POLYMERIC MATERIALS.

Abstract

The apparatus 110 for carrying out a chemical reaction comprises an elongated housing 112 and a receptacle 114. The elongated housing 112 may include a cooling means 116 and end fittings 118, 120 which may include ports where fluids can be introduced and / or removed; in the use of the apparatus 110, a chemical reaction product is formed within the receptacle 114; subsequently, the receptacle 114 containing the chemical reaction product is removed from the elongated housing 112.

Description

POLYMERIC MATERIALS DESCRIPTIVE MEMORANDUM This invention relates to polymeric materials and particularly, though not exclusively, to apparatus for producing polymers, a method for producing polymers per se, and related aspects. Preferred embodiments relate to a drag-reducing formulation comprising the polymers and their use in drag reduction, for example, to reduce the friction (drag) effect experienced by a liquid hydrocarbon flowing through a hydrocarbon pipeline. The use of alpha-olefin polymers and / or copolymers to reduce the frictional effect (drag) experienced by a liquid hydrocarbon flowing through a hydrocarbon pipeline is well known in the art. Reducing drag decreases the amount of energy required to achieve such flow and, therefore, also lowers the costs associated with pumping. These materials, often called drag-reducing agents (DRAs), can take various forms, including certain polymers in oil-soluble suspensions, emulsions, pellets, gels, microfine powders, and particulate suspensions, for example, comprising aqueous, organic, or aqueous / organic solvents. In some cases, the DRA may comprise a true solution in a suitable carrier solvent (e.g., a dilute polymer solution product produced in a solution polymerization process).However, particle suspensions comprising ground polymers are often the least expensive form. The polymers most commonly used in the preparation of drag-reducing agents (DRAs) are poly(alpha-olefins) with carbon chain lengths ranging from 2 to approximately 40 carbons. Typically, these polymers are prepared using Ziegler-Natta catalysts and often also cocatalysts such as alkylaluminum compounds. These polymerization reactions tend to be very efficient, producing relatively high yields when carried out on a large scale. However, they also tend to be highly exothermic. The exothermic reaction itself creates problems that reduce the usefulness of the product if it is not effectively managed. These problems include, but are not limited to, a substantial reduction in the molecular weight of the polymer. This can substantially reduce the polymer's effectiveness in a drag-reducing agent formulation. Various different types of apparatus have been described for producing alpha-olefin polymers and / or copolymers as described below. LCCAnn / Lznz / E / YiAi US patents 5504132 and 5504131 describe the preparation and use of non-crystalline, high-molecular-weight hydrocarbon drag-reducing polymers. The documents describe suitable polymerization reaction vessels such as polymer bottles and bags. It is claimed that the invention described therein has been demonstrated with bottles and bags containing five to seven layers, including a water-impermeable polyolefin such as polypropylene, polyethylene, or polybutylene, a bonding polymer, and an oxygen barrier of ethylene vinyl alcohol copolymer, another bonding polymer, and externally coated with polyethylene, polypropylene, or polybutylene. The use of polyethylene terephthalate as an additional layer to enhance reactor strength at high temperatures is considered preferable.One disadvantage of using the described bottle and bag method is that the poly(alpha-olefin) polymer produced adheres extremely strongly to the walls of the reactor vessels. As a result, the polymer vessels cannot be separated from the poly(alpha-olefin) polymer. Instead, the bottles or bags are ground up along with the polymer to form the drag-reducing material. However, this is disadvantageous and undesirable: the material from the bottles or bags can contaminate downstream processes or products, for example, within oil refineries. When this contamination reaches the refined fuel, adverse effects such as filter blockages can occur in the final fuel application. US patents 7534403, 7582708, 8105547, and 8110150 describe polymerization reactors for creating drag-reducing polymers. The reactors are said to address the problem of removing heat from the drag-reducing polymerization reactor (DRA) without the addition of cooling additives. The solution involves using a reactor that includes a tank incorporating a series of plates that define a heat exchanger. In one embodiment, seventeen 4-foot (121.92 cm) heat exchanger plates are spaced 4 13 / 16 inches (12.223 cm) apart. Unfortunately, the dimensions make it difficult to use the apparatus to achieve consistent product quality, and separating the polymer from the heat exchanger plates can be challenging. US patent 6649670B describes continuous polymerization and ambient milling methods for polyolefin drag-reducing agents. In one embodiment, a continuous polymerization method involving a form-fill-seal packaging process is described. The polymerization apparatus may comprise a continuous stirred-tank reactor (CSTR) where raw materials (e.g., monomers and catalysts) are continuously loaded, allowed an appropriate residence time in the reactor system so as to maintain a suitable molecular weight or viscosity, and subsequently continuously discharged into a form-fill-seal packaging device. The packaging device may form pouches that serve as LCCAnn / Lznz / E / YiAi temporary and isolated reactor vessels are collected, kept in the presence of an inert atmosphere, and allowed to polymerize the reagents at high conversion. US patent 6906150 describes a method for preparing polymers that are drag-reducing agents. The method comprises allowing a polymerization mixture to polymerize in at least one closed reaction chamber configured as a linear void space with a linear axis and a cross-section and first and second ends, where the linear void space is surrounded by a chamber wall having an inner chamber surface and an outer heat-exchange surface. Coolant is passed over the outer heat-exchange surface to remove heat therefrom. The ends of the reaction chamber are opened, and essentially all of the polymer is removed from each reaction chamber by a collection plunger. The collection plunger travels along the linear axis of the void space from the first end to the second end.However, the use of collection plungers is not practical, as the apparatus comprising such plungers is expensive to manufacture, the plungers are not very effective at removing the solid polymer from the reaction chambers, and, moreover, cleaning the apparatus ready for reloading the reaction chambers is time-consuming and difficult. It is an object of the present invention to provide an apparatus for producing drag-reducing polymers, which may be advantageous. It is an object of the present invention to provide a method for producing drag-reducing polymers, which may be advantageous. According to a first aspect of the invention, an apparatus is provided for carrying out a polymerization reaction to produce a drag-reducing polymer, wherein the apparatus comprises: (a) an elongated housing; and (b) an elongated receptacle within the housing, wherein said receptacle is arranged to receive reactants for the reaction in the apparatus for producing a drag-reducing polymer. In one embodiment, said elongated housing may comprise a rigid elongated support tube assembly 4 shown in Figure 1, and the elongated receptacle may comprise an inflatable plastic reaction tube 12, shown in the same figure. The receptacle in question is preferably not self-contained. It is preferably flaccid, unless it is inflated or otherwise supported by external means as described herein. The receptacle