JP2016210740A - Fluidized bed reactor and nitrile compound production process using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the accumulation of a catalyst on a partition plate within a fluidized bed reactor.SOLUTION: The fluidized bed reactor includes a partition plate (5) partitioning the inside of a fluidized bed reactor (11) into a lower region (A) and an upper region (B) and in which an opening area (25) is formed, and a tubular article (6) having open opening ends at both ends is provided in the opening area (25) of the partition plate (5).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluidized bed reactor and a method for producing a nitrile compound using the same, and more particularly to a fluidized bed reactor having a partition plate for partitioning the interior into two compartments and a method for producing a nitrile compound using the same. .

  Fluidized bed reactors are used for various industrial reactions. For example, nitrile compounds such as acrylonitrile are industrially produced by an ammoxidation reaction using a fluidized bed reactor. An ammoxidation reaction is a process in which a hydrocarbon such as propylene, ammonia, and an oxygen-containing gas such as air are introduced as raw materials into a fluidized bed reactor, and a nitrile compound is formed by a gas phase oxidation reaction in the presence of a metal oxide catalyst. This is a manufacturing method (Patent Document 1).

  Generally, the reaction gas generated by the reaction in the fluidized bed reactor is separated from the catalyst by a cyclone installed in the upper part of the fluidized bed reactor, and then discharged out of the fluidized bed reactor. At this time, if the catalyst is deposited on the horizontal portion of the upper part of the cyclone, the surfaces of the catalyst particles become sticky, and the particles adhere to each other and block. If this blocked catalyst falls on the catalyst layer, the flow of the reaction gas is disturbed, or in the extreme case, the entire fluidized bed of the catalyst becomes sticky and cannot flow, and the reaction gas blows off locally. There is a risk of doing.

  Therefore, in Patent Document 2, a partition plate that partitions the inside of a fluidized bed reactor into a lower region filled with a catalyst and an upper region other than that is deposited on a cyclone to form a block shape. There is disclosed a method for suppressing the catalyst that has become a catalyst layer from falling on the catalyst layer. Furthermore, in Patent Document 2, by introducing an inert gas from the upper part of the fluidized bed reactor, a gas flow from the upper region to the lower region is formed, and the catalyst is prevented from flowing into the upper region side. A method is also disclosed.

JP 2006-247452 A JP 2005-193172 A

  If the partition plate in the fluidized bed reactor is thin, the partition plate may be broken because it cannot withstand the reaction pressure. Therefore, by providing a pressure equalizing pipe or a hole necessary for the partition plate so as not to have a high pressure difference between the lower region and the upper region, the two sections of the lower region and the upper region are kept at a uniform pressure.

  Here, when the inert gas is introduced from the upper part of the fluidized bed reactor as in Patent Document 2, the gas flows from the upper region to the lower region. That is, the upper region is in a slightly higher pressure than the lower region. However, the pressure difference between the upper and lower regions must be reduced for the purpose of maintaining a uniform pressure between the upper and lower regions. When the pressure on the lower region side suddenly increases due to the closure of the discharge port to the outside of the reactor, the reaction gas flows backward to the upper region side, and the catalyst also flows backward accompanying the reaction gas.

  As described above, the conventional method as disclosed in Patent Document 2 cannot completely suppress the inflow of the catalyst to the upper region side. If the catalyst flows back to the upper region side accompanying the reaction gas, the catalyst is deposited on the partition plate, which may cause deterioration of the partition plate material, material corrosion, and the like. Further, when the catalyst is deposited on the partition plate, the unreacted raw material gas or the reaction product may cause a combustion reaction (afterburning) in the upper region or may have an adverse effect. Furthermore, the partition plate may be deformed by the weight of the accumulated catalyst, or may be damaged in an extreme case.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a fluidized bed reactor capable of suppressing the catalyst from being deposited on the partition plate in the fluidized bed reactor and the use thereof. Another object of the present invention is to provide a method for producing a nitrile compound.

  In order to solve the above problems, a fluidized bed reactor according to an aspect of the present invention includes a partition plate in which an interior of the fluidized bed reactor is partitioned into a lower region and an upper region, and an opening is formed. Tubular objects having open ends that are open at both ends are provided at the openings of the partition plate.

  In some cases, the reaction gas generated in the lower region of the partition plate of the fluidized bed reactor flows backward to the upper region side, and the catalyst also flows back along with the reaction gas. According to the above configuration, since the catalyst that flows along with the reaction gas and flows from the lower region of the fluidized bed reactor toward the upper region can be dropped to the lower region side by the tubular material, the catalyst is placed on the partition plate. Accumulation can be suppressed.

