Gas-phase feeding distributor, gas-phase reaction equipment, application of gas-phase reaction equipment and method for preparing nitrile compounds through ammoxidation

Abstract

The invention discloses a gas-phase feeding distributor, gas-phase reaction equipment, application of the gas-phase feeding distributor and the gas-phase reaction equipment and a method for preparing nitrile compounds through ammoxidation. The gas-phase feeding distributor comprises a branch pipe and a plurality of branch pipes, and tangential feeding ports are formed in the inner ends of the branch pipes; the tangential feed port is arranged to enable a gas-phase material entering the branch pipe through the feed port to flow along the inner circumferential wall of the branch pipe and form rotational flow gas flow propelled in the axial direction; the branch pipes are installed on the peripheral wall of the branch pipe at intervals in the axial direction of the branch pipe, and each branch pipe is provided with a plurality of nozzles arranged at intervals in the pipe length direction. The device has the advantages of eliminating gas bias flow, strengthening uniform distribution of gas flow and improving the utilization rate of raw materials.

Description

Technical Field

[0001] The invention relates to a gas phase feed distributor, a gas phase reaction device and application thereof, and a method for preparing nitrile compounds by ammoxidation. Background Art

[0002] The dendritic tubular gas distributor is a gas distributor widely used in large-scale industrial fluidized bed reactors such as catalytic cracking, aromatic ammoxidation and acrylonitrile. The branch pipes and branch pipe assemblies of the tubular distributor are simple in structure and easy to manufacture; the free pipe end design can better solve the problem of thermal deformation. However, the existing tubular gas distributor is directly connected by pipe fittings from the first-level main pipe to the last-level nozzle. Since the number of nozzles is extremely large, the flow inside the distributor is an extremely complex variable mass flow process. At the same time, the existing pipe connection combination causes the main direction of the gas to suddenly change during the process of the gas entering the next-level pipeline from the upper-level pipeline, resulting in serious large-scale flow deviation and local eddy currents, leading to serious uneven airflow distribution and additional resistance loss, deteriorating the raw gas distribution effect, reducing the reaction yield, and increasing production energy consumption. In large-scale chemical industrial equipment, as the fluidized bed reactor is enlarged as a whole, the scale of the tubular distributor increases accordingly, and the above-mentioned uneven situation will become more serious. Summary of the invention

[0003] The purpose of the present invention is to overcome the problem of serious flow deviation of the tubular distributor in the prior art, and to provide a gas phase feed distributor, a gas phase reaction device and its application and a method for preparing nitrile compounds by ammoxidation, which have the advantages of eliminating gas deviation, strengthening the uniform distribution of gas flow and improving the utilization rate of raw materials.

[0004] In order to achieve the above object, the present invention provides a gas phase feed distributor, comprising:

[0005] A branch pipe, wherein the inner end of the branch pipe is provided with a tangential feed port, and the tangential feed port is arranged so that the gaseous material entering the branch pipe through the feed port flows along the inner peripheral wall of the branch pipe and forms a swirling airflow that propels along the axial direction;

[0006] A plurality of branch pipes are installed on the outer peripheral wall of the branch pipe at intervals along the axial direction of the branch pipe, and each branch pipe is provided with a plurality of nozzles arranged at intervals along the length direction of the pipe.

[0007] In some embodiments of the present invention, the cross section of the tangential feed port is a rectangle, and the ratio of the side lengths of the rectangular cross section is 0.1-6.

[0008] In some other embodiments of the present invention, the cross section of the tangential feed port is elliptical, and the ratio of the major axis to the minor axis of the elliptical cross section is 1.0-6.

[0009] In some embodiments of the present invention, each branch pipe is connected to the branch pipe through a rectifying structure, wherein the ratio of the cross-sectional flow area of ​​one end of the rectifying structure connected to the branch pipe to the flow area of ​​one end connected to the branch pipe is 0.1 to 15.

[0010] In some embodiments of the present invention, the branch pipe is located on the side of the branch pipe, and the rectifying structure is configured as a streamlined channel for flowing gaseous materials, one end of the streamlined channel extends along the peripheral wall of the branch pipe, and the other end extends toward the branch pipe.