preferably comprises a plastic material (e.g., a polymeric material), for example, a plastic film material, which is arranged to define the receptacle. The film material may have a thickness of at least 20 µm, preferably at least 50 µm, and preferably at least 100 µm. LCCAnn / Lznz / E / YiAi The receptacle preferably includes a first end and a second end separated along the elongated length of the receptacle. The first end is preferably a closed end and, more preferably, is substantially permanently closed, i.e., preferably cannot be opened except, for example, by destruction of the receptacle. The first end preferably includes a sealed region, for example, a heat-sealed region, whereby the opposite walls of the receptacle are secured together, for example, by thermal bonding, thus defining the closed end. The length of the receptacle is appropriately the linear distance between the first end and the second end. In the context of this descriptive report and unless the context requires otherwise, the elongated receptacle diameter refers to the longest straight line passing from one side of the receptacle's cross-section to an opposite side, when the receptacle is in a distended (e.g., inflated) state and / or when configured to define its maximum cross-sectional area. In the context of an elongated receptacle having a substantially symmetrical cross-sectional shape (e.g., having a substantially circular cross-section), the diameter of the elongated receptacle refers to a straight line passing from one side to an opposite side of the receptacle, through the center of the cross-section, when the receptacle is in a distended (e.g., inflated) state and / or when configured to define its maximum cross-sectional area. Preferably, the diameter of the receptacle is substantially constant for at least 80% (preferably at least 90% or 95%) of its length. In a preferred embodiment, a region of the receptacle adjacent to the second end diverges (or extends appropriately) such that an opening in the receptacle at the second end has a larger diameter than a region of the receptacle further inward from the second end. This arrangement facilitates securing and sealing the second end in position in a manner that minimizes the creation of air gaps during use. The diameter of the receptacle may range from 1 cm to 45 cm throughout its length. When the second end diverges as described, the maximum diameter of the diverging region may be up to 30% greater than the diameter of the receptacle upstream of the diverging region. The length of the receptacle may range from 15 cm to 60 m. The volume of the receptacle may range from 12 cm³ to 4 m³. Preferably, the diameter of the receptacle (suitably across at least 80% of the receptacle length) is less than 30 cm. More preferably, it is less than 11 cm. It may be at least 7 cm. The length of the receptacle is preferably in the range of 3 m to 15 m, especially in the range of 4 m. LCCAnn / Lznz / E / YiAi The volume of the receptacle is preferably in the range of 4000 cm³ to 0.5 m³, for example, in the range of 10,000 cm³ to 0.15 m³, and more preferably in the range of 20,000 cm³ to 0.12 m³. The diameter, length, and / or volume are appropriately selected as described to optimize the polymerization and / or curing process of the polymer within the receptacle. It has been found that if the diameter, length, and / or volume are too large, there may be insufficient heat transfer during polymerization. This can mean that the degree of polymerization across the diameter and / or within the volume may be unacceptably variable, which can result in the production of a lower-drag-reducing polymer. The aspect ratio of the elongated receptacle can be defined as the length of the receptacle's internal volume divided by the diameter of the receptacle's internal volume. This aspect ratio can be at least 10, adequately at least 20, and preferably at least 30. This aspect ratio can be less than 600, preferably less than 300, and more preferably less than 150. This aspect ratio is preferably between 10 and 300, and more preferably between 30 and 150. Preferably, apart from any means by which the first end is arranged to define the closed end, the receptacle preferably includes no seams between said first and second ends. Said receptacle is preferably formed from horizontal tubing. It is preferably sealed at said first end as described and is divergent (e.g., when extended) at said second end. The elongated housing is preferably arranged to support the receptacle that is suitably arranged within the housing. The elongated housing preferably includes cooling means for cooling the reagents and the polymer contained within the receptacle in use. These cooling means may comprise a cooling and / or refrigeration device arranged to remove heat from the receptacle. Further details are provided below. However, it should be noted that if heating the receptacle is desired, the described cooling means may be modified to circulate a heating fluid instead of a coolant. Said elongated housing preferably includes inerting means to introduce and / or maintain an inert atmosphere in and / or around the receptacle. The elongated housing preferably comprises a first elongated tube in which the receptacle is placed. In use (for example, when inflated and / or when containing reagents for the preparation of a polymer as described herein), the receptacle preferably contacts an inner surface of the first elongated tube. At least 60%, at least 75%, or at least 90% of the area of ​​an outer wall of the receptacle is in contact with this inner surface. LCCAnn / Lznz / E / YiAi preferably makes contact with said internal surface. Said receptacle preferably has a substantially circular cross-section, for example along at least 50%, at least 75%, at least 90% or at least 95% of its length. The cross-sectional area of ​​the receptacle may be substantially constant, for example along at least 50%, at least 75%, at least 90% or at least 95% of its length. Preferably, the first elongated tube has a circular cross-section, and the receptacle may also have a circular cross-section. The ratio of the maximum diameter of the receptacle to the diameter of the first elongated tube, suitable in a region where the first elongated tube and the receptacle are opposite each other, may be at least 0.8, preferably at least 0.9, and more preferably at least 0.95. This ratio may be 1.2 or less, preferably less than 1.1, and more preferably less than 1.05. Suitablely, the ratios mentioned above apply along at least 50% or at least 80% of the length of the receptacle.Therefore, in a preferred embodiment, the ratio of the maximum diameter of the receptacle (measured at any position along at least 50% or at least 80% of the length of the receptacle) divided by the diameter of the first elongated tube in a position opposite to the position in which the diameter of the receptacle is measured is in the range of 0.8 to 1.2, preferably in the range of 0.95 to 1.1. The inner surface of the first elongated tube is preferably substantially smooth and / or preferably includes a relatively low coefficient of friction to allow the receptacle to slide over the inner surface when prompted to do so. The inner surface is preferably uninterrupted over most (for example, more than 80% or more than 90%) of its area. The inner surface is preferably cylindrical, preferably circularly cylindrical. The inner surface preferably has a constant cross-section over substantially its entire length. The first elongated tube is preferably cylindrical, for example circularly cylindrical. This first elongated tube is preferably rigid and / or self-contained. It can be made of a metal, for example steel. The first elongated tube may include a port (A) through one of its walls to allow fluid to enter and / or exit the first elongated tube in use. The elongated tube may include one or a plurality of such ports. The