Method of making alkylene glycols

Method for preparing alkylene glycolTechnical field

[0001] The present invention relates generally to the field of chemical reactions. More specifically, the present invention relates to a method comprising high shear mixing to prepare alkylene glycols.

Background technique

[0002] Ethylene glycol is used as an antifreeze in cooling and heating systems, in hydraulic brake fluids, as an industrial humectant, as a component of electrolytic capacitors, and as a solvent in the coating and plastic industries. Used as a softener for cellophane in the formulations of printer inks, pad inks and ballpoint pen inks, as well as for safety explosives, plasticizers, and synthetic fibers (TERYLENE^K,DACRON^!<) And the synthesis of synthetic wax. Ethylene glycol is also used for deicing airport runways and aircraft. Obviously, ethylene glycol is an important compound with many applications in industry.

[0003] Existing methods for hydrating alkylene oxide billets into alkylene glycols include direct hydration reactions without catalysts and catalytic hydration of alkylene oxide billets using inorganic acid catalysts. These inorganic acid catalyzed reactions are homogeneous and thus pose problems for the commercial production of diols because the catalyst is carried into the product and must be separated. Current commercial methods use non-catalytic hydration procedures, which must use a large ratio of water to alkylene oxide billets, thus presenting the problem of separating water from the final product. This separation consumes a lot of energy, which is the cause of a lot of attention recently.

[0004] Recently, various attempts have been made to discover new catalysts for the hydration of alkylene oxide into corresponding diols. For example, other catalytic methods use tetramethyl saddleium iodide and tetraethyl saddler bromide or organic tertiary amines such as triethylamine and pyrrolidone. Although focusing on catalyst technology, little has been done to improve the mixing of the alkylene oxide billet and the water phase to optimize the reaction.

[0005] Therefore, there is a need for an accelerated method for preparing alkyl diols by improving the mixing of ethylene oxide in the water phase.

Summary of the invention

[0006] Disclosed herein are methods of hydrating alkylene oxide billets. In an embodiment, the method includes (a) introducing the alkylene oxide billet into water to form a first stream; (b) passing the first stream through a high shear device to produce a second stream; and (c) The second stream is contacted with the catalyst in the reactor to hydrate and combine the alkylene oxide stock to form an alkylene glycol. In certain embodiments, the alkylene oxide billet comprises ethylene oxide, propylene oxide, butylene oxide, or a combination thereof. In certain embodiments, step (b) of the method includes subjecting the first stream to high shear mixing with a tip velocity of at least about 23 meters per second. In certain embodiments, step (b) of the method includes subjecting the first stream to greater than about 20,000 s¹The shear rate. In certain embodiments, generating the second stream comprises at least about 1000 W/m³Energy consumption. In certain embodiments, the catalyst comprises amines, acid catalysts, organometallic compounds, alkali metal halides, quaternary halides, zeolites, or combinations thereof. In certain embodiments, the alkylene glycol comprises ethylene glycol.

[0007] Also disclosed herein is a method of hydrating alkylene oxide billets. The method includes (a) introducing the alkylene oxide billet into water to form a first stream; (b) passing the first stream through a high shear device to hydrate the alkylene oxide billet to produce a second stream containing alkylene glycol Two streams; and (c) recovering the alkylene glycol from the second stream. In certain embodiments, the high shear device comprises a catalytic surface.

[0008] A method of producing polyethylene glycol is described in this disclosure. The method includes combining ethylene oxide and water or ethylene glycol

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Or the ethylene glycol oligomer is introduced into a high shear device to generate a first stream; and the first stream is subjected to a catalyst that promotes the formation of polyethylene glycol. In certain embodiments, the high shear device includes a catalytic surface that promotes the formation of polyethylene glycol.

[0009] In addition, the present invention discloses a system for hydrating alkylene oxide blanks. The system includes at least one high-shear device configured to form a mixed stream of alkylene oxide billet and water. The high-shear device includes a rotor and a stator, and the rotor and the stator are separated from about 0.02 mm to about The shear gap in the range of 5mm is separated, where the shear gap is the smallest distance between the rotor and the stator, and where the high shear device is capable of generating more than about 23 meters per second (4,500 feet per second). Min) at least one rotor tip speed; a pump configured to deliver a liquid stream to the high shear device; and a reactor for hydration of the alkylene oxide blank connected to the high shear device, the The reactor is configured to receive the mixed stream from the high shear device. In certain embodiments, the high shear device includes two or more rotors and two or more stators. In certain embodiments, the high shear device comprises a rotor tip, and the device is configured to operate at a flow rate of at least 300 liters/hour and a tip speed of at least about 23 meters/second. In certain embodiments, the high shear device is configured to provide greater than about 1000 W/m³Energy consumption. In certain embodiments, the system further comprises more than one high shear device. In certain embodiments, the high shear device has a tip speed greater than about 20 meters per second (4000 feet per minute). In certain embodiments, the system further comprises a fixed bed reactor, the reactor comprising a hydration catalyst. In certain embodiments, the high shear device comprises at least two generators. In certain embodiments, the high shear device comprises a catalytic surface.

[0010] The features and technical advantages of the present invention have been summarized quite extensively above, so that the following detailed description of the present invention can be better understood. Other features and advantages of the present invention will be described later, which form the subject of the claims of the present invention. Those skilled in the art should recognize that the disclosed concepts and specific embodiments can be easily used as a basis for modifying or designing other structures for performing the same purpose of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present invention as described in the claims.

Description of the drawings

[0011] In order to describe the preferred embodiments of the present invention in detail, reference will now be made to the accompanying drawings, in which:

[0012] FIG. 1 is a process flow diagram of a method for hydrating an alkylene oxide billet with water in the liquid phase according to certain embodiments of the present invention; and

[0013] FIG. 2 is a longitudinal cross-sectional view of a multi-stage high shear device used in the embodiment of the system of FIG. 1.

[0014] Marking and Naming

[0015] The term "catalytic surface" is used herein to refer to a surface composed of catalytic materials (such as metals, alloys, etc.) in a device such that when a suitable substrate comes into contact with the catalytic surface, it exhibits catalytic activity. In this document, the use of the term "catalytic surface" includes all such surfaces regardless of the shape and size of the surface, construction material, preparation method, degree of activity, or purpose of use.