[0011] In some embodiments of the present invention, the streamlined channel is preferably configured as one of a circular arc channel, an elliptical arc channel, or a channel that is in an involute shape with respect to the inner wall of the branch pipe.

[0012] In some embodiments of the present invention, the acute angle α between the end of the streamlined channel extending toward the branch pipe and the horizontal plane is preferably 0 to 60°, and more preferably α is 15 to 45°.

[0013] In some embodiments of the present invention, the gas phase feed distributor comprises:

[0014] Main pipe, arranged vertically; and

[0015] The plurality of branch pipes are arranged transversely and spaced apart along the circumference of the main pipe, wherein the tangential feed ports of the branch pipes are located inside the main pipe and the opening direction of the tangential feed ports is arranged opposite to the material flow direction in the main pipe.

[0016] The second aspect of the present invention discloses a gas phase reaction device, which includes a first gas phase feed distributor and a second gas phase feed distributor arranged in a reaction chamber, and the first gas phase feed distributor and / or the second gas phase feed distributor adopts the gas phase feed distributor described in the present invention.

[0017] In some embodiments, the first gas-phase feed distributor and the second gas-phase feed distributor are arranged relative to each other in the height direction, and the ratio of the vertical distance between the first gas-phase feed distributor and the second gas-phase feed distributor to the height of the gas-phase reaction equipment is 0.01 to 0.1.

[0018] The third aspect of the present invention provides the use of the gas phase reaction equipment of the present invention in the preparation of nitriles by ammonia oxidation.

[0019] The present invention provides a method for preparing nitrile compounds by ammoxidation, which is carried out in the gas phase reaction equipment of the present invention and comprises:

[0020] A mixed gas containing a hydrocarbon source and an ammonia source is fed into the first gas-phase raw material inlet, and the mixed gas enters the reaction chamber through the first gas-phase feed distributor. An oxygen-containing gas is fed into the second gas-phase raw material inlet and enters the reaction chamber through the second gas-phase feed distributor to contact with the mixed gas in the presence of a catalyst to generate a nitrile product.

[0021] In some embodiments, the hydrocarbon source includes hydrocarbons and / or hydrocarbon derivatives.

[0022] In some embodiments, 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).

[0023] In some embodiments, the hydrocarbon source preferably includes at least one of toluene, p-chlorotoluene, o-chlorotoluene, o-xylene, m-xylene, p-xylene, dichlorotoluene, trichlorotoluene or 4-nitro-o-xylene.

[0024] In some embodiments, the contact 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.

[0025] In some embodiments, the non-uniformity of the spray flow rate of the first gas-phase feed distributor and / or the second gas-phase feed distributor is 0 to 0.35.

[0026] Through the above technical scheme, the present invention sets a tangential feed port so that the gaseous material entering the branch pipe is in a swirl state, and when feeding at least two gaseous materials, the gaseous material in the swirl state enters the branch pipe along the tangent direction of the branch pipe and is ejected through a nozzle set on the branch pipe. The main pipe-branch pipe tangential gas channel generates a gas swirl flow inside the branch pipe, and the branch pipe-branch pipe tangential rectification structure is coupled to receive the gas swirl flow inside the branch pipe, realizing the coupling of the front and rear gas flow field structures, eliminating the bias flow of the gas phase feed distributor, and strengthening the uniform distribution of the gas phase feed flow, so that the gas distribution performance of the gas phase feed distributor is closer to the ideal gas distribution state, and further, it can improve the yield of the ammonia oxidation product. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of a gas phase feed distributor according to some embodiments of the present invention;

[0028] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle branch pipe-branch pipe;

[0029] Figure 3 yes Figure 2 The schematic diagram of the structure in the radial cross-section direction of the branch pipe;

[0030] Figure 4 It is a schematic diagram of the three-dimensional structure of the branch pipe-branch pipe;

[0031] Figure 5 A schematic diagram of the structure of a gas phase reaction device in some embodiments of the present invention;

[0032] Figure 6 It is a structural schematic diagram of a distributor in the prior art.