elongated housing preferably comprises a second elongated tube that is suitably coaxial with the first elongated tube, and the first elongated tube is suitably positioned within the second elongated tube. The first and second elongated tubes are preferably radially separated so as to define an annular space. LCCAnn / ίζηζ / E / γίΛΐ between the first and second elongated tubes, so that adequate spacer means exist to maintain the space. This annular space preferably defines a fluid passage for a refrigerant fluid. The annular space preferably extends around the first elongated tube so that the coolant adequately contacts at least 20%, at least 50%, at least 70%, at least 80%, or at least 90% of the surface area of ​​said first elongated tube, thereby cooling the first elongated tube (and consequently the receptacle within). In particular, substantially the entire surface area of ​​the first elongated tube is brought into contact with the coolant in use. Therefore, the arrangement may define part of said cooling means for cooling reagents in the receptacle in use. The cooling means are suitable for removing the heat generated by polymerization occurring within the receptacle due to physical and thermal contact between the external surface of the receptacle and the internal surface of the first elongated tube. This second elongated tube is preferably cylindrical, for example circularly cylindrical. This second, elongated tube is preferably rigid and / or self-contained. It can be made of a metal, for example, steel. Said second elongated tube may include one or, preferably, a plurality of ports (for example, a port (B) and a port (C)) through a wall of the second elongated tube to allow fluid to enter and exit the second elongated tube (and appropriately into and / or out of said annular space), in use. The first elongated tube is preferably closed at a first end (which is suitably adjacent to the first end of the receptacle) by a first end member. The first end member may include a port (for example, port (D)) extending through it to allow fluid to pass into and out of the elongated housing. The first end member may include one or a plurality of such ports. The elongated housing preferably includes fastening means for releasably securing the receptacle in position within the first elongated tube as described. The housing is therefore preferably arranged for the removal of the elongated receptacle from it after polymerization has occurred therein. In a preferred embodiment where the housing includes a first elongated tube as described, the housing and / or the first elongated tube may be arranged so that the receptacle slides out of the first elongated tube and is thereby removed and / or detached from it. Such fastening means may comprise a clamp for holding the receptacle in position. When the receptacle includes a second end (extending LCCAnn / ίζηζ / E / γίΛΐ appropriately as described), the clamping means may hold the second end and / or the regions adjacent to it in position. Such clamping may include a second end plate that is appropriately arranged to be operatively connected to the first elongated tube (when provided) of the elongated housing. Said second end plate may include one or a plurality of ports (for example, ports (E) and (F)), extending through it to allow fluid to pass into and / or out of the elongated housing and / or said receptacle, in use. When the apparatus includes cooling means as described, it may include a receptacle (Cl) for containing a coolant, wherein the apparatus is arranged to supply coolant from the receptacle (Cl) to a region outside the receptacle. When the apparatus includes first and second elongated tubes and an annular space as described, the apparatus is preferably arranged (for example, by including a pump) to supply coolant from the receptacle (Cl) to the annular space. The coolant may circulate during use. If it is desired to heat reactants in the receptacle, a heating fluid (for example, having a temperature higher than ambient temperature) may be used instead of the coolant.In some cases, at one point during a polymerization reaction using the apparatus, a coolant fluid may be supplied and at another point, a heating fluid may be supplied. As an alternative to providing the second elongated tube that cooperates with the first elongated tube to define an annular space for the circulation of the coolant as described, an alternative cooling device may be used. This may comprise a cooling assembly that includes an elongated tube (e.g., substantially rectangular in cross-section) arranged to be secured (e.g., releasably secured) adjacent to an outer surface of the first elongated tube. The cross-section is suitably configured so that one of its faces can make intimate thermal contact (e.g., face-to-face contact) with the first elongated tube. The coolant can circulate in use through the rectangular cross-section tube to cool the first elongated tube and, consequently, the receptacle in thermal contact with it. In one embodiment, said vessel (Cl) contains coolant for cooling reagents and / or polymers in the receptacle in use. Said vessel (Cl) is preferably operatively arranged, conveniently via piping, to supply coolant to said annular space. The apparatus may include a receptacle (C2) for holding a monomer, wherein the apparatus is arranged for the supply of monomer into the receptacle. In one form of In accordance with LCCAnn / Lznz / E / YiAi, said container (C2) contains monomer for supply to the receptacle. Said container (C2) is preferably operatively arranged, conveniently via a pipe, to supply monomer to said receptacle. The apparatus may include a container (C3) for holding a catalyst, wherein the apparatus is arranged for supplying the catalyst to the container. In one embodiment, the container (C3) contains catalyst for supply to the container. The container (C3) is preferably arranged, via a pipe, to supply catalyst to the container. Vessels (C2) and (C3) may be arranged to supply the monomer and catalyst, respectively, to a mixing region where they come into contact and mix, wherein the mixing region is upstream of said vessel. A pipeline is suitably arranged to supply a mixture comprising monomer and catalyst from said mixing region to said vessel. The apparatus may include a mixing device for mixing monomer and catalyst, and preferably said mixing device is provided upstream of said receptacle. The apparatus may include a container (C4) for holding an inert fluid (for example, an inert gas such as nitrogen), wherein the apparatus is arranged to supply the inert fluid to the apparatus and / or the receptacle to inert the apparatus and / or the receptacle. In one embodiment, the container (C4) contains inert fluid. The container (C4) is preferably operatively arranged, conveniently via piping, to supply inert fluid to inert the apparatus and / or the receptacle. According to a second aspect of the invention, a method for producing a drag-reducing polymer is provided, wherein the method comprises: (i) select a device according to the first aspect; (i) introducing reagents (for example, at least one monomer and at least one catalyst) for the preparation of said polymer into said receptacle of said apparatus; (i¡¡) control the conditions around said receptacle to control the polymerization of said reagents within. Step (iii) may include operating said cooling means as described in accordance with the first aspect to cool the reactants and / or the polymer in the receptacle during polymerization. Step (iii) may include the introduction of an inert fluid, for example inert gas, into the apparatus, the receptacle or adjacent area, to inertize the receptacle and / or a region around the receptacle. LCCAnn / Lznz / E / YiAi The total weight of the reagents introduced into said receptacle may be at least 12 g, adequately at least 1000 g, preferably at least 10,000 g, more preferably