Corrugated grid support for vertical boiling reactor

Abstract

A baffle (i.e., tube support) for a shell-and-tube heat exchange reactor (e.g., an ethylene oxide (EO) reactor) is provided, which is adapted to a reduced tube spacing, allowing more catalyst-filled tubes to be present in the reactor. The baffle, which may be referred to as a corrugated grid support, comprises multiple corrugated stainless steel strips interlocked to form a grid pattern with tube openings. Each tube opening is configured to allow insertion of a catalyst-filled tube while providing sufficient opening area along the shell side of the tube to allow coolant flow through the reactor.

Description

[Technical Field]

[0001] [Cross-reference to related applications]

[0002] This invention claims priority to U.S. Provisional Application Serial No. 63 / 132,262, filed on December 30, 2020, the entire contents and disclosure of which are incorporated herein by reference.

[0003] This invention relates to a vertical boiling reactor, and more specifically to a shell-and-tube heat exchange reactor with a reduced tube spacing. [Previous Technology]

[0004] Ethylene oxide (EO) is an important industrial chemical used as a raw material for the manufacture of various chemicals such as ethylene glycol, ethylene glycol ethers, ethanolamine, and detergents. One method for producing EO is through a catalytic oxidation process, in which ethylene reacts with oxygen in the presence of a silver-based epoxidation catalyst. In this process, a feed stream containing ethylene and oxygen passes through a silver-based epoxidation catalyst bed, which is contained within the reaction zone of an EO reactor maintained under specific reaction conditions.

[0005] Commercial EO reactors typically employ the form of shell-and-tube heat exchangers, in which multiple substantially parallel, relatively narrow tubes are filled with catalyst particles to form a packed bed, and the shell of the heat exchanger contains a coolant. Figure 1 illustrates such an EO reactor. The EO reactor 1 shown in Figure 1 comprises multiple elongated tubes 2, wherein the inlet end of each elongated tube 2 is fixed to an inlet tube sheet 3 and the outlet end of each elongated tube 2 is fixed to an outlet tube sheet 4. An inlet reactor head 5 and an outlet reactor head 6 are provided.

[0006] The EO reactor 1 also includes a shell-and-tube heat exchanger 7, which is fixed to and integrally formed with the outlet head 6. The outlet head 6 has an opening communicating with the heat exchanger 7, and the heat exchanger 7 is welded to the outlet head 6 around the opening, thus forming an integral structure with the reactor. The heat exchanger 7 has tubes 8 fixed to tube sheets 9 and 10. A heat exchanger outlet head 11 is also provided.

[0007] In practice, reactant gases such as ethylene, oxygen, and ballast gases are introduced into the EO reactor 1 via line 12 and pass through line 2, which is filled with a suitable silver-based epoxidation catalyst, under reaction conditions. The heat of reaction is removed by a circulating heat transfer fluid, such as water, which is introduced to the shell side of the EO reactor 1 via line 13 and removed via line 14.

[0008] The reactant gas passes through pipe 2, where EO is generated. Upon exiting pipe 2, the gas passes through outlet head 6 and then enters pipe 8 of heat exchanger 7, where it is immediately cooled to prevent further oxidation and isomerization. A cooling fluid, such as water, is introduced into the shell side of heat exchanger 7 through line 15 and discharged through line 16. The cooled reactant gas exits heat exchanger 7 through line 17 and is processed in a conventional manner to recover products and recycle various components.

[0009] Baffles (i.e., tube supports) are well-known components of shell-and-tube heat exchange reactors, including the aforementioned EO reactor. Typically, baffles are perforated plates located inside the shell side of the heat exchanger, supporting the catalyst-filled tubes along their entire length to prevent movement / vibration and to divert flow to increase heat transfer.

[0010] Figure 2A is an enlarged cross-sectional view of the EO reactor shown in Figure 1. In Figure 1, and between the inlet tube sheet 3 and the outlet tube sheet 4, are shown a plurality of vertically spaced baffles (i.e., tube supports) 20 for supporting each elongated tube 2. In some examples, the baffles 20 comprise stainless steel strips 21A, 21B, which interlock with each other and form a grid pattern as shown in Figure 2B; each prior art stainless steel strip providing the baffles shown in Figure 2B has a straight edge along its entire length. As shown in Figure 2B, the stainless steel strips 21A are positioned parallel to each other and extend in a first direction, while the stainless steel strips 21B are positioned parallel to each other and extend in a second direction different from the first direction of the stainless steel strips 21A. Each stainless steel strip 21B intersects each stainless steel strip 21A to form a grid pattern including tube openings 22. Each tube opening 22 has a size that allows one of the tubes 2 to pass through it and has a parallelogram shape; that is, a quadrilateral figure with parallel opposite sides.