[0033] Description of Reference Numerals

[0034] 1 gas collecting chamber; 2 reaction chamber; 3 heat exchanger; 4 first gas phase feed distributor; 5 hydrocarbon source; 6 ammonia source; 7 second gas phase feed distributor; 8 oxygen-containing gas; 9 second gas phase raw material inlet; 10 cyclone separator; 11 product discharge port; 12 main pipe; 13 branch pipe; 14 branch pipe; 15 tangential feed port; 16 rectification structure; 17 nozzle. DETAILED DESCRIPTION

[0035] 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.

[0036] 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.

[0037] In the present invention, unless otherwise specified, directional words such as "up, down, left, right" generally refer to the up, down, left, right shown in the reference drawings; "inside and outside" refer to the inside and outside relative to the contour of each component itself, and the upper part refers to the area of ​​0 to 30% from top to bottom of the cavity.

[0038] like Figure 1-Figure 2 As shown, the present invention discloses a gas-phase feed distributor, which includes:

[0039] A branch pipe 13, the inner end of which is provided with a tangential feed port 15, the tangential feed port 15 being arranged so that the gaseous material entering the branch pipe 13 through the feed port 15 flows along the inner peripheral wall of the branch pipe and forms a swirling airflow that propels in the axial direction;

[0040] A plurality of branch pipes 14 are installed on the outer peripheral wall of the branch pipe 13 at intervals along the axial direction of the branch pipe. Each branch pipe 14 is provided with a plurality of nozzles 17 arranged at intervals along the length direction of the pipe.

[0041] It should be noted that in the ammoxidation reaction of acrylonitrile and aromatics, which currently uses a tubular distributor, the current research focus is on catalysts and supporting processes, and there is little research on the gas distribution performance of the tubular distributor and its nozzle accessories. The existing tubular distributor nozzle is mostly a simple short tube connected to the branch pipe in the normal direction. When the airflow enters the nozzle from the branch pipe, it causes serious deviation due to the drastic change in flow direction, and even causes catalyst backflow due to local decompression. In view of the defects of the above-mentioned prior art, the present invention sets a tangential feed port 15 through a large amount of CFD simulation and flow field analysis in the early stage, so that the gas-phase material entering the branch pipe forms a swirl state along the inner wall of the pipe around the central axis of the pipe, and can strengthen the premixing of the gas-phase material when feeding two or more gas-phase materials. The tangential feed port 15 between the main pipe and the branch pipe generates a gas swirl airflow inside the branch pipe, and the tangential rectifying structure 16 between the branch pipe and the branch pipe is coupled to receive the gas swirl airflow inside the branch pipe, so as to achieve the coupling of the front and rear airflow flow field structures and produce a synergistic effect. The gaseous material in the swirl state enters the branch pipe 14 along the tangent direction of the branch pipe 13 and is sprayed out through the nozzle arranged on the branch pipe to eliminate the bias flow of the gas-phase feed distributor, strengthen the uniform distribution of the gas-phase feed flow rate, and make the gas distribution performance of the gas-phase feed distributor closer to the ideal gas distribution state.

[0042] In some embodiments of the invention, the tangential feed port 15 is configured to extend tangentially outward along the inner wall of the branch pipe, wherein the cross-sectional shape of the tangential feed port 15 is one of a rectangular, elliptical or circular shape.

[0043] In order to reduce the additional resistance loss during the flow process, in some embodiments of the present invention, the cross-section of the tangential feed port 15 is a rectangle, and the ratio of the side length of the rectangular cross-section is 0.1 to 6; in other embodiments of the present invention, the cross-section of the tangential feed port 15 is an ellipse, and the ratio of the major axis to the minor axis of the ellipse cross-section is 1.0 to 6.

[0044] like Figure 3 As shown, in order to further reduce the flow resistance, better receive the swirl airflow from the branch pipe 13, and further eliminate the gas deviation, in some embodiments of the present invention, on the basis of the tangent arrangement of the branch pipes, each branch pipe 14 is connected to the branch pipe 13 through a rectifying structure 16, wherein the ratio of the cross-sectional flow area of ​​the end of the rectifying structure 16 connected to the branch pipe 13 to the flow area of ​​the end connected to the branch pipe 14 is 0.1 to 15, thereby enhancing the uniform distribution of the flow rate and making the gas distribution performance of the gas-phase feed distributor closer to the ideal gas distribution state.