at least 20,000 g, and especially at least 30,000 g. The total weight may be less than 3300 kg, adequately less than 1000 kg, preferably less than 500 kg, more preferably less than 250 kg, and especially less than 100 kg. The total weight of the reagents introduced into said receptacle may be between 1000 g and 250 kg, and preferably between 10,000 g and 100 kg. The polymer produced in the method can be any conventional or known polymer drag-reducing agent (DRA), including, without limitation, poly(alpha-olefin), polychloroprene, vinyl acetate polymers and copolymers, poly(alkylene oxide) (PAO), and mixtures thereof and similar products. In one embodiment, the monomer can be any monomer that, when polymerized, forms a polymer suitable for use as a drag-reducing agent (DRA). Said at least one monomer can comprise an alpha-olefin. The preferred alpha-olefins can have a carbon chain length in the range of 2 to 40 carbon atoms, preferably 4 to 25, and more preferably 6 to 12 carbon atoms. Said at least one monomer may be selected from the group comprising: 1-hexene, 1-heptene, 1-nonene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, isobutylene; alkyl acrylates; alkyl methacrylates; styrene and alkyl styrene.Copolymers (which may include two or more different monomers) of these monomers can also form suitable drag-reducing agents. The preferred monomers include alpha-olefins with a carbon chain length in the range of 4 to 25, more preferably 6 to 12 carbon atoms. The preferred monomers are selected from the group comprising: 1-hexene, 1-heptene, 1-nonene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, and isobutylene. A particularly preferred monomer is 1-decene. The preferred copolymer drag-reducing agents may comprise repeating units derived from 1-decene, optionally (but preferably) in combination with repeating units of one or more additional monomers. Such additional monomers may be selected from 1-hexene, 1-octene, and 1-dodecene, for example, in a molar ratio of 1:9 to 9:1. A particularly preferred copolymer drag-reducing agent may be prepared from a mixture of monomers comprising 1-hexene and 1-decene. Any known suitable catalyst and / or cocatalyst may be used in the method, provided it sufficiently catalyzes the reaction. Metallocenes are useful catalysts for polymerizing some monomers. In the case of alpha-olefins, polymerization can be carried out by including a Ziegler catalyst mixture. LCCAnn / Lznz / E / YiAi Natta and cocatalysts in the monomer. Catalysts for the polymerization of alpha-olefins include, but are not necessarily limited to, TiCh.AA (aluminum-activated titanium trichloride) powder catalyst; cocatalyst(s), diethylaluminum chloride (DEAC) and diethylaluminum ethoxide (DEALE); TEAL (triethylaluminum chloride), trimethylaluminum, triisobutylaluminum, MAO (methylaluminoxane), haloalkanes (e.g., 1,2-dichloroethane), and the like. Of course, it will be necessary to make the cocatalyst compatible with the main catalyst so that the catalytic activity of the main catalyst is triggered only by the presence of a particular cocatalyst or class of cocatalysts. The method may comprise, after step (i), closing off (e.g., sealing) the receptacle, except, optionally, for an inlet through which an inert fluid, for example, an inert gas such as nitrogen, is introduced into the receptacle, for example, at a relatively low pressure (e.g., approximately 0.5 psi (34.47 kPa)). After step (i), a polymerization reaction may be carried out for a period of at least 10 hours, at least 1 day, at least 2 days, at least 3 days, at least 4 days, or at least 5 days. It is preferably carried out for less than 20 days. After a selected time, the polymer may be removed from the apparatus. This may include removing the polymer-containing receptacle from the apparatus. Preferably, the receptacle is slid out of the housing.For example, when the housing includes a first elongated tube as described, said receptacle slides over an inner surface of said first elongated tube, so as to remove it from said first elongated tube, appropriately so that said receptacle is completely detached from all other parts of the apparatus. This method is preferably a batch process, for example, to produce 12 to 3300 kg, preferably 20 kg to 100 kg, more preferably 30 kg to 50 kg of polymer in said receptacle. The method may include a step of removing the polymer from the receptacle. This method may comprise, for example, peeling the receptacle film off the polymer. Advantageously, this can be achieved without leaving any receptacle-derived film on the polymer. Therefore, in a preferred embodiment, at least 95% by weight, preferably at least 99% by weight, and more preferably 100% by weight of the receptacle film is removed from the polymer. Consequently, the polymer can be isolated from the receptacle and thus preferably includes less than 1% by weight, and more preferably less than 0.1% by weight, and especially substantially 0% by weight of film derived from the receptacle. The method may include the step of crushing the polymer to define a material in LCCAnn / Lznz / E / YiAi particles. The method may comprise producing a drag-reducing formulation, comprising shredded polymer and a carrier for the latter. In accordance with a third aspect, a drag-reducing formulation prepared as described in accordance with the second aspect is provided. In accordance with a fourth aspect, a drag reduction method is provided comprising the use of a drag-reducing formulation as described in the third aspect. The method may comprise contacting the drag-reducing formulation with a liquid hydrocarbon that is disposed to flow through a hydrocarbon pipeline. Any feature of any aspect of any invention or embodiment described herein may be combined with any feature of any aspect of any other invention described herein mutatis mutandis. Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a schematic representation of an apparatus for producing a polymer; Figures 2A to 2D illustrate, in schematic cross-section, the steps involved in the production of a plastic reaction tube of the apparatus; Figures 3A to 3D illustrate the stages involved in assembling the apparatus, including the plastic reaction tube; Figures 4A and 4B illustrate the steps involved in preparing the assembled apparatus of Figure 3D for use in a polymerization process; Figure 5 illustrates the apparatus that is loaded for bulk polymerization; Figures 6 and 7 show the steps in removing the plastic reaction tube from other parts of the apparatus; and Figure 8 shows a sealed tube containing polymer; Figure 9 shows a polymer log removed from the reaction tube; Figure 10A is a representation of the apparatus in Figure 1, but additionally includes a thermocouple to monitor the temperature during the polymerization process; Figure 10B is a side elevation representation of the thermocouple; Figure 10C is an end view in the direction of arrow X(c) of Figure LCCAnn / Lznz / E / YiAi 10B; and Figure 11 is a schematic diagram of a simplified apparatus for producing a polymer. In the figures, identical or similar parts are noted with the same reference numbers. With reference to Figure 1, the apparatus 2 for carrying out a polymerization reaction to produce, for example, a DRA involving monomer(s) and catalyst comprises a rigid elongated support tube assembly 4 including a coolant containing the cooling jacket 6. The jacket 6 includes a coolant inlet 8 and a coolant outlet 10. Within the support tube assembly 4 is disposed an inflatable plastic reaction tube 12 (shown in a substantially full state in Figure 1) abutting an inner wall 14 of the support tube assembly 4. The end fitting 16 at one end of the support tube assembly 4 includes a fluid port 18 through which an inert gas can exit the apparatus.The end fitting 20 at one end of the support tube assembly 4 includes fluid ports 22 and 24 through which fluids (e.g., monomer(s) and / or catalyst(s) and / or inert gas) can be introduced into and / or removed from the apparatus during operation. In use of the apparatus, polymer is produced within the plastic reaction tube 12 while the tube 12 is cooled by contact with the inner wall 14 of the support assembly 4, which is cooled by the coolant passing through the cooling jacket 6, and while a positive inert gas pressure is maintained around the tube 12. The contents of the plastic reaction tube can be maintained under inert gas conditions by applying inert gas through ports 22 and / or 24 while the polymerization process is carried out.Once polymerization is complete, the end fitting 20 is removed, and the plastic reaction tube 12 containing the produced polymer is removed from assembly 4. The reaction tube 12 (i.e., the plastic material it consists of) is detached, for example, peeled off the polymer to isolate the polymer from the reaction tube. The polymer can then be ground and formulated for use as a drag-reducing additive. The characteristics of the device and the associated processes are described in more detail below. Figures 2A to 2D illustrate the stages involved in the production of the inflatable plastic reaction tube 12, which, in its finished state, is as depicted in Figure 2D. Reaction tube 12 consists of a flat polyethylene tube of 125 pm (500 gauge) that is initially not closed at either end. The tube is about 600 cm long plus an additional 5 to 10 cm (to allow it to be clamped in position, as described later) and about 153 mm ± 5 mm wide when in the horizontal state shown in Figure 2A. LCCAnn / ίζηζ / E / γίΛΐ In a first stage, shown in Figure 2B, one end of the tube is heat-sealed as represented by the number 28, in order to completely close the end and define a closed end of a receptacle for a polymerizable mixture. In a second stage, shown in Figure 2C, the open end of tube 26 (opposite the closed end) is stretched (as illustrated by reference number 27) over a heated cone 30, thereby extending the tube in one of its regions toward its open end. As a result, the diameter of tube 26 adjacent to its open end gradually increases as it moves from region 32, inside the open end, toward region 34, located at that open end. In a third stage, shown in Figure 2D, the cone 30 and tube 26 are unhooked to leave the extended open end 35 that has been permanently deformed by the heat treatment using the heated cone 30. The open end is extended as previously mentioned to facilitate its attachment within the apparatus, thereby minimizing air gaps between the plastic reaction tube 12 and the associated apparatus fittings. If air were to become trapped within the folds of the plastic reaction tube 12, it could be detrimental to the polymerization process and / or the reagents used. Furthermore, the extension facilitates the creation of a fluid-tight seal between the plastic tube and the apparatus fittings. Apparatus 2 can be assembled as described with reference to Figures 3A to 3D. With reference to Figure 3A, the support tube assembly 4 includes an inner rigid tube 38 arranged inside an outer rigid tube 40. Spacers (not shown) are provided between tubes 38 and 40 to maintain the space between them so as to define a passage 42 between tubes 38 and 40, through which coolant can flow. The ends of the outer rigid tube are welded to the outer surface of the inner rigid tube to close the ends of the sleeve assembly. The coolant inlet 8 communicates with the passage 42 for the passage of coolant from the outside into the passage 42 through the inlet 8 and out of it through the outlet 10. The coolant can flow within the passage around substantially the entire length of tube 38 before exiting the passage through the coolant outlet 10.Therefore, a cooled and jacketed support tube assembly is arranged around the plastic reaction tube 12. The inner tube 38 can be suitably made of stainless steel (e.g., SS304L) with a thickness of 0.083 (2.1 mm) and can have an outer diameter of 4 LCCAnnan / izζ / E / γίΛΐ (101.6 mm). The length can be 20 feet (609.6 cm). An inlet 13 (Figure 1) is provided for the introduction of gas into the inner tube 38 as described below. The outer tube 40 can be made of stainless steel (e.g., SS304L) with a thickness of 0.12 inches (3 mm), and can have an inner diameter of 108 mm and an outer diameter of 4.5 inches (114.3 mm). The length can be 19 feet 7.5 inches (598.2 cm). The refrigerant inlet 8 and outlet 10 can be fabricated using a 0.5 Weldolet NPT fitting (trademark). A push-fit adapter can be used to allow for easy connection or removal of the refrigerant tubing. The end fitting 16 may comprise a suitable gasket and a stainless steel sanitary end plate with a single threaded connection for port 18. At the far left of Figure 3A, a 4" (101.6 mm) Viton (trademarked) triple clamp joint 44 and an end plate 46 are shown. The end plate 46 incorporates inlets and outlets 22 and 24, which can be attached to the end plate. A push-fit adapter can be provided to allow convenient connection and removal of the polyethylene (PE) tubing. Inlet / outlet 24 incorporates a 1 / 2" NPT ball valve. As described later, during the process described, inlet / outlet 24 is used in three different stages: (a) inflation and flooding of the reaction tube 12 with inert gas; (b) charging of the monomer / catalyst mixture; and (c) flooding with inert gas after charging with the monomer / catalyst mixture (to flush the supply lines and provide additional inertia to the apparatus contents). Also as described below, during the described process, inlet / outlet 22 can be used as an inert gas outlet during the inflation of the reaction tube 12, inerting and monomer / catalyst loading; and subsequently as an inert gas inlet (to maintain a small positive pressure inside the reaction tube 12 during the remainder of the bulk polymerization process). Although the apparatus is shown in the figures with the elongated axes of tubes 38 and 40 of the horizontal support tube assembly 4, it is preferable that the tubes be raised at the left end in Figures 3A to 3D to facilitate fluid flow from their inlet position and into the reaction tube 12 defined by tube 26, and to prevent monomer / catalyst loss through port 22 during loading. Typically, the angle defined by tubes 38 and 40 with respect to the horizontal is approximately 2 to 3° (or the gradient is about 1 in 2°). The reaction tube 12, produced from tube 26 as described in Figure 2D, is inserted into the inner tube 38 and pushed inwards so that its heat-sealed end 28 is adjacent to the end fitting 16. As shown in Figure 3B, Initially, the extended open end 35 protrudes from the inner tube 38. Then, as shown in Figure 3C, the extended open end 35 is folded back over the flange 48 formed in the inner tube 38. Next, as depicted in Figure 3D, the gasket 44 and end plate 46 are secured in position, thus firmly (and hermetically) holding the open end 35 in position as shown in Figure 3D. Note that in Figure 3D, the sanitary adjustment clamps have been omitted for clarity. As can be seen in Figure 3D, after the insertion of tube 12 (and before inflating it), the tube is flaccid as depicted in Figure 3D. After assembly of the apparatus as described with reference to Figures 3A to 3D, the apparatus can be prepared for use, as described with reference to Figures 4A and 4B, by inflating tube 12 and inertizing any region of the apparatus that may come into contact with the monomer / catalyst subsequently introduced into the apparatus, including indirect contact that occurs by gas diffusion through the tube. With reference to Figure 4A, initially the volume inside the apparatus outside of tube 12 and inside the inner tube 38 is inertized to a specified level (e.g., less than 0.3% by volume of oxygen) by introducing inert gas (e.g., nitrogen) through the inlet of port 13 represented by the arrows in Figure 4A. The inert gas exits