Sectional type temperature control methanation reactor

Abstract

The invention relates to the technical field of chemical reaction equipment, and provides a sectional type temperature control methanation reactor. Comprising an outer shell; the tubular reactor / heat exchanger is arranged in the outer shell; the coiled tube reactor is arranged in the outer shell, and the top of the coiled tube reactor is connected and communicated with the bottom of the tubular reactor / heat exchanger; a sealed annular space is formed between the outer shell and the inner shell, the outer side is communicated with a feed gas inlet, and the inner side is communicated with the interior of the tubular reactor / heat exchanger through an inner barrel opening; the central outer tube is arranged in the tubular reactor / heat exchanger and extends to the lower part of the coiled tubular reactor along the axial direction; the shell pass of the coiled tube reactor is filled with porcelain balls and a catalyst, and the tube pass of the tubular reactor / heat exchanger is filled with porcelain balls or porcelain balls and a catalyst; raw material gas enters the coiled tube reactor from the tubular reactor / heat exchanger, and product gas is discharged from a product gas outlet through the tubular reactor / heat exchanger. The temperature control is simple, the process flow is shortened, and the catalyst filling difficulty is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chemical reaction equipment, and in particular to a segmented temperature-controlled methanation reactor. Background Art

[0002] Methanation reaction is highly exothermic and controlled by thermodynamic equilibrium. At present, the methanation technology used in domestic industrialized coal-to-natural gas projects is a multi-stage adiabatic fixed bed process, in which the outlet temperature of the main reactor is relatively high and the carbon conversion rate is relatively low due to equilibrium constraints. Therefore, a large amount of product gas circulation is required to dilute the inlet raw gas and reduce the inlet temperature and partial pressure.

[0003] In contrast, the temperature-controlled methanation process has significant advantages such as low outlet temperature, high single-pass conversion rate, and simple process flow, and has great development potential. However, the performance of this type of reactor depends on the heat transfer capacity of the reactor. In recent years, the wound reactor has attracted widespread attention due to its large heat exchange area, as disclosed in many patents, but this type of reactor has the disadvantage of difficult catalyst loading, which restricts its application in industry.

[0004] In the process of preparing natural gas from coal or biomass, the hydrogen-carbon ratio of the raw gas needs to be adjusted through a conversion reaction. Similar to the methanation process, this process route often involves multiple reactors in series and parallel, and the process flow is relatively long.

[0005] Therefore, existing methanation reaction equipment has the defects of difficult reactor temperature control, difficult catalyst loading and long process route. Summary of the invention

[0006] In view of this, an embodiment of the present application provides a segmented temperature-controlled methanation reactor to overcome the defects of existing methanation reactors, such as difficulty in temperature control, difficulty in catalyst loading, and long process route.

[0007] The present application embodiment provides a segmented temperature-controlled methanation reactor, comprising:

[0008] The outer shell has a raw gas inlet and a heat transfer medium inlet on the side wall, a product gas outlet on the top, and a heat transfer medium outlet on the bottom;

[0009] A shell-and-tube reactor / heat exchanger is disposed in the outer shell, and the top thereof is connected to the product gas outlet;

[0010] A coiled tubular reactor is disposed in the outer shell, and the top thereof is connected and communicated with the bottom of the tubular reactor / heat exchanger;

[0011] The inner shell is formed by axially connecting the outer wall of the shell-and-tube reactor / heat exchanger and the outer wall of the winding tube reactor, and a sealing annular gap is formed between the outer shell and the inner shell, the outer side of the sealing annular gap is communicated with the raw gas inlet, and the inner side is communicated with the interior of the shell-and-tube reactor / heat exchanger through the inner cylinder opening on the outer wall of the shell-and-tube reactor / heat exchanger;

[0012] A central outer tube is disposed in the shell-and-tube reactor / heat exchanger and extends axially to the lower part of the coiled-tube reactor;

[0013] A heat transfer medium channel, used to connect the heat transfer medium inlet and the heat transfer medium outlet;

[0014] The shell side of the coiled tubular reactor is used to load ceramic balls and catalysts, and the tube side of the tubular reactor / heat exchanger is used to load ceramic balls or ceramic balls and catalysts;

[0015] The raw gas enters the coiled tubular reactor from the shell-and-tube reactor / heat exchanger, and the product gas is discharged from the product gas outlet through the shell-and-tube reactor / heat exchanger; the heat transfer medium enters the coiled tubular reactor through the heat transfer medium inlet for heat exchange and is discharged from the heat transfer medium outlet.