  Therefore, it is possible to suppress the deterioration of the material of the partition plate and the material corrosion caused by the accumulation of the catalyst on the partition plate. Moreover, it can also suppress that a reaction in a fluidized bed reactor is adversely affected by depositing a catalyst on a partition plate.

  Moreover, in the fluidized bed reactor which concerns on 1 aspect of this invention, the said tubular thing is fitted in the said opening part, or the opening edge is closely_contact | adhered and it is provided in the said partition plate.

  Moreover, in the fluidized bed reactor which concerns on 1 aspect of this invention, the said tubular thing has a part from which the flow-path area in the said tubular thing becomes large as it goes to the said upper area | region from the said lower area | region.

  According to the above configuration, as the flow path area in the tubular object increases from the lower opening end of the tubular object to the upper opening end, the flow rate at which the reaction gas accompanying the catalyst passes through the tubular object is increased. Can be dropped. Thereby, the catalyst can be naturally dropped again through the tubular object to the lower region side.

  In the fluidized bed reactor according to an aspect of the present invention, the flow path area in the tubular material is substantially constant from the lower region to the upper region.

  According to the above configuration, since the catalyst that flows along with the reaction gas and flows from the lower region of the fluidized bed reactor toward the upper region can be dropped to the lower region side by the tubular material, the catalyst is placed on the partition plate. Accumulation can be suppressed.

  Moreover, in the fluidized bed reactor which concerns on 1 aspect of this invention, the baffle plate is provided in the said tubular thing.

  According to the above configuration, since the catalyst flowing from the lower region through the tubular member toward the upper region collides with the baffle plate, the amount of catalyst scattered from the upper opening end of the tubular member to the upper region side is reduced. Can do.

  In the fluidized bed reactor according to one aspect of the present invention, an orifice plate in which at least one orifice is formed is provided in the tubular material. Furthermore, it is preferable that the flow path area in the said tubular thing becomes large as each said orifice goes to the said upper area | region from the said lower area | region.

  According to the above configuration, each orifice of the tubular object has a shape (throttle portion) in which the flow passage area in the tubular object increases as it goes from the lower opening end of the tubular object to the upper opening end. The flow rate at which the reaction gas accompanying the catalyst passes through the tubular material can be reduced, and the catalyst can be naturally dropped again through the tubular material to the lower region side.

  In the fluidized bed reactor according to one aspect of the present invention, the partition plate is formed with a plurality of the openings, and the plurality of openings are equally arranged on the partition plate. .

  According to said structure, it can prevent that a turbulent flow arises in the lower area | region of a fluidized bed reactor, and it can minimize the bad influence on the reaction in a fluidized bed reactor.

  In addition, you may manufacture a nitrile compound using the fluidized bed reactor mentioned above, In this case, the manufacturing method of the nitrile compound which uses the fluidized bed reactor mentioned above also falls under the category of the present invention.

  According to one aspect of the present invention, the catalyst entrained with the reaction gas and flowing from the lower region to the upper region of the fluidized bed reactor can be dropped to the lower region side by the tubular material. Accumulation of the catalyst can be suppressed.

It is a longitudinal cross-sectional view of the fluidized bed reactor which concerns on one Embodiment of this invention. It is a longitudinal section showing an example of a tubular thing concerning one embodiment of the present invention. (A) and (b) in a figure is a longitudinal section showing other examples of a tubular thing concerning one embodiment of the present invention. (A)-(e) in a figure is a perspective view which shows the other example of the tubular article which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

[Configuration of fluidized bed reactor]
A longitudinal sectional view of a fluidized bed reactor according to this embodiment is shown in FIG. The fluidized bed reactor 11 according to this embodiment is used, for example, for the production of acrylonitrile, the production of vinyl chloride, or the production of maleic anhydride. In the following, an embodiment of the present invention will be described by taking as an example a method for producing acrylonitrile by subjecting propylene, ammonia and air to a gas phase oxidation reaction in the fluidized bed reactor 11.

  As shown in FIG. 1, the fluidized bed reactor 11 is divided into two sections of a lower region A and an upper region B, the partition plate 5 in which an opening 25 is formed, and both ends are open. The tubular member 6 is provided in the partition plate 5 so that the opening portion 25 of the partition plate 5 is fitted in or close to the opening end. In this figure, the tubular object 6 is fitted in the opening 25 of the partition plate 5.

