JPWO2016147950A1 - Method for packing catalyst in fluidized bed reactor and method for producing nitrile compound - Google Patents

Abstract

In the catalyst filling method of the present invention, the effective sectional area of the fluidized bed reactor is B [m2], the temperature in the fluidized bed reactor is T [° C.], and the total flow rate of the gas introduced into the fluidized bed reactor is F. [Nm3 / h], the gas flow rate U [m / s] in the fluidized bed reactor obtained by substituting the top pressure in the fluidized bed reactor into the following formula (1) as P [kPa] Starting the charging of the catalyst into the fluidized bed reactor and then increasing the U. U = (F / B × ((273 + T) / 273) / ((101 + P) / 101)) / 3600 (1)

Description

  The present invention relates to, for example, a method for filling a fluidized bed reactor in a fluidized bed reactor used for hydrocarbon gas phase oxidation and a method for producing a nitrile compound.

  Various methods for producing a nitrogen-containing compound by a gas phase oxidation reaction using hydrocarbons, ammonia, and an oxygen-containing gas as raw materials are known. In particular, a method for producing unsaturated nitriles by a gas phase fluidized bed reaction using hydrocarbons, ammonia and an oxygen-containing gas as raw materials is known as an ammoxidation reaction. Among them, the production of acrylonitrile by propylene ammoxidation is widely carried out industrially.

  In general, a fluidized bed catalyst is used for the ammoxidation reaction. In a large-scale industrial-scale ammoxidation reaction, an optimized composition, preparation method, shape, particle size, density, and activity have been developed so that the performance of a fluidized bed catalyst can be fully demonstrated. Yes.

  Various proposals have been made regarding the composition and preparation method of the catalyst. With regard to the physical properties of the fluidized bed catalyst, preferred physical properties such as particle density, shape and particle diameter have been proposed. In particular, with respect to the particle size distribution, the ratio of fine powders of 44 μm or less is kept within a certain range, so Is known to improve (Non-patent Document 1), and the reaction results also change.

  As for the method for filling the fluidized bed catalyst, a method of raising the temperature in an atmosphere substantially free of oxygen and / or flammable gas (Patent Documents 1 and 2), a gas discharged from the process after the reactor An effective method (Patent Document 3) is known.

  Also, in the fluidized bed reactor, the reaction is carried out with the gas flow rate in the reactor equal to or higher than the terminal velocity of the fluidized bed catalyst, so a part of the fine powder of the fluidized bed catalyst from the fluidized bed reactor is in the reaction tower. Entrained by gas and scattered outside the reactor. For this reason, a reaction method that maintains a good catalyst flow state over a long period of time is generally adopted by replenishing the catalyst containing a large amount of fine powder during the reaction and maintaining the catalyst particle size distribution in the reactor within a preferable range. (Patent Document 4).

JP 2001-55355 A International Publication 2012/096367 Pamphlet JP 2002-53519 A JP 63-36831 A

Chemical engineering [10] p. 1013-1019, Vol. 34 (1970)

  In the production of the target product using a fluidized bed, not only optimization of the catalyst but also improvement of the final reaction performance can be achieved if the optimum operating conditions are not adopted in order to fully utilize the capacity of the catalyst. Can not do it. In particular, in order to achieve improved reaction results, the selection of conditions during catalyst filling is an important factor.

  All of the methods of Patent Documents 1 to 3 aim to reduce oxygen and flammable gases that adversely affect the catalyst, the device, and safety. Moreover, in patent document 4, it is aimed at maintaining the fluid state of a catalyst favorably after starting a reaction. A gas to be introduced into the reactor may be used when the fluid bed reactor is filled with the catalyst. However, Patent Documents 1 to 4 do not describe the flow rate of the gas. That is, for the purpose of improving the reaction performance of the catalyst, the optimization of the gas flow rate in the reactor when the fluid bed reactor is filled with the catalyst has not been studied.

  The inventors of the present application have examined the gas flow rate in the reactor and found the following.

  That is, the catalyst filling can be completed in a short time by increasing the gas flow rate in the reactor during the catalyst filling. However, the scattering amount of the catalyst (particularly fine powder) increases, and the possibility of occurrence of plant operation troubles such as blockage of piping due to the scattered catalyst increases.