[0011] Referring now to FIG. 3, a top view of the prior art baffle (i.e., tube support) shown in FIG. 2A-2B is presented. FIG. 2A-2B includes stainless steel straight strips 21A, 21B, which are interlocked to form a grid pattern containing tube openings 22; some of the tube openings 22 contain tubes 2 filled with catalyst. Each of the stainless steel straight strips 21A, 21B is fixed (welded) to the inner wall of the baffle support plate 20S. In some embodiments, particularly for EO reactors, the baffle support plate 20S is cylindrical.

[0012] Figures 4A-4D show the prior art baffle 20 (i.e., tube support) shown in Figures 2A-2B during various stages of assembly. It is noteworthy that Figures 4A-4B show various stainless steel straight strips 21A, 21B that can be used; these stainless steel straight strips 21A, 21B have straight edges along their entire length. In Figure 4A, the stainless steel straight strip 21A has a slit S1 positioned along the bottom surface of each stainless steel straight strip 21A. In Figure 4B, the stainless steel straight strip 21B has a slit S2 positioned along the top surface of each stainless steel straight strip 21B. Figure 4C shows the baffle 20 after assembling the stainless steel straight strips shown in Figures 4A-4B. Figure 4D shows the assembled baffle 20 (i.e., tube support) of Figure 4C containing an elongated tube 2 within the tube opening 22.

[0013] Designing and manufacturing EO reactors with baffles using existing technology has become very challenging because reactor sizes are constantly increasing for larger plants, and costs are rising exponentially. A persistent goal in EO reactor manufacturing is to reduce the size of EO reactors by reducing tube spacing. Tube spacing is the shortest center-to-center distance between adjacent (i.e., neighboring) tubes. Reduced tube spacing cannot be achieved using existing baffle designs shown in Figures 2A-2B, 3, and 4A-4D. Therefore, a new baffle design is needed for EO reactors and other shell-and-tube heat exchange reactors to achieve reduced tube spacing. [Summary of the Invention]

[0014] A baffle (i.e., tube support) for a shell-and-tube heat exchange reactor (e.g., an ethylene oxide (EO) reactor) is provided, which is adapted to a reduced tube spacing, allowing more catalyst-filled tubes to be present in the reactor. The baffle, which may be referred to as a corrugated grid support, comprises multiple corrugated stainless steel strips interlocked to form a grid pattern with tube openings. Each tube opening is configured to allow insertion of a catalyst-filled tube while providing sufficient opening area along the shell side of the tube to allow coolant to flow through the reactor.

[0015] In one aspect of the invention, a shell-and-tube heat exchange reactor is provided, comprising a plurality of elongated tubes, wherein the inlet end of each of the elongated tubes is fixed to an inlet tube sheet and the outlet end of each of the elongated tubes is fixed to an outlet tube sheet. The reactor further comprises at least one baffle positioned between the inlet tube sheet and the outlet tube sheet and configured to support each of the elongated tubes. The at least one baffle of the invention comprises a plurality of corrugated stainless steel strips configured in a grid pattern having tube openings. Each tube opening allows one of the elongated tubes to pass through it.

Implementation Method

[0017] This application will now be described in more detail with reference to the following discussion and accompanying drawings. Please note that the drawings in this application are for illustrative purposes only and are therefore not drawn to scale. Also note that identical and corresponding elements are indicated by the same reference numerals.

[0018] In the following description, numerous specific details, such as particular structures, components, materials, dimensions, process steps, and techniques, are set forth in order to provide an understanding of various embodiments of this application. However, those skilled in the art will understand that various embodiments of this application can be implemented without these specific details. In other instances, well-known structures or process steps have not been described in detail to avoid obscuring this disclosure.

