Gas distributor, hydrocarbon ammoxidation fluidized bed reactor and hydrocarbon ammoxidation method

Abstract

The invention discloses a gas distributor, a hydrocarbon ammoxidation fluidized bed reactor and a hydrocarbon ammoxidation method, the gas distributor comprises a branch pipe and a plurality of branch pipes tangentially communicated with the branch pipe, the branch pipes are distributed at intervals along the axial direction of the branch pipe, each branch pipe is provided with a plurality of nozzles, a rotational flow component is arranged in the branch pipe, and the nozzles are arranged in the rotational flow component. The rotational flow component enables gas entering the branch pipe to form axial rotational flow, and the rotational flow gas enters the branch pipe in the tangential direction of the branch pipe. The device has the advantages of eliminating gas bias flow and strengthening uniform distribution of gas flow, and the yield of ammoxidation products can be further improved.

Description

Technical Field

[0001] The invention relates to a gas distributor, a hydrocarbon ammoxidation fluidized bed reactor and a hydrocarbon ammoxidation method. Background Art

[0002] Dendritic tubular gas distributors are suitable for large fluidized bed reactors and are widely used in industry. Dendritic tubular distributors are composed of main pipes, branch pipes, branch pipes and nozzles. Branch pipes of different lengths are connected to each other, and the nozzles are arranged in a certain way so that the nozzles are evenly distributed on the cross section of the fluidized bed reactor. Another feature of the tubular distributor is that the ends of the main pipes, branch pipes and branch pipes are free ends, which can better cope with the thermal expansion caused by temperature differences in fluidized bed reactors. It is especially suitable for large reactors and processes that require multiple gas feeds.

[0003] In the existing tree-like tubular distributor technology, the simple vertical connection of branch pipes causes a large range of deviation flow in the pipe connection area during the step-by-step distribution flow of the gas in the three-level structure of branch pipe-branch pipe-nozzle, which seriously disrupts the uniform flow of the airflow. At the same time, a large number of eddies are formed locally, causing additional flow resistance, resulting in energy loss, and ultimately reducing production efficiency. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems of poor gas distribution uniformity and low raw material utilization caused by the bias flow of the tubular distributor in the prior art, and to provide a gas distributor, a hydrocarbon ammoxidation fluidized bed reactor and a hydrocarbon ammoxidation method, which have the advantages of eliminating gas bias flow and strengthening the uniform distribution of gas flow, and can further improve the yield of the ammoxidation product.

[0005] In order to achieve the above-mentioned object, the present invention provides a gas distributor, including a branch pipe and a branch pipe tangentially connected to the branch pipe, wherein the branch pipe is provided with a plurality of branch pipes and distributed at intervals along the axial direction of the branch pipe, each branch pipe is provided with a plurality of nozzles, and a swirl component is provided in the branch pipe, wherein the swirl component causes the gas entering the branch pipe to form an axial swirl, and the swirl gas enters the branch pipe tangentially along the branch pipe. The swirl component provided in the branch pipe and the tangentially provided branch pipe realize the flow coupling of the tangential swirl of the gas and the tangential swirl, and has the effect of eliminating bias flow and strengthening the uniform distribution of gas.

[0006] A second aspect of the present invention provides a fluidized bed reactor for hydrocarbon ammonia oxidation, which comprises a reaction chamber and a cyclone separator arranged in the reaction chamber and connected to a product discharge port, wherein a first gas distributor and a second gas distributor are arranged at intervals below the cyclone separator, wherein the first gas distributor is connected to a first feed pipeline for feeding a hydrocarbon source and an ammonia source, and the second gas distributor is connected to a second feed pipeline for feeding an oxygen-containing gas; wherein the first gas distributor and / or the second gas distributor is configured as the gas distributor described in the present invention.

[0007] The third aspect of the present invention provides a hydrocarbon ammoxidation method, which is carried out in the hydrocarbon ammoxidation fluidized bed reactor of the present invention, comprising the following:

[0008] The second gas distributor is fed with oxygen-containing gas to carry out catalyst lattice oxygen supplementation treatment; the first gas distributor is fed with a mixed gas containing a hydrocarbon source and an ammonia source, the mixed gas forms a vortex in the branch pipe of the first gas distributor and enters the branch pipe, is sprayed out from the nozzle and contacts with the oxygen-containing gas carrying the catalyst to generate a nitrile-containing product, and the nitrile-containing product is discharged from the product discharge port after the catalyst is separated by the cyclone separator.

