Patent Grant
10029230
Not applicable.
Not applicable.
The present invention generally relates to polymerization of olefin monomers.
Polyolefins, such as polyethylene and polypropylene, may be prepared by particle form polymerization, also referred to as slurry polymerization. In such processes, feed materials, such as monomer and catalyst are introduced to a reactor (such as a loop reactor), and a product slurry containing solid polyolefin particles in the liquid medium is taken off.
In continuous loop reactors, the various feed materials may be introduced to the loop reactor in various ways. For example, the monomer and catalyst may be introduced separately or together, and the monomer and catalyst may be mixed with varying amounts of diluent prior to introduction to the reactor. Within the loop reactor, the monomer and catalyst become dispersed in the fluid slurry and as they circulate through the loop reactor, the monomer reacts at the catalyst site, thereby yielding solid polyolefin particles in the fluid slurry.
Properties of the polyolefin are influenced by a variety of factors, including reactor conditions. Work is continuously underway to improve operability of such reactions.
The present invention is directed to resolving, or at least reducing, one or all of the problems mentioned above.
Various embodiments of the present invention include olefin polymerization processes. The processes generally include circulating a slurry including an olefin monomer selected from C2-C12 olefin monomers, a liquid diluent selected from C3-C7 alkanes, catalyst and polyolefin particles under polymerization conditions within a loop reactor, wherein, in operation, the process has a cavitation number (Ca) of from 6 to 60 and the polymerization conditions include a polymerization temperature of from 38° C. to 121° C. and a polymerization pressure of from 27 bar to 50 bar.
One or more embodiments include the process of the preceding paragraph, wherein the cavitation number (Ca) is from 12 to 50.
One or more embodiments include the process of any preceding paragraph, wherein the cavitation number (Ca) is from 18 to 40.
One or more embodiments include the process of any preceding paragraph, wherein the cavitation number (Ca) is from 24 to 36.
One or more embodiments include the process of any preceding paragraph and further including an average circulation velocity (v) of at least 7.0 m/s.
One or more embodiments include the process of any preceding paragraph and further including an average circulation velocity (v) of at least 10.7 m/s.
One or more embodiments include the process of any preceding paragraph and further including an average circulation velocity (v) of at least 12.2 m/s.
One or more embodiments include the process of any preceding paragraph, wherein the polymerization temperature is from 75° C. to 110° C.
One or more embodiments include the process of any preceding paragraph, wherein the slurry includes olefin monomer in a concentration of from 0.7 wt. % to 10.5 wt. %.
One or more embodiments include the process of any preceding paragraph, wherein the olefin monomer includes ethylene.
One or more embodiments include the process of any preceding paragraph, wherein the process has a Euler Number (Eu) of at least 5.
One or more embodiments include the process of any preceding paragraph, wherein the process has a length/diameter/Euler Number ratio (L/D/Eu) of less than 184.
One or more embodiments include the process of any preceding paragraph, wherein the process has a length/diameter/Euler Number ratio (L/D/Eu) of less than 184.
One or more embodiments include the process of any preceding paragraph, wherein the slurry includes greater than 48 wt. % polyolefin particles.
One or more embodiments include the process of any preceding paragraph, wherein the slurry includes greater than 48 wt. % polyolefin particles.
In one or more embodiments, the polymerization process includes circulating a slurry including olefin monomer, liquid diluent, catalyst and polyolefin particles under polymerization conditions within a loop reactor, wherein, in operation, the process has a Euler Number (Eu) of at least 5.
One or more embodiments include the process of the preceding paragraph, wherein the Euler number (Eu) is at least 6.
One or more embodiments include the process of any preceding paragraph, wherein the Euler number (Eu) is at least 7.
One or more embodiments include the process of any preceding paragraph and further including a length/diameter/Euler Number ratio (L/D/Eu) of less than 184.
One or more embodiments include the process of any preceding paragraph and further including a length/diameter/Euler Number ratio (L/D/Eu) of less than 180.
One or more embodiments include the process of any preceding paragraph and further including a length/diameter/Euler Number ratio (L/D/Eu) of less than 175.
One or more embodiments include the process of any preceding paragraph and further including a length/diameter/Euler Number ratio (L/D/Eu) of less than 170.
One or more embodiments include the process of any preceding paragraph, wherein the slurry includes greater than 48 wt. % polyolefin particles.
One or more embodiments include the process of any preceding paragraph, wherein the slurry includes greater than 50 wt. % polyolefin particles.
One or more embodiments include the process of any preceding paragraph, wherein the slurry includes greater than 52 wt. % polyolefin particles.
One or more embodiments include the process of any preceding paragraph and further including a length/diameter/Euler Number ratio (L/D/Eu) of less than 184 and wherein the slurry includes greater than 48 wt. % polyolefin particles.
The above paragraphs present a simplified summary of the presently disclosed subject matter in order to provide a basic understanding of some aspects thereof. The summary is not an exhaustive overview, nor is it intended to identify key or critical elements to delineate the scope of the subject matter claimed below. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description set forth below.
The following FIGURES form part of the present specification and are included to further demonstrate certain aspects of the present invention. The claimed subject matter may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
The drawing illustrates an exemplary embodiment of a loop reactor system.