  When the catalyst (especially fine powder) is flowed in a state of being scattered in a large amount, if the catalyst is charged and the reaction after filling is performed, the flow state of the catalyst deteriorates and the reaction becomes unstable, yielding the desired product Causes industrial problems of lowering and partial catalyst degradation.

  Moreover, the amount of catalyst scattering can be suppressed by slowing the gas flow rate and extending the catalyst filling time. However, it takes a long time to complete the filling of the catalyst, and the energy cost for the flammable gas used when preheating the gas introduced into the reactor becomes excessive.

  None of the methods described in Patent Documents 1 to 4 is industrial because no consideration was given to optimizing the flow rate of the gas in the reactor when the fluid bed reactor was charged with the catalyst. The reaction performance of the catalyst could not be improved to a level that satisfies the above.

  The present invention has been made in view of the above circumstances, and by suppressing the amount of catalyst scattered outside the reactor and filling the catalyst in a shorter time, a higher yield reaction can be achieved. The goal is to be efficient.

  The inventor of the present application diligently studied a method for charging a fluidized bed catalyst into a fluidized bed reactor. As a result, by performing an operation to increase the gas flow rate after starting the catalyst filling, the amount of catalyst scattered outside the reactor is suppressed, and a high target product yield is obtained without causing deterioration of the flow state of the catalyst. It has been found that the reaction can be performed at a high rate, and the present invention has been achieved. It has also been found that the gas flow rate can be increased after a certain amount of catalyst is filled in the dipreg which is a catalyst introduction pipe of a cyclone (catalyst collector).

That is, in order to solve the above-mentioned problem, a method of filling a fluidized bed reactor according to the present invention with a catalyst (hereinafter referred to as “catalyst charging method according to the present invention”) is an effective disconnection of the fluidized bed reactor. The area is B [m ² ], the temperature in the fluidized bed reactor is T [° C.], the total flow rate of the gas introduced into the fluidized bed reactor is F [Nm ³ / h], The charging of the catalyst into the fluidized bed reactor is started at the gas flow rate U in the fluidized bed reactor obtained by substituting the top pressure as P [kPa] into the following formula (1), and then It is characterized by including a step of increasing U.

U = (F / B × ((273 + T) / 273) / ((101 + P) / 101)) / 3600 (1)
In the catalyst filling method according to the present invention, the value of T is more preferably 100 to 500 ° C. Further, in the catalyst filling method according to the present invention, it is more preferable that U is increased by increasing F.

  In the catalyst filling method according to the present invention, a catalyst return unit is provided in the fluidized bed reactor, and the catalyst return unit is perpendicular to the position where the catalyst recovered in the fluidized bed reactor is recovered. The amount of catalyst is returned from the lower position into the fluidized bed reactor, and the amount of catalyst is calculated from the difference in pressure between at least two different positions in the vertical direction inside the catalyst return section. It is more preferable to increase the U when a predetermined value is reached.

  The catalyst filling method according to the present invention can be suitably employed in a form in which the catalyst is a catalyst for producing a nitrile compound.

  Moreover, the manufacturing method of the nitrile compound which concerns on this invention is characterized by including the process of performing the catalyst filling method which concerns on the above-mentioned this invention.

  According to the present invention, by suppressing the amount of catalyst scattered outside the reactor and filling the catalyst in a shorter time, the flow state of the catalyst is kept good, hot spots are not generated, and energy is There is an effect that the cost can be reduced and a higher yield reaction can be performed with higher efficiency.

It is a figure which shows schematic structure of one Embodiment of the fluidized bed reactor used with the catalyst filling method which concerns on this invention.

(Catalyst filling method)
In the catalyst filling method according to the present invention, the effective cross-sectional area of the fluidized bed reactor is B [m ² ], the temperature in the fluidized bed reactor is T [° C.], and the total flow rate of the gas introduced into the fluidized bed reactor. Is F [Nm ³ / h], and the top pressure in the fluidized bed reactor is P [kPa], and is obtained by substituting into the following formula (1), the flow rate at the gas flow rate U in the fluidized bed reactor. Starting the charging of the catalyst into the bed reactor and then increasing the U.