[0019] It should be understood that when an element that is a layer, region, or substrate is referred to as being "on" or "above" another element, it may be directly on the other element or there may be intermediate elements present. Conversely, when an element is referred to as being "directly on" or "directly above" another element, there are no intermediate elements present. It should also be understood that when an element is referred to as being "below" or "under" another element, it may be directly below or under the other element, or there may be intermediate elements present. Conversely, when an element is referred to as being "directly below" or "directly below" or "under" another element, there are no intermediate elements present. When used in conjunction with numerical values, the term "about" indicates that the difference between the numerical value and a given numerical value may fluctuate within ±10%.

[0020] As described above, the present invention provides a baffle (i.e., tube support) for a shell-and-tube heat exchange reactor, such as the ethylene oxide (EO) reactor shown in Figure 1 above. The baffle of the present invention supports the catalyst-packed tubes present in the reactor to prevent movement / vibration and diverts flow to increase heat transfer. Furthermore, the baffle of the present invention is designed to accommodate reduced tube spacing (compared to prior art baffle designs shown in Figures 2B, 3, and 4A-4D above), thus allowing for more catalyst-packed tubes to be present inside the reactor.

[0021] Referring now to FIG. 5, a portion of a baffle 50 according to an embodiment of the present invention is shown. The baffle 50 shown comprises a plurality of corrugated stainless steel strips 51A, 51B, which are interlocked with each other and form a grid pattern having tube openings (not specifically labeled in FIG. 5, but labeled as element 52 in FIG. 6C). Each tube opening 52 has a curved outer wall defined by the corrugated sidewall surfaces of the corrugated stainless steel strips 51A, 51B. Each provided tube opening 52 has a total area from about 550 mm2 to about 5000 mm2.

[0022] "Corrugated" refers to the fact that the strain-free steel strips 51A, 51B used to provide the baffle 50 of the present invention have wavy (i.e., wavy, and therefore not straight) sidewall surfaces extending along the entire length of the strips 51A, 51B. Each tube opening 52 of the baffle 50 of the present invention is configured such that an elongated tube 54 can be inserted therein, while providing sufficient opening area (not marked in FIG. 5) along the shell side of the tube 54 to allow coolant to flow through the reactor. The baffle 50 of the present invention is typically used in conjunction with other vertically spaced baffles having the same baffle design (i.e., baffles comprising multiple corrugated stainless steel strips 51A, 51B that are interlocked with each other to form a grid pattern with tube openings). The elongated tube 54 used in the present invention includes a shell side and a tube side, and can have a diameter known to those skilled in the art. For example, for a typical EO reactor, the elongated tube 54 may have a diameter of about 25 mm to about 70 mm.

[0023] A plurality of vertically spaced baffles having the baffle design shown in FIG. 5 are positioned between the inlet tube sheet (i.e., inlet tube sheet 3 shown in FIG. 1) and the outlet tube sheet (i.e., outlet tube sheet 6 shown in FIG. 1) of a shell-and-tube heat exchange reactor. Each of the plurality of corrugated stainless steel strips 51A, 51B has a first end and a second end fixed to the inner wall of a baffle support plate (e.g., baffle support plate 20S shown in FIG. 3) by welding or other fixing methods; the baffle support plate is fixed to the inner wall of the reactor. The baffle support plate used with the corrugated stainless steel strips 51A, 51B to provide the baffle of the present invention may be cylindrical.

[0024] An elongated tube 54 (similar to tube 2 shown in Figure 1) is filled with catalyst and has a first end fixed to an inlet tube sheet of a shell-and-tube heat exchange reactor and a second end fixed to an outlet tube sheet of a shell-and-tube heat exchange reactor. Each baffle 50 is configured to support each elongated tube 54. When multiple baffles 50 are used, the multiple baffles support the entire length of each elongated tube 54.