  The lower region A of the fluidized bed reactor 11 is filled with the catalyst 7. In the oxidation reaction, a metal oxide catalyst containing molybdenum, iron, antimony, or the like is preferably used as the catalyst 7. Further, in the lower region A of the fluidized bed reactor 11, an air introduction pipe 12 for introducing air 1, a blowout port 13 for blowing out the air 1 introduced from the air introduction pipe 12 into the lower region A, a reaction A raw material introduction pipe 14 for introducing the raw material and a cooling coil 15 through which the refrigerant 4 passes are provided. In the oxidation reaction of this example, a mixed gas 2 of propylene and ammonia is introduced as a reaction raw material.

  In the fluidized bed reactor 11, the air 7 is introduced from the air introduction pipe 12 and the air 1 is blown out from the outlet 13, thereby fluidizing the catalyst 7 filled in the lower region A. When the mixed gas 2 is introduced from the raw material introduction pipe 14 and the mixed gas 2 and the air 1 are brought into contact with each other, an oxidation reaction occurs due to oxygen in the air 1 and a product is obtained. In the oxidation reaction of this example, 1 equivalent of acrylonitrile and 3 equivalents of water are produced per 1 equivalent of propylene. At this time, in order to keep the reaction temperature of the oxidation reaction constant at an appropriate temperature, the reaction gas 3 in the fluidized bed reactor 11 is cooled by the cooling coil 15 through which the refrigerant 4 is passed and the temperature is controlled while the temperature is controlled. The reaction is going on.

  In the upper region B of the fluidized bed reactor 11, the reaction gas is recovered by the reaction gas recovery pipe 16 and the reaction gas recovery pipe 16 that are inserted into the partition plate 5 and recover the reaction gas 3 containing the compound generated by the oxidation reaction. A cyclone 17 for separating the catalyst 7 from the reaction gas 3, a product extraction pipe 18 for extracting the reaction gas 3 from which the catalyst 7 has been separated by the cyclone 17 to the outside of the fluidized bed reactor 11, and a product extraction pipe 18 A heat exchanger 19 for cooling the reaction gas 3 is provided.

  The reaction gas 3 containing the compound produced by the oxidation reaction is recovered by the reaction gas recovery pipe 16 and then separated from the catalyst 7 by the cyclone 17 to produce the product as the reaction gas 3 containing unreacted raw materials and by-product impurities. It is extracted from the extraction tube 18. The extracted reaction gas 3 is cooled by the heat exchanger 19 and then purified to obtain a final product.

  In the upper region B of the fluidized bed reactor 11, a gas introduction pipe 21 for introducing a gas 20 (for example, air, inert gas or water vapor) that does not adversely affect the oxidation reaction is provided. By introducing the gas 20 from the gas introduction pipe 21, an air flow from the upper region B to the lower region A is formed, and the catalyst 7 is prevented from flowing into the upper region B side and accumulating on the partition plate 5. Can do.

  The material of the various members constituting the fluidized bed reactor 11 such as the main body of the fluidized bed reactor 11, the partition plate 5 and the tubular material 6 is not particularly limited as long as it is a metal material that can withstand the oxidation reaction. Steel or the like can be used. Although there is no limitation in particular as carbon steel, S45C, S55C, or S65C etc. can be used conveniently. The stainless steel is not particularly limited, but SUS27, SUS304, SUS304L, SUS316, SUS316L, or the like can be suitably used.

  Various members formed of a metal material can be subjected to surface treatment by thermal spraying or plating treatment as necessary. Examples of the metal constituting the metal film formed by thermal spraying or plating include metals such as molybdenum, copper, silver, titanium, aluminum, chromium and nickel, and nickel-chromium-molybdenum- such as INCONEL (registered trademark). Alloys including iron, alloys including aluminum-chromium-iron such as INCOLOY (registered trademark), alloys including nickel-molybdenum-tungsten such as HASTELLOY (registered trademark), alloys including nickel-copper such as MONEL (registered trademark) , Alloys including cobalt-chromium-tungsten such as STELLITE (registered trademark), stainless steel alloys made of nickel-chromium-iron such as SUS304 and SUS27, cermet, chromium carbide or titanium oxide. Can be used.

[Function of partition plate]
Since the partition plate 5 is provided with a tubular object 6 that is open at both ends, the partition plate 5 is substantially open. In the fluidized bed reactor 11, the two sections of the lower region A and the upper region B are maintained at a uniform pressure by opening the partition plate 5.

  Here, since the gas 20 is introduced from the gas introduction pipe 21 in the upper region B of the fluidized bed reactor 11, the reaction gas 3 flows backward to the upper region B side, and the catalyst 7 also flows back with the reaction gas 3. There is a case.

  When the back-flowed catalyst 7 is deposited on the cyclone 17, the surfaces of the catalyst particles become sticky and the particles adhere to each other and block. In the fluidized bed reactor 11, by installing the partition plate 5, the block-shaped catalyst 7 is suppressed from falling on the catalyst layer.

