CHEMICAL REACTIONS

Abstract

The invention relates to a method of assembling the apparatus 110 for containing reagents for a chemical reaction; the apparatus 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; specifically, the method relates to fixing a receptacle relative to the outward-facing surface of the housing.

Description

CHEMICAL REACTIONS DESCRIPTIVE MEMORANDUM This invention relates to chemical reactions, and particularly, though not exclusively, to a method of assembling an apparatus for containing reactants for a chemical reaction, an apparatus per se, a method of preparing a receptacle, and a receptacle per se. The embodiments relate to a chemical reaction, for example, a polymerization reaction. The preferred embodiments relate to drag-reducing polymers and their uses in drag reduction, for example, to reduce the frictional effect (drag) 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. frccAnn / Lznz / E / viAi Se han descripto diversos tipos diferentes de aparetos para producir pôs y / o copolos de alfa-olefinas como se describe a continuación. 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 can form bags that serve as temporary, isolated reactor containers that 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 desirable that the apparatus for use in chemical reactions be capable of efficient and cost-effective assembly and disassembly, so that it can be largely reused in multiple sequential processes for the discontinuous production of products. It is an object of the preferred embodiments of the present invention to address the problems described above. It is an object of the preferred embodiments of the invention to provide a simple and / or advantageous method of assembling apparatus for use in chemical reactions, preferably polymerization reactions for the production of drag-reducing polymers. It is an object of the preferred embodiments of the invention to provide a simple and / or advantageous apparatus and / or its components for use in chemical reactions, preferably polymerization reactions for the production of drag-reducing polymers. According to a first aspect of the invention, a method is provided for assembling an apparatus for containing reagents for a chemical reaction, wherein the method comprises: (i) selecting an elongated receptacle comprising a plastic material, wherein said receptacle is arranged to define an internal volume for containing reagents, wherein said receptacle includes a first end and a second end that are separated along the elongated extension of the receptacle, wherein said receptacle defines an opening at said second end, wherein the diameter of said opening is greater than the diameter of a region of said receptacle towards the inside of said second end; (i) selecting a housing to contain the receptacle, wherein said housing includes a first end and a second end, wherein said second end includes an outward-facing surface; (iii) with the receptacle inside the housing, so that the second end of the receptacle is adjacent to the second end of the housing, position the second end of the receptacle on the outward-facing surface; and (iv) secure the second end of the receptacle in position with respect to the outward-facing surface. By using this method, the second end of the receptacle can be positioned while minimizing folds in the receptacle at or adjacent to this end; such folds could otherwise contain undesirably air and / or oxygen, which could be detrimental to a reaction that may be carried out in the apparatus. In a preferred embodiment, the apparatus is for carrying out a polymerization reaction to produce a drag-reducing polymer, as suitably described herein. The receptacle in question is preferably not inherently self-contained. It is preferably flaccid when it does not contain a solid or fluid (e.g., reagents or polymer) and / or unless it is inflated or otherwise supported by external means as described herein. The receptacle preferably comprises a plastic material, for example, a plastic film material, 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. The thickness of the film material may be less than 2000 µm, preferably less than 1000 µm, and more preferably less than 500 µm. The thickness of the film material may be between 20 µm and 1000 µm, preferably between 50 µm and 500 µm. The internal wall area of ​​the receptacle can be defined as the area of ​​the receptacle that contains said polymer. Suitablely, at least 50%, preferably at least 75%, more preferably at least 90%, and especially about 100% of the internal wall area is defined by said plastic film material having a thickness within the defined range. The inner wall area of ​​the receptacle, as described, is preferably defined by a single-layer plastic film material. Therefore, the receptacle frccAnn / Lznz / E / YiAi preferably does not comprise a laminate and / or a multi-fold material. This inner wall area of ​​the receptacle preferably has a substantially smooth surface. An outer wall area of ​​the receptacle, which is the wall area of ​​the receptacle on a side of the film material opposite the inner wall area, preferably has a substantially smooth surface as described for the inner wall area. This inner wall area and the outer wall area preferably consist of identical materials and, preferably, represent opposite surfaces of the same material. Preferably, substantially the entirety of said receptacle comprises said plastic material, more preferably said plastic film material as described. As described, said receptacle preferably comprises a plastic material, for example, a plastic film material. Suitablely, at least 90% by weight, preferably at least 95% by weight, more preferably 