[0016] Certain terms are used throughout and in the claims to refer to specific system components. This document does not intend to distinguish between components that differ in name but not in function. In the following discussion and in the claims, the terms "including" and "including" are used in an open manner and should therefore be interpreted as meaning "including but not limited to...".

[0017] Detailed description of the preferred embodiment

[0018] Described herein are methods and systems for preparing alkylene glycols. The method and system include a new application of a high shear device to promote the dispersion and dissolution of the alkylene oxide billet in water. The high shear device can allow lower reaction temperature and pressure, and can also reduce the reaction time. Other advantages and features of the disclosed method and system are described below.

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[0019] In an embodiment, a method of preparing an alkylene glycol includes introducing an alkylene oxide blank gas into a liquid water stream to form a gas-liquid stream. The method also includes flowing a gas-liquid stream through a high shear device to form a dispersion containing bubbles having an average diameter of less than about 1 micron. In addition, the method includes contacting a gas-liquid stream with a catalyst in a reactor to hydrate the alkylene oxide billet and form an alkylene glycol.

[0020] In an embodiment, the system for preparing an alkylene glycol includes at least one high shear device configured to form a dispersion of the alkylene oxide body and water. The high shear device includes a rotor and a stator. The rotor and stator are separated by a shear gap in the range of about 0.02 mm to about 5 mm. The shear gap is the smallest distance between the rotor and the stator. The high shear device is capable of generating a tip speed of at least one rotor greater than about 23 meters per second (4,500 feet per minute). In addition, the system includes a pump configured to deliver a liquid stream containing a liquid phase to the high shear device. The system also includes a reactor for hydration of the alkylene oxide blank connected to the high shear device. The reactor is configured to receive the dispersion from the high shear device.

[0021] The disclosed method and system for hydration of alkylene oxide billets uses a high shear mechanical device to provide rapid contact and mixing of alkylene oxide billet gas and water in a controlled environment in a reactor/mixer device. As used herein, the term "alkylene oxide billet gas" includes both substantially pure alkylene oxide billets and gas mixtures containing alkylene oxide billets. Specifically, embodiments of the system and method can be used to produce alkylene glycols from the hydration of alkylene oxide billets. In a preferred case, the method includes a heterogeneous reaction of liquid water with the oxyalkylene blank gas. The high-shear device reduces the mass transfer restriction on the reaction, thus increasing the overall reaction rate. In addition, in some embodiments, the liquid alkylene oxide billet is introduced into a high-shear mechanical device to be intimately mixed with water for the hydration reaction of the alkylene oxide billet.

[0022] Chemical reactions involving liquids, gases, and solids rely on time, temperature, and pressure to determine the rate of reaction. In situations where it is desired to react two or more different-phase raw materials (such as solid and liquid, liquid and gas, solid, liquid and gas), one of the limiting factors controlling the reaction rate includes the contact time of the reactants. In the case of heterogeneously catalyzed reactions, there are other rate-limiting factors that remove the reacted product from the surface of the catalyst so that the catalyst can catalyze other reactants. The contact time of reactants and/or catalysts is often controlled by mixing, which provides contact for two or more reactants participating in a chemical reaction. Reactor components containing external high shear devices or mixers as described herein make it possible to reduce the mass transfer limit, thereby bringing the reaction closer to the kinetic limit. As the reaction rate accelerates, the residence time may decrease, thereby increasing the achievable throughput. As a result of the high shear system and method, the product yield may increase. Optionally, if the product yield of the existing method is acceptable, reducing the required residence time by including suitable high shear may allow the use of lower temperatures and/or pressures than conventional methods.

[0023] Alkylene oxide billet hydration system

[0024] The high-shear alkylene oxide billet hydration system will now be described with reference to FIG. 1, which is a process flow diagram of an embodiment of the high-shear system 100 for producing alkylene glycol through the hydration of alkylene oxide billet . The basic components of a representative system include an external high shear device (HSD) 140, a container 110, and a pump 105. As shown in FIG. 1, the high shear device may be located outside the vessel/reactor 110. Each of these components will be described in further detail below. The pipeline 121 is connected to the pump 105, and is used to introduce any kind of alkylene oxide billet reactant. The line 113 connects the pump 105 to the HSD 140, and the line 118 connects the HSD 140 to the container 110. The pipeline 122 is connected to the pipeline 113 and is used to introduce the alkylene oxide billet gas. The pipeline 117 is connected to the container 110 and is used to remove unreacted alkylene oxide billets and other reactive gases. If necessary, other components or method steps can be included between the container 110 and the HSD 140 or in front of the pump 105 or the HSD 140. High-shear devices (HSD) such as high-shear or high-shear mills are generally classified according to their ability to mix fluids. Mixing is the process of reducing the size of heterogeneous species or particles in a fluid. A metric for the degree or adequacy of mixing is the damage produced by the mixing device to destroy fluid particles.

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Energy density per unit volume. Distinguish the types according to the energy density delivered. There are three types of industrial mixers with sufficient energy density to consistently produce mixtures or emulsions with particle or bubble sizes in the range of 0 to 50 microns. The high-shear mechanical device includes a homogenizer and a colloid mill.

[0025] High-shear devices (HSD) such as high-shear or high-shear mills are generally classified according to their ability to mix fluids. Mixing is the process of reducing the size of heterogeneous species or particles in a fluid. One measure of the degree or adequacy of mixing is the energy density per unit volume produced by the mixing device to destroy fluid particles. Distinguish the types according to the energy density delivered. There are three types of industrial mixers with sufficient energy density to consistently produce mixtures or emulsions with particle or bubble sizes in the range of 0 to 50 microns.