[0045] In some embodiments of the present invention, the branch pipe 14 is located on the side of the branch pipe 13, and the rectifying structure 16 is configured as a streamlined channel defined by the shell. Figure 3-Figure 4As shown, one end of the streamlined channel extends along the outer circumferential wall of the branch pipe 13 and is connected to the branch pipe at the end of the extension, and the other end extends toward the branch pipe and is connected to the end of the branch pipe. The overall shape of the streamlined channel can be an arc, an elliptical arc, or an involute shape with the inner circumferential wall of the branch pipe 13. Preferably, the acute angle α between the end of the streamlined channel extending toward the branch pipe 14 and the horizontal plane is 0 to 60°, and more preferably α is 15 to 45°. The above-mentioned preference can improve the utilization rate of raw materials and can improve the yield of ammoxidation products when used for ammoxidation to prepare nitriles.

[0046] In some embodiments of the invention, Figure 2 As shown, a plurality of branch pipes 14 are arranged on both sides of the branch pipe 13 and the length of the branch pipes 14 on the same side gradually decreases from the middle of the branch pipe 13 to both ends. The branch pipes 14 on both sides along the axial direction of the branch pipe 13 are arranged alternately, that is, along the axial direction of the branch pipe 13, a branch pipe on the other side is arranged between two branch pipes 14 on the same side; along the axial direction of the branch pipe 13, the orthographic projections of the rectifying components of two adjacent branch pipes on the radial cross section of the branch pipe are arranged symmetrically at the center; one end of each branch pipe 14 is connected to the tangent direction of the branch pipe 13 through the rectifying structure 16, and the other end is closed.

[0047] In some embodiments of the invention, Figure 1 As shown, the gas phase feed distributor comprises:

[0048] A main flow pipe 12 is arranged vertically, the top opening of the main flow pipe is set as an air flow inlet, and the bottom end is closed; and

[0049] A plurality of branch pipes 13 are arranged transversely and are arranged at equal intervals along the circumference of the main pipe 12, wherein a tangential feed port 15 of the branch pipe 13 is located inside the main pipe 12 and an opening direction of the tangential feed port 15 is arranged opposite to the material flow direction in the main pipe 12, so that the gaseous material is fed axially from the main pipe 12 through the tangential feed port 15 into the branch pipe 13 and forms a vortex, wherein the outer end of the branch pipe is closed.

[0050] like Figure 5 As shown, the present invention discloses a gas phase reaction equipment, comprising a reaction chamber 2 and a first gas phase feed distributor 4 arranged in the reaction chamber 2 and a second gas phase feed distributor 7 located below the first gas phase feed distributor 4, the first gas phase feed distributor 4 is connected to a first gas phase raw material inlet arranged on the chamber wall of the reaction chamber 2, the second gas phase feed distributor 7 is connected to a second gas phase raw material inlet 9 arranged on the chamber wall of the reaction chamber 2, and a product discharge port 11 is also arranged on the chamber wall of the reaction chamber 2; wherein the first gas phase feed distributor 4 and / or the second gas phase feed distributor 7 adopt the gas phase feed distributor of the present invention, the nozzle outlet of the first gas phase feed distributor 4 is arranged downward, and the nozzle outlet of the second gas phase feed distributor 7 is arranged upward.

[0051] In some embodiments of the present invention, the first gas-phase feed distributor 4 and the second gas-phase feed distributor 7 are arranged relative to each other in the height direction, and the ratio of the vertical distance between the first gas-phase feed distributor 4 and the second gas-phase feed distributor 7 to the height of the gas-phase reaction equipment is 0.01 to 0.1.

[0052] The gas phase reaction equipment in the present invention can be configured as a fluidized bed reaction equipment, a gas collecting chamber 1 is arranged at the top of the reaction chamber 2, the gas collecting chamber 1 is connected to the product discharge port, a heat exchanger 3 and a cyclone separator 10 installed above the first gas phase feed distributor are arranged in the reaction chamber 2, the cyclone separator 10 is connected to the gas collecting chamber 1, when the gas phase reaction equipment of the present invention is used in the reaction of preparing nitriles by ammoxidation of hydrocarbons, the gas phase feed distributor used to distribute the oxygen-containing gas can be selected from the gas distribution plate in the prior art.