100% by weight of said receptacle is made of said plastic material. The plastic material is sufficiently strong and inert to withstand a polymerization reaction as described herein, and not to significantly adhere to the polymer while it is forming. It is also preferably relatively inexpensive, so that it can be disposed of after use. The plastic material is preferably heat-sealable. It is preferably a thermoplastic polymer. It is preferably chemically compatible with the reagents used and the polymer produced in the polymerization reaction. The plastic material preferably comprises repeating alkylene units (e.g., ethylene), optionally substituted, preferably unsubstituted, which may be components of a homopolymer or copolymer. The plastic material preferably comprises an optionally substituted, preferably unsubstituted, polyolefin polymer, such as a polyalkylene polymer, e.g., polyethylene. As described, the receptacle appropriately includes a first end and a second end that are 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 by, for example, 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 have been 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 memorandum and unless the context requires otherwise, the elongated receptacle diameter refers to the longest straight line that passes from one side of the receptacle cross-section to an opposite side, when the receptacle is in a distended (e.g., inflated) state and / or when it is 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 elongated receptacle is substantially constant for at least 80% (preferably at least 90% or 95%) of the distance from the first end to the second end. In a preferred embodiment, a region (e.g., the mouth) 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 slightly larger diameter than a region of the receptacle further inward from the second end. As described, this arrangement facilitates securing and sealing the second end in position in an apparatus in which the polymer can be produced in a manner that minimizes the creation of air spaces in use and / or forms a leak-proof seal. The internal diameter of the receptacle (when extended) may range from 1 cm to 45 cm along its entire length. When the second end defines an opening at that second end that has a larger diameter and / or 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 internal volume of the receptacle may range from 15 cm to 60 m. The internal volume of the receptacle may range from 12 cm³ to 4 m³. Preferably, the diameter of the receptacle (suitably throughout at least 80% of the receptacle length) is less than 30 cm. More preferably, it is less than 11 cm (suitably throughout at least 80% of the receptacle length). It can be at least 5 cm or at least 7 cm (suitably across at least 80% of the length of the receptacle).The length of the receptacle is preferably in the range of 3 to 15 m, especially in the range of 4 to 11 m. The internal 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, or in the range of 20,000 cm³ to 0.12 m³. The diameter, length, and / or volume are appropriately selected as described to optimize a chemical reaction, for example, a polymerization process and / or polymer curing within the receptacle as described herein, and / or to allow the receptacle to be handled and / or operated by a single human operator. It is found that if the diameter, length, and / or volume are too large, there may be insufficient heat transfer during a chemical reaction, for example, polymerization.This may mean that the degree of reaction, for example, polymerization across the diameter and / or within the volume, may be unacceptably variable, which may result in the production of an inferior product, such as a lower drag-reducing polymer. Preferably, apart from any means by which the first end is arranged to define the closed end, the receptacle includes no seams between said first and second ends. Said receptacle is preferably formed from horizontal tubes. Preferably, it is sealed at said first end as described, and is divergent (e.g., when extended) at said second end. The aspect ratio of the 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, preferably at least 20, and preferably at least 30. Alternatively, this aspect ratio can be less than 600, preferably less than 300, and more preferably less than 150. Finally, this aspect ratio can be between 10 and 300, more preferably between 30 and 150. Said housing is preferably an elongated housing, which is preferably arranged to support the receptacle that is suitably arranged within the housing. This housing preferably includes cooling means for cooling reagents and / or products (e.g., polymer) contained in the apparatus in use. Said elongated housing preferably includes inert means for introducing and / or maintaining an inert atmosphere in and / or around the receptacle. The elongated housing preferably comprises a first elongated tube in which the receptacle is positioned. In use (for example, when inflated and / or when containing reagents as described herein), the receptacle preferably contacts an inner surface of the first tube, with at least 60%, at least 75%, or at least 90% of the area of ​​an outer wall of the receptacle preferably arranged to make contact with said inner surface in use. The receptacle is preferably arranged to have 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 receptacle may be arranged such that the cross-sectional area of ​​the receptacle is substantially constant, for example, along at least 50%, at least 75%, at least 90%, or at least 95% of its length. frccAnn / Lznz / E / YiAiPreferably, the elongated housing has a circular cross-section, and the receptacle may be arranged to have a