[0009] Through the above technical solution, the present invention provides a swirl component at the inlet end of the branch pipe to make the gas form a swirl and tangential motion and strengthen the premixing of the gas. Furthermore, a rectifying structure is provided to couple and receive the swirl gas flow to eliminate the gas distributor bias flow, strengthen the uniform distribution of the gas flow, make the gas distribution performance of the gas distributor closer to the ideal gas distribution state, and further, can improve the yield of the ammonia oxidation product. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure of a gas distributor according to an embodiment of the present invention;

[0011] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle branch pipe-branch pipe;

[0012] Figure 3 It is a schematic structural diagram of a branch pipe of a gas distributor of the present invention equipped with a swirl component in a cross-sectional direction;

[0013] Figure 4 It is a schematic structural diagram of a swirl component according to an embodiment of the present invention;

[0014] Figure 5 yes Figure 4 A top view of

[0015] Figure 6 1 is a schematic structural diagram of a fluidized bed reactor for hydrocarbon ammoxidation according to an embodiment of the present invention;

[0016] Figure 7 It is a gas distributor in the prior art.

[0017] Description of Reference Numerals

[0018] 1 gas collecting chamber; 2 reaction chamber; 3 heat exchange element; 4 first gas distributor; 5 hydrocarbon source; 6 ammonia source; 7 second gas distributor; 8 oxygen-containing gas; 9 second feed pipeline; 10 cyclone separator; 11 product outlet; 12 main pipe; 13 branch pipe; 14 branch pipe; 15 swirl component; 16 rectification structure; 17 nozzle. DETAILED DESCRIPTION

[0019] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0020] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0021] In the present invention, unless otherwise specified, directional words such as "up, down, left, right" generally refer to up, down, left, right as shown in the reference drawings; "inside and outside" refer to inside and outside relative to the outline of each component itself.

[0022] The existing tubular distributor nozzle is mostly a short tube that is simply connected to the branch pipe in a normal direction. When the airflow enters the nozzle from the branch pipe, it will cause serious deviation due to the sudden change of flow direction, and even cause catalyst backflow due to local pressure reduction. In the ammoxidation reaction of acrylonitrile and aromatics, which currently uses tubular distributors, the current research focus is on catalysts and supporting processes, and there is little research on the gas distribution performance of tubular distributors and their nozzle accessories.

[0023] In view of the defects of the above-mentioned prior art, the present invention proposes a gas distributor, a hydrocarbon ammoxidation fluidized bed reactor and a hydrocarbon ammoxidation method through a large amount of CFD simulation and flow field analysis in the early stage. The gas distribution performance of the gas distributor of the present invention is obviously closer to the ideal gas distribution state, and has the effect of strengthening the uniform gas distribution performance of the tubular distributor, and further improving the yield of the ammoxidation product.

[0024] like Figure 1-Figure 2As shown, in order to solve the problem of serious deviation of gas flow in a tubular distributor in the prior art, the present invention discloses a gas distributor, including a branch pipe 13 and a branch pipe 14 tangentially connected to the branch pipe 13, wherein a plurality of branch pipes 14 are provided and are distributed at intervals along the axial direction of the branch pipe 13, each branch pipe 14 is provided with a plurality of nozzles 17, and a swirl component 15 is provided in the branch pipe 13, wherein the swirl component 15 enables the gas entering the branch pipe 13 to form an axial swirl, and the swirl gas enters the branch pipe 14 along the tangent direction of the branch pipe 13, thereby eliminating the deviation of the gas distributor. In particular, when the present invention is applied to distributing two or more gases, for example, a mixed gas of a hydrocarbon source and ammonia, the formation of swirl gas in the present invention also has the advantage of enhancing gas premixing.