[Function of tubular material]
If the back-flowed catalyst 7 accumulates on the partition plate 5, there is a possibility that the material of the partition plate 5 is deteriorated and the material is corroded.

  Therefore, in the fluidized bed reactor 11, the tubular product 6 is fitted into the opening 25 of the partition plate 5, or the open end of the tubular product 6 is closely provided, so that the fluidized bed reaction is accompanied by the reaction gas 3. The catalyst 7 flowing from the lower region A of the vessel 11 to the upper region B through the tubular material 6 is dropped to the lower region A side.

  In FIG. 2, the longitudinal cross-sectional view of the tubular article 6 is shown. As shown in FIG. 2, the tubular object 6 is a cylindrical member having two open ends (a lower open end 10a and an upper open end 10b). In order to drop the catalyst 7 flowing along the reaction gas 3 from the lower region A of the fluidized bed reactor 11 through the tubular material 6 toward the upper region B to the lower region A side, There is a constricted portion in which the flow path area in the tubular object 6 increases from the lower region toward the upper region (that is, from the lower opening end 10a to the upper opening end 10b). The tubular object 6 in this figure is provided with two narrowed portions where the flow path area in the tubular object 6 increases.

  The reaction gas 3 accompanied by the catalyst 7 is tubular because the flow passage area in the tubular material 6 increases from the lower opening end 10a of the tubular material 6 toward the upper opening end 10b. The flow velocity passing through the object 6 can be reduced. Specifically, the linear velocity at which the reaction gas 3 accompanied by the catalyst 7 passes through the vicinity of the upper opening end 10 b of the tubular product 6 is smaller than the linear velocity at which the reaction gas 3 passing through the throttle portion of the tubular product 6. Therefore, the catalyst 7 whose linear velocity has decreased naturally passes through the tubular object 6 again and naturally falls to the lower region A side.

  In the fluidized bed reactor 11 according to this embodiment, the catalyst 7 flowing along the reaction gas 3 from the lower region A of the fluidized bed reactor 11 through the tubular material 6 toward the upper region B is supplied to the lower region A side. Therefore, it is possible to suppress the catalyst 7 from being deposited on the partition plate 5. Therefore, it is possible to prevent the catalyst 7 from being deposited on the partition plate 5 from causing material deterioration, material corrosion, and the like of the partition plate 5. Moreover, it can also suppress that a catalyst 7 deposits on the partition plate 5 and exerts a bad influence on ammoxidation reaction.

  The tubular product 6 provided in the fluidized bed reactor 11 according to the present invention has a structure in which the catalyst 7 flowing from the lower region A toward the upper region B is dropped to the lower region A side and both ends are open. However, it is more preferable that it is a diffuser or a part of the tubular article 6 is a diffuser. The diffuser has a function of reducing the flow rate of the reaction gas 3 accompanied by the catalyst 7 due to the structure in which the flow path area in the tubular object 6 increases from the inlet to the outlet of the flow path of the catalyst 7.

  Since the tubular product 6 shown in FIG. 2 has two throttle portions, the flow rate of the reaction gas 3 accompanied by the catalyst 7 passing through the tubular product 6 can be reduced more effectively. It is possible to more effectively suppress the catalyst 7 from being deposited on the partition plate 5.

  The ratio of the smallest flow path area R2 in the tubular body 6 to the largest flow path area R1 in the tubular body 6 may be set as appropriate according to the amount of catalyst 7 that can be deposited on the partition plate 5. However, for example, the lower limit of the ratio is preferably 0.02 or more, more preferably 0.10 or more, and the upper limit of the ratio is preferably 0.40 or less, more preferably 0.25 or less. Here, the “deposition amount of the catalyst 7 that can be deposited on the partition plate 5” means the deposition amount of the catalyst 7 that can be deposited on the opened partition plate 5 when the tubular material 6 is not provided on the partition plate 5. Means.

  Further, the ratio of the length between the lower opening end 10a and the upper opening end 10b of the tubular product 6 to the length between the partition plate 5 and the top of the fluidized bed reactor 11 has a lower limit of 0.002 or more. Preferably, it is 0.01 or more, more preferably 0.90 or less, and even more preferably 0.75 or less. If the ratio is within the above range, the catalyst 7 that flows along with the reaction gas 3 and flows from the lower region A toward the upper region B can be efficiently dropped into the lower region A. This is because the length of the tubular product 6 is equal to or longer than the distance traveled until the acceleration of the upward velocity becomes zero after the catalyst particles enter the tubular product 6. Since the catalyst particles fall at a downward speed after the upward acceleration becomes zero, the catalyst 7 can be efficiently dropped into the lower region A.