[0016] The first aspect of the embodiment of the present application provides a segmented temperature-controlled methanation reactor, which is configured such that the raw gas enters the coiled-tube reactor from the coiled-tube reactor / heat exchanger, the product gas is discharged from the product gas outlet through the coiled-tube reactor / heat exchanger, the heat transfer medium enters the coiled-tube reactor through the heat transfer medium inlet for heat exchange, and is discharged from the heat transfer medium outlet, so that the direction of the shell-and-tube gas and the heat transfer medium is reasonable, the product gas and the raw gas can be exchanged with each other in the coiled-tube reactor / heat exchanger, thereby realizing self-heating of the raw gas and cooling of the product gas, the temperature control is simple, and the inlet heater, outlet cooler or inlet and outlet heat exchanger are omitted, shortening the process flow. Since the coiled-tube reactor and the coiled-tube heat exchanger / reactor are assembled, they can be disassembled when loading the catalyst and then assembled after loading, reducing the difficulty of loading the catalyst. At the same time, according to actual needs, based on different catalyst filling structures, chemical reactions with different characteristics can be achieved along the gas flow direction in the reactor, further optimizing the process and making the reactor suitable for more application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of a segmented temperature-controlled methanation reactor provided in one embodiment of the present application;

[0019] Figure 2 This is a schematic diagram of the internal filling of a shell-and-tube reactor / heat exchanger provided in one embodiment of the present application;

[0020] Figure 3 This is a schematic diagram of the internal filling of a shell-and-tube reactor / heat exchanger provided in another embodiment of the present application;

[0021] Figure 4 This is a schematic diagram of the internal filling of a shell-and-tube reactor / heat exchanger provided in another embodiment of the present application;

[0022] In the figure: 1-outer shell, 101-product gas outlet, 102-top cover, 103-outer cylinder, 104-raw gas inlet, 105-heat transfer medium inlet, 106-end, 107-heat transfer medium outlet;

[0023] 2-tube reactor / heat exchanger, 201-tube sheet, 202-gasket, 203-outer wall of tube reactor / heat exchanger, 204-draft guide tube, 205-central outer tube, 206-first heat exchange tube, 207-inner cylinder opening, 208-tube gas collecting plate, 209-flange;

[0024] 3-winding reactor, 301-annular manifold, 302-connecting pipe, 303-second heat exchange pipe, 304-central inner pipe, 305-outer wall of winding reactor, 306-gas distribution orifice plate;

[0025] N-ceramic ball, M1, M2, M3-methanation catalyst, C1-shift catalyst. DETAILED DESCRIPTION

[0026] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0027] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0028] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0029] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0030] like Figure 1 As shown, the segmented temperature-controlled methanation reactor provided in the embodiment of the present application comprises

[0031] The outer shell 1 has a raw gas inlet 104 and a heat transfer medium inlet 105 on its side wall, a product gas outlet 101 on the top, and a heat transfer medium outlet 107 on the bottom;

[0032] The shell-and-tube reactor / heat exchanger 2 is arranged in the outer shell 1, and the top is connected to the product gas outlet 101;

[0033] The coiled tubular reactor 3 is disposed in the outer shell 1, and the top is connected and communicated with the bottom of the tubular reactor / heat exchanger 2;

[0034] The inner shell is formed by axially connecting the outer wall 203 of the shell-and-tube reactor / heat exchanger and the outer wall 305 of the winding tube reactor. A sealing annular gap is formed between the outer shell 1 and the inner shell. The outer side of the sealing annular gap is connected to the raw gas inlet 104, and the inner side is connected to the inside of the shell-and-tube reactor / heat exchanger 2 through the inner cylinder opening 207 on the outer wall 203 of the shell-and-tube reactor / heat exchanger.

[0035] The central outer tube 205 is disposed in the shell-and-tube reactor / heat exchanger 2 and extends axially to the lower part of the coiled-tube reactor 3;

[0036] A heat transfer medium channel, used to connect the heat transfer medium inlet 105 and the heat transfer medium outlet 107;

[0037] The shell side of the coiled tubular reactor 3 is used to load ceramic balls and catalysts, and the tube side of the shell-and-tube reactor / heat exchanger 2 is used to load ceramic balls or ceramic balls and catalysts;

[0038] The raw gas enters the coiled tubular reactor 3 from the shell-and-tube reactor / heat exchanger 2, and the product gas is discharged from the product gas outlet 101 through the shell-and-tube reactor / heat exchanger 2; the heat transfer medium enters the coiled tubular reactor 3 through the heat transfer medium inlet 105 for heat exchange, and is discharged from the heat transfer medium outlet 107.

[0039] In application, the outer shell 1 includes an outer cylinder 103, a sealing head 106 for sealing the bottom of the outer cylinder 103, and a top cover 102 for sealing the top of the outer cylinder 103. The sealing head 106 is a hemispherical structure, and a product gas outlet 101 is arranged at the center of the top cover 102. The raw gas inlet 104 and the heat transfer medium inlet 105 are both arranged on the outer cylinder 103 and located at the lower part of the outer cylinder 103.