While the claimed subject matter is susceptible to various modifications and alternative forms, the drawings illustrate specific embodiments herein described in detail by way of example. It should be understood, however, that the description herein of specific embodiments is not intended to limit the claimed subject matter to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives failing within the spirit and scope of the invention as defined by the appended claims.
illustrative embodiments of the subject matter claimed below will now be disclosed. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort, even if complex and time-consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
In the description below, unless otherwise specified, all compounds described herein may be substituted or unsubstituted and the listing of compounds includes derivatives thereof. Further, various ranges and/or numerical limitations may be expressly stated below. It should be recognized that unless stated otherwise, it is intended that endpoints are to be interchangeable. Further, any ranges include iterative ranges of like magnitude falling within the expressly stated ranges or limitations.
In the specification and appended claims, the terms “connect”, “connection”, “connected”, “in connection with” and “connecting” are used to mean “in direct connection with” or “in connection with via another element”, and the term “set” is used to mean “one element” or “more than one element”. As used herein, the terms “up” and “down”, “upper” and “lower”, “upwardly” and “downwardly”, “upstream” and “downstream”, “above” and “below” and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left or other relationship as appropriate.
Embodiments described herein include processes of forming polyolefins (i.e., olefin polymerization processes). As known in the art, olefin polymerization processes include contacting an olefin monomer with a catalyst within a reaction zone to form a polyolefin.
The olefin monomers utilized in the processes described herein may be selected from C2 to C30 olefin monomers, or C2 to C12 olefin monomers (e.g., ethylene, propylene, 1-butene, pentene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene), for example. The monomers may include olefinic unsaturated monomers, C4 to C18 diolefins, conjugated or nonconjugated dienes, polyenes, vinyl monomers and cyclic olefins, for example. Non-limiting examples of other monomers may include norbornene, norbornadiene, isobutylene, isoprene, vinylbenzycyclobutane, styrene, alkyl substituted styrene, ethylidene norbornene, dicyclopentadiene and cyclopentene, for example. The formed polyolefin may include homopolymers, copolymers or terpolymers, for example. In one or more embodiments, the olefin monomers are selected from C2-C3 olefin monomers. In other embodiments, the olefin monomer includes ethylene.
In one or more embodiments, the processes described herein include the homopolymerization of ethylene. In alternative embodiments, the processes described herein include the copolymerization of ethylene and a higher 1-olefin, such as 1-butene, 1-pentene, 1-hexene, 1-octene or 1-decene, for example. For example, the process may include the copolymerization of ethylene and a starting amount of comonomer ranging from about 0.01 wt. % to about 10 wt. %, or from about 0.01 wt. % to about 5 wt. %, or from about 0.1 wt. % to about 4 wt. % (wherein the resulting copolymers may still be referred to as polyethylene).
Catalysts may include any catalyst(s) or catalyst system(s) useful for polymerizing olefin monomers. For example, the catalyst may be selected from chromium based catalyst systems, single site transition metal catalyst systems including both single and multiple (two or more) metallocene catalyst systems, Ziegler-Natta catalyst systems and combinations thereof, for example. As known in the art, the catalysts may be activated for subsequent polymerization and may or may not be associated with a support material, for example.
Once the catalyst is prepared, as described above and/or as known to one skilled in the art, a variety of olefin polymerization processes may be carried out using that catalyst. The polymerization conditions (e.g., equipment, process conditions, reactants, additives and other materials used in polymerization processes) will vary in a given process, depending on the desired composition and properties of the polyolefin being formed. Such processes may include solution phase, gas phase, slurry phase, bulk phase, high pressure processes or combinations thereof, for example.
Slurry phase processes (also referred to as particle form polymerization) generally include forming a suspension of solid, particulate polymer in a liquid polymerization medium, to which monomers and optionally hydrogen, along with catalyst, are added. The suspension (which may include diluents) may be intermittently or continuously removed from the reaction zone, where the volatile components can be separated from the polymer and recycled, optionally after a distillation, to the reaction zone. Liquefied diluent may optionally be employed in the polymerization medium and may be a diluent for the solid polymer particles that is separate from and in addition to the unreacted monomers. Suitable diluents included those known in the art and include hydrocarbons which are inert and liquid or are super critical fluids under slurry polymerization conditions. For example, suitable diluents may include C3-C7 alkanes, such as isobutane, propane, n-pentane, i-pentane, neopentane, n-hexane and n-heptane. In one or more embodiments, the diluent includes isopentane (i-pentane). In further embodiments, the diluent includes isobutane. A bulk phase process is similar to that of a slurry process with the exception that the liquid medium is also the reactant (e.g., monomer) in a bulk phase process. However, a process may be a bulk process, a slurry process or a bulk slurry process, for example.
In a specific embodiment, the polymerization process may be carried out continuously in one or more loop reactors. In continuous loop reactors, feed materials, such as monomer and catalyst are introduced to the reactor and a product slurry containing solid polyolefin particles in the liquid medium is taken off. In continuous loop reactors, the various feed materials may be introduced to the loop reaction zone in various ways. For example, the monomer and catalyst may be introduced separately or together and the monomer and catalyst may be mixed with varying amounts of diluent prior to introduction to the reaction zone. In the loop reaction zone, the monomer and catalyst become dispersed in the fluid slurry. As they circulate through the loop reaction zone in the fluid slurry, the monomer reacts at the catalyst site in a polymerization reaction and the polymerization reaction yields solid polyolefin particles in the fluid slurry.