  The tubular object 6 and the partition plate 5 may be formed as separate bodies or may be integrally formed. The partition plate 5 may be provided with at least one tubular product 6. When the tubular product 6 is not provided on the partition plate 5, depending on the amount of catalyst 7 that can be deposited on the partition plate 5, What is necessary is just to determine the number of the tubular objects 6 provided in the partition plate 5. FIG. For example, 4 to 10 tubular objects 6 can be suitably provided for one partition plate 5.

  The arrangement of the tubular objects 6 provided on the partition plate 5 is not particularly limited, but it is preferable that the tubular objects 6 are arranged uniformly on the partition plate 5. By arranging the tubular objects 6 evenly on the partition plate 5, it is possible to prevent the turbulent flow from occurring in the lower region A and to minimize the adverse effect on the oxidation reaction.

[Installation of baffle plates]
As shown in FIG. 2, baffle plates 8 and 9 may be provided in the tubular object 6. Although the position where the baffle plates 8 and 9 are installed is not limited, it is preferable that the baffle plates 8 and 9 are arranged at positions that block the flow path of the catalyst 7. For example, the baffle plate 8 may be disposed at a position facing the central portion of the upper opening end 10b in the horizontal cross section, or the baffle plate 9 may be disposed at the edge of the upper opening end 10b. Good.

  Since the baffle plates 8 and 9 are provided in the tubular body 6, the catalyst 7 flowing toward the upper region B through the tubular body 6 collides with the baffle plates 8 and 9. The amount of the catalyst 7 scattered from 10b to the upper region B side can be reduced.

  The number of the baffle plates 8 and 9 is not particularly limited. However, when the tubular material 6 is not provided on the partition plate 5, the tubular material is formed according to the amount of catalyst 7 that can be deposited on the partition plate 5. What is necessary is just to determine the number of baffle plates 8 and 9 provided in 6.

  For example, 1 to 5 baffle plates 8 and 9 can be suitably provided for one tubular object 6. In FIG. 2, an inverted baffle-shaped annular baffle plate 9 is installed at the edge of the upper opening end 10 b, and is below the baffle plate 9 (more specifically, facing the central portion of the horizontal section of the upper opening end 10 b. In this position, one conical baffle plate 8 is installed, and a total of two baffle plates 8 and 9 are installed.

  Further, the shape of the baffle plates 8 and 9 is not particularly limited, but the baffle plate 8 is set according to the amount of the catalyst 7 that can be deposited on the partition plate 5 when the tubular material 6 is not provided on the partition plate 5. , 9 can be determined. For example, as the baffle plates 8 and 9, a rectangular shape or a triangular shape can be suitably used. Moreover, the thing bent in the L shape so that it may become convex toward the upper opening end 10b like the baffle plate 8 can be used suitably.

  Furthermore, the baffle plates 8 and 9 are not limited to flat plate-like ones. For example, corrugated plates may be used as the baffle plates 8 and 9.

  The size of the baffle plates 8 and 9 with respect to the tubular object 6 is not particularly limited. For example, the ratio of the length of the hypotenuse in the cross-sectional shape of the baffle plate 8 to the opening diameter of the upper opening end 10b of the tubular object 6 is approximately 0. .47, and the ratio of the length of the hypotenuse in the cross-sectional shape of the baffle plate 9 to the opening diameter of the upper opening end 10b is preferably about 0.42.

[Tubular installation example]
Although FIG. 2 shows a form in which the tubular object 6 is fitted into the opening 25 of the partition plate 5, the present invention is not limited to this. As described above, the tubular object 6 may be provided on the partition plate 5 with the opening end in close contact with the opening 25 of the partition plate 5.

  For example, tubular objects 6a and 6b as shown in FIGS. 3A and 3B may be provided on the partition plate 5 with their open ends in close contact with the openings 25 of the partition plate 5. (A) and (b) in FIG. 3 are longitudinal sectional views showing the tubular objects 6a and 6b, respectively.

  3 is provided in the partition plate 5 with the lower opening end 10a in close contact with the opening 25 of the partition plate 5 (that is, the upper portion of the opening 25) from the upper region B side. May be. Alternatively, the tubular member 6a may be provided on the partition plate 5 with the upper opening end 10b in close contact with the opening 25 of the partition plate 5 (that is, the lower portion of the opening 25) from the lower region A side. In this case, the upper opening of the tubular object 6a is such that the flow area in the tubular object 6 at the upper opening end 10b of the tubular object 6a is the same as the flow area in the opening 25 of the partition plate 5. What is necessary is just to make it the shape which the flow-path area in the tubular article 6 becomes small as the edge 10b goes to the upper area | region B from the lower area | region A (namely, lower opening edge 10a to the upper opening edge 10b).