[0053] The invention discloses application of the gas phase reaction equipment of the invention in preparing nitriles by ammonia oxidation.

[0054] The present invention discloses a method for preparing nitrile compounds by ammonia oxidation. The method is carried out in a gas phase reaction device of the present invention, comprising feeding a mixed gas containing a hydrocarbon source 5 and an ammonia source 6 into a first gas phase raw material inlet, the mixed gas entering a reaction chamber 2 through a first gas phase feed distributor 4, feeding an oxygen-containing gas 8 into a second gas phase raw material inlet 9 and entering the reaction chamber 2 through a second gas phase feed distributor 7, wherein a catalyst is pre-installed between the first gas phase feed distributor 4 and the second gas phase feed distributor 7 using the prior art, and the oxygen-containing gas 8 is fed from bottom to top and the mixed gas is fed from top to bottom. The gases are contacted and mixed in the presence of a catalyst to undergo an ammoxidation reaction to generate nitrile products. Subsequently, the generated nitrile products enter a cyclone separator 10 to separate the catalyst carried therein. The separated catalyst is returned to the dense phase region of the reaction through the feed leg of the cyclone separator 10. The separated nitrile products enter a gas collecting chamber 1 and are discharged through a product discharge port 11. The separated nitrile products are received and refined using existing technology to obtain products. For example, the separated nitrile products are received by condensation or solvent absorption, and refined by distillation or recrystallization to obtain products.

[0055] The method for preparing nitrile compounds by ammonia oxidation in the gas phase reaction equipment of the present invention can form a mixed gas containing a hydrocarbon source and an ammonia source into a cyclonic state and strengthen the premixing of the two gases, while overcoming the bias flow problem existing in the gas distributor in the prior art, so that the mixed gas and the oxygen-containing gas are closer to the ideal gas distribution state, and can improve the raw material utilization rate and the yield of the ammonia oxidation product.

[0056] In some embodiments of the invention, the hydrocarbon source 5 includes hydrocarbons and / or hydrocarbon derivatives, and the ammonia source is ammonia gas.

[0057] In some embodiments of the 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).

[0058] In some embodiments of the invention, the hydrocarbon source (5) includes at least one of toluene, p-chlorotoluene, o-chlorotoluene, o-xylene, m-xylene, p-xylene, dichlorotoluene, trichlorotoluene or 4-nitro-o-xylene.

[0059] In some embodiments of the invention, the method includes feeding an oxygen-containing gas 8 into a second gas-phase raw material inlet 9 and feeding the oxygen-containing gas into the reaction chamber 2 through a second gas-phase feed distributor 7 for catalyst lattice oxygen supplementation.

[0060] In some embodiments of the invention, the contact 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.

[0061] In some embodiments of the present invention, the non-uniformity of the spray flow rate of the first gas-phase feed distributor 4 and / or the second gas-phase feed distributor 7 is 0-0.35.

[0062] In the present invention, the method for calculating the unevenness 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.

[0063] In the present invention, in the specific implementation process, only the inlet flow of the main flow 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 spray flow rate of the gas phase feed distributor of the present invention can reach 0 to 0.35.

[0064] The advantages of the present invention are described below by way of examples, but the present invention is not limited thereto.

[0065] The following examples are Figure 1-Figure 5The gas phase reaction is carried out in the gas phase reaction equipment shown, which is a fluidized bed reaction equipment, including a reaction chamber 2, in which are arranged from bottom to top a second gas phase feed distributor 7 connected to a second gas phase raw material inlet 9, a first gas phase feed distributor 4 connected to a first gas phase raw material inlet, a heat exchanger 3 and a cyclone separator 10 connected to a gas collecting chamber 1, the gas collecting chamber 1 is connected to a product discharge port 11, and the catalyst is pre-installed between the first gas phase feed distributor 4 and the second gas phase feed distributor 7.