circular cross-section. The ratio of the maximum diameter of the receptacle to the diameter of the housing, suitably in a region where the housing and 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 housing at 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 internal surface is preferably substantially smooth and / or preferably includes a relatively low coefficient of friction to allow the receptacle to slide over the internal surface when prompted to do so. The internal surface is preferably uninterrupted over most (for example, more than 80% or more than 90%) of its area. The internal surface is preferably cylindrical, preferably circularly cylindrical. The internal surface preferably has a constant cross-section over substantially its entire extent. The first elongated tube is preferably cylindrical, for example circularly cylindrical. This first tube is preferably rigid and / or self-contained. It can be made of a metal, for example steel. The first tube may include a port (A) through one of its walls to allow fluid to enter and / or exit the first tube in use. The elongated tube may include one or a plurality of such ports. The elongated casing preferably comprises a second elongated tube that is suitably coaxial with the first tube, and the first tube is suitably positioned within the second tube. The first and second tubes are preferably radially separated so as to define an annular space between them, and spacer means are provided to maintain this space. The annular space preferably defines a fluid passage for a refrigerant. The annular space preferably extends around the first 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 ​​the first elongated tube, thereby cooling the first elongated tube (and consequently the receptacle within). Specifically, substantially the entire surface area of ​​the first elongated tube is contacted by the coolant during use. Therefore, the arrangement may define part or all of the cooling means for cooling reagents in the receptacle during 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 tube is preferably cylindrical, for example circularly cylindrical. This second tube is preferably rigid and / or self-contained. It can be made of a metal, for example, steel. Said second 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 tube to allow fluid to enter and exit the second tube (and appropriately into and / or out of said annular space), in use. The second tube is preferably closed at a first end (which is suitably adjacent to the first end of the receptacle) by a first end plate. The first end plate may include a port (for example, port (D)) extending through it to allow fluid to enter and exit the first and / or second tubes. The first end plate may include one or a plurality of such ports. The outward-facing surface referred to in step (iii) of the method is appropriately oriented outward in a direction that is parallel to the elongated extension of the casing, and / or perpendicular to the diameter of the casing. The outward-facing surface is appropriately an end face of the casing. It is appropriately an end face of the first elongated tube of the described elongated casing. The housing may include a flange, for example, an annular flange, that appropriately defines the outward-facing surface. The flange may be secured to a cylindrical wall of the housing, for example, a cylindrical wall of the first elongated tube when provided. The flange preferably includes a substantially flat face that extends substantially perpendicular to the diameter of the housing, for example, the diameter of the first elongated tube. The main face of the flange is appropriately oriented outward in a direction parallel to the elongated extension of the housing, and / or the flange extends perpendicular to the diameter of the housing. In step (iii) of the method, the receptacle is suitably placed inside the housing. The second end of the receptacle (e.g., its extended end) can be extended outside the housing, suitably beyond the outward-facing surface, e.g., the flange. The second end can then be folded over the outward-facing surface, e.g., the flange. It is preferably folded over the outward-facing surface so as to be substantially evenly distributed over the surface, thereby minimizing the production of creases or other irregularities in the receptacle, at least to a position where the receptacle makes contact (e.g., face-to-face contact) with the outward-facing surface, e.g., the flange.Advantageously, the deployment extent and / or the larger diameter at the second end (relative to the inward diameter of said second end) of the receptacle (e.g., of said mouth) is selected to minimize the production of folds or other irregularities in the receptacle as described. In step (iv) of the method, said receptacle is preferably releasably secured in its position, suitably within the housing. Therefore, the housing is preferably arranged for the removal of the elongated receptacle from it, appropriately, after a product, for example, a polymer, has been produced therein. In a preferred embodiment where the housing includes a first tube as described, the housing and / or the first tube may be arranged so that the receptacle slides out of the first tube and is thereby removed and / or detached from it. In step (iv), the second end is properly secured in position by clamping means. These clamping means may comprise a clamp for holding the receptacle in position. When the receptacle includes a second end (extending as described), the clamping means may be arranged to apply a force to hold the second end and / or adjacent regions in position. These clamping means may include a second end plate that is properly arranged to apply a clamping force. 