  Alternatively, the tubular product 6b shown in FIG. 3B may be provided on the partition plate 5 with the upper opening end 10b in close contact with the opening 25 of the partition plate 5 from the lower region A side. Alternatively, the tubular member 6b may be provided on the partition plate 5 with the lower opening end 10a in close contact with the opening 25 of the partition plate 5 from the upper region B side.

  The tubular object 6a is a constricted portion in the vicinity of the lower opening end 10a, in which the flow path area in the tubular object 6 increases as it goes from the lower area A to the upper area B (that is, from the lower opening end 10a to the upper opening end 10b). It has one place. Similarly, in the tubular object 6b, the flow path area in the tubular object 6 increases in the vicinity of the lower opening end 10a from the lower area A to the upper area B (that is, from the lower opening end 10a to the upper opening end 10b). It has one aperture part.

  Since the reaction gas 3 accompanied by the catalyst 7 can sufficiently reduce the flow velocity of passing through the tubular objects 6a and 6b even if it has only one throttle portion as in the tubular objects 6a and 6b. The catalyst 7 can be sufficiently prevented from being deposited on the partition plate 5. As described above, the tubular material installed in the fluidized bed reactor 11 is at least at one place in the tubular material 6 from the lower region A toward the upper region B (that is, from the lower opening end 10a to the upper opening end 10b). It is preferable to have a throttle portion that increases the flow path area.

  In addition, you may provide the baffle plates 8 and 9 similarly to the tubular thing 6a also with respect to the tubular thing 6b. Thereby, the amount of the catalyst 7 scattered from the upper opening end 10b to the upper region B side can be reduced.

  Here, the tubular object provided in the partition plate 5 with the opening end in close contact with the opening 25 of the partition plate 5 is not limited to the tubular objects 6a and 6b. For example, the tubular object 6 shown in FIG. 2 may be provided on the partition plate 5 with the lower opening end 10 a in close contact with the opening 25 of the partition plate 5 from the upper region B side.

  Alternatively, the tubular object 6 shown in FIG. 2 may be provided on the partition plate 5 with the upper opening end 10b in close contact with the opening 25 of the partition plate 5 from the lower region A side. In this case, the upper opening of the tubular object 6 is such that the flow area in the tubular object 6 at the upper opening end 10 b of the tubular object 6 is the same as the flow area in the opening 25 of the partition plate 5. What is necessary is just to make it the shape which has the aperture | diaphragm | squeeze part which the flow-path area in the tubular article 6 becomes small as the edge 10b goes to the upper area | region B from the lower area | region A (namely, lower opening edge 10a to the upper opening edge 10b).

[Examples of tubular shapes]
The tubular object 6 may have a cylindrical shape, a triangular prism shape, a quadrangular prism shape, or other polygonal column shape. Among these, it is preferable that the tubular body 6 has a columnar shape or a quadrangular prism shape because the catalyst 7 hardly flows into the upper region B side.

  In addition, the specific shape is not limited to the shape of FIG. 2 (and FIG. 3), if the tubular thing 6 has a shape which functions as a diffuser which naturally drops the catalyst 7 to the lower area | region A side. For example, like the tubular object 6 of FIG. 2 (and FIG. 3), the throttle part may not be provided in a part of the tubular object 6, and the entire tubular object 6 may be the throttle part. That is, the entire tubular object 6 may have a drawn shape in which the flow path area in the tubular object 6 increases as it goes from the lower region A to the upper region B.

  An example in which the tubular object 6 has a drawn shape is shown in FIGS. The tubular product 6c shown in FIG. 4A has a cylindrical shape (conical shape) in which the flow path area in the tubular product 6 increases from the lower region A toward the upper region B. 4B has a quadrangular prism shape (quadrangular pyramid shape) in which the flow path area in the tubular product 6 increases from the lower region A toward the upper region B. Yes. The tubular product 6e shown in FIG. 4C has a triangular prism shape (triangular pyramid shape) in which the flow path area in the tubular product 6 increases from the lower region A toward the upper region B.

  The tubular objects 6c to 6e have a throttle shape in which the flow passage area in the tubular object 6 increases from the lower opening end 10a to the upper opening end 10b of the tubular objects 6c to 6e. The flow rate of the reaction gas 3 passing through the tubular objects 6c to 6e can be decreased, and the catalyst 7 can be naturally dropped again to the lower region A side through the tubular objects 6c to 6e.