[0026] Homogenizing valve systems are typically classified as high energy devices. The fluid to be processed is pumped through the slit valve at a very high pressure and enters the lower pressure environment. The pressure gradient at both ends of the valve and the resulting vortex and cavitation play a role in destroying any particles in the fluid. These valve systems are most commonly used in the homogenization of milk and can produce an average particle size range from about O. OUm to about lwn. At the other end of the energy density spectrum are high-shear systems classified as low-energy devices. These systems typically have paddles or fluid rotors that rotate at high speeds in a reservoir of the fluid to be processed, which in many more common applications is food. These systems are generally used in situations where average particle or bubble sizes greater than 20 microns can be accepted in the fluid being processed.

[0027] From the perspective of the mixing energy density delivered to the fluid, between the low-energy high-shear device and the homogenization valve system is a colloid mill classified as a medium-energy device. A typical colloid mill configuration includes a conical or disc-shaped rotor separated from a complementary, liquid-cooled stator by a tightly controlled rotor-stator gap, which can be between 0.025mm and 10.0mm between. The rotor is usually driven by an electric motor through direct drive or belt machinery. Many colloid mills can produce an average particle or bubble size of about 0.01um to about 25 pm in the processed fluid when properly adjusted. These capabilities make the colloid mill suitable for a variety of different applications, including the processing of colloids and oil/water-based emulsions, such as the emulsion processing required for cosmetics, mayonnaise, silicone/amalgam formation or roofing asphalt mixing.

[0028] The approximate value of the energy input into the fluid (kW/L/min) can be estimated by measuring the motor energy (kW) and the fluid output (L/min). In the embodiment, the energy consumption of the high shear device is greater than 1000W/m³_oIn the embodiment, the energy consumption is about 3000W/m³To about 7500W/m³In the range. The shear rate generated in the high shear device can be greater than 20,000 s. In the embodiment, the shear rate generated is 20,000 s¹To the range of 100,000s.

[0029] The tip speed is the speed (meters per second) associated with the end of one or more rotating elements that transfer energy to the reactant. For rotating elements, the tip speed is the circumferential distance traveled by the tip of the rotor in a unit time, and is generally defined by the equation V (m/sec) = n · D · η, where V is the tip speed and D is the rotor's The diameter, in meters, and η is the rotation speed of the rotor, in revolutions per second. Therefore, the tip speed is a function of the diameter of the rotor and the rate of rotation. In addition, the tip speed can be calculated by multiplying the rotation frequency (eg revolutions per minute, rpm) by the circumferential distance traveled by the rotor tip 2nR, where R is the radius of the rotor (eg meters).

[0030] For colloid mills, typical tip speeds exceed 23 meters/second (4500 feet/minute) and can exceed 40 meters/second (7900 feet/minute). For the purpose of this disclosure, the term "high shear" refers to those capable of generating a tip speed exceeding 5 m/sec (1000 ft/min) and requiring an external mechanical driving force device to drive energy into the stream of the product to be reacted Mechanical rotor-stator devices, such as mills or mixers. The high shear device combines a high tip speed with a very small shear gap, which generates significant friction on the material to be processed. Therefore, during operation, approximately

Local pressure and elevated temperature in the range of 1000 MPa (about 145,000 psi) to about 1050 MPa (152,300 psi). In certain embodiments, the partial pressure is at least about 1034 MPa (about 150,000 psi).

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[0031] Referring now to FIG. 1, a schematic diagram of a high shear device 200 is provided. The high shear device 200 includes at least one rotor-stator combination. The rotor-stator combination can also be referred to as generator 220, 230, 240 or stage, without limitation. The high shear device 200 contains at least two generators, and in the most preferred case, the high shear device contains at least three generators.

[0032] The first generator 220 includes a rotor 222 and a stator 227. The second generator 230 includes a rotor 223 and a stator 228; the third generator includes a rotor 224 and a stator 229. For each generator 220, 230, 240, the rotor is rotatably driven through the input 250. The generator 220, 230, 240 rotates around the shaft 260 in a rotation direction 265. The stator 227 may be fixedly connected to the wall 255 of the high shear device.

[0033] The generator includes a gap between the rotor and the stator. The first generator 220 includes a first gap 225; the second generator 230 includes a second gap 235; and the third generator 240 includes a third gap 245. The width of the gaps 225, 235, 245 is between approximately 0.025 mm (0.01 inches) and 10.0 mm (0.4 inches). Optionally, the method includes using a high shear device 200 in which the gaps 225, 235, 245 are between about 0.5 mm (0.02 inches) and about 2.5 mm (0.1 inches). In some cases, the gap is maintained at about 1.5 mm (0.06 inches). Optionally, between the generators 220, 230, 240, the gaps 225, 235, 245 are different. In some cases, the gap 225 of the first generator 220 is approximately larger than the gap 235 of the second generator 230, which is approximately larger than the gap 245 of the third generator 240.

[0034] In addition, the width of the gaps 225, 235, and 245 may include coarse, medium, fine, and ultra-fine features. The rotors 222, 223, and 224 and the stators 227, 228, and 229 may be toothed designs. As is known in the art, each generator may contain two or more sets of rotor-stator teeth. The rotors 222, 223, and 224 may include a plurality of rotor teeth circumferentially spaced around the periphery of each rotor. The stators 227, 228, and 229 may include a plurality of stator teeth circumferentially spaced around the periphery of each stator. The rotor and stator can have any suitable size. In one embodiment, the inner diameter of the rotor is about 64 mm and the outer diameter of the stator is about 60 mm. In other embodiments, the inner diameter of the rotor is about 11.8 cm and the inner diameter of the stator is about 15.4 cm. In other embodiments, the rotor and stator may have alternating diameters in order to vary the tip speed and shear pressure. In certain embodiments, each of the three stages is operated with an ultra-fine generator that includes a gap between about 0.025 mm and about 3 mm. When the feed stream 205 including solid particles is to be transported through the high-shear device 200, a suitable gap width is first selected to appropriately reduce the particle size and increase the particle surface area. In embodiments, this is advantageous for increasing the surface area of the catalyst by shearing and dispersing the particles.