[0040] In application, the inner shell is a cylindrical structure formed by the axial tight connection between the outer wall 203 of the shell-and-tube reactor / heat exchanger and the outer wall 305 of the winding tube reactor. The bottom of the inner shell is provided with an outward annular flange, the outer edge of which is sealed with the inner wall of the outer cylinder 103, and the top of the inner shell is sealed by the tube sheet 201 of the shell-and-tube reactor / heat exchanger 2, thereby forming a sealed annular gap between the inner shell and the outer cylinder 103 of the outer shell 1. The shell-and-tube reactor / heat exchanger 2 and the winding tube reactor 3 are tightly connected axially by the flange 209. When the winding tube reactor 3 needs to be loaded with catalysts and porcelain balls, the shell-and-tube reactor / heat exchanger 2 can be removed by removing the flange 209, thereby forming an open cavity at the top of the winding tube reactor 3, which is convenient for rapid filling of the interior. When the inside of the coiled tubular reactor 3 is completely filled, the shell-and-tube reactor / heat exchanger 2 is connected to the coiled tubular reactor 3 via the flange 209 , and the tube sheet 201 is removed to fill the shell-and-tube reactor / heat exchanger 2 .

[0041] In application, there are two inner cylinder openings 207. The raw gas enters the sealing annular gap through the raw gas inlet 104, and then enters the inside of the shell-and-tube reactor / heat exchanger 2 through the inner cylinder openings 207 on the outer wall 203 of the shell-and-tube reactor / heat exchanger. The raw gas enters the inside of the central outer tube 205 through the first gas distribution hole on the central outer tube 205, and follows the central outer tube 205 to enter the bottom of the coiled tube reactor 3. The raw gas flows from bottom to top in the shell side of the coiled tube reactor 3, and in this process, it exchanges heat with the heat transfer medium in the tube side of the coiled tube reactor 3, and reacts under the action of the catalyst loaded in the shell side of the coiled tube reactor 3. Finally, the unreacted gas or the high-temperature product gas after the reaction rises into the tube side of the shell-and-tube reactor / heat exchanger 2, exchanges heat with the low-temperature raw gas that has just entered the shell side of the shell-and-tube reactor / heat exchanger 2, and is discharged along the product gas outlet 101.

[0042] The embodiment of the present application combines a coiled tubular reactor with a shell-and-tube heat exchanger / reactor, and combines the structural design inside the outer shell with the central outer tube, inner shell and other structural settings, so that the raw gas enters the coiled tubular reactor from the shell-and-tube reactor / heat exchanger, the product gas is discharged from the product gas outlet through the shell-and-tube reactor / heat exchanger, the heat transfer medium enters the coiled tubular reactor through the heat transfer medium inlet for heat exchange, and is discharged from the heat transfer medium outlet, so that the direction of the shell-and-tube gas and the heat transfer medium is reasonable, and the product gas and the raw gas can be exchanged with heat in the shell-and-tube reactor / heat exchanger, thereby realizing self-heating of the raw gas and cooling of the product gas, and the temperature control is simple, and the inlet heater, outlet cooler or inlet and outlet heat exchanger are omitted, shortening the process flow. Since the coiled tubular reactor and the shell-and-tube heat exchanger / reactor are assembled parts, they can be disassembled when loading the catalyst and then assembled after loading, which reduces the difficulty of loading the catalyst. At the same time, according to actual needs, based on different catalyst filling structures, chemical reactions with different characteristics can be achieved along the gas flow direction in the reactor, further optimizing the process and making the reactor suitable for more application scenarios.

[0043] In one embodiment, the shell-and-tube reactor / heat exchanger 2 also includes a tube sheet 201, a first heat exchange tube 206 and a tube-side gas collecting plate 208 located inside the outer wall 203 of the shell-and-tube reactor / heat exchanger. The tube sheet 201 is arranged at the top, and the tube-side gas collecting plate 208 is arranged at the bottom. The outer edges of the tube sheet 201 and the tube-side gas collecting plate 208 are respectively sealed and connected to the outer shell 1 and the inner wall of the shell-and-tube reactor / heat exchanger 2. One end of the first heat exchange tube 206 passes through the tube sheet 201 and is connected to the product gas outlet 101, and the other end passes through the tube-side gas collecting plate 208 and is connected to the top of the spiral tube reactor 3. The central outer tube 205 is arranged on the inner side of the first heat exchange tube 206, and the central outer tube 205 is connected to the inner cylinder opening 207.

[0044] In application, the tube sheet 201 is arranged at the top, and a gasket 202 is arranged between the tube sheet 201 and the outer cylinder 103, which is used to support and fix the first heat exchange tube 206 and ensure good sealing between the outside of the first heat exchange tube 206 and the product gas outlet 101. The tube side gas collecting plate 208 is arranged at the bottom, which is used to collect the rising gas of the winding tube reactor 3 and guide the gas flow to the shell and tube reactor / heat exchanger 2. The outer edges of the tube sheet 201 and the tube side gas collecting plate 208 are sealed and connected to the inner wall of the outer shell 1 and the shell and tube reactor / heat exchanger 2 respectively by welding or flange connection, ensuring the closure and controllability of the internal fluid path.