  Alternatively, as shown in FIG. 4 (d), a cylindrical (conical) throttle that increases the flow area in the tubular object 6 from the lower region A toward the upper region B inside the single tube. A tubular object 6f having a structure in which the portion 22 is installed is also applicable to the present invention.

  The tubular product 6f also has the throttle portion 22 in which the flow passage area in the tubular product 6 increases from the lower opening end 10a to the upper opening end 10b of the tubular product 6f. The flow velocity at which the reaction gas 3 passes through the tubular product 6f can be reduced, and the catalyst 7 can be naturally dropped again to the lower region A side through the tubular product 6f.

  Further, the tubular object 6 may be provided with an orifice plate having at least one orifice formed therein. Each orifice preferably has a shape in which the flow path area in the tubular object 6 increases as it goes from the lower region A to the upper region B.

  In this case, each orifice of the tubular object 6 has a shape (a throttle portion) in which the flow path area in the tubular object 6 increases as it goes from the lower opening end 10a of the tubular object 6 toward the upper opening end 10b. The flow rate at which the reaction gas 3 accompanied by the catalyst 7 passes through the tubular product 6 can be lowered, and the catalyst 7 can be naturally dropped again through the tubular product 6 to the lower region A side.

  In addition, even if it has a shape in which the flow passage area in the tubular product 6g is substantially constant from the lower region A to the upper region B like the tubular product 6g shown in FIG. A function as a diffuser that naturally drops 7 to the lower region A side can be exhibited.

[Method for producing nitrile compound]
The method for producing a nitrile compound according to the present invention is performed using the fluidized bed reactor according to the present invention described above. For example, one embodiment of the method for producing a nitrile compound according to the present invention is performed using a fluidized bed reactor 11. By using the fluidized bed reactor 11, the catalyst 7 flowing from the lower region A to the upper region B of the fluidized bed reactor 11 along with the reaction gas containing the produced nitrile compound is converted into the lower region B by the tubular material 6. Therefore, the catalyst 7 can be prevented from being deposited on the partition plate 5. For this reason, it is possible to prevent the catalyst 7 from being deposited on the partition plate 5 from adversely affecting the ammoxidation reaction, and the nitrile compound can be manufactured satisfactorily.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example, unless the summary is exceeded.

[Example 1]
Using the fluidized bed reactor shown in FIG. 1, acrylonitrile was produced by ammoxidation of propylene.

  As the tubular object, the tubular object shown in FIG. 2 is used, and the smallest flow path area in the tubular object (R1 in FIG. 2) relative to the flow area (R1 in FIG. 2) in the tubular object at the upper open end of the tubular object. A tubular product having a ratio of R2) of 0.153 was used. A total of two baffle plates were installed in the tubular object. One reverse tapered annular baffle plate (baffle plate 9 in FIG. 2) is installed at the edge of the upper opening end, and below the baffle plate (more specifically, in the horizontal section of the upper opening end). One conical baffle plate (baffle plate 8 in FIG. 2) was installed at a position facing the central portion. In addition, six said tubular objects were installed on the partition plate.

In a fluidized bed reactor whose main body (inner wall) is made of SUS27, as a catalyst, a MoBi-based catalyst (catalyst composition Mo: Bi: Fe: Ce: Cr: Ni: Mg: Co: K: Rb: O: SiO ₂ = 12 : 0.5: 2: 0.5: 0.4: 4: 1.5: 1: 0.07: 0.06: X: 42 (X satisfies the valence of each of the above elements except silicon) 84 kg of the atomic ratio of oxygen necessary for the above was introduced.

Inside the cooling coil (heat transfer area: 0.33 m ² ), steam having a gauge pressure of 3 kg / cm ² was circulated as a refrigerant. From the gas introducing tube, a differential pressure between the upper opening end and a lower open end of the tubing is such that a 0.0015kg / cm ^2, gauge pressure was introducing steam of 0.8 kg / cm ^2.

Next, propylene is introduced into the fluidized bed reactor at a flow rate of 7.8 kg / h from the raw material introduction tube, ammonia is introduced at a flow rate of 3.5 kg / h, and air is introduced from the air introduction tube at a flow rate of 54 kg / h. Then, an ammoxidation reaction was carried out for 360 days under a reaction temperature of 440 ° C., a reaction pressure of 0.6 to 1 kg / cm ² , and a reaction gas linear velocity of 58 to 64 cm / sec. During this period, the overall reaction yield of acrylonitrile was 78.0%.

  On the partition plate after the reaction was completed, 0.9 kg of catalyst was confirmed to be deposited. However, since the amount of catalyst deposited was small, the partition caused by the graphitization phenomenon of steel caused by abnormal heating of the partition plate. There was almost no deterioration of the material of the plate.