[0035] The reaction mixture containing the feed stream 205 is fed to the high shear device 200. The feed stream 205 contains an emulsion of a dispersible phase and a continuous phase. Emulsion refers to a liquefied mixture containing two distinguishable substances (or phases) that are not easy to mix and dissolve together. Most emulsions have a continuous phase (or matrix) that contains discrete droplets, bubbles, and/or particles of other phases or substances. The emulsion can be highly viscous, such as a paste or paste, or it can be a foam with small bubbles suspended in a liquid. As used herein, the term "emulsion" encompasses a continuous phase containing bubbles, a continuous phase containing particles (such as a solid catalyst), a continuous phase containing fluid droplets that are substantially insoluble in the continuous phase, and combinations thereof.

[0036] The feed stream 205 may include particulate solid catalyst components. The feed stream 205 is pumped through the generator 220,

230, 240 to form a product dispersion 210. In each generator, the rotors 222, 223, 224 are relative to the fixed stator

227,228,229 rotate at high speed. The rotation of the rotor pumps fluid, such as the feed stream 205, between the outer surface of the rotor 222 and the inner surface of the stator 227, creating localized high shear conditions. The gaps 225, 235, 245 generate high shear forces for processing the feed stream 205. The function of the high shear force between the rotor and stator is to process the feed stream 205 to produce the product dispersion 210. Each generator 220, 230, 240 of the high shear device 200 has an interchangeable rotor-stator combination for generating the desired bubble size (if the feed stream 205 contains gas) or the droplet size (if the feed stream 205 contains gas) in the product dispersion 210 Stream 205 contains liquid) of

Narrow distribution ο

[0037] The product dispersion 210 of gas particles or bubbles in a liquid comprises an emulsion. In an embodiment, the product dispersion 210 may comprise a dispersion of a previously immiscible or insoluble gas, liquid, or solid in a continuous phase. The product dispersion 210 has an average gas particle or bubble size of less than about 1.5 wn, and in a preferred case, the diameter of the bubbles is sub-micron. In some cases, the average bubble size is in the range of about 1.0 Own to about 0.1 pm. Optionally, the average bubble size is less than about 400nm (0.4pm), most preferably less than about 100nm (0. lum)_o

[0038] The high shear device 200 produces a gaseous emulsion capable of maintaining dispersion for at least about 15 minutes at atmospheric pressure. For the purpose of the present disclosure, in the product dispersion 210, an emulsion of gas particles or bubbles with a diameter of less than 1.5 wn in the dispersed phase may include microfoam. Without being limited by a particular theory, it is known in emulsion chemistry that submicron particles or bubbles dispersed in a liquid mainly move through the Brownian motion effect. The bubbles in the emulsion of the product dispersion 210 produced by the high shear device 200 may have higher mobility through the boundary layer of the solid catalyst particles, thereby promoting and accelerating the catalytic reaction by increasing the transport of the reactants.

[0039] The rotor is set to rotate at a speed commensurate with the diameter of the rotor and the required tip speed as described above. By including the high shear device 200, the transportation resistance is reduced, so that the reaction speed is increased by at least about 5%. Optionally, the high-shear device 200 includes a high-shear colloid mill, which functions as an accelerated rate reactor (ARR). The rate-accelerating reactor contains a single-stage dispersion chamber. The rate-accelerating reactor contains a multi-stage inline disperser, which contains at least two stages.

[0040] The selection of the high shear device 200 depends on the throughput requirements and the required particle or bubble size in the outlet dispersion 210. In some cases, the high shear device 200 includes the Dispax Reactor® of IKA Works, Inc., Wilmington, NC and APV North America, Inc., W. Mington, MA. For example, DR 2000/4 model contains belt drive, 4M generator, PTFE sealing ring, inlet flange 1" sanitary clamp, outlet flange 3/4" sanitary clamp, 2HP power, output speed 7900rpm, flow rate ( Water) about 300 liters/hour to about 700 liters/hour (depending on the generator), tip speed 9.4 m/s to about 41 m/s (about 1850 ft/min to about 8070 ft/min). Several optional models are available with various inlet/outlet connections, horsepower, rated tip speed, output rpm, and rated flow rate.

[0041] Not wishing to be limited by a specific theory, but it is believed that the level or degree of high shear is sufficient to increase the mass transfer rate, and can also produce local non-ideal conditions that can be predicted based on Gibbs free energy. Reactions that won't happen happen. Local non-ideal conditions are believed to occur inside the high-shear device, leading to an increase in temperature and pressure, of which the most significant increase is considered to be an increase in local pressure. The pressure and temperature increase in the high-shear device is instantaneous and local, once it leaves the high-shear device, it quickly returns to the main or average system conditions. In some cases, the high-shear device induces cavitation of sufficient strength to dissociate one or more reactants into free radicals, which can aggravate the chemical reaction or allow the reaction to be more stringent than it might otherwise be. Occurs under lower conditions. Cavitation can also increase the rate of the transportation process by generating local vortices and liquid microcirculation (acoustic currents).

[0042] Container

[0043] The vessel or reactor 110 is any type of vessel in which a heterogeneous reaction can spread to perform the conversion reaction described above. For example, continuous or semi-continuous stirred tank reactors, or one or more batch reactors can be used in series or in parallel. In some applications, the vessel 110 may be a tower reactor, in other applications a tubular reactor or a multi-tubular reactor. The catalyst inlet line 115 may be connected to the container 110 for receiving catalyst solution or slurry during the operation of the system.

[0044] As is known in the field of reaction vessel design, vessel 110 may include one or more of the following components: a stirring system, heating and/or cooling capabilities, pressure measuring instruments, temperature measuring instruments, one or more injection points, and Liquid level adjustment

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Device (not shown). For example, the stirring system may include a motor-driven mixer. The heating and/or cooling device may comprise, for example, a heat exchanger. Optionally, because in some embodiments, most of the conversion reaction can occur in the HSD 40, the container 110 may mainly function as a storage container in some cases. Although generally less desirable, the vessel 110 can be omitted in certain applications, especially if multiple high shear devices/reactors are used in series, as described further below.

[0045] Heat Exchanger

[0046] In addition to the heating/cooling capabilities of the vessel 110 mentioned above, in a variant of the embodiment shown in FIG. 1, other external or internal heat exchange devices for heating or cooling process streams are also envisaged. When the system 1 is operating in multi-pass mode, some suitable locations for one or more such heat exchange devices are between the pump 105 and the HSD 140, between the HSD 140 and the container 110, and between the container 110 and the pump 105 between. Some non-limiting examples of such heat exchange devices are shell, tube, plate and coil heat exchangers, as known in the art.