[0045] In addition, in order to facilitate maintenance and catalyst loading, the shell-and-tube reactor / heat exchanger 2 and the coiled tubular reactor 3 are tightly connected axially through the flange 209. When the coiled tubular reactor 3 needs to be loaded with catalyst and porcelain balls, the shell-and-tube reactor / heat exchanger 2 can be removed by removing the flange 209, thereby forming an open cavity for convenient and quick loading. After loading, the two parts are reconnected through the flange 209, and the shell-and-tube reactor / heat exchanger 2 is loaded by removing the tube sheet 201. This design not only improves the maintainability of the equipment, but also simplifies the catalyst replacement process and reduces downtime.

[0046] In one embodiment, the top end of the central outer tube 205 is sealed, and the tube wall of the central outer tube 205 is evenly provided with first gas distribution holes connecting the inside and outside of the tube wall along the radial direction.

[0047] In application, a sealing design is adopted at the top of the central outer tube 205 to prevent gas leakage and ensure safe operation. The tube wall of the central outer tube 205 is evenly provided with first gas distribution holes connecting the inside and outside of the tube wall along the radial direction. These distribution holes not only ensure that the gas can be evenly distributed around the central outer tube 205, increase the chance of gas contact with the heat exchange surface, but also improve the heat exchange efficiency. At the same time, the evenly distributed gas helps to reduce the generation of local hot spots and extend the service life of the equipment. The size and spacing of the first gas distribution holes are accurately calculated to ensure the best gas flow characteristics and heat transfer effects. In one embodiment, the shell-and-tube reactor / heat exchanger 2 also includes a guide tube 204, which is sleeved on the outside of the first heat exchange tube 206, and the bottom of the guide tube 204 is connected to the tube side gas collecting plate 208, and there is a gap between the top of the guide tube 204 and the tube plate 201 for the raw gas to pass through.

[0048] In application, the guide tube 204 is used to guide the raw gas to flow along the expected path to ensure that the gas is fully preheated before entering the reaction zone. In addition, the existence of the guide tube 204 can also protect the first heat exchange tube 206 from damage caused by direct contact with high-temperature gas. The gap between the guide tube 204 and the first heat exchange tube 206 is designed to be of appropriate width, which can ensure smooth flow of gas without affecting the heat exchange efficiency. The gap between the top of the guide tube 204 and the tube sheet 201 is also optimized to ensure that the gas can be fully preheated before entering the reaction zone, further improving the gas conversion rate under reaction conditions.

[0049] In one embodiment, the coiled tubular reactor 3 further includes an annular manifold 301, a connecting pipe 302, a second heat exchange pipe 303 and a central inner pipe 304 located within the outer wall 305 of the coiled tubular reactor. An annular manifold 301 is provided at the upper and lower parts of the coiled tubular reactor 3 around the central outer pipe 205, respectively. The central inner pipe 304 is nested in the central outer pipe 205. The annular manifold 301 located at the upper part is connected to the upper part of the central inner pipe 304 through the connecting pipe 302. The annular manifold 301 located at the lower part is connected to the heat transfer medium inlet 105. The upper and lower annular manifolds 301 are connected through the second heat exchange pipe 303. The bottom of the central inner pipe 304 extends and protrudes from the bottom of the outer shell 1. A heat transfer medium channel is formed between the annular manifold 301, the connecting pipe 302, the second heat exchange pipe 303 and the central inner pipe 304. The bottom of the central inner pipe 304 forms a heat transfer medium outlet 107.

[0050] In application, the design of the annular manifold 301 allows the heat transfer medium to be collected inside the device, which is different from the traditional design of collecting on the tube sheet and then extending outside the device, improving the defects of the traditional manifold method of messy manifold sections and interference with catalyst loading. The reasonable arrangement of the connecting pipe 302 and the second heat exchange pipe 303 ensures the uniform distribution of the heat transfer medium and avoids the problem of local overheating. The bottom of the central inner pipe 304 extends to the outside of the outer shell 1, so that the heat transfer medium can be discharged from the system more conveniently, and it also helps to monitor the status of the heat transfer medium and ensure the stable operation of the system.

[0051] In one embodiment, the wound tube reactor 3 also includes a gas distribution orifice plate 306, the axial hole of the gas distribution orifice plate 306 is tightly fitted at the lower part of the central outer tube 205, the outer edge of the gas distribution orifice plate 306 is sealed and connected to the inner wall of the outer shell 1, and the gas distribution orifice plate 306 is evenly provided with axially penetrating second gas distribution holes, and the bottom of the central outer tube 205 is provided with an axial opening below the gas distribution orifice plate 306.

[0052] In application, the presence of the gas distribution orifice plate 306 ensures uniform distribution of gas over the entire cross section, improves the contact effect between the raw gas and the catalyst, and thus improves the reaction efficiency and product quality. The second gas distribution holes on the gas distribution orifice plate 306 are carefully designed, and the aperture size and spacing take into account factors such as gas flow rate and pressure drop to achieve the best gas dispersion effect. In addition, the close fit between the gas distribution orifice plate 306 and the central outer tube 205 ensures the stability of the structure, avoids displacement or damage caused by gas impact, and thus extends the service life of the equipment.