[0025] In some embodiments of the present invention, Figure 1-Figure 5 As shown, the swirl component 15 is arranged at one end of the gas entering the branch pipe, including a guide center body 19 arranged in the branch pipe 13 and a plurality of guide blades 18 arranged at equal intervals along the peripheral wall of the guide center body 19. In this way, the gas entering the branch pipe 13 passes through the swirl component 15 to form a swirl, as shown in FIG. Figure 4-Figure 5 As shown, in some embodiments of the present invention, the guide center body 19 is configured as a cylindrical body with convex curved surfaces at both axial ends, and a plurality of guide blades are evenly spaced and distributed on the outer peripheral wall of the cylindrical body.

[0026] Through simulation and flow field analysis, in some embodiments of the present invention, the number of guide blades 18 in the present invention is 6 to 12, each guide blade 18 is smoothly connected to the guide center body 19, and the width of each guide blade 18 is 0.2 to 0.8 times the radius of the branch pipe 13. Figure 5 As shown, when the outlet angle θ is less than 60° and the distance between the outlet end and the nearest branch pipe 14 on the branch pipe 13 is 0.1 to 3 times the diameter of the branch pipe 13, the gas flow can be swirled at the cost of a smaller increase in flow resistance, and tangential motion occurs, thereby strengthening the premixing of the gas raw materials and preparing for the subsequent gas to flow into the branch pipe 14 along the tangential distribution, thereby suppressing gas deviation and strengthening the effect of uniform gas distribution; in some embodiments of the present invention, the guide vane 18 is configured to be a smooth wavy shape along its own length.

[0027] In some embodiments of the present invention, Figure 1-Figure 3 As shown, in order to better receive the swirl from the branch pipe 13, reduce the flow resistance, and enhance the effect of uniform distribution of the airflow, in the present invention, on the basis of setting the swirl component 15, each branch pipe 14 is connected to the branch pipe 13 through a rectifying structure 16 that can reduce the airflow flow resistance. The rectifying structure 16 is configured as a rectifying pipe, one end of the rectifying pipe extends along the peripheral wall of the branch pipe 13 and an air port is opened on the branch pipe wall at the extension, and the other end extends toward the branch pipe and is connected to the end of the branch pipe 14.

[0028] In some embodiments of the present invention, the ratio of the cross-sectional area of ​​one end of the rectifier tube connected to the branch pipe 13 to the cross-sectional area of ​​one end connected to the branch pipe 14 is 0.1 to 15. Within this area ratio range, the flow rate of the airflow entering the branch pipe 14 can be better regulated, and the additional flow resistance can be reduced while ensuring uniform gas flow.

[0029] In some embodiments of the present invention, Figure 3 As shown, the rectifier tube is configured as a tapered tube whose cross-sectional area gradually decreases from the branch tube 14 to the branch tube 13. One end of the tapered tube extends along the peripheral wall of the branch tube, and the port at the other end is connected to the port of the branch tube.

[0030] In the present invention, the cross-section of the rectification structure is circular, elliptical or rectangular. The above-mentioned flow cross-section structure can better realize the smooth transition of the pipe connection position in the tangential connection configuration of the branch pipe 13 and the branch pipe 14, optimize the uniform distribution of gas, and reduce the gas flow resistance.

[0031] In some embodiments of the present invention, the cross-section of the rectifying structure 16 is elliptical, and the ratio of the major axis to the minor axis of the cross-section of the ellipse is 1.2 to 8; within this range, when the rectifying structure is coupled to receive the tangential swirl gas, the rectifying structure can further reduce the additional flow resistance.

[0032] In some other embodiments of the present invention, the cross-section of the rectifying structure 16 is rectangular, and the ratio of the cross-section to the side length of the rectangle is 0.1 to 8. Within this range, when the rectifying structure is coupled to receive the tangential swirl gas, the rectifying structure can better suppress turbulence.

[0033] In the present invention, Figure 1 As shown, the gas distributor includes a vertically installed main pipe 12 and a branch pipe 13 connected to the main pipe 12 . A plurality of branch pipes 13 are provided and are laterally distributed on the side of the main pipe 12 .

[0034] In the present invention, in order to better receive the swirl flow from the branch pipe 13, as Figure 3 As shown, along the axial direction of the branch pipe 13, multiple branch pipes 14 are alternately arranged at both sides of the branch pipe 13, and the length of the branch pipe 14 on the same side decreases from the middle of the branch pipe 13 to both ends.