through port 18. The oxygen content of the gas exiting the inner tube 38 can be monitored at a downstream sampling point (not shown) using standard methods. Next, tube 12 is inflated as shown in Figure 4B, using an inert gas (e.g., nitrogen). Inert gas is passed through the tube until the inert gas exiting port 22 has an oxygen content (e.g., less than 0.3% vol.), as measured at a downstream sampling point (not shown). Inflation involves introducing the inert gas through port 24 into tube 12. Gas circulates inside tube 12 to inflate it and exits through port 22. During inflation of tube 12, the supply of inert gas through port 13 is stopped. Inflation of tube 12 can be verified by observing the gas flow from port 18, resulting from the displacement of a volume of gas from outside tube 12 due to its inflation. Once inflation of tube 12 is complete, as shown in Figure 4B, port 18 is temporarily closed while tube 12 is inerted to prevent air from entering through port 18. Port 18 is reopened before monomer(s) / catalyst(s) are loaded into the apparatus. As an alternative to the sequence of steps described with reference to Figures 4A and 4B, the sequence of steps can be interchanged; e.g., tube 12 can be inflated first and then sealed before inerting the region outside tube 12. Alternatively, the steps in Figures 4A LCCAnn / Lznz / E / YiAi and 4B could be carried out substantially simultaneously, with a slightly higher gas pressure inside tube 12 to keep it in an inflated condition. After completing step 4B, the apparatus is ready to be charged with reagents and begin polymerization. With reference to Figure 5, the flow of coolant in passage 42 between tubes 38 and 40 is advanced by introducing coolant through inlet 8 and removing it through outlet 10. A monomer / catalyst mixture is then introduced into the inflated tube 12 through port 24 to fill it. The polymerization reaction is allowed to continue for an appropriate period (typically around 6 days). During this time, the coolant flows continuously, and the temperature can be monitored. For example, some apparatuses may include a suitably positioned thermocouple 91 (Figures 10A-10C).In addition, a relatively low pressure (about 0.5 psi (34.47 kPa)) of inert gas is applied through ports 22 and 13, to ensure that tube 12 (and its polymerization contents) is kept under an inert atmosphere. The monomer(s) / catalyst(s) mixture is suitably arranged to produce an ultra-high molecular weight polymer for use in drag reduction. The polymer may be suitably a polymer and / or copolymer of alpha-olefin(s). Using the apparatus, the polymer was prepared from 1-decene monomer, as described in Example 1. Example 1 - Polymer production. The 1-decene monomer (31.6 kg) was purged with nitrogen for 60 minutes to remove dissolved oxygen, which would otherwise be toxic to the catalyst. The monomer was then passed through a pretreatment column containing 1.5 kg of a 50:50 mixture of 13X and 5A molecular sieves (previously dried under high-temperature vacuum). After the pretreatment column, the monomer was pumped into a 90-liter, jacketed, stirred, glass-lined reactor that had been previously dried and inerted to 0.3% oxygen by volume or less. The 1-decene was cooled to 5°C, and then 25 wt% (80.45 g) diethylaluminum chloride (DEAC) in heptane was transferred to a Swagelok pump (trademarked) inside a glove box. This was then added to the 1-decene under an inert atmosphere to remove any wastewater or protic impurities. The mixture was then stirred for 20–30 minutes in a 90-liter reactor. Inside a glove box, aluminum titanium trichloride-activated TiCls(AAD) (3.7888 g) was dispersed with stirring in anhydrous heptane (157.6 ml), and anhydrous 1,2-dichloroethane (1.37 ml) and isobutylaluminoxane (IBAO) in heptane (3.5 wt% aluminum content in heptane) (41.4 ml) were added to the catalyst dispersion. The mixture was stirred, then LCCAnn / Lznz / E / YiAi was transferred to a Swagelok pump and subsequently transferred to the 90-liter reactor, while maintaining an inert atmosphere, to initiate Ziegler Natta polymerization. It was found that, upon mixing monomer and catalyst, polymerization began instantaneously and thus proceeded rapidly. The mixture was then rapidly introduced using inert gas pressure into the inflated tube 12 through port 24 as previously described with reference to Figure 5. The reaction mixture was kept inside tube 12, as shown in Figure 5, at a jacket temperature of 5°C. Cold water was flowed into passage 42. After 24 hours, the temperature of the fluid in passage 42 was increased, and the reaction continued. Throughout the process, both the outside and inside of tube 12 were kept under a nitrogen pressure of approximately 0.5 psi (34.47 kPa) by introducing nitrogen through ports 13 and 22 to help restrict oxygen from entering the polymerization mixture. At the end of the aforementioned 6-day reaction time, joint 44 and end plate 46 were disengaged as shown in Figure 6 to provide access to tube 12 containing polymer 50. End plate 16 can also be optionally removed to allow visual inspection of the polymer in tube 12. Tube 12 (and the polymer) were then manually removed from the inner tube 38, as shown in Figure 7. During extraction, the open end of tube 26 was closed by a tightly stretched cable tie 52 (or similar). The tube was then completely removed to isolate the sealed tube 12 containing an approximately 20-foot (610 cm) log of polymer 50, as shown in Figure 8. Tube 12 (which is made of polyethylene as described) can be easily separated, for example, by cutting and / or peeling it from the polymer trunk 50, thereby producing an isolated polymer trunk 50 as a single piece, as shown in Figure 9. Substantially no PE residue contaminates the polymer after removing tube 12, which can minimize polymer contamination and, in turn, may be advantageous in its subsequent uses. While it is not desirable to be subject to any theory, the ease with which the polymer tube 50 can be cut may be related to the fact that the polymer has a higher bulk density (approximately 0.85 g / cm³) than the 1-decene (density of 0.74 g / cm³) starting material, meaning that the polymer tends to shrink from the receptacle wall as it is formed. The polymer 50 stem of Figure 9 can be processed by known methods and brought into contact with a carrier to produce a formulation comprising a DRA. LCCAnn / Lznz / E / YiAi Other procedures performed are described in Examples 2 to 7. Examples 2 to 6 describe procedures for evaluating the characteristics of the polymers produced as described herein, and the results of such evaluations. Example 2 - Determining the percentage of polymer conversion in a produced polymer. A disposable aluminum plate was weighed to four decimal places, and the weight was recorded (A). A sample of the test material (2–3 g) was placed on the plate, and the combined weight of the plate and sample was also weighed to four decimal places (B). The sample was dried in a vacuum oven (200°C, 0.04 Torr (0.53 kPa)) for one hour, removed, and reweighed. This process was repeated until a constant weight was achieved (C). The polymer conversion percentage was calculated as follows: % conversion = (C - A) / ((B - A)*D) where D is equivalent to the percentage purity of the commercial alphaolefin monomer used / 100. For example, D = 0.994 for commercial 1-decene of 99.4% purity. Example 3 - Determination of the percentage reduction of drag of the produced polymer. Step 1 - Preparation of the working solution. n-Hexane (~80 ml) was loaded into a 250 ml bottle. A sample of the test polymer was extracted directly from the polymer stalk, as prepared in the bulk polymerization reaction, and weighed accurately to four decimal places (0.0150–0.0200 g). The polymer was then dissolved in the n-hexane by mixing for 2 days under low-shear conditions to provide solution (A). Solution (A) was then transferred to a pre-weighed, clean 