[0066] Among them, the first gas phase feed distributor 4 is provided with a main pipe 12 and a plurality of branch pipes 13 arranged at equal intervals along the circumference of the main pipe 12, one end of the branch pipe 13 is connected to the main pipe 12, and the other end is set to be closed; a plurality of branch pipes 14 are arranged at intervals along the axial direction of the branch pipe 13, and each branch pipe 14 is provided with a plurality of nozzles 17 along the axial direction.

[0067] The following examples are Figure 1-Figure 5 The method carried out in the gas phase reaction equipment shown includes feeding a mixed gas containing a hydrocarbon source 5 and an ammonia source 6 into a first gas phase raw material inlet, the mixed gas enters the reaction chamber 2 through a first gas phase feed distributor 4, and feeding an oxygen-containing gas 8 into a second gas phase raw material inlet 9 and enters the reaction chamber 2 through a second gas phase feed distributor 7.

[0068] In the following embodiments, the number of branch pipes, branch pipes and nozzles of the first gas phase feed distributor 4 is as follows: Figure 1 As shown, the flow rate of the first gas phase raw material inlet connected to the main flow pipe 12 is 60m 3 / h, the unevenness of the spray flow rate of the first gas-phase feed distributor 4 in Examples 1-5 can all reach 0 to 0.35.

[0069] Example 1

[0070] In the gas phase reaction equipment of this embodiment, the first gas phase feed distributor 4 adopts the gas phase feed distributor of the present invention, and the second gas phase feed distributor 7 is set as a gas distribution plate. The ratio of the vertical distance between the first gas phase feed distributor 4 and the second gas phase feed distributor 7 to the height of the gas phase reaction equipment is 0.03;

[0071] The tangential feed port 15 of each branch pipe 13 in the first gas phase feed distributor 4 is located inside the main pipe 12, and the opening direction of the tangential feed port 15 is arranged opposite to the material flow direction in the main pipe 12, wherein the cross section of the tangential feed port 15 is rectangular, and the ratio of the side length of the rectangular cross section is 1.75; one end of each branch pipe 14 is connected to the tangent of the branch pipe 13 through the rectifying structure 16, and the ratio of the cross-sectional flow area of ​​the end of the rectifying structure 16 connected to the branch pipe 13 to the flow area of ​​the end connected to the branch pipe 14 is 1.2; the acute angle α between the inner edge of the rectifying structure 16 and the horizontal plane is 37.5°;

[0072] The raw materials for the hydrocarbon ammoxidation reaction are meta-xylene, ammonia and air; the molar ratio of meta-xylene, ammonia and air is 1:5.9:23.1; 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 0.034, and isophthalonitrile yield of 83.2%.

[0073] Example 2

[0074] In the gas phase reaction equipment of this embodiment, the first gas phase feed distributor 4 adopts the gas phase feed distributor of the present invention, and the second gas phase feed distributor 7 is set as a gas distribution plate. The ratio of the vertical distance between the first gas phase feed distributor 4 and the second gas phase feed distributor 7 to the height of the gas phase reaction equipment is 0.06;

[0075] The tangential feed port 15 of each branch pipe 13 in the first gas phase feed distributor 4 is located inside the main pipe 12, and the opening direction of the tangential feed port 15 is arranged opposite to the material flow direction in the main pipe 12, wherein the cross section of the tangential feed port 15 is an ellipse, and the ratio of the major axis to the minor axis of the ellipse cross section is 2.5; one end of each branch pipe 14 is connected to the tangent of the branch pipe 13 through a rectifying structure 16, and the ratio of the cross-sectional flow area of ​​the end of the rectifying structure 16 connected to the branch pipe 13 to the flow area of ​​the end connected to the branch pipe 14 is 1.2; the acute angle α between the inner edge of the rectifying structure 16 and the horizontal plane is 22.5°;

[0076] The raw materials for the hydrocarbon ammoxidation reaction are meta-xylene, ammonia and air; the molar ratio of meta-xylene, ammonia and air is 1:5.5:22; 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 0.038, and isophthalonitrile yield of 82.3%.