[0035] In the present invention, in order to ensure that the branch pipes 14 on both sides can couple and receive the tangential swirl airflow in the same direction and enhance the uniformity of the airflow, in some embodiments of the present invention, Figure 4 As shown, along the axial direction of the branch pipe 13, the orthographic projections of the rectifying pipes of two adjacent branch pipes on the radial cross section of the branch pipe are arranged in a centrally symmetrical manner.

[0036] The present invention is based on the above-mentioned gas distributor. Figure 6As shown, a hydrocarbon ammonia oxidation fluidized bed reactor is also disclosed, the hydrocarbon ammonia oxidation fluidized bed reactor comprises a reaction chamber 2 and a heat exchanger 3 (e.g., a heat exchange tube connected to a heat exchanger) disposed in the reaction chamber 2 and a cyclone separator 10 connected to a product discharge port 11 through a gas collecting chamber 1 disposed at the top of the reaction chamber, a first gas distributor 4 and a second gas distributor 7 are arranged below the cyclone separator 10, the first gas distributor 4 is connected to a first feed line for feeding a hydrocarbon source 5 and an ammonia source 6, and the second gas distributor 7 is connected to a second feed line 9 for feeding an oxygen-containing gas 8; wherein the first gas distributor 4 and / or the second gas distributor 7 adopt the aforementioned gas distributor of the present invention, and the nozzles of the two are arranged facing each other. The hydrocarbon ammonia oxidation fluidized bed reactor of the present invention has the effect of improving the yield of ammonia oxidation products.

[0037] The present invention adopts the existing technology to pre-load the catalyst above the second gas distributor 7. In order to save costs while meeting the performance requirements, the second gas distributor 7 can be a gas distribution plate. In some embodiments of the present invention, the ratio of the vertical distance between the first gas distributor 4 and the second gas distributor 7 to the height of the hydrocarbon ammonia oxidation fluidized bed reactor is 0.01 to 0.1, which improves the uniformity and utilization of the raw material distribution, thereby increasing the yield of the ammonia oxidation product.

[0038] The present invention discloses a hydrocarbon ammoxidation method, which is carried out in a hydrocarbon ammoxidation fluidized bed reactor of the present invention and comprises the following steps:

[0039] An oxygen-containing gas 8 is fed into the second gas distributor 7 to perform catalyst lattice oxygen supplementation treatment; a mixed gas containing a hydrocarbon source 5 and an ammonia source 6 is fed into the first gas distributor 4, the mixed gas forms a vortex in the branch pipe 13 of the first gas distributor 4 and enters the branch pipe 14, is sprayed out from the nozzle 17 and contacts with the oxygen-containing gas carrying the catalyst to generate a nitrile-containing product, the nitrile-containing product is separated from the catalyst by the cyclone separator 10 and discharged from the product discharge port 11, the separated catalyst is returned to the reaction zone through the feed leg of the cyclone separator, the nitrile effluent collected from the product discharge port 11 is treated in the prior art to obtain a product gas, for example, it is received by a condensation and / or solvent absorption method, and then refined by distillation or recrystallization to obtain a product gas.

[0040] The hydrocarbon ammonia oxidation method proposed in the present invention makes the mixed gas entering the reaction chamber significantly closer to the ideal gas distribution state, avoids serious deviation caused by drastic change in flow direction when the gas flow enters the nozzle from the branch pipe, and even catalyst backflow caused by local decompression, which has the effect of improving the yield of the ammonia oxidation product.

[0041] The mixed gas containing the hydrocarbon source 5 and the ammonia source 6 includes hydrocarbons and / or hydrocarbon derivatives and ammonia, and the oxygen-containing gas is selected from air.

[0042] In the present invention, the reaction conditions include: reaction temperature of 300-500° C., pressure of 0.01-0.2 MPa, and gas superficial velocity of 0.1-0.8 m / s.

[0043] In some embodiments of the present invention, the non-uniformity of the nozzle flow rate of the first gas distributor 4 and / or the second gas distributor 7 is 0 to 0.35. It should be noted that the non-uniformity calculation method in the present invention is: Where n is the number of nozzles (for example, n can be 200-5000), u i is the nozzle discharge flow rate, is the average flow rate discharged from the nozzle.