[Example 2]
The same operation as in Example 1 was performed except that the tubular product described in (b) of FIG. 4 was used as the tubular product instead of the tubular product described in FIG. In addition, the ratio of the channel area in the tubular object in the lowest part which is the smallest channel area in the tubular object with respect to the channel area in the tubular object in the uppermost opening end is the tubular object used in the present Example. 0.137. Also, from the gas inlet pipe, the differential pressure between the upper opening end and a lower open end of the tubing is such that a 0.0037kg / cm ^2, gauge pressure was allowed to flow steam 0.8 kg / cm ^2.

  When the ammoxidation reaction was carried out for 360 days, the overall reaction yield of acrylonitrile during this period was 77.8%.

  1.1 kg of catalyst was confirmed to be deposited on the partition plate after the reaction was completed, but the amount of catalyst deposited was small, so that the catalyst was deposited on the partition plate and the partition plate was abnormally heated. Almost no deterioration of the partition plate material due to the graphitization phenomenon of the steel was observed.

Example 3
The same operation as in Example 1 was performed except that the tubular product described in (e) of FIG. 4 was used as the tubular product instead of the tubular product described in FIG. In addition, as for the tubular thing used in the present Example, the flow-path area in a tubular thing is constant from a lower area to an upper area. Also, from the gas inlet pipe, as the differential pressure between the upper opening end and a lower open end of the tubing is 0.0037kg / cm ^2, while the gauge pressure allowed to flow steam 0.8 kg / cm ² amm The oxidation reaction was carried out for 360 days.

  After the reaction was completed, 1.3 kg of catalyst was confirmed to be deposited on the partition plate, but since the amount of catalyst deposited was small, the catalyst was deposited on the partition plate and the partition plate was abnormally heated. Almost no deterioration of the partition plate material due to the graphitization phenomenon of the steel was observed.

[Comparative Example 1]
On the partition plate used in Example 1, the same operation as in Example 1 was performed without installing a tubular material. That is, the same operation as in Example 1 was performed using a fluidized bed reactor in which six holes having the same channel area as the smallest channel area in the tubular article shown in FIG.

  When the ammoxidation reaction was carried out for 360 days, the overall reaction yield of acrylonitrile during this period was 74.2%.

  On the partition plate after completion of the reaction, 5.0 kg of catalyst was confirmed to be deposited. Further, since the amount of catalyst deposited was large, deterioration of the partition plate material due to the graphitization phenomenon of steel caused by the catalyst being deposited on the partition plate and abnormal heating of the partition plate was observed.

  INDUSTRIAL APPLICABILITY The present invention can be widely applied as a fluidized bed reactor having a partition plate that partitions the interior into two upper and lower sections and a method for producing a nitrile compound using the same.

DESCRIPTION OF SYMBOLS 1 Air 2 Mixed gas 3 Reaction gas 4 Refrigerant 5 Partition plate 6,6a-6g Tubular material 7 Catalyst 8,9 Baffle plate 10a Lower opening end 10b Upper opening end 11 Fluidized bed reactor 12 Air introduction pipe 13 Outlet 14 Raw material introduction Pipe 15 Cooling coil 16 Reaction gas recovery pipe 17 Cyclone 18 Product extraction pipe 19 Heat exchanger 20 Gas 21 Gas introduction pipe 25 Opening

Claims (9)

Partitioning the inside of the fluidized bed reactor into a lower region and an upper region, comprising a partition plate in which an opening is formed,
The tubular product having open ends at both ends is a fluidized bed reactor provided at the opening of the partition plate.   2. The fluidized bed reactor according to claim 1, wherein the tubular member is provided in the partition plate by being fitted into the opening or having an open end in close contact.   3. The fluidized bed reactor according to claim 1, wherein the tubular material has a portion in which a flow passage area in the tubular material increases from the lower region toward the upper region.   The fluidized bed reactor according to claim 1 or 2, wherein a flow path area in the tubular material is substantially constant from the lower region to the upper region.   The fluidized bed reactor according to any one of claims 1 to 4, wherein a baffle plate is provided in the tubular material.   The fluidized bed reactor according to claim 1 or 2, wherein an orifice plate in which at least one or more orifices are formed is provided in the tubular material.   The fluidized bed reactor according to claim 6, wherein each of the orifices has a channel area in the tubular material that increases from the lower region toward the upper region. The partition plate is formed with a plurality of the openings.
The fluidized bed reactor according to any one of claims 1 to 7, wherein the plurality of openings are equally arranged on the partition plate.   The manufacturing method of the nitrile compound using the fluidized bed reactor of any one of Claims 1-8.

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