[0025] The plurality of corrugated stainless steel strips 51A, 51B provided for each baffle 50 include a first set of corrugated stainless steel strips 51B positioned parallel to each other and extending along a first direction (see FIG. 6B), and a second set of corrugated stainless steel strips 51A positioned parallel to each other and extending along a second direction different from the first direction of the first set of corrugated stainless steel strips (see FIG. 6C) (see FIG. 6A). Each of the first set of corrugated stainless steel strips 51B intersects each of the second set of corrugated stainless steel strips 51A to form a grid pattern. The angle α between the first set of corrugated stainless steel strips 51B and the second set of corrugated stainless steel strips 51A can be configured based on the tube pattern. In one embodiment, for an EO reactor, the angle α between the first set of corrugated stainless steel strips 51B and the second set of corrugated stainless steel strips 51A can be from 90° to 150°, preferably 120°. In other applications, the angle α between the first set of corrugated stainless steel strips 51B and the second set of corrugated stainless steel strips 51A can be from 30° to 90°. The angle α is shown in FIG. 6C. As shown in Figure 6B, each corrugated stainless steel strip 51B in the first group of corrugated stainless steel strips includes a slit S4 positioned along its upper surface, and each corrugated stainless steel strip 51A in the second group of corrugated stainless steel strips includes a slit S3 positioned along its bottom surface. The slits (S3, S4) do not extend completely through the respective corrugated stainless steel strips 51A, 51B. Each corrugated stainless steel strip 51A, 51B typically has a thickness from about 0.5 mm to about 5 mm. As shown in Figure 6C, the slit S3 on the second group of corrugated stainless steel strips 51A is embedded in the slit S4 of the first group of corrugated stainless steel strips 51B. The slits S3 and S4 are thus used to configure the multiple corrugated stainless steel strips into the gripping patterns shown in Figures 5 and 6.

[0026] Each baffle 50 of the present invention can be assembled by first providing a baffle support plate, and then placing and fixing a first set of corrugated stainless steel strips 51B inside the baffle support plate. In the present invention, the placement and fixing of the first set of corrugated stainless steel strips 51B begins from the center of the baffle support plate and proceeds outward from there. Next, the slit S3 of the second set of corrugated stainless steel strips 51A is inserted into the slit S4 of the first set of corrugated stainless steel strips 51B (again, working outward from the center). After placing the second set of corrugated stainless steel strips 51A, the second set of corrugated stainless steel strips 51A is fixed to the inner wall of the baffle support plate.

[0027] For reactors of the same volume, the baffle design of the present invention accommodates a reduced tube spacing (compared to the prior art baffle designs shown in Figures 2B, 3, and 4A-4D above), thus allowing more catalyst-filled tubes to be present inside the reactor incorporating the baffle design of the present invention. This is illustrated in Figures 7A and 7B of the present invention. Notably, Figure 7A shows the tube spacing of the prior art baffle shown in Figure 2B, while Figure 7B shows the tube spacing for baffle 50, which comprises a plurality of corrugated stainless steel strips 51A, 51B that are interlocked with each other and form a grid pattern having tube openings 52 for supporting elongated tubes 54 filled with catalyst. With the prior art baffle design, the spacing between each adjacent elongated tube is from about 30 mm to about 80 mm, while with the baffle design of the present invention, the spacing between each adjacent elongated tube is from about 27 mm to about 70 mm. The spacing between adjacent tubes (i.e., tube spacing) is a measurement from the center of one tube to the center of another. This reduced tube spacing allows for a greater number of tubes to be present in the reactor (compared to Figures 7A and 7B). In some instances, the baffle design of the present invention can result in 7% to 14% more tubes in the reactor compared to equivalent reactors including prior art baffle designs.

[0028] The baffle design of the present invention provides an open region A1 (see FIG. 7B) surrounding each elongated tube 54, wherein the open region A1 is configured to allow coolant to pass through. The open region A1 is located on the shell side of each tube 54 and is contained within each individual tube opening provided by a corrugated stainless steel strip. In one embodiment, the total area of ​​the open region is about 60 mm2 to about 2000 mm2.

[0029] The following description provides some details regarding the silver-based epoxidation catalyst that may be present inside an EO reactor comprising multiple baffles (i.e., corrugated grid supports) according to the invention, as well as some details regarding the EO operating conditions used during EO production. The following description is not exhaustive, but rather provides a general description of the silver-based epoxidation catalyst and EO operating conditions that can be used in the present invention.

[0030] Typical silver-based epoxidation catalysts include a support and at least a catalytically effective amount of silver or a silver-containing compound; optionally, a promoting amount of rhenium or a rhenium-containing compound is also present; optionally, one or more alkali metals or alkali metal-containing compounds are also present. The support used can be selected from a large number of solid refractory supports, which can be porous and can provide a preferred pore structure. Alumina is well known to be used as a catalyst support for olefin epoxidation and is a preferred support for silver-based epoxidation catalysts.