In one or more embodiments, the slurry may include olefin monomer in a concentration of greater than about 4 wt. %, or greater than about 5 wt. %, or from about 0.7 wt. % wt. % to about 10.5 wt. %, or from about 5 wt. % to about 8 wt. %, for example. In one or more embodiments, the slurry may include greater than about 48 wt. %, or greater than about 50 wt. %, or greater than about 52 wt. % polyolefin particles (i.e., solids), for example. As used herein, reference to slurry composition refers to a point in time in the polymerization wherein steady state conditions have been achieved.
The loop reactor may be maintained at a pressure of from about 27 bar to about 50 bar or from about 35 bar to about 45 bar and a temperature of from about 38° C. (100° F.) to about 121° C. (250° F.), or from about 75° C. (167° F.) to about 110° C. (230° F.), or less than about 103° C. (217° F.), for example. Depending on the selection of diluent, monomer and optional comonomer, the reactor may also be operated at super-critical conditions. Reaction heat may be removed through the loop wall via any suitable method, such as via a double-jacketed pipe or heat exchanger, for example. Additional details regarding loop reactor apparatus and polymerization processes may be found, for example, in U.S. Pat. No. 4,674,290, U.S. Pat. No. 5,183,866, U.S. Pat. No. 5,455,314, U.S. Pat. No. 5,565,174, U.S. Pat. No. 6,045,661, U.S. Pat. No. 6,051,631, U.S. Pat. No. 6,114,501, and U.S. Pat. No. 6,262,191, the contents of which are incorporated in their entirety herein.
In operation, it is important to maintain suspension within loop slurry reactors. If suspension of the solids within the liquid is not maintained, solid particles can settle at locations within the reactor, thereby causing plugging. Accordingly, slurry phase processes generally utilize one or more pumps to provide motive force for circulation of the fluid slurry. Such pumps generally circulate the fluid slurry at a circulation velocity. The pumps may include those known in the art capable of providing operation within the operating specifications described herein and include for example those described in U.S. Pat. No. 8,354,063, U.S. Pat. No. 7,736,597, and U.S. Pat. No. 7,014,821, the contents of all of which are incorporated by reference in their entirety herein.
Maintaining the suspension can be accomplished by operating the loop slurry reactor at or above a minimum average circulation velocity. In one or more embodiments, the minimum average circulation velocity is maintained at a level higher than in typical polymerization processes. For example, the minimum average circulation velocity may, in one or more embodiments, be at least 7.0 m/s, or at least 10.7 m/s, or at least 12.2 m/s, or at least 13.7 m/s, for example. However, in other embodiments, such as those having small diameter (about 6 inches, for example) loop reactor pipes, the minimum average circulation velocity may be as low as about 3 m/s, or 4 m/s, or 5 m/s, for example. The circulation velocity in the reactor is calculated from the reactor volume flow divided by the cross-sectional area of the reactor pipe section. It is recognized that the localized velocity of the slurry at a given location in the loop reactor may vary slightly and have a profile that is generally slower at the loop reactor wall than in the central area of the loop reactor. However, reference to the minimum circulation velocity means that the localized slurry velocity is the same or greater than the identified minimum average circulation velocity.
One method of maintaining the specified minimum circulation velocity is to operate the loop reactor at a reactor pressure above the suction pressure required to provide Net Positive Suction Head (NPSH) to the one or more pumps as measured by the manufacturer. However, it has been demonstrated that operating at or below such pressures can result in erosion damage to the loop reactor pumps (e.g., as a result of cavitation). In addition, increased slurry velocities can require more power supplied by the pump motor, higher head, and more shaft, bearing, seal and impeller strength.
Cavitation refers to the formation of vapor cavities, such as bubbles or voids, formed within a liquid, which can lead to significant wear within a reactor system, including surface fatigue of metal components therein. It is defined as the process of formation of the vapor phase of a liquid (vapor bubbles) when it is subjected to reduced pressures at constant temperature. Further, cavitation can cause noise, damage to components, vibrations and loss of efficiency in pumps, as well as mechanical seal damage in loop slurry reactors, for example. Accordingly, polymerization processes tend to operate at conditions that avoid cavitation.
The degree of cavitation can be estimated with the aid of a non-dimensional parameter typically referred as Cavitation number (Ca), conventionally represented as a. Cavitation number (Ca) is useful analyzing or characterizing fluid flow dynamics where cavitation may occur. Cavitation number (Ca) expresses the relationship between the difference of a local absolute pressure and the vapor pressure and the kinetic energy per volume and is used to characterize the potential of the flow to cavitate (i.e., the lower the number the increased likelihood that the flow is to cavitate). Dimensionless numbers are often defined as products or ratios of quantities that are not dimensionless, but whose dimensions cancel out when their powers are multiplied. One of skill in the art would understand, particularly in light of the present disclosure, that the measured parameters used to calculate the dimensionless numbers referenced herein must be converted to like or consistent units before making the calculation such that the units cancel each other out to result in the dimensionless number.