[0044] In the specific implementation process of the present invention, only the inlet flow of the main pipe 12 is controlled (generally controlled to be 5×10 -3 -80m 3 / h), and the flow rate of each nozzle can be naturally formed by setting the device of the present invention, and the technical solution of the present invention is adopted, u i The range is 0-10m 3 / h, The range interval is 1×10 -6 -0.8m 3 / h. Thus, the unevenness of the gas distributor spray flow rate of the present invention can reach 0 to 0.35.

[0045] In the present invention, the molar ratio of the hydrocarbon source in terms of hydrocarbon groups, the ammonia source in terms of amino groups and the oxygen-containing gas in terms of oxygen molecules is 1:1-10:(10-40).

[0046] In the present invention, the hydrocarbon source preferably includes one or more of toluene, p-chlorotoluene, o-chlorotoluene, o-xylene, m-xylene, p-xylene, dichlorotoluene, trichlorotoluene or 4-nitro-o-xylene.

[0047] The present invention solves the defects of poor gas distribution uniformity and low raw material utilization rate in the prior art of hydrocarbon ammoxidation.

[0048] It should be noted that the hydrocarbon source, ammonia source, catalyst, etc. in the present invention can be obtained from the market or prepared by conventional methods in the art. The specific types have no effect on the technical effects of the present invention, and the present invention will not elaborate on this.

[0049] The advantages of the present invention will be described below by way of examples, but the present invention is not limited thereto.

[0050] The following examples adopt Figure 1 to Figure 6The hydrocarbon ammonia oxidation fluidized bed reactor shown is carried out, which includes a heat exchange tube arranged in a reaction chamber 2 and a cyclone separator 10 connected to a product discharge port 11 through a gas collecting chamber 1 arranged at the top of the reaction chamber. A first gas distributor 4 and a second gas distributor 7 are arranged below the cyclone separator 10. The first gas distributor 4 is connected to a first feed line for feeding a hydrocarbon source 5 and an ammonia source 6 and the nozzle faces downward. The second gas distributor 7 is configured as a gas distribution plate. The bottom end of the reaction chamber is configured as a downwardly tapered bottom and penetrates the side to connect to a second feed line for feeding an oxygen-containing gas 8. The opening of the second feed line in the reaction chamber faces downward, so that the oxygen-containing gas entering the reaction chamber is reflected and dispersed through the gas distribution plate by the tapered bottom wall to further disperse and contact the hydrocarbon source 5 and the ammonia source 6.

[0051] The first gas distributor 4 includes a main pipe 12 and branch pipes 13 uniformly arranged on the side of the main pipe 12, and multiple branch pipes 14 are evenly and staggeredly arranged on both sides of each branch pipe 13, and the length of the branch pipes 14 on the same side decreases from the middle of the branch pipe 13 to both ends; wherein, of the two adjacent branch pipes 14 on the branch pipe 13, one branch pipe 14 is tangent to the top end of the branch pipe 13, and the other branch pipe 14 is tangent to the bottom end of the branch pipe 13; each branch pipe 14 is connected to the branch pipe 13 through a rectifying structure 16, and the rectifying structure 16 is configured as a rectifying pipe, one end of the rectifying pipe is tangentially connected to the branch pipe 13, and the other end is connected to the branch pipe 14; a swirl component 15 is arranged at one end where the gas enters the branch pipe 13, and includes a guide center body 19 rotatably connected to the branch pipe 13 and a plurality of guide blades 18 evenly spaced along the peripheral wall of the guide center body 19, and the guide blades 18 are smoothly connected to the guide center body 19;

[0052] The method carried out in the hydrocarbon ammonia oxidation fluidized bed reactor includes: feeding oxygen-containing gas 8 into the second gas distributor 7 to perform catalyst lattice oxygen supplementation treatment; feeding a mixed gas containing hydrocarbon source 5 and ammonia source 6 into the first gas distributor 4.

[0053] In the following embodiments, the number of branch pipes, branch pipes and nozzles of the first gas distributor 4 is as follows: Figure 1 As shown, the inlet flow rate of the first feed line connected to the main pipe 12 is 60m 3 / h, the unevenness of the ejection flow rate of the first gas distributor 4 in Examples 1-5 can all reach 0 to 0.35.