[0031] Regardless of the characteristics of the carrier used, it is generally shaped into particles, lumps, fragments, agglomerates, rings, spheres, spokes, cross-sectioned hollow cylinders, etc., of a size suitable for use in a fixed-bed epoxidation reactor. The carrier particles will preferably have an equivalent diameter in the range of about 3 mm to about 12 mm, more preferably in the range of about 5 mm to about 10 mm. (Equivalent diameter is the diameter of a sphere having the same outer surface (i.e., ignoring the surface within the particle pores) to volume ratio as the carrier particles used. Suitable carriers are available from Saint-Gobain Norpro Co., Sud Chemie AG, Noritake Co., CeramTec AG, and Industrie Bitossi SpA. Further information regarding carrier compositions and methods of producing carriers can be found in U.S. Patent Publication No. 2007 / 0037991, without being limited to the specific compositions and formulations contained therein.

[0032] Next, in order to produce a catalyst for oxidizing olefins to olefin oxides, a catalytically effective amount of silver is provided on the surface of a support having the above-described properties. In one embodiment, the catalytically effective amount of silver is 10% to 45% by weight. The catalyst can be prepared by using a silver compound, complex, or salt-impregnated support dissolved in a suitable solvent sufficient to cause the silver precursor compound to deposit on the support. Preferably, an aqueous solution of silver can be used.

[0033] The rhenium component in the promoting amount may also be deposited on the support before, simultaneously with, or after silver deposition. The rhenium component may be a rhenium-containing compound or a rhenium-containing complex. Based on the weight of the total catalyst, including the support, expressed in rhenium metal, the rhenium promoter may be present in an amount of about 0.001% to about 1% by weight, preferably in an amount of about 0.005% to about 0.5% by weight, and more preferably in an amount of about 0.01% to about 0.1% by weight.

[0034] Other components may also be deposited on the support before, simultaneously with, or after the deposition of silver and rhenium. These other components are, in a promoting amount, an alkali metal or a mixture of two or more alkali metals, and optionally, a promoting amount, a Group IIA alkaline earth metal component or a mixture of two or more Group IIA alkaline earth metal components, and / or a transition metal component or a mixture of two or more transition metal components, all of which are soluble in a suitable solvent in the form of metal ions, metal compounds, metal complexes, and / or metal salts. The support may be impregnated with various different catalyst promoters simultaneously or in different steps. The specific combination of the support, silver, alkali metal promoter, rhenium component, and optional additional promoters of the present invention will provide one or more improvements in catalytic performance compared to the same combination of silver and support with or without a promoter or with only one promoter.

[0035] As used herein, the term "promoting amount" for a component of a catalyst refers to the amount of that component that effectively improves the catalytic performance of the catalyst compared to a catalyst without that component. Of course, the precise concentration used depends, among other factors, on the desired silver content, the nature of the support, the viscosity of the liquid, and the solubility of the specific compound used to deliver the promoter into the impregnation solution. Examples of catalytic performance include, in particular, operability (resistance to runaway), selectivity, activity, conversion, stability, and yield. Those skilled in the art will understand that one or more individual catalytic performance characteristics can be enhanced by a "promoting amount," while other catalytic performance characteristics may or may not be enhanced, or may even be reduced.

[0036] A suitable alkali metal promoter may be selected from lithium, sodium, potassium, rubidium, cesium, or combinations thereof, preferably cesium, and particularly preferably a combination of cesium and other alkali metals. The amount of alkali metal deposited or present on the support is the promoting amount. Preferably, the amount, measured in metal, based on the total catalyst weight, ranges from about 10 ppm to about 3000 ppm, more preferably from about 15 ppm to about 2000 ppm, even more preferably from about 20 ppm to about 1500 ppm, and particularly preferably from about 50 ppm to about 1000 ppm.

[0037] Suitable alkaline earth metal promoters include elements from Group IIA of the periodic table, which may be beryllium, magnesium, calcium, strontium, and barium, or combinations thereof. Suitable transition metal promoters may include elements from Groups IVA, VA, VIA, VIIA, and VIIIA of the periodic table, and combinations thereof.