500 mL bottle and precisely made up to volume with more n-hexane to provide a final polymer concentration of 100 mg / kg (100 ppm w / w). The sample was mixed manually, avoiding vigorous shaking, to provide a partially diluted solution (B). An aliquot of solution (B) (4 g) was accurately weighed into a pre-weighed, clean 1000 ml bottle, then accurately filled with more n-hexane to the target sample weight (400 g). The sample was then manually mixed as before to provide the working solution (C), 1 mg / kg (1 ppm w / w). Stage 2 - Drag Reduction Test Procedure. Pre-weighed and cleaned collection bottles (1000 ml) were used for liquid collection during the test runs. LCCAnn / Lznz / E / YiAi The test apparatus consisted of a 2-liter pressure vessel, equipped with a solvent inlet, a bottom drain (used for cleaning at the end of the experiments), and an immersion leg connected to a length of stainless steel tubing external to the vessel (7 ft (213.36 cm) long, 6.35 mm OD, 0.89 mm wall thickness). The tubing was fitted with a control valve at the outlet. The pressure vessel was further equipped with an inert gas inlet, connected to a supply line via a precision pressure control valve. This was set to a constant pressure (2.6 psi (179.26 kPa)) for all experiments. The vessel was filled with approximately 400 g of working solution (C) as prepared in Step 1, or untreated n-hexane (control sample), then sealed and pressurized with inert gas (2.6 psi (179.26 kPa)) with the outlet control valve closed. This valve was then opened to allow the liquid to purge the external tubing, then closed (this liquid was discarded). A pre-weighed collection bottle (1000 ml) was placed at the outlet, then the valve was reopened for 12–13 seconds to allow the liquid to flow again, and the elapsed time was recorded using a stopwatch. The remaining liquid in the vessel was then discarded, and the vessel was thoroughly rinsed with untreated n-hexane (for test cycles where solution (C) was used). The percentage improvement in flow (% FI) and the percentage reduction in carryover (% DR) were calculated from the blank hexane flow rate (F0) and the flow rate of the treated sample (solution (C)) (Fa), as follows: FO in g / sec = (weight collected in g) / (time valve opened in seconds) Fa in g / sec = (weight collected in g) / (time valve opened in seconds) then, % FI = 100 * (Fa - F0) / F0 % DR = [(1 + o / oFI)1-9- 1] / (1 + %FI)1·9 Examples 4 to 6 - Production of polymers using different amounts of catalysts. Three separate bulk polymerization reactions (Examples 4 to 6 respectively) were carried out using the apparatus described above, with 1-decene as the monomer. The synthesis procedure was identical to that described in Example 1, apart from the modification of the loadings of TiChíAAD), 1,2-dichloroethane, isobutylaluminoxane solution, and heptane diluent. LCCAnn / Lznz / E / YiAi to provide different levels of catalyst loading (expressed as ppm w / w of Ti relative to the monomer loading weight). After completion of bulk polymerization, the reaction tube comprising the polymer was removed according to the above procedure, and the polymer was sampled for analysis, as described in Examples 2 and 3. For each polymer product, polymer conversion percentages were determined for 10 samples taken from different points within the polymer strand. These points were selected to provide information on the consistency of polymerization along both the long axis and the cross-sectional diameter of the polymer strand. For each polymer product, the drag reduction percentage (%DR) was determined as described in Example 3, for four samples taken from different points within the polymer stalk. These points were selected to provide information on the consistency of the product's performance characteristics along the long axis of the polymer stalk. The results of these experiments are shown in Table 1. LCCAnn / Lznz / E / YiAi Table 1 Example No. Catalyst (ppm w / w Ti) % Polymer Conversion % Drag Reduction Average Standard Deviation Average Standard Deviation 4 120 87 1 50.49 1.61 5 100 87 1 49.60 0.81 6 80 83 1 51.62 0.68 The results show that bulk polymerizations performed using the described apparatus yielded products with excellent performance characteristics. The data demonstrate that polymerization could be successfully achieved using the apparatus within a range of catalyst concentrations typical for this application. Furthermore, for each individual experiment, the data showed excellent consistency in both chemical composition and performance characteristics throughout the entire polymerized reaction volume. Examples 7 to 9 - Production of copolymers. Three separate bulk polymerization reactions (Examples 7 to 9, respectively) were carried out using the apparatus described above, with a monomer mixture of 1-hexene and 1-decene. The synthesis procedure was identical to that described in Example 1 (120 ppm w / w Ti relative to the monomer loading weight), except for the monomer selection. After completion of the bulk polymerization, the reaction tube 12 containing the polymer was removed according to the procedure described above, and the polymer was sampled for analysis, as described in Examples 2 and 3. Polymer conversion percentages and percentage drag reduction (% DR) measurements were taken from multiple points within the polymer stalk and reported identically to Examples 4 to 6. The results of these experiments are shown in Table 2. LCCAnn / Lznz / E / YiAi Table 2 Example No. 1-hexene 1-decene % polymer conversion % drag reduction % wt % mol % wt % mol Average Standard deviation Average Standard deviation 7 60.0 71.4 40.0 28.6 87 1 51.92 0.67 8 35.7 48.0 64.3 52.0 88 3 50.90 0.68 9 28.6 40.0 71.4 60.0 89 3 51.66 0.35 The results show that bulk polymerizations using the described apparatus for making copolymers also yielded products with excellent performance characteristics. Similar to Examples 4 to 6, the data showed excellent consistency in both chemical composition and performance characteristics throughout the entire polymerized reaction volume. Figure 11 shows a simplified alternative apparatus 110. The apparatus 110 for carrying out a chemical reaction comprises an elongated housing 112 and a receptacle 114. The elongated housing 112 includes a cooling medium 116 and end fittings 118, 120, which include ports through which fluids can be introduced and / or removed. In the use of the apparatus 110, a chemical reaction product is formed within the receptacle 114. Subsequently, the receptacle 114 containing the chemical reaction product is removed from the elongated housing 112. Although only one apparatus 2,110 has been described, an assembly including multiple apparatus 2,110s can be provided for manufacturing larger quantities of polymer. Such reactors could be filled sequentially or simultaneously, optionally by using a collection system. In another embodiment, shown in Figure 11, the apparatus for carrying out a polymerization reaction may comprise multiple assemblies, each comprising a reaction tube 2 within a rigid tube 38. The assemblies may be collectively surrounded by a single cooling jacket arranged to cool all the reaction tubes 5 simultaneously. For example, two or more assemblies, each comprising a reaction tube 2 within a rigid tube 38, may be axially aligned, and a single cooling jacket may enclose the tubes. Alternatively, a plurality of assemblies, each comprising a reaction tube 2 within a rigid tube 38, may be in a stacked arrangement, with a single cooling means arranged to cool the plurality. The invention is not restricted to the details of the prior embodiments. The invention extends to any novel feature, or any novel combination, of the features described in this specification (including the claims, abstract, and accompanying drawings), or to any novel step, or any novel combination, of the steps of any disclosed method or process.