[0054] Example 1

[0055] The structural parameters of the hydrocarbon ammonia oxidation fluidized bed reactor include: the first gas distributor 4 is set as the gas distributor of the present invention, the second gas distributor 7 is set as a gas distribution plate, and the ratio of the vertical distance between the first gas distributor 4 and the second gas distributor 7 to the height of the hydrocarbon ammonia oxidation fluidized bed reactor is 0.03; the number of guide blades 18 of the swirl member 15 in the first gas distributor 4 is 9, the width is 2 / 3 of the radius of the branch pipe 13, the outlet angle θ is 45°, and the distance between the outlet end and the nearest branch pipe 14 on the branch pipe 13 is 1.25 times the diameter of the branch pipe 13; the ratio of the cross-sectional area of ​​the end of the rectifying structure 16 that is tangent to the branch pipe 13 and the cross-sectional area of ​​the end connected to the branch pipe 14 is 0.5, the cross-sectional area of ​​the rectifying structure 16 is a rectangle, and the ratio of the side lengths of the rectangle is 1.75;

[0056] The raw materials for the hydrocarbon ammoxidation reaction are meta-xylene, ammonia and air; the molar ratio of meta-xylene, ammonia and air is 1:5.7:24; the catalyst is selected from a vanadium-chromium series silica carrier particle catalyst, and the reaction conditions include: reaction temperature of 415°C, pressure of 0.05MPa, gas superficial linear velocity of 0.4m / s, unevenness of 0.035, and isophthalonitrile yield of 83.4%.

[0057] Example 2

[0058] The structural parameters of the hydrocarbon ammonia oxidation fluidized bed reactor include: the first gas distributor 4 is set as the gas distributor of the present invention, the second gas distributor 7 is set as a gas distribution plate, and the ratio of the vertical distance between the first gas distributor 4 and the second gas distributor 7 to the height of the hydrocarbon ammonia oxidation fluidized bed reactor is 0.06; the number of guide blades 18 of the swirl member 15 in the first gas distributor 4 is 6, the width is 1 / 3 of the radius of the branch pipe 13, the outlet angle θ is 53°, and the distance between the outlet end and the nearest branch pipe 14 on the branch pipe 13 is 0.75 times the diameter of the branch pipe 13; the ratio of the cross-sectional area of ​​the end of the rectifying structure 16 that is tangent to the branch pipe 13 and the cross-sectional area of ​​the end connected to the branch pipe 14 is 1.25, the cross-sectional area of ​​the rectifying structure 16 is an ellipse, and the ratio of the major axis to the minor axis of the ellipse is 1.5;

[0059] The raw materials for the hydrocarbon ammoxidation reaction are meta-xylene, ammonia and air; the molar ratio of meta-xylene, ammonia and air is 1:5.4:22.5; the catalyst is selected from a vanadium-chromium series silica carrier particle catalyst, and the reaction conditions include: reaction temperature of 415°C, pressure of 0.05MPa, gas superficial linear velocity of 0.4m / s, unevenness of 0.04, and isophthalonitrile yield of 82.6%.

[0060] Example 3

[0061] The structural parameters of the hydrocarbon ammonia oxidation fluidized bed reactor include: the first gas distributor 4 is set as the gas distributor of the present invention, the second gas distributor 7 is set as a gas distribution plate, and the ratio of the vertical distance between the first gas distributor 4 and the second gas distributor 7 to the height of the hydrocarbon ammonia oxidation fluidized bed reactor is 0.09; the number of guide blades 18 of the swirl member 15 in the first gas distributor 4 is 8, the width is 2 / 3 of the radius of the branch pipe 13, the outlet angle θ is 45°, and the distance between the outlet end and the nearest branch pipe 14 on the branch pipe 13 is 1.75 times the diameter of the branch pipe 13; the ratio of the cross-sectional area of ​​the end of the rectifying structure 16 that is tangent to the branch pipe 13 and the cross-sectional area of ​​the end connected to the branch pipe 14 is 0.75, the cross-sectional area of ​​the rectifying structure 16 is a rectangle, and the ratio of the side lengths of the rectangle is 1.5;

[0062] The raw materials for the hydrocarbon ammoxidation reaction are toluene, ammonia and air; the molar ratio of toluene, ammonia and air is 1:3.8:13; the catalyst is selected from a vanadium-chromium series silica carrier particle catalyst; the reaction conditions include: reaction temperature of 405°C, pressure of 0.1MPa, gas superficial linear velocity of 0.5m / s, unevenness of 0.029, and benzonitrile yield of 84.3%.