[0038] The amount of alkaline earth metal promoter and / or transition metal promoter deposited on the carrier is the promotion amount. The amount of transition metal promoter present can typically be from about 0.1 μmol / g to about 10 μmol / g, preferably from about 0.2 μmol / g to about 5 μmol / g.

[0039] The silver solution used for impregnating the carrier may also contain optional solvents or complexing agents / solvents, as are known in the art. A variety of solvents or complexing agents / solvents can be used to dissolve the silver in the impregnation medium to the desired concentration. Useful complexing agents / solvents include amines, ammonia, oxalic acid, lactic acid, and combinations thereof. Amines include alkylene diamines having 1 to 5 carbon atoms. In a preferred embodiment, the solution comprises an aqueous solution of silver oxalate and ethylenediamine. The complexing agent / solvent can be present in the impregnation solution in an amount of about 0.1 to about 5.0 moles per mole of silver, preferably in an amount of about 0.2 to about 4.0 moles per mole of silver, and more preferably in an amount of about 0.3 to about 3.0 moles per mole of silver.

[0040] When using a solvent, it can be an organic solvent or water, and can be polar or substantially or completely nonpolar. Generally, the solvent should have sufficient dissolving power to dissolve the solution components. At the same time, it is preferable to choose a solvent to avoid undue influence on or interaction with the solvation promoter. Organic-based solvents having 1 to about 8 carbon atoms per molecule are preferred. Mixtures of several organic solvents or mixtures of organic solvents and water can be used, provided that such mixed solvents function as intended herein.

[0041] The concentration of silver in the impregnation solution is typically in the range of about 0.1% by weight to the maximum solubility provided by the particular solvent / solvent combination used. Generally, solutions containing from 0.5% to about 45% by weight of silver are preferred, and preferably from 5% to 35% by weight of silver.

[0042] The impregnation of the selected carrier can be achieved using any conventional method; for example, excess solution impregnation, initial wet impregnation, spraying, etc. Typically, the carrier material is contacted with a silver-containing solution until a sufficient amount of solution is absorbed by the carrier. Preferably, the amount of silver-containing solution used to impregnate the porous carrier does not exceed the amount required to fill the carrier pores. A single impregnation or a series of impregnations can be used, with or without intermediate drying, depending in part on the concentration of the silver component in the solution. Impregnation processes are described, for example, in U.S. Patents 4,761,394, 4,766,105, 4,908,343, 5,057,481, 5,187,140, ​​5,102,848, 5,011,807, 5,099,041, and 5,407,888. Known existing processes for pre-deposition, co-deposition, and post-deposition using various accelerators can be used.

[0043] After impregnating the support with a silver-containing compound (i.e., a silver precursor, optionally a rhenium component, optionally an alkali metal component, and optionally other promoters), the impregnated support is calcined for a sufficient time to convert the silver containing the compound into an active silver substance and to remove volatile components from the impregnated support, thereby producing a catalyst precursor. Calcination can be performed by heating the impregnated support to a temperature of approximately 200°C to approximately 600°C at a pressure of approximately 0.5 to approximately 35 bar, preferably at a gradual rate. Generally, the higher the temperature, the shorter the required heating time. A wide range of heating cycles has been proposed in the art; for example, U.S. Patent No. 3,563,914 discloses heating for less than 300 seconds, and U.S. Patent No. 3,702,259 discloses heating at temperatures of 100°C to 375°C for 2 to 8 hours, typically lasting approximately 0.5 to approximately 8 hours. However, it is only important that the heating time is temperature-dependent, such that substantially all of the contained silver is converted into an active silver substance. Continuous or gradual heating can be used for this purpose.

[0044] During calcination, the impregnated support may be exposed to a gaseous environment containing an inert gas or a mixture of an inert gas and about 10 ppm to 21% by volume of an oxygen-containing oxidizing component. For the purposes of this invention, an inert gas is defined as a gas that does not substantially react with the catalyst or catalyst precursor under the conditions selected for calcination. Further information regarding catalyst production can be found in the aforementioned U.S. Patent Publication No. 2007 / 0037991.