Claims

NOVELTY OF THE INVENTION CLAIMS 1.- Apparatus for carrying out a polymerization reaction to produce a drag-reducing polymer, wherein the apparatus comprises: (a) an elongated housing; and (b) an elongated receptacle within the housing, wherein said receptacle is arranged to receive reagents for the reaction in the apparatus to produce a drag-reducing polymer.

2. Apparatus according to claim 1, wherein said receptacle comprises a plastic film material having a thickness of at least 20 pm (preferably at least 50 pm) and a thickness of less than 2000 pm (preferably less than 1000 pm).

3. Apparatus according to claim 1 or claim 2, wherein the inner wall area of ​​the receptacle is defined as the area of ​​the receptacle that is arranged to contain material (e.g., polymer in use), wherein at least 50% (preferably about 100%) of the inner wall area is defined by said plastic film material consisting of a single layer. 4 - Apparatus according to claim 2 or claim 3, wherein said plastic material of said film comprises an optionally substituted polyolefin polymer, for example, polyethylene.

5. Apparatus according to any of the preceding claims, wherein said receptacle includes a first end and a second end that are separated along the elongated extension of the receptacle, wherein said first end is a closed end and includes a sealed region, for example, a heat-sealed region.

6. Apparatus according to claim 5, wherein the length of the receptacle is the linear distance between said first end and said second end, wherein the diameter of the receptacle is substantially constant for at least 80% (preferably at least 90% or 95%) of its length; and wherein a region of the receptacle adjacent to said second end diverges such that an opening of the receptacle at said second end has a larger diameter than a region of the receptacle towards the inside of the second end.

7. Apparatus according to any of the preceding claims, wherein the diameter of the receptacle is in the range of 1 cm to 45 cm (and preferably is at least 7 cm and less than 30 cm) throughout its extent; and / or the length of the receptacle is in the range of 15 cm to 60 m (and preferably is in the range of 3 m to 15 m); and / or the volume of the receptacle is in the range of 12 cm3 to 4 m3 (preferably in the range of 4000 cm3 to 0.5 m3); and / or the aspect ratio of the elongated receptacle, defined as the length of the internal volume of the receptacle divided by the diameter of the internal volume of the receptacle, is at least 10 and less than 600, and wherein said aspect ratio is preferably between 30 and 150.

8. Apparatus according to any of the preceding claims, wherein a ratio of the maximum diameter of the receptacle divided by the diameter of the housing, in a region where the housing and the receptacle are opposite each other, is at least 0.8, and is 1.2 or less.

9. Apparatus according to any of the preceding claims, wherein said receptacle is formed from horizontal tubes.

10. Apparatus according to any of the preceding claims, wherein said elongated housing is arranged to support the receptacle arranged within the housing; wherein said elongated housing includes cooling means for cooling the reagents and the polymer contained in the receptacle in use; and wherein said elongated housing includes inerting means for introducing and / or maintaining an inert atmosphere in and / or around the receptacle.

11. Apparatus according to any of the preceding claims, wherein said elongated housing comprises a first elongated tube in which said receptacle is placed, wherein said receptacle contacts an internal surface of the first elongated tube, wherein at least 60% (preferably at least 90%) of the area of ​​an external wall area of ​​said receptacle contacts said internal surface.

12. Apparatus according to any of the preceding claims, wherein said receptacle has a substantially circular cross-section in use, along at least 50% or at least 95% of its length; and / or the cross-sectional area of ​​the receptacle in use is substantially constant, along at least 50%, preferably at least 90%, of its length.

13. Apparatus according to claim 11 or claim 12, when dependent on claim 11, wherein said first elongated tube has a circular cross-section, and said receptacle can be arranged to have a circular cross-section, wherein an internal surface of said first elongated tube is uninterrupted over more than 80% (or more than 90%) of its area; and / or said internal surface is cylindrical, and has a constant cross-section over substantially its entire length. 14.- Apparatus according to any of claims 11 to 13, wherein said elongated housing comprises a second elongated tube that is coaxial with said first elongated tube, and said first elongated tube is positioned with the second elongated tube, said first and second elongated tubes being radially separated so that an annular space LCCAnn / Lznz / E / YiAi is defined between the first and second elongated tubes, wherein said annular space defines a fluid passage for a refrigerant fluid.

15. Apparatus according to claim 14, wherein the annular space extends around the first elongated tube so that the coolant can contact at least 20% (preferably at least 70%) of the first elongated tube in use, thereby cooling the first elongated tube.

16. Apparatus according to claim 14 or claim 15, wherein said first and second elongated tubes are cylindrical.

17. Apparatus according to any of claims 11 to 16, wherein said elongated housing includes fastening means for freely securing the receptacle in position within the first elongated tube.

18. Apparatus according to any of the preceding claims, wherein the housing includes a first elongated tube, and the housing and / or the first elongated tube are arranged so that the receptacle slides out of the first elongated tube and is thereby removed and / or detached from the housing.

19. Apparatus according to any of the preceding claims, wherein said apparatus includes a container (Cl) for containing a coolant, wherein the apparatus is arranged to supply coolant from the container (Cl) to a region outside said container; and / or wherein said apparatus includes a container (C2) for containing a monomer, wherein the apparatus is arranged for supplying monomer into the container; and / or wherein said apparatus includes a container (C3) for containing a catalyst, wherein the apparatus is arranged for supplying catalyst into the container; and / or wherein said apparatus includes a container (C4) for containing an inert fluid, wherein the apparatus is arranged to supply the inert fluid to the container to inertize the container.

20. Apparatus according to claim 19, wherein the container (C2) contains monomer and the container (C3) contains catalyst, wherein the containers (C2) and (C3) are arranged to supply monomer and catalyst respectively to a mixing region in which they are arranged to come into contact and mix, wherein the mixing region is upstream of said container.

21. A method for producing a drag-reducing polymer, wherein the method comprises: (i) selecting an apparatus according to any preceding claim; (ii) introducing reagents (for example, at least one monomer and at least one catalyst) for the preparation of said polymer into said receptacle of said apparatus; (iii) controlling the conditions around said receptacle to control the polymerization of said reagents therein. LCCAnn / Lznz / E / YiAi 22. A method according to claim 19, wherein step (iii) includes operating a cooling means to cool the reactants and / or the polymer in the receptacle during polymerization; and / or step (iii) includes introducing an inert fluid into the apparatus in or adjacent to the receptacle, to inertize the receptacle and / or a region around the receptacle. 5 23. A method according to claim 21 or claim 22, wherein after step (i), a polymerization reaction is carried out for a period of at least 10 hours, preferably at least 1 day, and subsequently said receptacle containing polymer is slid out of the housing.

24. A method according to any of claims 21 to 23, wherein the method includes a step of removing the polymer from said receptacle by detaching the film from the polymer receptacle.

25. A method according to any of claims 21 to 24, wherein the method comprises producing a drag-reducing formulation comprising shredded polymer and a carrier therefor. 15 26.- A drag reduction formulation prepared as described in any of claims 21 to 25 and / or using an apparatus according to any of claims 1 to 20. 27.- A drag reduction method comprising the use of a drag reduction formulation according to claim 26.