The Cavitation number is defined by the following equation (1):
where ρ is the density of the fluid slurry as measured in units known to one skilled in the art, such as, for example, kg/m3, Pr is the local pressure (or ambient, absolute pressure) as measured in units known to one skilled in the art, such as, for example, Pa (Pascals), Pv is the vapor pressure of the fluid slurry as measured in units known to one skilled in the art, such as, for example, Pa, and V is a characteristic velocity of the flow (i.e., the circulation velocity) as measured in units known to one skilled in the art, such as, for example, m/s.
In one or more embodiments of the invention, the polymerization process has a control cavitation number of less than 35.7. Alternative embodiments include control cavitation numbers of less than 30, or less than 20, or less than 10, or from 6 to 60, or from 12 to 50, or from 18-40, or from 24-36, for example. As used herein, the term “control cavitation number” refers to upper limit of the cavitation number at any point throughout the process. In another embodiment, the polymerization process has an average cavitation number of less than 35.7. Alternative embodiments include average cavitation numbers of less than 30, or less than 20, or less than 10, or in the range from 6 to 60, or from 12 to 50, or from 18-40, or from 24-36, for example.
Euler number is also a dimensionless number used in fluid flow calculations. It expresses the relationship between a local pressure drop (i.e., pressure differential) and the kinetic energy per volume and is used to characterize losses in flow, where a perfect frictionless flow corresponds to a Euler number of 1. The Euler number is defined by the following equation (2):
where ρ is the density of the fluid slurry as measured in units known to one skilled in the art, such as, for example, kg/m3, ΔP is the difference between the upstream pressure and the downstream pressure measured in units known to one skilled in the art, such as, for example, Pa, and V is a characteristic velocity of the flow (i.e., circulation velocity) as measured in units known to one skilled in the art, such as, for example, m/s. While those of skill in the art may utilize the Euler number to characterize fluid flow characteristics, others may use the Ruark number (designated by the symbol Ru), which is the reciprocal of the Euler number.
One or more embodiments include polymerization processes having a Euler Number of at least 5, or at least 6, or at least 7, for example.
Further, one or more embodiments include a length/diameter/Euler Number ratio (L/D/Eu) of less than 184, or less than 180, or less than 175, or less than 170, for example. As used herein, “length” is defined as flow length (described subsequently herein) and “diameter” is defined as internal diameter (described subsequently herein).
The above recited conditions can be met via a variety of process operation configurations. For example, the conditions may be met through reactor configuration, such as the direction and radius of elbows and direction and length of horizontal sections, operating conditions, such as pressure and temperature, as discussed herein, and diluent selection.
Upon removal from the reactor, the polyolefin may be passed to a polymer recovery system for further processing, such as the addition of additives and/or extrusion. Such recovery systems are known to one skilled in the art and therefore are not described in detail herein.
The polyolefins (and blends thereof) formed via the processes described herein may include, but are not limited to, linear low density polyethylene (LLDPE), low density linear polyethylene (LDLPE), elastomers, plastomers, high density polyethylenes (HDPE), low density polyethylenes (LDPE), medium density polyethylenes (MDPE), polypropylene and polypropylene copolymers.
In one or more embodiments, the formed polyolefin may include polyethylene having a density (as measured by ASTM D-792) of from about 0.86 g/cc to about 0.98 g/cc, or from about 0.88 g/cc to about 0.965 g/cc, or from about 0.90 g/cc to about 0.965 g/cc or from about 0.925 g/cc to about 0.97 g/cc.
In one or more embodiments, the formed polyolefin may include high density polyethylene. As used herein, the term “high density polyethylene” refers to ethylene based polymers having a density of from about 0.94 g/cc to about 0.97 g/cc.
In one or more embodiments, the formed polyolefin may include low density polyethylene. As used herein, the term “low density polyethylene” refers to ethylene based polymers having a density of less than about 0.92 g/cc.
The polyolefins and blends thereof are useful in applications known to one skilled in the art, such as forming operations (e.g., film, sheet, pipe and fiber extrusion and co-extrusion as well as blow molding, injection molding and rotary molding). Films include blown, oriented or cast films formed by extrusion or co-extrusion or by lamination useful as shrink film, cling film, stretch film, sealing films, oriented films, snack packaging, heavy duty bags, grocery sacks, baked and frozen food packaging, medical packaging, industrial liners, and membranes, for example, in food-contact and non-food contact application. Fibers include slit-films, monofilaments, melt spinning, solution spinning and melt blown fiber operations for use in woven or non-woven form to make sacks, bags, rope, twine, carpet backing, carpet yarns, filters, diaper fabrics, medical garments and geotextiles, for example. Extruded articles include medical tubing, wire and cable coatings, sheets, such as thermoformed sheets (including profiles and plastic corrugated cardboard), geomembranes and pond liners, for example. Molded articles include single and multi-layered constructions in the form of bottles, tanks, large hollow articles, rigid food containers and toys, for example.
The drawing illustrates a loop reactor (or loop reaction zone) 10 having vertical segments 12, upper horizontal segments 14 and lower horizontal segments 16. These upper and lower horizontal segments 14 and 16 define upper and lower zones of horizontal flow. An impeller (not shown), driven by motor 24, is located in the loop reactor 10 to circulate the slurry. Each vertical segment 12 is connected to another vertical segment through a corresponding horizontal segment (14 or 16). The vertical segment 12 may include heat exchange jackets (or cooling jackets) 18. The vertical segments 12 and horizontal segments 14 and 16 define a loop reaction zone. The loop reaction zone 10 may include more or fewer vertical segments 12 and corresponding horizontal segments 14 and 16 than shown in the drawing. Further, the loop reaction zone 10 may be oriented vertically or horizontally. Additionally, some or all of the horizontal segments 14 and 16 may be curved members that connect vertical segments 12. The connecting segments 14 and 16 may be any shape or form that connects the vertical segments 12 and allows fluid to flow there between. In some configurations, the vertical segments 12 may be connected with a U-shaped segment (not shown) rather than horizontal segments 14 and 16, as shown.