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. Preferably, the second end of the receptacle is secured in position by a surface of a fastening means (e.g., a gasket) that is pressed against part of the receptacle (e.g., the opening) so as to clamp the receptacle between the fastening means (e.g., gasket) and the outward-facing surface (e.g., flange) of the housing. Preferably, in step (iv), the receptacle is clamped between two opposing flat surfaces, for example, one defined by the outward-facing surface and a second defined by the fastening means, for example, one of its gaskets. frccAnn / Lznz / E / YiAi According to a second aspect of the invention, an apparatus assembled according to the method of the first aspect is provided. The apparatus may comprise: (i) an elongated receptacle wherein said receptacle includes a first end and a second end that are separated along the elongated extension of the receptacle, wherein said receptacle defines a mouth at said second end, wherein the diameter of the mouth is greater than the diameter of a region of said receptacle towards the inside of said second end; (i) a housing containing the receptacle, wherein said housing includes a first end and a second end, wherein said second end includes an outward-facing surface; (ii) wherein the second end of the receptacle is positioned on said outward-facing surface of the housing; (iv) wherein the second end of the receptacle is secured in position with respect to said outward-facing surface. The apparatus of the second aspect may include any feature of the invention and / or apparatus described in the first aspect. Any feature of the receptacle and / or housing of the second aspect may be as described for said first aspect. The apparatus in the second aspect may be for carrying out a chemical reaction, for example, a polymerization reaction to produce a drag-reducing polymer. According to a third aspect of the invention, a method is provided for preparing an elongated receptacle for use in the method and / or apparatus of the first and / or second aspect, wherein the method comprises: (a) selecting a precursor of a receptacle comprising a plastic material, wherein said precursor of said receptacle is arranged to define an internal volume for containing reagents, wherein said precursor of said receptacle includes a first end and a second end that are separated along the elongated extension of said precursor of said receptacle; (b) treating a region of the precursor of said receptacle adjacent to said second end to define an opening of a receptacle for containing reagents, wherein said opening of said receptacle has a larger diameter than a region of the receptacle inside said second end. Therefore, preferably, said precursor is treated so that, adjacent to the second end, the precursor diverges in such a way that the maximum diameter of the receptacle is appropriately located at said second end. Thus, said formed receptacle converges appropriately when moving inwards from said second end, for example, towards said first end. In step (b), the precursor of the receptacle is suitably heated to allow its shape to change, preferably in a substantially permanent and / or non-elastic manner. Preferably, in step (b), the precursor of the receptacle (for example, a region thereof that includes the second end) is coupled with a former, for example, a shaped object, which is arranged to facilitate the formation of the divergent second end of the receptacle as described. The former may be conical or frustoconical. Suitably, the former is positioned within the precursor of the receptacle and is heated, suitably, to cause a substantially permanent thermal deformation of the precursor of the receptacle, thereby defining the described receptacle. Before or after step (b), the method may comprise treating the precursor of said receptacle to close a first end of the receptacle. Such treatment may comprise heating a region of the precursor of said receptacle adjacent to said first end. The treatment may comprise heat-sealing contiguous faces of the precursor of said receptacle adjacent to said first end. The receptacle prepared in the third aspect method may have any feature described according to the inventions of the first and / or second aspects. For example, the receptacle produced in the third aspect method may include any feature of the receptacle described according to the first and / or second aspects. According to a fourth aspect of the invention, an elongated receptacle is provided for containing reagents for a chemical reaction, wherein said elongated receptacle comprises a plastic material, wherein said receptacle is arranged to define an internal volume for containing reagents, wherein said receptacle includes a first end and a second end that are separated along the elongated extension of the receptacle, wherein said receptacle defines an opening at said second end, wherein the diameter of said opening is greater than the diameter of a region of said receptacle towards said second end. Said receptacle may have any characteristic of the receptacle described in any of the above aspects. The elongated receptacle of the fourth aspect can be produced in a method as described in the third aspect. The receptacle may include reagents and / or products produced from reagents. In a preferred embodiment, the receptacle includes a drag-reducing polymer or reagents for the production of a drag-reducing polymer. The weight of the materials, for example, the drag-reducing polymer, in the 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 may be between 1000 g and 250 kg, preferably between 10 kg and 100 kg. A drag-reducing polymer