[0047] Pump

[0048] The pump 105 is configured for continuous or semi-continuous operation, and may be any that can provide a pressure greater than 2 atmospheres, preferably greater than 3 atmospheres, to allow controlled flow through the HSD 140 and the system 1. Suitable pump unit. For example, Roper 1 type gear pump, Roper Pump Company (Commerce Georgia) Dayton Pressure Booster Pump model 2P372E, Dayton Electric Co. (Norders, IL) is a suitable pump. In a preferred case, all contact parts of the pump contain stainless steel. In certain embodiments of the system, the pump 105 is capable of generating a pressure greater than about 20 atmospheres. In addition to the pump 105, one or more other high-pressure pumps (not shown) may be included in the system shown in FIG. 1. For example, a booster pump may be included between the HSD 140 and the container 110 to push pressure into the container 110, and the booster pump may be similar to the pump 105. As another example, a feed pump may be included for introducing other reactants or catalysts into the container 110, and the feed pump may be similar to the pump 105.

[0049] Hydration of alkylene oxide billets

[0050] In the operation for the catalytic hydration of alkylene oxide, the dispersible alkylene oxide gas stream is introduced into the system 100 via line 122, and is combined with the water stream in line 113 to form a gas-liquid stream. . Alternatively, the alkylene oxide billet gas may be directly fed into the HSD 140 instead of being combined with the liquid reactant (ie, water) in the line 113. The pump 105 is operated to pump the liquid reactant (water) through the line 121, build up the pressure, and feed the HSD 140, thereby providing a controlled flow through the high shear device (HSD) 140 and the high shear system 100.

[0051] In a preferred embodiment, the alkylene oxide billet gas may be continuously fed into the water stream 112 to form a high shear feed stream 113 (eg, a gas-liquid stream). In the high-shear device 140, water and alkylene oxide blank vapor are highly dispersed, so that nano-sized bubbles and/or micro-sized bubbles of the alkylene oxide blank are formed because the alkylene oxide blank vapor is excellently dissolved in the solution. After dispersion, the dispersion can leave the high shear device 140 at the high shear outlet line 118. Instead of a slurry catalyst process, stream 118 may optionally enter a fluidized bed or fixed bed 142. However, in a slurry catalyst embodiment, the high shear outlet stream 118 may directly enter the hydration reactor 110 for hydration. A cooling coil used to maintain the reaction temperature in the reactor 110 can be used to maintain the reaction stream at a specified reaction temperature. The hydration product (e.g., alkylene glycol) can be retrieved at product stream 116.

[0052] In an exemplary embodiment, the high-shear device includes a commercially available disperser such as IKA^DR 2000/4 model, which is a high-shear three-stage dispersion configured with a combination of three rotors and stators arranged in series. Device. The disperser is used to produce a dispersion (ie, "reactant") of the alkylene oxide body in a liquid medium containing water. The rotor/stator may be configured as shown in Fig. 2 for example. The combined reactants enter the high-shear device via line 113 and enter the first stage with a peripheral interval

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First-stage rotor/stator combination with shear openings. The coarse dispersion exiting from the first stage enters the second stage rotor/stator with second stage shear openings. The reduced bubble size dispersion from the second stage enters the third stage rotor/stator combination with third stage shear openings. The dispersion exits the high shear device via line 118. In certain embodiments, the shear rate is gradually increased longitudinally along the flow direction. For example, in certain embodiments, the shear rate in the first stage rotor/stator is greater than the shear rate in subsequent stages. In other embodiments, the shear rate is substantially constant along the flow direction, and the shear rate within each stage or multiple stages is the same. If the high shear device contains, for example, a PTFE seal, the seal can be cooled using any suitable technique known in the art. For example, the reactant stream flowing in line 113 can be used to cool the seal, and in doing so, it is preheated as needed before entering the high shear device.

[0053] The rotor of the HSD 140 is set to rotate at a speed commensurate with the diameter of the rotor and the required tip speed. As mentioned above, high shear devices (such as colloid mills) have a fixed gap between the stator and the rotor, or have an adjustable gap. HSD 140 is used to intimately mix the vapor of the alkylene oxide billet with the reactant liquid (ie, water). In certain embodiments of the method, the operation of the high shear device reduces the transport resistance of the reactants, so that the reaction rate (ie, the reaction rate) is increased by more than about 5 times. In certain embodiments, the reaction rate is increased by at least 10-fold. In certain embodiments, the speed increase factor is in the range of about 10 times to about 100 times. In certain embodiments, the HSD 140 delivers at least 300 liters/hour at a rated tip speed of at least 4500 feet/minute, and can exceed 7,900 feet/minute (140 meters/second), with a power consumption of 1.5kW_oAlthough it is difficult to measure the instantaneous temperature and pressure at the tip of the rotating shear unit or rotating element in the HSD 140, it is estimated that under high shear conditions, the local temperature observed in the intimately mixed reactants can be Above 500°C, the pressure exceeds 500kg/cm2. The high shear causes the alkylene oxide billet gas to be dispersed in micron or sub-micron-sized bubbles. In certain embodiments, the resulting dispersion has an average bubble size of less than about 1.5 wn. Therefore, the dispersion exiting HSD 140 via line 118 contains micro- and/or sub-micron sized bubbles. In certain embodiments, the average bubble size is in the range of about 0.4 pm to about 1.5 pm. In some embodiments, the average bubble size is less than about 400 nm, and in some cases can be about 100 nm. In many embodiments, the microbubble dispersion can remain dispersed for at least 15 minutes at atmospheric pressure.