In the drawing olefin monomer and make up diluent are introduced via lines 26 and 28, respectively, which can enter the loop reactor 10 directly at one or a plurality of locations or can combine with condensed diluent recycle line 30, as shown. Comonomer may also be introduced to the loop reactor 10 by these lines. The monomer and comonomer may be fed to the loop reactor 10 by any suitable techniques, such as a simple opening to the reactor, a nozzle, a sparger, or other distribution apparatus, for example.
Catalyst may be introduced to loop reactor 10 via catalyst introduction means 32 that provides a zone (location) for catalyst introduction. Any suitable means of introducing catalyst to the loop reactor may be employed. For example, the process and apparatus disclosed in U.S. Pat. No. 6,262,191, which is incorporated by reference herein, for preparing a catalyst and providing to a loop reaction zone may be utilized.
The elongated hollow appendage for continuously taking off an intermediate product slurry from the loop reactor 10 is designated broadly by reference to character 34. Continuous take off mechanism 34 may be located in or adjacent to a downstream end of one of the lower horizontal segments 16 and adjacent or on a connecting elbow 20. The loop reactor 10 can have one or more continuous take off appendages. It is to be recognized that although depicted as continuous take off mechanisms 34 in the particular embodiments illustrated in the drawing, it is contemplated that settling legs may be used as an alternative or in combination with the continuous take off mechanisms, as known to one skilled in the art.
Any number of vertical segments 12 or “legs” can be employed, although the drawing depicts eight legs. For example, a six-leg reactor may be utilized or a twelve-leg reactor may be utilized. The flow length of the loop reaction zone may be greater than 900 feet, or greater than 1000 feet, or greater than 1100 feet, or greater than 1200 feet, or greater than 1300 feet, or greater than 1400 feet, or greater than 1500 feet or greater than 1.600 feet, or greater than 1700 feet, or greater than 1800 feet, or greater than 1900 feet, or greater than 2000 feet. The foregoing lengths may be approximate in some situations. As utilized herein, the term “flow length” refers to the total length of the path that it takes for the slurry to circulate through the loop reactor one time.
In one or more embodiments, each vertical section 12 and each horizontal section 14 and 16 have substantially equal diameters. As used herein, the term “diameter” refers to the internal diameter of the pipe of the loop reactor. In one or more embodiments, the diameter is from 0.25 m to 1.0 m, or from 0.30 m to 0.8 m, or from 0.35 m to 0.76 m, for example.
The loop reactor 10 may be operated so as to generate a pressure differential of at least 18 psig, or at least 20 psig, or at least 22 psig, or at least 24 psig, or at least 26, psig, or at least 28 psig, or at least 30 psig, for example. As used herein, the term “pressure differential” refers to the difference between an upstream and downstream end of one or more pumps utilized to circulate the slurry.
To further illustrate correlation of reactor conditions, cavitation and Euler Number, sample calculations are included below for a theoretical ethylene polymerization process carried out in isobutane in a loop reactor with eight vertical legs.
As shown in Table 1, as the circulation velocity (V) increases, the cavitation number (Ca) decreases. Such lower cavitation numbers further allow for decreased reactor temperatures (TR) and increased ethylene (C2) concentrations within the reactor during operation.
As shown in Table 2, as the Euler Number increases, higher solids contents within the reactor can be achieved.
As illustrated herein, embodiments of the invention provide adequate (and in instances, improved) operation to polymerization processes at cavitation numbers that are lower than previously recognized. In fact, embodiments of the invention provide for polymerization process operability at cavitation numbers that may approach cavitation. Further, such processes including lower cavitation numbers are capable of operation without significantly increase reactor pressures, thereby avoiding or minimizing the increased costs usually associated with decreased cavitation numbers.
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present invention.
The invention illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values.
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope of the invention. Accordingly, the protection sought herein is as set forth in the claims below.