[0053] In one embodiment, the bottom side wall of the central outer tube 205 is evenly provided with third gas distribution holes along the radial direction.

[0054] In application, the gas distribution orifice 306 can also be eliminated. In this case, the bottom of the central outer tube 205 is sealed with the axial opening below the central inner tube 304, and the third gas distribution holes are evenly arranged in the radial direction on the bottom side wall to ensure that the gas can flow evenly into the shell side of the coiled tube reactor 3, thereby improving the mixing effect of the gas and making the reaction more uniform. At the same time, these distribution holes are also conducive to the uniform distribution of heat and prevent local overheating. The size and spacing of the third gas distribution holes are optimized to ensure that the gas can smoothly enter the coiled tube reactor 3 without causing excessive pressure loss. In addition, the design of these distribution holes also takes into account the changes in gas flow under different operating conditions to meet the needs of various working conditions. In this way, the central outer tube 205 not only plays a role in gas distribution, but also enhances the stability and durability of the overall structure.

[0055] In application, when the gas distribution orifice plate 306 is provided, the filling area of ​​the coiled tubular reactor 3 is between the upper part of the gas distribution orifice plate 306 and the tube-side gas collecting plate 208. When the gas distribution orifice plate 306 is not provided, the filling area of ​​the coiled tubular reactor 3 is the entire area below the tube-side gas collecting plate 208.

[0056] In one embodiment, the shell-and-tube reactor / heat exchanger 2 is a shell-and-tube reactor or a shell-and-tube heat exchanger;

[0057] When the shell-and-tube reactor / heat exchanger 2 is a shell-and-tube reactor, the tube side of the shell-and-tube reactor / heat exchanger 2 is used to load porcelain balls and catalysts;

[0058] When the shell-and-tube reactor / heat exchanger 2 is a shell-and-tube heat exchanger, the tube path of the shell-and-tube reactor / heat exchanger 2 is used to load ceramic balls.

[0059] In the application, the shell-and-tube reactor / heat exchanger 2 is a shell-and-tube reactor or a shell-and-tube heat exchanger, which can be selected according to the object to be filled in the first heat exchange tube. When the objects to be filled are porcelain balls and catalysts, the shell-and-tube reactor / heat exchanger 2 adopts a shell-and-tube reactor. When the objects to be filled are only porcelain balls and no catalysts, the shell-and-tube reactor / heat exchanger 2 adopts a shell-and-tube heat exchanger.

[0060] This flexibility of the embodiments of the present application allows the function of the reactor to be adjusted according to different chemical reaction requirements to meet diverse process needs. For example, in a methanation reaction, if a higher single-pass conversion rate is required, a shell-and-tube reactor configuration can be selected; and in certain preheating or cooling processes, a shell-and-tube heat exchanger configuration can be selected. In addition, the selection of different filling materials can also optimize the reaction conditions. For example, the use of a specific type of catalyst can increase the reaction rate and product selectivity, while the ceramic balls provide additional surface area to promote the dispersion and mixing of the reactants. By flexibly configuring the shell-and-tube reactor / heat exchanger, the performance and economic benefits of the entire system can be significantly improved.

[0061] In one embodiment, when the tube side of the shell-and-tube reactor / heat exchanger 2 is used to load porcelain balls, the catalyst loaded in the shell side of the coiled tubular reactor 3 is the first methanation catalyst or the third methanation catalyst. When the catalyst loaded in the shell side of the coiled tubular reactor 3 is the third methanation catalyst, a shift catalyst is loaded between the outer wall 203 of the shell-and-tube reactor / heat exchanger and the draft tube 204.

[0062] When the tube side of the shell-and-tube reactor / heat exchanger 2 is used to load ceramic balls and catalysts, the catalyst loaded in the shell side of the wound tube reactor 3 is the first methanation catalyst, and the catalyst loaded in the tube side of the shell-and-tube reactor / heat exchanger 2 is the second methanation catalyst.

[0063] In application, when the tube side of the shell-and-tube reactor / heat exchanger 2 is filled with ceramic balls and catalysts, the ceramic balls and catalysts are alternately distributed along the axial direction;

[0064] When the conversion catalyst is loaded between the outer wall 203 of the shell-and-tube reactor / heat exchanger and the draft tube 204, the ceramic balls and the catalyst are alternately distributed in the radial direction, and the ceramic ball layer and the catalyst layer are separated by a cylindrical separation net;

[0065] The ceramic balls and catalysts filled in the shell side of the wound tubular reactor 3 are alternately distributed along the axial direction.

[0066] This alternating distribution method effectively increases the reaction rate. The ceramic balls can provide additional surface area to promote the dispersion of reactants, while the catalyst layer can catalyze the reaction more effectively. The use of the separator ensures that different materials will not mix, maintaining their respective characteristics and activities, thereby improving the overall reaction efficiency and product quality. The above-mentioned catalyst and ceramic ball loading scheme can achieve the optimal reaction environment and improve production efficiency and product quality.