[0077] Example 3

[0078] In the gas phase reaction equipment of this embodiment, the first gas phase feed distributor 4 adopts the gas phase feed distributor of the present invention, and the second gas phase feed distributor 7 is set as a gas distribution plate. The ratio of the vertical distance between the first gas phase feed distributor 4 and the second gas phase feed distributor 7 to the height of the gas phase reaction equipment is 0.09;

[0079] The tangential feed port 15 of each branch pipe 13 in the first gas phase feed distributor 4 is located inside the main pipe 12, and the opening direction of the tangential feed port 15 is arranged opposite to the material flow direction in the main pipe 12, wherein the cross section of the tangential feed port 15 is rectangular, and the ratio of the side length of the rectangular cross section is 1.5; one end of each branch pipe 14 is connected to the tangent of the branch pipe 13 through a rectifying structure 16, and the ratio of the cross-sectional flow area of ​​the end of the rectifying structure 16 connected to the branch pipe 13 to the flow area of ​​the end connected to the branch pipe 14 is 1.05; the acute angle α between the inner edge of the rectifying structure 16 and the horizontal plane is 45°;

[0080] The raw materials for the hydrocarbon ammoxidation reaction are toluene, ammonia and air; the molar ratio of toluene, ammonia and air is 1:3.6:13.5; 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 84.2%.

[0081] Example 4

[0082] Different from the first embodiment, the ratio of the cross-sectional flow area of ​​the end of the rectifying structure 16 connected to the branch pipe 13 to the flow area of ​​the end connected to the branch pipe 14 is 5; the acute angle α between the inner edge of the rectifying structure 16 and the horizontal plane is 60°.

[0083] The raw materials for the hydrocarbon ammoxidation reaction are meta-xylene, ammonia and air; the molar ratio of meta-xylene, ammonia and air is 1:7:24, the unevenness is 0.065, and the yield of isophthalonitrile is 81%.

[0084] Example 5

[0085] Different from the first embodiment, the ratio of the cross-sectional flow area of ​​the end of the rectifying structure 16 connected to the branch pipe 13 to the flow area of ​​the end connected to the branch pipe 14 is 16; the acute angle α between the inner edge of the rectifying structure 16 and the horizontal plane is 12.5°.

[0086] The raw materials for the hydrocarbon ammoxidation reaction are m-xylene, ammonia and air, the non-uniformity is 0.072, and the yield of isophthalonitrile is 77.9%.

[0087] Example 6

[0088] Different from Example 1, the branch pipe 14 is directly connected to the side of the branch pipe 13, the unevenness is 0.11, and the yield of isophthalonitrile is 75.2%.

[0089] Comparative Example 1

[0090] The number of branch pipes, branch pipes and nozzles is the same as that in Example 1, except that Figure 6As shown, the branch pipe 13 is not provided with a tangential feed port 15, and the branch pipe 13 is directly connected to the side of the main pipe 12, the unevenness is 0.11, and the yield of isophthalonitrile is 75.3%.

[0091] Comparative Example 2

[0092] The number of branch pipes, branch pipes and nozzles is the same as that in Example 1, except that Figure 6 As shown, the branch pipe 13 is not provided with a tangential feed port 15 , the branch pipe 13 is directly connected to the side of the main pipe 12 , and each branch pipe 14 is directly connected to the side of the branch pipe 13 .

[0093] The raw materials of the hydrocarbon ammoxidation reaction are meta-xylene, ammonia and air; the molar ratio of meta-xylene, ammonia and air is 1:7:27, the reaction temperature is 445°C, the non-uniformity is 0.10, and the yield of isophthalonitrile is 75.2%.

[0094] Comparative Example 3

[0095] The number of branch pipes, branch pipes and nozzles is the same as that of Example 3, except that Figure 6 As shown, the branch pipe 13 is not provided with a tangential feed port 15 , the branch pipe 13 is directly connected to the side of the main pipe 12 , and each branch pipe 14 is directly connected to the side of the branch pipe 13 .

[0096] The raw materials for the hydrocarbon ammoxidation reaction are toluene, ammonia and air; the molar ratio of toluene, ammonia and air is 1:4:15.5, the reaction temperature is 415°C, the non-uniformity is 0.099, and the yield of benzonitrile is 77.8%.