| Number | Name | Date | Kind |
|---|---|---|---|
| 1693786 | Isaachsen | Dec 1928 | A |
| 2770295 | Allen | Nov 1956 | A |
| 2825721 | Hogan et al. | Mar 1958 | A |
| 2915513 | Leatherman et al. | Dec 1959 | A |
| 2943082 | Cottle | Jun 1960 | A |
| 2951067 | Cash | Aug 1960 | A |
| 2952671 | Cottle | Sep 1960 | A |
| 2982763 | McLeod | May 1961 | A |
| 2988527 | Tegge | Jun 1961 | A |
| 3001978 | McLeod | Sep 1961 | A |
| 3126365 | Hooker | Mar 1964 | A |
| 3152872 | Scoggin et al. | Oct 1964 | A |
| 3172737 | Whittington | Mar 1965 | A |
| 3203766 | Mudd et al. | Aug 1965 | A |
| 3242150 | Scoggin | Mar 1966 | A |
| 3248179 | Norwood | Apr 1966 | A |
| 3257363 | Miller et al. | Jun 1966 | A |
| 3262922 | Payne | Jul 1966 | A |
| 3285899 | Houser et al. | Nov 1966 | A |
| 3293000 | Marwil | Dec 1966 | A |
| 3309350 | Kelley et al. | Mar 1967 | A |
| 3318857 | Dietz | May 1967 | A |
| 3324093 | Alleman | Jun 1967 | A |
| 3418305 | Payne et al. | Dec 1968 | A |
| 3551403 | Delbouille et al. | Dec 1970 | A |
| 3594356 | Hinton | Jul 1971 | A |
| 3625658 | Closon | Dec 1971 | A |
| 3640980 | Baba | Feb 1972 | A |
| 3642731 | Tegge et al. | Feb 1972 | A |
| 3794627 | Giachetto | Feb 1974 | A |
| 3816383 | Stotko | Jun 1974 | A |
| 3858943 | Bose et al. | Jan 1975 | A |
| 3879361 | Wyatt et al. | Apr 1975 | A |
| 3912701 | Dunn, Jr. | Oct 1975 | A |
| 3956061 | Young et al. | May 1976 | A |
| 3956257 | Hogan | May 1976 | A |
| 4007321 | Scholz et al. | Feb 1977 | A |
| 4099335 | Jezl et al. | Jul 1978 | A |
| 4121029 | Irvin et al. | Oct 1978 | A |
| 4126743 | Shiomura et al. | Nov 1978 | A |
| 4199546 | Kirch | Apr 1980 | A |
| 4211863 | McDaniel et al. | Jul 1980 | A |
| 4258158 | Pfeiffer | Mar 1981 | A |
| 4372758 | Bobst et al. | Feb 1983 | A |
| 4383972 | McCurdy et al. | May 1983 | A |
| 4395523 | Kirch | Jul 1983 | A |
| 4424341 | Hanson et al. | Jan 1984 | A |
| 4436902 | Wood et al. | Mar 1984 | A |
| 4439601 | McCurdy et al. | Mar 1984 | A |
| 4461889 | Hanson | Jul 1984 | A |
| 4499263 | Messura et al. | Feb 1985 | A |
| 4501885 | Sherk et al. | Feb 1985 | A |
| 4528337 | Kreilein et al. | Jul 1985 | A |
| 4543399 | Jenkins, III et al. | Sep 1985 | A |
| 4589957 | Sherk et al. | May 1986 | A |
| 4613484 | Ayres et al. | Sep 1986 | A |
| 4632976 | Asanuma et al. | Dec 1986 | A |
| 4654801 | Stewart et al. | Mar 1987 | A |
| 4674290 | Verser | Jun 1987 | A |
| 4676870 | Stewart et al. | Jun 1987 | A |
| 4690804 | Rohlfing | Sep 1987 | A |
| 4737280 | Hanson | Apr 1988 | A |
| 4740550 | Foster | Apr 1988 | A |
| 4754007 | Pullukat et al. | Jun 1988 | A |
| 4794151 | Mueller-Mall et al. | Dec 1988 | A |
| 4832915 | Messura et al. | May 1989 | A |
| 5183866 | Hottovy | Feb 1993 | A |
| 5207929 | Sung et al. | May 1993 | A |
| 5225465 | Eichenauer et al. | Jul 1993 | A |
| 5272236 | Lai et al. | Dec 1993 | A |
| 5276115 | Bohmer et al. | Jan 1994 | A |
| 5278272 | Lai et al. | Jan 1994 | A |
| 5292863 | Wang | Mar 1994 | A |
| 5314579 | Sung | May 1994 | A |
| 5326835 | Ahvenainen et al. | Jul 1994 | A |
| 5371158 | Brekner et al. | Dec 1994 | A |
| 5387659 | Hottovy et al. | Feb 1995 | A |
| 5391654 | Ahvenainen et al. | Feb 1995 | A |
| 5416179 | Welch et al. | May 1995 | A |
| 5455314 | Bums et al. | Oct 1995 | A |
| 5473020 | Peifer et al. | Dec 1995 | A |
| 5480948 | Geerts | Jan 1996 | A |
| 5492985 | Peifer et al. | Feb 1996 | A |
| 5565174 | Burns et al. | Oct 1996 | A |
| 5565175 | Hottovy et al. | Oct 1996 | A |
| 5575979 | Hanson | Nov 1996 | A |
| 5597892 | Hanson | Jan 1997 | A |
| 5638834 | White et al. | Jun 1997 | A |
| 5639834 | Debras et al. | Jun 1997 | A |
| 5712365 | Arai et al. | Jan 1998 | A |
| 5744555 | Ames et al. | Apr 1998 | A |
| 5747407 | Martin | May 1998 | A |
| 5898053 | Leaney et al. | Apr 1999 | A |