[0063] Example 4

[0064] The difference from Example 1 is that the number of guide vanes 18 of the swirl member 15 in the first gas distributor 4 is 10, the width is 1 / 3 of the radius of the branch pipe 13, and the outlet angle θ is 30°; the second gas distributor 7 is the same as Example 1.

[0065] The raw materials for the hydrocarbon ammoxidation reaction are meta-xylene, ammonia and air; the molar ratio of meta-xylene, ammonia and air is 1:6.5:24.5, the unevenness is 0.05, and the yield of isophthalonitrile is 81.0%.

[0066] Example 5

[0067] The difference from Example 1 is that the first gas distributor 4 is not provided with a swirl member 15, the number of guide blades 18 is 2, the width is 1 / 3 of the radius of the branch pipe 13, the outlet angle θ is 68°, the unevenness is 0.07, and the yield of isophthalonitrile is 78.5%.

[0068] Example 6

[0069] The difference from Example 1 is that the first gas distributor 4 is not provided with the rectifying structure 16, and the branch pipe 14 is directly connected with the branch pipe 13 vertically; the unevenness is 0.078, and the yield of isophthalonitrile is 75.2%.

[0070] Comparative Example 1

[0071] The difference from Example 1 is that the first gas distributor 4 is not provided with a swirl component 15, the non-uniformity is 0.11, and the yield of isophthalonitrile is 75.3%.

[0072] Comparative Example 2

[0073] The difference from Example 1 is that the first gas distributor 4 adopts the prior art Figure 7 The tubular distributor shown, i.e., the swirl component 15 is not provided in the branch pipe 13; the rectifying structure 16 is not provided, the branch pipe 14 is directly connected to the branch pipe 13 vertically, and the number of nozzles is the same as that in the embodiment; the molar ratio of m-xylene, ammonia and air is 1:7:26.5, the reaction temperature is 445°C; the unevenness is 0.12, and the yield of isophthalonitrile is 74.9%.

[0074] Comparative Example 3

[0075] The difference from Example 3 is that the first gas distributor 4 adopts the prior art Figure 7 The tubular distributor shown, i.e., the swirl component 15 is not provided in the branch pipe 13; the rectifying structure 16 is not provided, the branch pipe 14 is directly connected to the branch pipe 13 vertically, and the number of nozzles is the same as that in the embodiment; the molar ratio of toluene, ammonia and air is 1:4:15, the reaction temperature is 415°C; the unevenness is 0.098, and the yield of benzonitrile is 77.6%.

[0076] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any appropriate manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A gas distributor, characterized in that: The invention comprises a branch pipe (13) and a branch pipe (14) tangentially connected to the branch pipe (13); a plurality of branch pipes (14) are provided and are spaced apart along the axial direction of the branch pipe (13); each branch pipe (14) is provided with a plurality of nozzles (17); a swirl component (15) is provided inside the branch pipe (13); the swirl component (15) causes the gas entering the branch pipe (13) to form an axial swirl; the swirl gas enters the branch pipe (14) along the tangent direction of the branch pipe (13).

2. The gas distributor according to claim 1, characterized in that The swirl component (15) comprises a flow guide center body (19) arranged at the gas inlet end of the branch pipe (13) and a plurality of flow guide blades (18) arranged at equal intervals along the peripheral wall of the flow guide center body (19).

3. The gas distributor according to claim 2, characterized in that: The number of the guide blades (18) is 6 to 12, the width is 0.2 to 0.8 times the radius of the branch pipe (13), the outlet angle θ is less than 60°, and the distance between the outlet end of the guide blade (18) and the nearest branch pipe (14) on the branch pipe (13) is 0.1 to 3 times the diameter of the branch pipe (13).