[0054] Once dispersed, the resulting alkylene oxide/water dispersion leaves HSD 140 via line 118 and is fed into vessel 110, as shown in FIG. 1. Since the reactants are intimately mixed before entering the vessel 110, a significant portion of the chemical reaction can occur in the HSD 140 in the presence or absence of a catalyst. Therefore, in certain embodiments, the reactor/vessel 110 may be used primarily for heating and separating volatile reaction products from the alkylene glycol product. Alternatively or in addition, the vessel 110 can be used as the main reaction vessel in which most of the alkylene glycol product is produced. The vessel/reactor 110 may be operated in a continuous or semi-continuous flow mode, or it may be operated in a batch mode. Heating and/or cooling capabilities (such as cooling coils) and temperature measuring instruments may be used to maintain the contents of the container 110 at a specified reaction temperature. A suitable pressure measuring instrument can be used to monitor the pressure in the container, and a liquid level regulator (not shown) can be used to control the level of reactants in the container using techniques known to those skilled in the art. The contents are continuously or semi-continuously stirred.

[0055] A well-known hydration reaction condition can be suitably used as a condition for producing an alkylene glycol by hydrating the alkylene oxide body using a catalyst. There are no particular restrictions on the reaction conditions. For illustrative purposes, the method will be discussed from the perspective of ethylene glycol. However, it is envisaged that the embodiment of the method can be used to produce any alkylene glycol. In the production of ethylene glycol, 1 mole of water is theoretically needed to hydrate 1 mole of ethylene oxide. In practice, however, in order to obtain good results, a greater than equal molecular ratio of water and ethylene oxide is required. Although when a reactant ratio of water to ethylene oxide of about 2 is used, a conversion of about 90% can sometimes be obtained, but in order to obtain a reasonably high product yield, a reactant ratio of greater than 6 is generally required, otherwise the formed ethylene glycol Reacts with ethylene oxide to form diethylene glycol and triethylene glycol. For the production of ethylene glycol and other alkylene glycols, the effect of reactant ratios on the results obtained is well known. On the fixed bed of the claimed catalyst, the ratio is

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At least 17:1 reactive vapor and ethylene oxide were found to be reasonably high based on the ethylene oxide yield consumed.

[0056] The main by-products of the hydration reaction are di- and polyglycols (di-and polyglycols), such as di-alkylene glycol, trialkylene glycol, and tetraalkylene glycol. It is believed that the formation of diglycol and polyglycol is mainly caused by the reaction of the alkylene oxide billet and the alkylene glycol. Since the reactivity of the alkylene oxide billet with the alkylene glycol is generally higher than the reactivity of the alkylene oxide billet with water, a large excess of water is used in order to facilitate the reaction of the alkylene oxide billet with water, and thus obtained commercially Attractive selectivity to monodiol products.

[0057] The reaction temperature varies according to the type of starting alkylene oxide billet, the type of catalyst, the composition of the reaction mixture in the early stage of the reaction, etc., and is usually 50°C to 200°C, preferably 110°C to 160° C. The reaction pressure varies according to the reaction temperature and the degree of reaction progress, usually 3 to 50 kg/cm²_oIf necessary, the pressure in the reactor can be adjusted from time to time. The reaction time can be about 30 minutes to about 3 hours. The contact time of the reactants on the catalyst can be arbitrarily changed from a time length of less than 1 second to a time length of up to 25 seconds.

[0058] The alkylene oxide billets used for the reaction may be used alone or in combination as a mixture of different types. The alkylene oxide body can have any structure, such as aliphatic, aromatic, heteroaromatic, aliphatic-aromatic, or aliphatic-heteroaromatic. They can also contain other functional groups, and it should be determined in advance whether these functional groups should remain unchanged or should hydrate themselves.

[0059] Embodiments of the disclosed method may be suitable for hydrating linear or branched alkylene oxide billets. Examples of alkylene oxide billets include, but are not limited to, ethylene oxide, butylene oxide, propylene oxide, and the like. The alkylene oxide billet may have 2 to 4 carbon atoms.

[0060] In an embodiment, the liquid alkylene oxide billet is used as a feed in the hydration reaction. For example, ethylene oxide (E0) is introduced into the HSD device as a liquid. Due to the cavitation conditions caused by high shear, the alkylene oxide billet can form small bubbles (less than 1 micron in diameter) dispersed in the liquid phase, or the alkylene oxide billet can remain as a liquid and become intimately mixed with water for hydration React to produce alkylene glycol.

[0061] In certain embodiments, the hydration reaction occurs in HSD as a thermal conversion reactor. A thermal conversion reactor is a reactor in which the reaction can be promoted by heating alone without requiring or containing a catalyst. After the alkylene oxide is converted to its corresponding alkylene glycol, the effluent from HSD is sent to a distillation tower to separate the alkylene glycol from unreacted reactants (such as excess water). The reaction conditions in HSD (acting as a thermal conversion reactor) are generally the same as those commonly used in the thermal production of alkylene glycols. The difference is that HSD can generate high temperature and high pressure in a localized manner due to the cavitation effect. Therefore, the overall temperature and pressure may not need to be as stringent as those required for the hydration reaction. The reaction conditions listed below as examples are considered to be local reaction conditions in HSD. The ratio of water to alkylene oxide billet is in the range of 15 to 30 moles of water per mole of alkylene oxide billet. The reaction temperature is in the range of 150°C to 250°C. The reaction pressure is in the range of 500 to 5000 kPa.

[0062] In certain other embodiments, the hydration reaction occurs in a vessel that receives the effluent of HSD, wherein the vessel contains a suitable catalyst for the hydration reaction of the alkylene oxide billet. Such vessels are used as catalytic conversion reactors. The catalytic conversion reactor is a reactor containing a catalyst capable of promoting the conversion of the alkylene oxide billet to the alkylene glycol. The catalytic conversion reaction can be carried out in the presence of carbon dioxide. Whether to provide carbon dioxide to the reaction may depend on whether a catalyst is used in the reactor and the type of catalyst used. For example, if an anion exchange resin is used as the catalyst, it may be desirable to provide a certain amount of carbon dioxide to the catalyst bed. The carbon dioxide can be supplied to the catalytic conversion reactor in any convenient way. For example, carbon dioxide can be introduced separately and/or with one or more feed streams. Carbon dioxide may be present in the reaction mixture in the form of a gas or in the form of carbonic acid or in the form of carbonate. Based on the total amount of reactants in the catalytic conversion reactor, in some cases, carbon dioxide is present in the reaction mixture in an amount not exceeding 0.1% by weight; in some other cases, carbon dioxide is not more than 0.05% by weight Is present in the reaction mixture; in other cases, dioxygen

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Carbonized carbon is present in the reaction mixture in an amount not exceeding 0.01% by weight.