[0067] Embodiment 1

[0068] The embodiment of the present application is described by taking the shell-and-tube reactor / heat exchanger 2 as a shell-and-tube heat exchanger, in which only porcelain balls are filled in the tube side of the shell-and-tube heat exchanger, and porcelain balls and the first methanation catalyst are filled in the shell side of the coiled tubular reactor 3. The embodiment of the present application is applicable to a highly exothermic reaction system such as methanation, where the raw gas temperature is lower than 200°C, the carbon concentration (CO+CO2) is 3-10%, and the raw gas is preheated by the high-temperature product gas at the outlet of the coiled tubular reactor 3.

[0069] like Figure 2 As shown, the shell side of the winding tube reactor 3 is filled with porcelain balls and the first methanation catalyst, i.e., the methanation catalyst M1 (specifically, a 3mm*3mm cylindrical catalyst with an active component nickel oxide loading of 15-25wt%). Among them, the porcelain balls and the methanation catalyst M1 are alternately distributed along the axial direction. For example, the top layer and the bottom layer may be porcelain balls, and the middle layer is the methanation catalyst M1. For a reactor with a gas distribution orifice 306, the filling range is between the gas distribution orifice 306 and the tube side gas collecting plate 208. For a reactor without a gas distribution orifice 306, the filling range is the entire area below the tube side gas collecting plate 208. The first heat exchange tube 206 of the shell-and-tube heat exchanger is only filled with porcelain balls, and the specific filling range is between the tube side gas collecting plate 208 and the tube sheet 201.

[0070] The raw gas enters the sealing annular gap from the raw gas inlet 104, enters the shell side of the shell-and-tube heat exchanger from the inner cylinder opening 207, passes through the first heat exchange tube 206 in the radial direction, enters the interior of the central outer tube 205 through the first gas distribution hole on the wall of the central outer tube 205, and enters the bottom of the gas distribution plate 306 axially downward (for a reactor without a gas distribution plate 306, directly enters the bottom area of ​​the coiled tubular reactor 3 through the third gas distribution hole at the bottom of the central outer tube 205), enters the shell side of the coiled tubular reactor 3 from the bottom to react with the catalyst, and the product gas after the reaction enters the tube side of the shell-and-tube heat exchanger to preheat the raw gas in the shell side. The product gas leaves the reactor from the reactor outlet 101.

[0071] Saturated water with a pressure of 3.5 MPa enters the tube side of the coiled tubular reactor 3 from the heat transfer medium inlet 105, and takes away the reaction heat in the shell side of the coiled tubular reactor 3. The saturated water passes through the annular manifold 301, the second heat exchange tube 303, the connecting tube 302, and the central inner tube 304 in sequence, and finally flows out of the reactor from the heat transfer medium outlet 107.

[0072] Embodiment 2

[0073] The embodiment of the present application is described by taking the shell-and-tube reactor / heat exchanger 2 as a shell-and-tube reactor, the tube side of the shell-and-tube reactor is filled with porcelain balls and a second methanation catalyst, and the shell side of the coiled tubular reactor 3 is filled with porcelain balls and a first methanation catalyst. The embodiment of the present application is applicable to a highly exothermic reaction system such as methanation, where the feed gas temperature is lower than 150°C and the carbon concentration is 10-15%. Due to the high carbon concentration of the feed gas, the coiled tubular reactor 3 cannot completely convert the carbon, and further reaction is required in the shell-and-tube reactor.

[0074] like Figure 3 As shown, the shell side of the winding tube reactor 3 at the lower part of the reactor is filled with a first methanation catalyst of ceramic balls, i.e., a methanation catalyst M1 (specifically, a cylindrical catalyst of 3mm*3mm, whose active component nickel oxide loading is 15-25wt%). Among them, the ceramic balls and the methanation catalyst M1 are alternately distributed along the axial direction, for example, the top layer and the bottom layer can be ceramic balls, and the middle layer is the methanation catalyst M1. For a reactor with a gas distribution orifice 306, the filling range is between the gas distribution orifice 306 and the tube side gas collecting plate 208. For a reactor without a gas distribution orifice 306, the filling range is the entire area below the tube side gas collecting plate 208. The shell-and-tube reactor at the upper part of the reactor is filled with ceramic balls and a second methanation catalyst, i.e., a methanation catalyst M2 (specifically, a cylindrical catalyst of 3mm*3mm, whose active component nickel oxide loading is 5-15wt%), in the tube side of the first heat exchange tube 206, and the specific filling range is between the tube side gas collecting plate 208 and the tube sheet 201.

[0075] The flow direction of the raw gas and product gas is the same as that of Example 1, except that the raw gas that has not been fully reacted in the shell side of the bypass reactor 3 enters the tube side of the shell-and-tube reactor through the opening of the tube side gas collecting plate 208 and the first heat exchange tube for further reaction, which not only effectively improves the single-pass conversion rate, but also further preheats the cold raw gas through the reaction heat of the shell-and-tube reactor.