4. The gas distributor according to claim 3, characterized in that: The number of the guide blades (18) is 6 to 9, the width is 0.4 to 0.8 times the radius of the branch pipe (13), and the outlet angle θ is 30°<θ<60°.

5. The gas distributor according to claim 1, characterized in that: Each branch pipe (14) is connected to the branch pipe (13) via a rectifying structure (16); the rectifying structure (16) is configured as a rectifying pipe, one end of the rectifying pipe is tangentially connected to the branch pipe (13), and the other end is connected to the branch pipe (14).

6. The gas distributor according to claim 5, characterized in that: The ratio of the cross-sectional area of ​​the end of the rectifier tube connected to the branch tube (13) to the cross-sectional area of ​​the end of the rectifier tube connected to the branch tube (14) is 0.1 to 15; and / or The cross section of the rectification structure is circular, elliptical or rectangular.

7. The gas distributor according to claim 6, characterized in that: The cross section of the rectifying structure (16) is an ellipse, and the ratio of the major axis to the minor axis of the cross section of the ellipse is 1.2 to 8; or The cross section of the rectifying structure (16) is a rectangle, and the ratio of the cross section to the side length of the rectangle is 0.1-8.

8. The gas distributor according to claim 1, characterized in that: The gas distributor comprises a main pipe (12) and a branch pipe (13) connected to the main pipe (12), wherein a plurality of branch pipes (13) are provided and distributed on the side of the main pipe (12); and / or Along the axial direction of the branch pipe (13), a plurality of branch pipes (14) are staggered at intervals and tangentially arranged on both sides of the branch pipe (13), and the length of the branch pipe (14) decreases from the middle of the branch pipe (13) to both ends.

9. A fluidized bed reactor for hydrocarbon ammoxidation, characterized in that: The hydrocarbon ammonia oxidation fluidized bed reactor comprises a reaction chamber (2) and a first gas distributor (4) and a second gas distributor (7) arranged in the reaction chamber (2), wherein the first gas distributor (4) is used to feed a first feed pipeline containing a hydrocarbon source (5) and an ammonia source (6), and the second gas distributor (7) is connected to a second feed pipeline for feeding an oxygen-containing gas (8); wherein the first gas distributor (4) and / or the second gas distributor (7) is configured as a gas distributor according to any one of claims 1 to 8.

10. The hydrocarbon ammoxidation fluidized bed reactor according to claim 9, characterized in that: The ratio of the vertical distance between the first gas distributor (4) and the second gas distributor (7) to the height of the hydrocarbon ammoxidation fluidized bed reactor is 0.01 to 0.

1.

11. A method for ammoxidation of hydrocarbons, characterized in that: The hydrocarbon ammoxidation method is carried out in a hydrocarbon ammoxidation fluidized bed reactor as claimed in claim 9 or 10, comprising the following: An oxygen-containing gas (8) is fed into the second gas distributor (7), and a mixed gas containing a hydrocarbon source (5) and an ammonia source (6) is fed into the first gas distributor (4). The mixed gas forms a vortex in the branch pipe (13) of the first gas distributor (4) and enters the branch pipe (14), and is ejected from the nozzle (17) to contact with the oxygen-containing gas entrained with the catalyst to generate a nitrile-containing product.

12. The method for ammoxidation of hydrocarbons according to claim 11, wherein: The non-uniformity of the spray flow rate of the nozzle of the first gas distributor (4) and / or the second gas distributor (7) is 0 to 0.35; and / or The molar ratio of the hydrocarbon source in terms of hydrocarbon groups, the ammonia source in terms of amino groups and the oxygen-containing gas in terms of oxygen molecules is 1:(1-10):(10-40); and / or The reaction conditions include: reaction temperature of 300-500°C, pressure of 0.01-0.2MPa, gas superficial velocity of 0.1-0.8m / s; and / or The hydrocarbon source includes hydrocarbons and / or hydrocarbon derivatives, and the ammonia source is ammonia gas; Preferably, the hydrocarbon source includes at least one of toluene, p-chlorotoluene, o-chlorotoluene, o-xylene, m-xylene, p-xylene, dichlorotoluene, trichlorotoluene and 4-nitro-o-xylene.

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