concentration of the polymerization catalyst
in the polymerization catalyst solution using an
ultraviolet-visible photometric analyzer.
Embodiment 20
[0061] The method or system defined in any preceding embodiment,
comprising maintaining the concentration of the polymerization
catalyst in the polymerization catalyst solution above
approximately 0.40 weight percent in the solvent.
Embodiment 21
[0062] A system, comprising: one or more automation controllers
configured to: receive a first input indicative of a demand for a
metallocene catalyst in a metallocene catalyst tank; activate a
first output to supply the metallocene catalyst to the metallocene
catalyst tank, such that the metallocene catalyst and a solvent mix
in the metallocene catalyst tank to form a metallocene catalyst
solution; receive a second input indicative of a demand for the
metallocene catalyst solution in a precontactor; and activate a
second output to supply the metallocene catalyst solution to the
precontactor; such that the metallocene catalyst solution and an
activator mix in the precontactor to form a metallocene catalyst
complex.
Embodiment 22
[0063] The method or system defined in any preceding embodiment,
wherein the one or more automation controllers are configured to:
receive a third input indicative of a demand for the metallocene
catalyst complex in a reactor; and activate a third output to
supply the metallocene catalyst complex to the reactor.
Embodiment 23
[0064] The method or system defined in any preceding embodiment,
wherein the first and second outputs comprise a control valve
actuator, a pump actuator, or any combination thereof.
Embodiment 24
[0065] The method or system defined in any preceding embodiment,
wherein the second input comprises a concentration of the
metallocene catalyst in the metallocene catalyst tank.
Embodiment 25
[0066] The method or system defined in any preceding embodiment,
comprising a sensor configured to generate the second input,
wherein the sensor comprises an ultraviolet-visible photometric
analyzer.
Embodiment 26
[0067] The method or system defined in any preceding embodiment,
wherein the one or more automation controllers are configured to:
receive a fourth input indicative of a temperature of the
metallocene catalyst solution in the metallocene catalyst tank; and
activate a fourth output to supply heat to the metallocene catalyst
tank.
Embodiment 27
[0068] A catalyst complex, comprising: a metallocene catalyst
solution, comprising a mixture of a metallocene catalyst and a
solvent, wherein a concentration of the metallocene catalyst in the
metallocene catalyst solution is greater than approximately 0.40
weight percent in the solvent; and an activator.
Embodiment 28
[0069] The method, system, or catalyst complex defined in any
preceding embodiment, wherein the solvent comprises a comonomer,
1-hexene, cyclohexane, heptane, an alkene, an alkane, a
cycloalkene, a cycloalkane, or a combination thereof.
Embodiment 29
[0070] The method, system, or catalyst complex defined in any
preceding embodiment, comprising a cocatalyst.
Embodiment 30
[0071] The method, system, or catalyst complex defined in any
preceding embodiment, wherein the cocatalyst comprises
triisobutylaluminum, triethylaluminum, or any combination
thereof.
Embodiment 31
[0072] The method, system, or catalyst complex defined in any
preceding embodiment, wherein the activator comprises a solid super
acid.
[0073] While the present disclosure may be susceptible to various
modifications and alternative forms, specific embodiments have been
shown by way of example in the drawings and tables and have been
described in detail herein. However, it should be understood that
the embodiments are not intended to be limited to the particular
forms disclosed. Rather, the disclosure is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the disclosure as defined by the following
appended claims. Further, although individual embodiments are
discussed herein, the disclosure is intended to cover all
combinations of these embodiments.
* * * * *