[0063] In certain other embodiments, the thermal conversion reactor and the catalytic conversion reactor are arranged in a series configuration. For example, as shown in FIG. 1, the HSD 140 acts as a thermal conversion reactor, and the vessel 110 acts as a catalytic conversion reactor for the hydration of the alkylene oxide billet. The effluent 118 from the HSD 140 may contain some unreacted reactants (for example, alkylene oxide billets and water), and such residual reactants may be reacted in the catalytic conversion reactor 110 to continue the production of alkylene glycol. Other reactants (such as alkylene oxide billet or water or both) and additives (such as carbon dioxide) may be added to the container 110 by any means known to those skilled in the art (not shown in FIG. 1). The effluent 116 from the container 110 contains alkylene glycol, water, and may contain some unreacted alkylene oxide billets. In some cases, the effluent 116 is sent to a distillation column to recover the alkylene glycol. In certain other cases, the effluent 116 is recycled to the HSD 140 for further reactions.

[0064] In certain other embodiments, the thermal conversion reactor and the catalytic conversion reactor are arranged in a parallel configuration (not shown). In other embodiments, the thermal conversion reactor and the catalytic conversion reactor are in a combined series Arrangement with parallel configuration o In the series configuration, the catalytic conversion reactor is usually downstream of the thermal conversion reactor. With the help of the present disclosure, ordinary professionals in the field can design various configurations of thermal conversion reactors and catalytic conversion reactors for the hydration reaction of alkylene oxide billets; therefore, all such configurations are within the scope of the present disclosure within.

[0065] In certain other embodiments, the catalyst slurry is introduced into the HSD along with the alkylene oxide billet and water so that the HSD acts as a catalytic conversion reactor promoted by the cavitation effect. In some other embodiments, the HSD contains a catalytic surface, and thus functions as a catalytic conversion reactor promoted by the cavitation effect. The localized high temperature and high pressure in HSD cause the catalytic conversion reaction (conversion from alkylene oxide billet to alkylene glycol) to occur under mild overall temperature and pressure conditions. In some cases, the reaction rate and selectivity are improved. In some cases, the molar ratio of water to alkylene oxide billet is reduced, making the recovery of alkylene glycol easier. In certain embodiments, sintered metals (eg INCONEL® alloys, H ASTELLOY® materials) are used to construct at least one surface of the HSD. For example, the rotor, stator, and/or other components of the HSD may be made of refractory materials (such as sintered metal). In certain embodiments, the rotor and stator do not contain teeth, thus forcing the reactant to flow through holes such as sintered material.

[0066] Catalyst

[0067] If a catalyst is used to promote the hydration reaction, it can be introduced into the vessel via line 115 as an aqueous or non-aqueous slurry or stream. Alternatively or in addition, the catalyst may be added elsewhere in the system 100. For example, the catalyst slurry may be injected into the line 121. In certain embodiments, line 121 may contain a flowing water stream and/or a recycle stream of alkylene oxide billets from vessel 110.

[0068] In embodiments, any catalyst suitable for catalyzing a hydration reaction can be used. An inert gas such as nitrogen may be used to fill the reactor 110 and purge any air and/or oxygen therein. According to one embodiment, the catalyst useful in the disclosed method may be an acid catalyst. For example, a partially amine-neutralized sulfonic acid catalyst can be used as the catalyst. These catalysts are heterogeneous and can be more fully described as ion exchange resins of the sulfonic acid type. These resins are then modified by passing enough amine through the resin to partially neutralize the sulfonic acid groups contained therein. Primary, secondary or tertiary amines are all acceptable. Tertiary amines can be used in the disclosed methods. The result is a catalyst consisting of a mixture of both the initially free sulfonic acid and the amine salt of the sulfonic acid, all still in a heterogeneous form.

[0069] In a particular embodiment, the catalyst comprises a styrene-divinylbenzene copolymer matrix with pendant sulfonic acid groups. Catalysts belonging to this category are available from Rohm and Haas under the names AmberlystTM RTM 15 and AmberlystTM

XN-1010 is obtained, and their difference lies in the amount of available surface area. Other substrates other than styrene-divinylbenzene type can be used, including other organic polymers and inorganic materials, as long as the substrate provided can bind sulfonic acid groups to maintain

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A heterogeneous catalyst system is sufficient.

[0070] Other representatives of many acid catalysts that have been suggested for the hydration of alkylene oxide blanks include fluorinated alkyl sulfonic acid ion exchange resins, acid and hydrohalic acids, strong acid cation exchange resins, aliphatic monoacids and/or poly Press acid, cation exchange resin, acid zeolite, sulfur dioxide, trihaloacetic acid.

[0071] In addition to acid catalysts, many catalysts have been suggested for the hydration of alkylene oxide billets. For example, the catalyst may be an aluminum phosphate catalyst, organic tertiary amines such as triethylamine and pyrrolidone, quaternary ortho-salts, fluoroalkyl sulfonic acid resins, alkali metal halides such as potassium, sodium, and lithium chlorides, bromides, and iodine Compounds, or quaternary halides such as tetramethyl iodide and tetraethyl bromide, or combinations thereof.

[0072] Various metal-containing compounds including metal oxides can be used as catalysts for the hydrolysis of alkylene oxide billets. For example, dehydrating metal oxides such as, but not limited to, oxides of aluminum oxide, oxide or hook, titanium, sail, button, or aluminum. Or alternatively, alkali metal bases such as alkoxides, oxides of titanium, hook and jade may be used.

[0073] The catalyst may also contain organometallic compounds, including metals such as sails, buttons, hooks, titanium, iron, aluminum, selenium, yards, pincers, baht, uranium or combinations thereof.