U = (F / B × ((273 + T) / 273) / ((101 + P) / 101)) / 3600 (1)
Hereinafter, the gas flow rate U [m / s] in the fluidized bed reactor is set to “gas flow rate U”, the effective sectional area of the fluidized bed reactor is set to B [m ² ] “effective sectional area B”, and the fluidized bed reaction. The temperature T [° C.] in the reactor is “temperature T”, the gas introduced into the fluidized bed reactor is “introduction gas”, the total flow rate F [Nm ³ / h] of the introduction gas is “total flow rate F of the introduction gas”, The top pressure P [kPa] in the fluidized bed reactor may be referred to as “top pressure P”.

  For example, it is possible to prevent the packed catalyst from being scattered outside the fluidized bed reactor by increasing the gas flow rate U in the fluidized bed reactor during the catalyst filling process after starting the catalyst filling. it can. The smaller the catalyst particle size, the easier it is to fly out of the fluidized bed reactor. If the scattered catalyst is biased toward a particle having a small particle size, the particle size distribution is changed as compared with that before the catalyst is packed, and the flow state of the catalyst is deteriorated. However, according to the present invention, since the deterioration of the fluid state of the catalyst can be prevented, the target product can be obtained in a high yield by the subsequent reaction. Further, since the filling can be completed in a short time, the catalyst can be efficiently charged in the fluidized bed reactor. Moreover, scattering of the catalyst with a small particle diameter can be prevented, and deterioration of the flow state of the catalyst can be prevented. For this reason, the fluid state of the catalyst is kept good. Furthermore, since the fluid state is maintained well, the occurrence of temperature spots (hot spots) is suppressed even in the subsequent reaction of producing the target product. In addition, since the filling can be completed in a short time, the energy cost can be reduced.

  The catalyst filling method according to the present invention can be suitably applied to the filling of a catalyst when synthesizing nitriles by ammoxidation of a hydrocarbon having 1 to 6 carbon atoms. Among them, the present invention is more suitably applied as a catalyst filling method for the synthesis of acrylonitrile by the ammoxidation reaction of propylene and / or propane, and the synthesis of methacrylonitrile by the ammoxidation reaction of isobutylene and / or isobutane.

(Step of increasing the gas flow rate U [m / s] in the reactor)
The catalyst filling method according to the present invention includes a step of increasing the gas flow rate U represented by the above formula (1).

  The gas flow rate in the fluidized bed reactor is a value obtained by temperature correction and pressure correction of a value obtained by dividing the flow rate of the introduced gas by the effective sectional area. As a specific value range of U, 0.07 m / s or more is preferable, 0.10 m / s or more is more preferable, 0.46 m / s or less is preferable, and 0.43 m / s or less is more preferable. . Within the above range, the larger the gas flow rate in the reactor, the faster the reactor can be filled with the catalyst and the higher the productivity of the reaction. Moreover, if it is in the said range, the scattering of the catalyst during the filling of a catalyst can be suppressed, and the fall of the temperature in a reactor can be suppressed, so that the gas flow rate in a reactor is small.

(Effective cross-sectional area B [m ² ] of fluidized bed reactor)
The effective sectional area B refers to an area obtained by subtracting the sectional area of the interior from the sectional area when the fluidized bed reactor is cut in the horizontal direction. Specifically, the effective cross-sectional area is, for example, a cross-sectional area in a portion (reaction portion or concentrated layer) where the reaction between the source gas and the catalyst occurs above the position (height) at which the source gas to be described later is introduced (height). It means the cross-sectional area obtained by reducing the cross-sectional area of interior objects such as diplegs.

The size of the fluidized bed reactor used in the catalyst filling method according to the present invention is not particularly limited, but for industrial production, the effective sectional area of the reactor is usually in the range of 10 to ²⁰⁰ m ² . If it is in the said range, productivity of a target product can be made high, so that an effective cross-sectional area is large. Moreover, if it is in the said range, operativity of apparatuses, such as temperature control, can be improved, so that an effective area is small.