described in any statement herein may be any conventional or known polymeric drag-reducing agent (DRA), including, without limitation, poly(alpha-olefin), polychloroprene, vinyl acetate polymers and copolymers, poly(alkylene oxide) (PAO), and mixtures thereof and the like. In one embodiment, the monomer may be any monomer that, when polymerized, forms a polymer suitable for use as a drag-reducing agent (DRA). Said at least one monomer may comprise an alpha-olefin. Preferred alpha-olefins may 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.At least one of the monomers 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 may 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 can be used in the preparation of a drag-reducing polymer, provided they sufficiently catalyze the reaction. Metallocenes are useful catalysts for polymerizing some monomers. In the case of alpha-olefins, polymerization can be carried out by incorporating a mixture of Ziegler-Natta catalyst and cocatalysts into the monomer. Catalysts for the polymerization of alpha-olefins include, but are not necessarily limited to, TiCb.AA (aluminum-activated titanium trichloride) powder catalyst; cocatalyst(s), diethylaluminum chloride (DEAC) and diethylaluminum ethoxide (DEALE); TEAL (triethyl aluminum chloride), tri-methyl aluminum, tri-isobutyl aluminum, 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 its classes. 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) in Figure 10B; and Figure 11 is a schematic diagram of a simplified apparatus for producing a polymer. In the figures, equal 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 open at both ends. The tube is approximately 600 cm long plus an additional 5 to 10 cm (to allow it to be clamped in position, as described later) and approximately 153 mm ± 5 mm wide when in the horizontal state shown in Figure 2A. 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. bccAnn / Lznz / E / YiAi 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 may be suitably made of stainless steel (e.g., SS304L) with a thickness of 0.083 in (2.1 mm) and may have an outside diameter of 4 in (101.6 mm). The length may be 20 ft (609.6 cm). An inlet 13 (Figure 1) is provided for the introduction of gas into the inner tube 38 as described below. At its left end, as shown in Figure 3B, the inner tube 38 includes a narrow annular flange 48 which includes an outwardly facing flat annular face 49. The flange 48 and face 49 are arranged to secure the open end of the tube frccAnn / Lznz / E / YiAi in position, while minimizing folds and / or other regions that may contain undesirable air and / or oxygen, as described later. 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 the tube 26 as described in Figure 2D, is inserted into the inner tube 38 and pushed inward so that its heat-sealed end 28 is adjacent to the end fitting 16. As shown in Figure 3B, the extended open end 35 initially protrudes from the inner tube 38. The extension of the open end 35 is suitably such that the open end 35 can be folded back over the flange 48 without further stretching, and suitably so as to introduce minimal creasing as the open end 35 is extended over the face 49 of the flange 48. Next, as shown 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. Note that in Figure 3D, the sanitary fitting clamps have been omitted for clarity. It should be appreciated that gasket 44 makes face-to-face contact with the tube end, and the tube end is held between the gasket and flange 48. The simple arrangement described is found to minimize and / or substantially prevent the formation of folds and / or pockets at the tube end, which could otherwise contain air and / or oxygen that could be detrimental to any reaction taking place in the tube. 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 of tube 12. Alternatively, the steps in Figures 4A 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. frccAnn / Lznz / E / YiAi 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, titanium aluminum trichloride-activated TiCl3(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 transferred to a Swagelok pump and subsequently transferred to the 90-liter reactor, while maintaining an inert atmosphere, to initiate the 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. The 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 the tube 12, which can minimize polymer contamination and, in turn, may be advantageous in its subsequent uses. While it is not desired 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. 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 dish 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 dish, and the combined weight of the dish 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 a final concentration of frccAnn / Lznz / E / YiAi polymer 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. 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: F0 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, frccAnn / ίζηζ / Ε / γίΛΐ % FI = 100 * (Fa - F0) / F0 % DR = [(1 + %ΕΙ)19- 1] / (1 + ^oFI)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, except for modifying the loadings of TiCh(AAD), 1,2-dichloroethane, isobutylaluminoxane solution, and heptane diluent to provide different catalyst loading levels (expressed as ppm w / w of Ti relative to the monomer loading weight). After completion of the bulk polymerization, the reaction tube 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. 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. frccAnn / 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. frccAnn / 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 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