[0076] Embodiment 3

[0077] The embodiment of the present application takes the shell-and-tube reactor / heat exchanger 2 as a shell-and-tube heat exchanger, the tube side of the shell-and-tube heat exchanger is only filled with porcelain balls, the shell-and-tube heat exchanger outer wall 203 and the guide tube 204 are filled with a shift catalyst, and the shell side of the wound tube reactor 3 is filled with porcelain balls and a third methanation catalyst as an example for explanation. The embodiment of the present application is applicable to continuous multi-stage reactions, that is, the raw gas of the latter stage reaction is the product gas of the previous stage reaction, for example, in the coal-to-methanol process, after the water gas is subjected to a shift reaction to adjust the hydrogen-carbon ratio, its product gas is purified and reacted as a methanol synthesis raw gas.

[0078] like Figure 4 As shown, the shell side of the winding reactor 3 is filled with porcelain balls and a third methanation catalyst, namely, a sulfur-resistant methanation catalyst M3 (specifically, a cylindrical catalyst of 3 mm*3 mm, the active component of which is molybdenum oxide), wherein the porcelain balls and the methanation catalyst M3 are alternately distributed along the axial direction, for example, the top layer and the bottom layer may be porcelain balls, and the middle layer is the methanation catalyst M3. For a reactor with a gas distribution orifice 306, the filling range is between the gas distribution orifice 306 and the tube side gas collecting plate 208. For a reactor without a gas distribution orifice 306, the filling range is the entire area below the tube side gas collecting plate 208. The first heat exchange tube 206 of the shell-and-tube heat exchanger in the upper part of the reactor is only filled with porcelain balls, and the specific filling range is between the tube side gas collecting plate 208 and the tube sheet 201. The area between the outer wall 203 of the shell-and-tube reactor / heat exchanger and the guide tube 204 is radially filled with 1 layer of porcelain balls, 1 layer of conversion catalyst C1 (specifically 3mm*4mm cylindrical catalyst, cobalt-molybdenum-based sulfur-resistant conversion catalyst), and 1 layer of porcelain balls, and each layer is separated by a cylindrical separator net.

[0079] The raw gas composition is 25% carbon concentration, 15% hydrogen, 60% water, and the temperature is 200° C. The raw gas enters the sealing annular gap from the raw gas inlet 104, enters the shell side of the shell-and-tube heat exchanger from the inner cylinder opening 207, passes through the catalyst bed in the radial direction and undergoes a shift reaction, fine-tuning the hydrogen-carbon ratio, and then the product gas after the reaction enters the coiled tubular reactor 3 for a methanation reaction.

[0080] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A segmented temperature-controlled methanation reactor, characterized in that: include The outer shell (1) has a raw gas inlet (104) and a heat transfer medium inlet (105) on its side wall, a product gas outlet (101) on its top, and a heat transfer medium outlet (107) on its bottom; A shell-and-tube reactor / heat exchanger (2) is disposed in the outer shell (1), and the top of the tube side is connected to the product gas outlet (101); A wound tube reactor (3) is arranged in the outer shell (1), and the top of the shell side is connected and communicated with the bottom of the tube side of the shell-and-tube reactor / heat exchanger (2); An inner shell is formed by axially connecting the outer wall (203) of the shell-and-tube reactor / heat exchanger and the outer wall (305) of the winding tube reactor, a sealing annular gap is formed between the outer shell (1) and the inner shell, the outer side of the sealing annular gap is connected to the raw gas inlet (104), and the inner side is connected to the inside of the shell-and-tube reactor / heat exchanger (2) through the inner cylinder opening (207) on the outer wall (203) of the shell-and-tube reactor / heat exchanger; A central outer tube (205) is disposed in the shell-and-tube reactor / heat exchanger (2) and extends axially to the lower part of the coiled-tube reactor (3); A heat transfer medium channel, used to connect the heat transfer medium inlet (105) and the heat transfer medium outlet (107); The shell side of the coiled tubular reactor (3) is used to load ceramic balls and catalysts, and the tube side of the tubular reactor / heat exchanger (2) is used to load ceramic balls or ceramic balls and catalysts; The raw gas enters the coiled tubular reactor (3) from the shell-and-tube reactor / heat exchanger (2), and the product gas is discharged from the product gas outlet (101) through the shell-and-tube reactor / heat exchanger (2); the heat transfer medium enters the coiled tubular reactor (3) through the heat transfer medium inlet (105) for heat exchange, and is discharged from the heat transfer medium outlet (107).

2. The segmented temperature-controlled methanation reactor according to claim 1, characterized in that: The shell-and-tube reactor / heat exchanger (2) further comprises a tube sheet (201), a first heat exchange tube (206) and a tube-side gas collecting plate (208) located inside the outer wall (203) of the shell-and-tube reactor / heat exchanger, wherein the tube sheet (201) is arranged at the top, and the tube-side gas collecting plate (208) is arranged at the bottom, and the outer edges of the tube sheet (201) and the tube-side gas collecting plate (208) are respectively sealed and connected to the inner wall of the outer shell (1) and the shell-and-tube reactor / heat exchanger (2), one end of the first heat exchange tube (206) passes through the tube sheet (201) and is connected to the product gas outlet (101), and the other end passes through the tube-side gas collecting plate (208) and is connected to the top of the coiled tubular reactor (3), and the central outer tube (205) is arranged inside the first heat exchange tube (206), and the central outer tube (205) is connected to the inner cylinder opening (207).