| 5959044 | Villar | Sep 1999 | A |
| 5986021 | Hokkanen et al. | Nov 1999 | A |
| 6042790 | Hottovy et al. | Mar 2000 | A |
| 6045661 | Kreischer et al. | Apr 2000 | A |
| 6051631 | Hottovy | Apr 2000 | A |
| 6114501 | Hottovy et al. | Sep 2000 | A |
| 6204344 | Kendrick et al. | Mar 2001 | B1 |
| 6225421 | Promel et al. | May 2001 | B1 |
| 6225422 | Power et al. | May 2001 | B1 |
| 6239235 | Hottovy et al. | May 2001 | B1 |
| 6239300 | Stouffer et al. | May 2001 | B1 |
| 6262191 | Hottovy et al. | Jul 2001 | B1 |
| 6281300 | Kendrick | Aug 2001 | B1 |
| 6319997 | Kendrick et al. | Nov 2001 | B1 |
| 6355741 | Marechal | Mar 2002 | B1 |
| 6380325 | Kendrick | Apr 2002 | B1 |
| 6533988 | Kallio et al. | Mar 2003 | B2 |
| 6566460 | Salmon | May 2003 | B1 |
| 6699947 | Evertz et al. | Mar 2004 | B1 |
| 6743869 | Franklin, III et al. | Jun 2004 | B2 |
| 6806324 | Hottovy et al. | Oct 2004 | B2 |
| 6815511 | Verser et al. | Nov 2004 | B2 |
| 6833415 | Kendrick et al. | Dec 2004 | B2 |
| 6858682 | Kendrick et al. | Feb 2005 | B2 |
| 6926868 | Kendrick et al. | Aug 2005 | B2 |
| 6967230 | Hottovy et al. | Nov 2005 | B2 |
| 7005485 | Burns et al. | Feb 2006 | B2 |
| 7014821 | Hottovy et al. | Mar 2006 | B2 |
| 7015289 | Hottovy et al. | Mar 2006 | B2 |
| 7033545 | Kufeld et al. | Apr 2006 | B2 |
| 7034090 | Kendrick | Apr 2006 | B2 |
| 7037980 | Stacy et al. | May 2006 | B2 |
| 7109290 | McElvain et al. | Sep 2006 | B2 |
| 7179426 | Hottovy et al. | Feb 2007 | B2 |
| 7268194 | Kendrick et al. | Sep 2007 | B2 |
| 7517947 | McElvain et al. | Apr 2009 | B2 |
| 7524904 | Verser et al. | Apr 2009 | B2 |
| 7547750 | McElvain et al. | Jun 2009 | B2 |
| 7615596 | Burns et al. | Nov 2009 | B2 |
| 7645841 | Shaw et al. | Jan 2010 | B2 |
| 7718732 | Lee et al. | May 2010 | B2 |
| 7736597 | Hottovy et al. | Jun 2010 | B2 |
| 7957947 | Odi | Jun 2011 | B2 |
| 7999044 | Hottovy et al. | Aug 2011 | B2 |
| 8017701 | McElvain et al. | Sep 2011 | B2 |
| 8058367 | Hottovy et al. | Nov 2011 | B2 |
| 8202949 | McElvain et al. | Jun 2012 | B2 |
| 8344078 | Hottovy | Jan 2013 | B2 |
| 8354063 | Hottovy et al. | Jan 2013 | B2 |
| 8871886 | Hottovy et al. | Oct 2014 | B1 |
| 9340629 | Bhandarkar et al. | May 2016 | B2 |
| 9358515 | Hottovy et al. | Jun 2016 | B2 |
| 20010012497 | Debras | Aug 2001 | A1 |
| 20020086955 | Kendrick | Jul 2002 | A1 |
| 20020111441 | Kendrick et al. | Aug 2002 | A1 |
| 20020132936 | Kendrick et al. | Sep 2002 | A1 |
| 20020173598 | Kendrick et al. | Nov 2002 | A1 |
| 20020182121 | Kendrick | Dec 2002 | A1 |
| 20020187081 | Hottovy et al. | Dec 2002 | A1 |
| 20030012705 | Hottovy et al. | Jan 2003 | A1 |
| 20030023010 | Hottovy et al. | Jan 2003 | A1 |
| 20030027944 | Hottovy et al. | Feb 2003 | A1 |
| 20030050409 | Hottovy et al. | Mar 2003 | A1 |
| 20030083444 | McElvain et al. | May 2003 | A1 |
| 20030092856 | Hottovy et al. | May 2003 | A1 |
| 20030229187 | Kufeld et al. | Dec 2003 | A1 |
| 20040116625 | Hottovy et al. | Jun 2004 | A1 |
| 20040122187 | Verser et al. | Jun 2004 | A1 |
| 20040136881 | Verser et al. | Jul 2004 | A1 |
| 20040192860 | Hottovy et al. | Sep 2004 | A1 |
| 20050095176 | Hottovy | May 2005 | A1 |
| 20060063896 | McElvain et al. | Mar 2006 | A1 |
| 20060100591 | Alheidt et al. | May 2006 | A1 |
| 20060159595 | Hottovy et al. | Jul 2006 | A1 |
| 20080052058 | Odi | Feb 2008 | A1 |
| 20090124779 | Cousin et al. | May 2009 | A1 |
| 20090326168 | Burns et al. | Dec 2009 | A1 |
| 20100056707 | Hottovy et al. | Mar 2010 | A1 |
| 20100056732 | McElvain et al. | Mar 2010 | A1 |
| 20100130704 | Hottovy et al. | May 2010 | A1 |
| 20110288247 | Hottovy | Nov 2011 | A1 |
| 20150175721 | Hendrickson | Jun 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 353479 | Nov 1979 | AT |