[0097] 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 phase feed distributor, characterized in that: include: A branch pipe (13), wherein a tangential feed port (15) is provided at the inner end of the branch pipe (13), and the tangential feed port (15) is arranged so that the gaseous material entering the branch pipe (13) through the feed port (15) flows along the inner peripheral wall of the branch pipe and forms a swirling airflow that propels along the axial direction; A plurality of branch pipes (14) are installed on the outer peripheral wall of the branch pipe (13) at intervals along the axial direction of the branch pipe, and each branch pipe (14) is provided with a plurality of nozzles (17) arranged at intervals along the length direction of the pipe.

2. The gas phase feed distributor according to claim 1, characterized in that The cross section of the tangential feed port (15) is a rectangle, and the ratio of the side lengths of the rectangular cross section is 0.1 to 6; or The cross section of the tangential feed port (15) is elliptical, and the ratio of the major axis to the minor axis of the cross section of the elliptical shape is 1.0-6.

3. The gas phase feed distributor according to claim 1 or 2, characterized in that: Each branch pipe (14) is connected to the branch pipe (13) via a rectifying structure (16), wherein the ratio of the cross-sectional flow area of ​​one end of the rectifying structure (16) connected to the branch pipe (13) to the flow area of ​​one end connected to the branch pipe (14) is 0.1 to 15.

4. The gas phase feed distributor according to claim 3, characterized in that The branch pipe (14) is located on the side of the branch pipe (13), and the rectifying structure (16) is configured as a streamlined channel for flowing gaseous materials, one end of the streamlined channel extends along the peripheral wall of the branch pipe, and the other end extends toward the branch pipe; Preferably, the streamlined channel is configured as one of a circular arc channel, an elliptical arc channel or a channel in an involute shape with the inner wall of the branch pipe (13); and / or Preferably, the acute angle α between the end of the streamlined channel extending toward the branch pipe (14) and the horizontal plane is 0 to 60°, more preferably α is 15 to 45°.

5. The gas phase feed distributor according to claim 1, characterized in that The gas phase feed distributor comprises: A main flow pipe (12), arranged vertically; and The plurality of branch pipes (13) are arranged transversely and spaced apart along the circumference of the main pipe (12), wherein the tangential feed port (15) of the branch pipe (13) is located inside the main pipe (12) and the opening direction of the tangential feed port (15) is arranged opposite to the material flow direction in the main pipe (12).

6. A gas phase reaction device, characterized in that: The gas-phase reaction equipment comprises a first gas-phase feed distributor (4) and a second gas-phase feed distributor (7) arranged in a reaction chamber (2); the first gas-phase feed distributor (4) and / or the second gas-phase feed distributor (7) adopt the gas-phase feed distributor described in any one of claims 1 to 5.

7. The gas phase reaction equipment according to claim 6, characterized in that: The first gas-phase feed distributor (4) is located above the second gas-phase feed distributor (7) and is arranged relative to the second gas-phase feed distributor (7) at a distance; The ratio of the vertical distance between the first gas-phase feed distributor (4) and the second gas-phase feed distributor (7) to the height of the gas-phase reaction equipment is 0.01 to 0.

1.

8. Use of the gas phase reaction equipment according to claim 6 or 7 in the preparation of nitriles by ammoxidation.

9. A method for preparing nitrile compounds by ammoxidation, characterized in that: The method adopts the gas phase reaction equipment according to claim 6 or 7, and comprises: Feeding a mixed gas containing a hydrocarbon source (5) and an ammonia source (6) into the reaction chamber (2) through the first gas phase feed distributor (4); The oxygen-containing gas (8) is fed into the reaction chamber (2) through the second gas phase feed distributor (7), so that the oxygen-containing gas is contacted with the mixed gas in the presence of a catalyst to generate nitrile products.

10. The method according to claim 9, wherein: The hydrocarbon source (5) includes hydrocarbons and / or hydrocarbon derivatives, preferably includes at least one or more of toluene, p-chlorotoluene, o-chlorotoluene, o-xylene, m-xylene, p-xylene, dichlorotoluene, trichlorotoluene and 4-nitro-o-xylene; and / or The ammonia source is ammonia gas; 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 contact 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 non-uniformity of the spray flow rate of the first gas-phase feed distributor (4) and / or the second gas-phase feed distributor (7) is 0 to 0.35.

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