3. The segmented temperature-controlled methanation reactor according to claim 2, characterized in that: The top end of the central outer tube (205) is sealed, and the tube wall of the central outer tube (205) is evenly provided with first gas distribution holes connecting the inside and outside of the tube wall along the radial direction.

4. The segmented temperature-controlled methanation reactor according to claim 2, characterized in that: The shell-and-tube reactor / heat exchanger (2) further comprises a draft tube (204), wherein the draft tube (204) is sleeved outside the first heat exchange tube (206), the bottom of the draft tube (204) is connected to the tube-side gas collecting plate (208), and a gap is provided between the top of the draft tube (204) and the tube plate (201) for the raw gas to pass through.

5. The segmented temperature-controlled methanation reactor according to claim 1, characterized in that: The coiled tubular reactor (3) further comprises an annular manifold (301), a connecting pipe (302), a second heat exchange pipe (303) and a central inner pipe (304) located within the outer wall (305) of the coiled tubular reactor. An annular manifold (301) is provided at the upper and lower parts of the coiled tubular reactor (3) surrounding the central outer pipe (205). The central inner pipe (304) is nested in the central outer pipe (205). The annular manifold (301) located at the upper part is connected to the upper part of the central inner pipe (304) through a connecting pipe ( The annular manifold (301) is connected to the heat transfer medium inlet (105), the upper and lower annular manifolds (301) are connected via a second heat exchange tube (303), the bottom of the central inner tube (304) extends and protrudes from the bottom of the outer shell (1), a heat transfer medium channel is formed between the annular manifold (301), the connecting tube (302), the second heat exchange tube (303) and the central inner tube (304), and the bottom of the central inner tube (304) forms the heat transfer medium outlet (107).

6. The segmented temperature-controlled methanation reactor according to claim 1, characterized in that: The coiled tubular reactor (3) further comprises a gas distribution orifice plate (306), the axial hole of the gas distribution orifice plate (306) being tightly fitted in the lower part of the central outer tube (205), the outer edge of the gas distribution orifice plate (306) being sealedly connected to the inner wall of the outer shell (1), the gas distribution orifice plate (306) being evenly provided with axially penetrating second gas distribution holes, and the bottom of the central outer tube (205) being provided with an axial opening below the gas distribution orifice plate (306).

7. The segmented temperature-controlled methanation reactor according to claim 1, characterized in that: The bottom side wall of the central outer tube (205) is evenly provided with third gas distribution holes along the radial direction.

8. The segmented temperature-controlled methanation reactor according to claim 1, characterized in that: The shell-and-tube reactor / heat exchanger (2) is a shell-and-tube reactor or a shell-and-tube heat exchanger; When the shell-and-tube reactor / heat exchanger (2) is the shell-and-tube reactor, the shell side of the shell-and-tube reactor / heat exchanger (2) is used to load ceramic balls and catalysts; When the shell-and-tube reactor / heat exchanger (2) is the shell-and-tube heat exchanger, the shell side of the shell-and-tube reactor / heat exchanger (2) is used to load ceramic balls.

9. The segmented temperature-controlled methanation reactor according to claim 4, characterized in that: When the tube side of the shell-and-tube reactor / heat exchanger (2) is used to load porcelain balls, the catalyst loaded in the shell side of the coiled tubular reactor (3) is the first methanation catalyst or the third methanation catalyst; when the catalyst loaded in the shell side of the coiled tubular reactor (3) is the third methanation catalyst, a shift catalyst is loaded between the outer wall (203) of the shell-and-tube reactor / heat exchanger and the draft tube (204); When the tube side of the shell-and-tube reactor / heat exchanger (2) is used to load porcelain balls and catalysts, the catalyst loaded in the shell side of the coiled tubular reactor (3) is a first methanation catalyst, and the catalyst loaded in the tube side of the shell-and-tube reactor / heat exchanger (2) is a second methanation catalyst.

10. The segmented temperature-controlled methanation reactor according to claim 9, characterized in that: When the tube side of the shell-and-tube reactor / heat exchanger (2) is filled with ceramic balls and catalysts, the ceramic balls and catalysts are alternately distributed along the axial direction; When a conversion catalyst is loaded between the outer wall (203) of the shell-and-tube reactor / heat exchanger and the guide tube (204), the ceramic balls and the catalyst are alternately distributed in the radial direction, and the ceramic ball layer and the catalyst layer are separated by a cylindrical separation net; The ceramic balls and the catalyst filled in the shell side of the wound tube reactor (3) are alternately distributed along the axial direction.

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