1. A method for assembling an apparatus for containing reagents for a chemical reaction, wherein the method comprises: (i) selecting an elongated receptacle comprising a plastic material, said receptacle being arranged to define an internal volume for containing reagents, wherein said receptacle includes a first end and a second end that are separated along the elongated extension of the receptacle, wherein said receptacle defines an opening at said second end, wherein the diameter of said opening is greater than the diameter of a region of said receptacle extending inward from said second end; (ii) selecting a housing for containing the receptacle, wherein said housing includes a first end and a second end, wherein said second end of said housing includes an outward-facing surface;(iii) with the receptacle inside the housing so that the second end of the receptacle is adjacent to the second end of the housing, position the second end of the receptacle on the outward-facing surface; and (iv) secure the second end of the receptacle in position with respect to the outward-facing surface. 2.- A method 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. A method according to claim 1 or claim 2, wherein said first end of said receptacle is a closed end and includes a sealed region, for example, a heat-sealed region. 4 - A method according to any of the preceding claims, wherein the length of the receptacle is the linear distance between its first end and its second end, wherein the diameter of the receptacle is substantially constant for at least 80% (preferably at least 90% or 95%) of the distance from the first end to said second end of the receptacle.

5. A method 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 length; 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).

6. A method according to any of the preceding claims, wherein the maximum diameter of the mouth is up to 30% greater than the diameter of the receptacle inside the mouth.

7. A method according to any of the preceding claims, wherein, apart from any means by which the first end is arranged to define the closed end, the receptacle does not include seams between its first and second ends. 8 - A method according to any preceding claim, wherein said receptacle is formed from horizontal pipe, wherein preferably said pipe is sealed at said first end and is divergent at said second end. 9 - A method according to any preceding claim, wherein the aspect ratio of the receptacle is defined as the length of the internal volume of the receptacle divided by the diameter of the internal volume of the receptacle, wherein said aspect ratio is at least 10, and is less than 600.

10. A method according to any preceding claim, wherein said housing is an elongated housing and is arranged to support the receptacle that is arranged within the housing, wherein the outward-facing surface mentioned in step (iii) of the method is oriented outwards in a direction that is parallel to the elongated extension of the housing and / or perpendicular to the diameter of the housing. 11 - A method according to any preceding claim, wherein the housing includes a flange defining the outward-facing surface, wherein the flange includes a substantially flat face extending substantially perpendicular to the elongated extension of the housing.