[0074] Recently, U.S. Patent No. 4,277,632 issued on July 7, 1981 discloses a method for producing alkylene glycol by hydrolysis of an alkylene oxide billet in the presence of a catalyst selected from the group consisting of button and hook. At least one member. The catalyst may be fed into the reactor 110 through the catalyst feed stream 115. Alternatively, the catalyst may be present in a fixed bed or a fluidized bed 142.

[0075] Ideally, the bulk or overall operating temperature of the reactants is maintained below their flash point. In certain embodiments, the operating conditions of the system 100 include a temperature in the range of about 50°C to about 300°C. In a particular embodiment, the reaction temperature in the vessel 110 specifically ranges from about 90°C to about 220°C. In certain embodiments, the reaction pressure in vessel 110 is in the range of about 5 atmospheres to about 50 atmospheres.

[0076] If desired, the dispersion can be further processed before entering the vessel 110 (as indicated by arrow 18). In the container 110, alkylene oxide hydration occurs by catalytic hydration. The contents of the container are continuously or semi-continuously stirred, the temperature of the reactants is controlled (for example, using a heat exchanger), and the fluid level in the container 110 is adjusted using standard techniques. Depending on the needs of the specific application, the hydration of the alkylene oxide blank can occur in a continuous, semi-continuous or batch manner. Any reaction gas generated leaves the reactor 110 via a gas line 117. The gas stream may contain, for example, unreacted alkylene oxide billets. The reaction gas removed via line 117 can be further processed, and components can be recycled when needed.

[0077] A reaction product stream containing unconverted alkylene oxide billets and corresponding by-products (such as di- and polyglycols, dialkylene glycols, trialkylene glycols, and tetraalkylene glycols) passes through line 116 Leave the container 110. The alkylene glycol product can be recovered and processed as known to those skilled in the art.

[0078] Production of polyethylene glycol (PEG)

[0079] In certain embodiments, the hydration of ethylene oxide results in the production of polyethylene glycol (PEG). In an embodiment, PEG is produced by reacting ethylene oxide with water. In another embodiment, PEG is produced by reacting ethylene oxide with ethylene glycol. In another embodiment, PEG is produced by reacting ethylene oxide with ethylene glycol oligomers. In certain embodiments, ethylene glycol or ethylene glycol oligomers are used instead of water as the starting material because it allows the production of PEG with low polydispersity. Such reactions are catalyzed by acidic or basic catalysts such as compounds of magnesium, aluminum or calcium with organic elements and basic catalysts (sodium hydroxide, potassium hydroxide or sodium carbonate).

[0080] In an embodiment, a feed stream of ethylene oxide and water or ethylene glycol or ethylene glycol oligomers is intimately mixed in HSD 140 (Figure 1). The effluent 118 from HSD 140 is introduced into a fixed bed containing a catalyst that promotes PEG formation

Or in the fluidized bed 142. In some cases, a catalyst slurry is used, and such slurry is introduced into the vessel 110 via line 115 together with the effluent 119 from the bed reactor 142. In some other cases, the bed reactor 142 is omitted, and the catalyst slurry and the effluent 118 from the HSD 140 are introduced into the vessel/reactor 110. The production of PEG takes place under the action of a suitable catalyst. Due to the exothermic nature of the reaction, a cooling system is provided for the bed reactor 142 and/or vessel 110 to prevent runaway polymerization reactions. In certain embodiments, the PEG produced is recovered from the effluent 116 from the container 110. In certain embodiments, the effluent 116 from the vessel 110 is recycled to the HSD 140 for further processing.

[0081] In an embodiment, a feed stream of ethylene oxide and water (or ethylene glycol or ethylene glycol oligomers) is introduced into the HSD, wherein the HSD comprises a catalytic surface that promotes the formation of PEG. In another embodiment, a feed stream of catalyst slurry with ethylene oxide and water (or ethylene glycol or ethylene glycol oligomer) is introduced into the HSD. Under the action of the catalyst, the production of PEG takes place in HSD. In some cases, cooling systems are provided to the HSD to prevent runaway polymerization reactions. In certain embodiments, the effluent from the HSD is recycled as feed to the HSD for further processing. In certain other embodiments, the effluent from the HSD is introduced into a second HSD to further produce PEG.

[0082] Multi-pass operation

[0083] In the embodiment shown in Figure 1, the system is configured for single-pass operation, where the output from the vessel 110 goes directly to further processing to recover the alkylene glycol product. In certain embodiments, it may be desirable to split the contents of container 110 or the liquid containing unreacted alkylene oxide billets through HSD 140 a second time. In this case, the line 116 is connected to the line 121 through the dashed line 120, and the recirculation stream from the container 110 is pumped through the pump 105 to the line 113, and thus enters the HSD 140. Other alkylene oxide billet gas may be injected into line 113 via line 122, or it may be directly added to a high shear device (not shown).

[0084] Multiple high shear devices

[0085] In certain embodiments, two or more high shear devices similar to HSD 140 or having different configurations are arranged in series and used to further enhance the reaction. Their operation can be batch or continuous. In certain situations where a single pass or "one pass" method is required, it may also be advantageous to use multiple high shear devices in series. In certain embodiments where multiple high shear devices are operated in series, the vessel 110 may be omitted. In certain embodiments, multiple high-shear devices 140 operate in parallel, and the outlet dispersion from them is introduced into one or more vessels 110.

[0086] Although the preferred embodiments of the present invention have been shown and described, those skilled in the art can modify them without departing from the spirit and teachings of the present invention. The embodiments described herein are merely exemplary and not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the present invention. When a numerical range or limitation is clearly indicated, these stated ranges or limitations shall be understood to include the same order of iteration range or limitation that falls within the clearly indicated range or limitation. The use of broader terms such as including, including, having, etc., should be understood as providing support for narrower terms such as consisting of, consisting essentially of, consisting essentially of, and so on. Therefore, the scope of protection is not limited by the foregoing, but only by the claims, and the scope of protection includes all equivalents of the subject matter of the claims. Each and every original claim is integrated as an embodiment of the present invention. Therefore, the claims are a further description and are an additional part of the preferred embodiment of the present invention. The disclosures of all patents, patent applications, and publications cited herein, to the extent that they provide exemplary, procedural, or other detailed information supplements to the content described herein, are incorporated herein by reference.

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