| 695770 | Sep 1967 | BE |
| 865789 | Jul 1978 | BE |
| 857386 | Dec 1970 | CA |
| 1019899 | Oct 1977 | CA |
| 1800935 | May 1969 | DE |
| 0415427 | Mar 1991 | EP |
| 0416379 | Mar 1991 | EP |
| 0432555 | Jun 1991 | EP |
| 0519266 | Dec 1992 | EP |
| 0648697 | Apr 1995 | EP |
| 0891990 | Jan 1999 | EP |
| 0891990 | Nov 1999 | EP |
| 2055725 | May 2009 | EP |
| 647754 | Nov 1928 | FR |
| 590595 | Jul 1947 | GB |
| 790547 | Feb 1958 | GB |
| 828791 | Feb 1960 | GB |
| 841263 | Jul 1960 | GB |
| 863055 | Mar 1961 | GB |
| 887707 | Jan 1962 | GB |
| 905879 | Nov 1962 | GB |
| 1147019 | Apr 1969 | GB |
| 1435965 | May 1976 | GB |
| 2018611 | Oct 1979 | GB |
| 52147689 | Dec 1977 | JP |
| 56093701 | Jul 1981 | JP |
| 58132009 | Aug 1983 | JP |
| 5949233 | Mar 1984 | JP |
| 61089211 | May 1986 | JP |
| 6213408 | Jan 1987 | JP |
| 62007704 | Jan 1987 | JP |
| 1178503 | Jul 1987 | JP |
| 62151412 | Jul 1987 | JP |
| 62164703 | Jul 1987 | JP |
| 56100632 | Aug 1987 | JP |
| 1139602 | Jun 1989 | JP |
| 1139603 | Jun 1989 | JP |
| 1178504 | Jul 1989 | JP |
| 3084014 | Apr 1991 | JP |
| 04230863 | Aug 1992 | JP |
| 6073168 | Mar 1994 | JP |
| 7286004 | Oct 1995 | JP |
| 2514386 | Jul 1996 | JP |
| 10087738 | Apr 1998 | JP |
| 10168115 | Jun 1998 | JP |
| 82848 | Oct 1975 | PL |
| 9308221 | Apr 1993 | WO |
| 9616996 | Jun 1996 | WO |
| 9618659 | Jun 1996 | WO |
| 9634895 | Nov 1996 | WO |
| 9736942 | Oct 1997 | WO |
| 9801477 | Jan 1998 | WO |
| 9947251 | Sep 1999 | WO |
| 9960028 | Nov 1999 | WO |
| 0002929 | Jan 2000 | WO |
| 0005277 | Feb 2000 | WO |
| 0105842 | Jan 2001 | WO |
| 2004024780 | Mar 2004 | WO |
| 2006019494 | Feb 2006 | WO |
| 2006028778 | Mar 2006 | WO |
| 2006056761 | Jun 2006 | WO |
| 2010027912 | Mar 2010 | WO |
| 2011097119 | Aug 2011 | WO |
| 2012141974 | Oct 2012 | WO |
| Entry |
|---|
| Mirzae, A., et al, “Prepolymerization of Ethylene with a Ziegler-Natta Catalyst,” Journal of Applied Polymer Science, May 14, 2007, pp. 2703-2711, vol. 105, Wiley Periodicals, Inc. |
| Foreign communication from the corresponding application International Application No. PCT/US2013/073054, International Search Report and Written Opinion, dated Mar. 6, 2014, 9 pages. |
| Michael Arne, SRI International, High Density Polyethylene, Supplement D, A private report by the Process Economics Program, May 1989. |
| J.P. Hogan et al., “Phillips Petroleum company Loop Reactor Polyethylene Technology,” Journal of Applied Polymer Science Applied Polymer Symposium, 36, 49-60 (1981). |
| R.H. Perry & C.H. Chilton (Eds.). Chemical Engineers' Handbook (5th ed.). McGraw-Hill, Inc., New York, New York, pp. 5-46-5-47 (1973). |
| Magelli et al., “Solids Separation at the Exit of a Continuous-flow Slurry Reactor Stirred With Multiple Axial Impellers,” Trans IChemE, vol. 75, Part A, Mar. 1997, 284-287. |
| Foreign communication from the corresponding application International Application No. PCT/US2011/036434, International Search Report and Written Opinion, dated Jul. 26, 2011, 11 pages. |
| Bibliographic data of U.S. Appl. No. 09/080,412 entitled “Continuous Slurry Polymerization Volatile Removal”, filed May 18, 1998, Inventor: James Austin Kendrick. |
| Bibliographic data of U.S. Appl. No. 09/955,729 entitled “Continuous Slurry Polymerization Volatile Removal”, filed Sep. 19, 2001, Inventor: James Austin Kendrick (98B014A13). |
| Bibliographic data of U.S. Appl. No. 09/586,370 entitled “High Solids Slurry Polymerization Apparatus”, filed Jun. 2, 2000, Inventor: John Hottovy, et al. |
| Declaration of Scott T. Roger in a sealed envelope labeled as “Proprietary Information” under the provisions of MPEP §724. |
| Foreign communication from a related counterpart application—International Search Report & Written Opinion, PCT/US2018/012726, May 28, 2018, 9 pages. |