12. A method according to any preceding claim, wherein in step (iii) of the method, the receptacle is positioned inside the housing, with the second end of the receptacle extending out of the housing, and said second end is then folded over the outward-facing surface, for example, said flange.

13. A method according to any preceding claim, wherein in step (iv) of the method, said receptacle is releasably secured within the housing by a clamping means for holding the receptacle in position and, preferably, said second end of said receptacle is secured in position by a surface of said clamping means that is pushed against part of the receptacle (e.g., said mouth) to hold the receptacle between the clamping means and said outward-facing surface (e.g., a flange) of the housing.

14. Apparatus assembled according to the method of any preceding claim, wherein the apparatus comprises: (i) an elongated receptacle, wherein said receptacle includes a first end and a second end that are separated along the elongated extension of the receptacle, wherein said receptacle defines an opening at said second end, wherein the diameter of the opening is greater than the diameter of a region of said receptacle extending inward from said second end; (ii) a housing for containing the receptacle, wherein said housing includes a first end and a second end, wherein said second end of said housing includes an outward-facing surface; (iii) wherein the second end of the receptacle is positioned on said outward-facing surface of the housing; (iv) wherein the second end of the receptacle is secured in position with respect to said outward-facing surface.

15. Apparatus according to claim 14, wherein any feature of said receptacle and / or housing of claim 14 may be as described in any of claims 1 to 13.

16. A method for preparing an elongated receptacle for use in the method and / or apparatus of any preceding claim, wherein the method comprises: (a) selecting a precursor of a receptacle comprising a plastic material, wherein said precursor of said receptacle is arranged to define an internal volume for containing reagents, wherein said precursor of said receptacle includes a first end and a second end that are separated along the elongated extension of said precursor of said receptacle; (b) treating a region of the precursor of said receptacle adjacent to said second end to define an opening of a receptacle for containing reagents, wherein said opening of said receptacle has a larger diameter than a region of the receptacle inside said second end. 17.- A method according to claim 16, wherein said precursor is treated so that, adjacent to the second end, the precursor diverges, and the maximum diameter of the receptacle is located at said second end.

18. A method according to claim 16 or claim 17, wherein in step (b), said precursor of said receptacle is heated to allow its shape to change, preferably in a substantially permanent and / or non-elastic manner. 19 - A method according to any of claims 16 to 18, wherein, in step (b), the precursor of said receptacle (for example, a region thereof including said second end) is coupled with a former, for example, a shaped object, which is arranged to facilitate the formation of said second divergent end of the receptacle.

20. A method according to claim 19, wherein said former is conical or truncated conical. 21A method according to claim 19 or claim 20, wherein said former is positioned within the precursor of the receptacle and is subjected to heat, suitably, to cause a substantially permanent thermal deformation of said precursor of said receptacle, so as to define the described receptacle.

22. A method according to any of claims 19 to 21, wherein before or after step (b), the method comprises treating the precursor of said receptacle to close a first end of the receptacle, wherein, preferably, said treatment comprises heating a region of the precursor of said receptacle adjacent to said first end. frccAnn / Lznz / E / YiAi 23. An elongated receptacle for containing reagents for a chemical reaction, wherein said elongated receptacle comprising a plastic material, said receptacle is arranged to define an internal volume for containing reagents, wherein said receptacle includes a first end and a second end that are separated along the elongated extension 5 of the receptacle, wherein said receptacle defines an opening at said second end, wherein the diameter of said opening is greater than the diameter of a region of said receptacle towards the inside of said second end. 24.- An elongated receptacle according to claim 23, wherein any feature of said receptacle may be as described in any claim 10 above.

25. A receptacle according to claim 23 or claim 24, wherein said receptacle includes reagents and / or products produced from reagents and, preferably, includes a drag-reducing polymer.