[0045] For illustrative purposes only, the following conditions are commonly used in currently commercial EO reactor units: gas hourly space velocity (GHSV) of 1500-10,000 h⁻¹, reactor inlet pressure of 1 MPa to 3 MPa, coolant temperature of 180-315 °C, oxygen conversion of 10-60%, EO production rate (operating rate) of 100-350 kg EO / m³ catalyst / hour, and ethylene oxide concentration variation ΔEO of about 1.5% to about 4.5%. After startup and during normal operation, the feed composition at the reactor inlet typically includes (by volume%) 1-40% ethylene, 3-12% O₂; 0.2% to 10%, preferably 0.2% to 6%, more preferably 0.2% to 5% CO₂; 0-5% ethane; a certain amount of one or more chloride modifiers (described herein); and the remainder of the feed consists of argon, methane, nitrogen, or mixtures thereof.

[0046] Although the invention has been specifically shown and described with respect to its preferred embodiments, those skilled in the art will understand that the foregoing changes and other modifications to form and detail may be made without departing from the spirit and scope of the invention. Therefore, the invention is not limited to the exact forms and details described and illustrated, but falls within the scope of the appended claims. [Simplified Explanation of the Diagram]

[0016] [Figure 1] is a schematic diagram of a prior art EO reactor. [Figure 2A] is a schematic diagram of an enlarged cross-sectional view of a portion of the EO reactor shown in Figure 1, which includes baffles (i.e., tube supports) for supporting multiple elongated tubes. [Figure 2B] is a diagram of a prior art baffle (i.e., tube support) comprising stainless steel strips interlocked with each other to form a grid pattern. [Figure 3] is a top view of the prior art baffle (i.e., tube support) depicted in Figures 2A-2B. [Figures 4A-4B] are schematic diagrams of various stainless steel strips that can be used to form the prior art baffle (i.e., tube support) shown in Figure 2B. [Figure 4C] is a schematic diagram of the stainless steel strips shown in Figures 4A-4B assembled to provide a prior art baffle (i.e., tube support) with a grid pattern. [Figure 4D] is a schematic diagram of the assembled baffle (i.e., tube support) of Figure 4C containing elongated tubes within tube openings. [Figure 5] is a schematic diagram of a baffle (i.e., tube support) according to one embodiment of this application, the baffle comprising a plurality of corrugated stainless steel strips interlocked with each other to form a grid pattern. [Figures 6A-6B] are schematic diagrams of various corrugated stainless steel strips that can be used to form the baffle (i.e., tube support) shown in Figure 5. [Figure 6C] is a schematic diagram after assembling the corrugated stainless steel strips shown in Figures 6A-6B to provide the baffle (i.e., tube support) shown in Figure 5. [Figure 7A] is a top view of the prior art baffle shown in Figure 2B, illustrating the tube spacing of this baffle design. [Figure 7B] is a top view of the baffle shown in Figure 5, illustrating the tube spacing of this baffle design.

Claims

1. A shell-and-tube heat exchange reactor, comprising: A plurality of slender tubes, wherein the inlet end of each of the slender tubes is fixed to an inlet tube sheet and the outlet end of each of the slender tubes is fixed to an outlet tube sheet; And at least one baffle positioned between the inlet tube sheet and the outlet tube sheet and configured to support each of the elongated tubes, wherein the at least one baffle comprises a plurality of corrugated stainless steel strips configured in a grid pattern having tube openings; wherein each tube opening is spaced apart from an adjacent tube opening by a portion of one of the corrugated stainless steel strips, and each tube opening allows one of the elongated tubes to pass through therethrough; wherein the reactor is used for the production of ethylene oxide (EO), and each elongated tube is filled with a silver-based epoxidation catalyst.

2. The shell-and-tube heat exchange reactor as described in claim 1, wherein, Each of the corrugated stainless steel strips is fixed to the baffle support plate.

3. The shell-and-tube heat exchange reactor as described in claim 2, wherein, The baffle support plate is cylindrical.

4. The shell-and-tube heat exchange reactor as described in claim 1, wherein, The spacing between each adjacent slender tube is approximately 27 mm to approximately 70 mm.

5. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein, The total area of ​​each pipe opening is approximately 550 mm² to approximately 5000 mm².

6. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein, The plurality of corrugated stainless steel strips include a first group of corrugated stainless steel strips positioned parallel to each other and extending along a first direction, and a second group of corrugated stainless steel strips positioned parallel to each other and extending along a second direction different from the first direction of the first group of corrugated stainless steel strips.

7. The shell-and-tube heat exchange reactor as described in claim 6, wherein, The angle α between the first group of corrugated stainless steel strips and the second group of corrugated stainless steel strips is 90° to 150°.

8. The shell-and-tube heat exchange reactor as claimed in claim 6, wherein, The angle α between the first group of corrugated stainless steel strips and the second group of corrugated stainless steel strips is 30° to 90°.

9. The shell-and-tube heat exchange reactor as claimed in claim 6, wherein each of the first set of corrugated stainless steel strips includes a slit positioned along its upper surface, and wherein each of the second set of corrugated stainless steel strips includes a slit positioned along its bottom surface.

10. The shell-and-tube heat exchange reactor as claimed in claim 9, wherein, The slits of the second set of corrugated stainless steel strips are embedded in the slits of the first set of corrugated stainless steel strips.

11. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein each tube opening of one of the elongated tubes further includes an open region surrounding the elongated tube, wherein the open region is configured to allow coolant to pass through.

12. The shell-and-tube heat exchange reactor as claimed in claim 11, wherein the open area surrounding the elongated tube has a total area from about 60 mm² to about 2000 mm².

13. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein the at least one baffle comprises a plurality of vertically spaced baffles supporting the entire length of each elongated tube, wherein each of the plurality of vertically spaced baffles comprises a plurality of the corrugated stainless steel strips configured to form the grid pattern having the tube openings.

14. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein the diameter of each elongated tube is approximately 25 mm to 70 mm.

15. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein the EO reactor further comprises an inlet line for introducing a feed gas containing 1% to 40% ethylene and 3% to 12% oxygen into the EO reactor.

16. The shell-and-tube heat exchange reactor as claimed in claim 15, wherein the EO reactor is configured to operate under the following conditions: a gas hourly space velocity of 1,500 to 10,000 h⁻¹, a reactor inlet pressure of 1 MPa to 3 MPa, a coolant temperature of 180°C to 315°C, an oxygen conversion rate of 10–60%, an EO production rate (operating rate) of 100–350 kg EO / m³ catalyst / hour, and an ethylene oxide concentration variation ΔEO of about 1.5% to about 4.5%.

17. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein the thickness of each corrugated stainless steel strip is approximately 0.5 mm to 5.0 mm.

18. The shell-and-tube heat exchange reactor as claimed in claim 1, wherein the silver-based epoxidation catalyst comprises an alumina support, a catalytically effective amount of silver or a silver-containing compound, and a promoting amount of one or more promoters.

19. The shell-and-tube heat exchange reactor as claimed in claim 18, wherein the one or more promoters include at least one rhenium promoter.

20. An ethylene oxide reactor (EO), comprising: A plurality of elongated tubes, wherein the inlet end of each of the elongated tubes is fixed to an inlet tube sheet and the outlet end of each of the elongated tubes is fixed to an outlet tube sheet; at least one baffle positioned between the inlet tube sheet and the outlet tube sheet and configured to support each of the elongated tubes, wherein the at least one baffle comprises a plurality of corrugated stainless steel strips configured in a grid pattern having tube openings, wherein each tube opening is spaced apart from an adjacent tube opening by a portion of one of the corrugated stainless steel strips, and each tube opening allows one of the elongated tubes to pass through therethrough; and an inlet line for introducing a feed gas containing 1% to 40% ethylene and 3% to 12% oxygen into the EO reactor, wherein the EO reactor is configured to operate under the following conditions: a gas hourly space velocity of 1500 to 10,000 h⁻¹, a reactor inlet pressure of 1 MPa to 3 MPa, a coolant temperature of 180°C to 315°C, an oxygen conversion rate of 10–60%, and a fuel density of 100–350 kg / m³. The EO production rate (operating rate) is EO / m3 catalyst / hour, the ethylene oxide concentration change ΔEO is about 1.5% to about 4.5%, and each elongated tube is filled with a silver-based epoxidation catalyst, the silver-based epoxidation catalyst comprising an alumina support, a catalytically effective amount of silver or a silver-containing compound, and a promoting amount of one or more promoters.

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