(Temperature T [° C] in the fluidized bed reactor)
The temperature T is determined by measuring the temperature in the fluidized bed reactor. What is necessary is just to make a measurement location into the part (reaction part or rich layer) where reaction with a catalyst above the position (height) which introduces the source gas mentioned later, for example. The temperature T is the temperature after the change, if the temperature is changed by performing the process of increasing the gas flow rate U. The equation (1) is obtained by multiplying the flow rate (F / B) of the introduced gas per unit effective sectional area, which is obtained by dividing the total flow rate F of the introduced gas by the effective sectional area B, by (273 + T) / 273. Thus, the influence of temperature change is corrected. The influence of the change in temperature may be, for example, a change in gas volume due to a change in temperature, and a change in flow velocity. Therefore, the gas flow rate U can be increased also by changing the temperature T. For example, the gas flow rate U can be increased by increasing the temperature T. “273” is an approximate value of a value for calculating the Celsius temperature (° C.) by the thermodynamic temperature (K).

  The temperature T in the fluidized bed reactor at the time of catalyst filling in the fluidized bed catalyst filling method of the present invention is usually in the range of 100 to 500 ° C. Within the above range, the higher the temperature, the sooner the reaction can be started after filling, and the better the flow state of the catalyst. Moreover, if it is in the said range, the fuel cost per unit time used for the heating of the gas introduced into a fluidized bed reactor during catalyst filling can be restrained low, so that temperature is low.

(Top pressure P [kPa] in fluidized bed reactor)
The top pressure P is determined by measuring the pressure at the top of the fluidized bed reactor. The tower top pressure P is the tower top pressure after the change, if the temperature is changed by performing the process of increasing the gas flow rate U. The equation (1) corrects the influence of the change in pressure by dividing the flow rate (F / B) of the introduced gas per unit effective cross-sectional area by (101 + P) / 101. The influence of the change in pressure may be, for example, a change in gas volume due to a change in pressure, and a change in flow velocity. Therefore, the gas flow rate U can be increased also by changing the tower top pressure P. For example, the gas flow rate U can be increased by decreasing the tower top pressure P. Note that “101” is an approximate value of a value for calculating a value whose unit is Pascal at the standard atmospheric pressure.

(Total flow rate F [Nm ³ / h] of gas introduced into the fluidized bed reactor)
Examples of the gas introduced into the fluidized bed reactor include a fluidizing gas for fluidizing the catalyst charged in the fluidized bed reactor 10 and a catalyst transporting gas for transporting the catalyst to the fluidized bed reactor. . Since the flow rates of these gases are set by the user, the total flow rate F of the introduced gas can be obtained by summing the gas flow rates set by the user.

  Although it does not specifically limit regarding the kind of gas for flow and gas for catalyst conveyance, For example, pure oxygen, air, the mixed gas of pure oxygen and air, etc. can be mentioned. These gases may be diluted with other gases. The gas for dilution is not particularly limited, and may be any gas that does not adversely affect the catalyst performance and the gas phase oxidation reaction. Examples thereof include air, nitrogen, and helium. In general, air, oxygen gas, or an oxygen-containing gas diluted to an arbitrary concentration with an inert gas may be used.

  It should be noted that the total flow rate F of the introduced gas includes the flow rate of any gas introduced into the fluidized bed reactor in addition to the flowing gas and the catalyst carrying gas. Examples of such a gas include a purge gas to a source gas line or each differential pressure measurement line.

(Preferable combination of temperature T, tower top pressure P and total flow rate F of introduced gas)
The values of the temperature T, the top pressure P, and the total flow rate F of the introduced gas are not particularly limited because they vary depending on the size and structure of the fluidized bed reactor. The gas flow rate U is calculated by determining the effective cross-sectional area B and determining a combination of three values of the temperature T, the top pressure P, and the total flow rate F of the introduced gas.

(Time to increase the gas flow rate U [m / s] in the fluidized bed reactor)
The timing of increasing the gas flow rate U can be set as appropriate according to the target filling time, how much catalyst scattering is to be suppressed, etc. May be after it enters the fluidized bed reactor.

  In addition, fluidized bed reactors are often connected and installed with a plurality of cyclones in order to increase the catalyst collection efficiency. Usually, a cyclone is provided with a dipleg. The dipreg is an apparatus for returning the catalyst recovered in the fluidized bed reactor from the lower part of the fluidized bed reactor (a position vertically below the recovered position) into the fluidized bed reactor.

  In general, the first stage of the dipleg has a large amount of catalyst circulation, so the bottom part is open in the reactor (or a reversing plate is installed), and the second and third stage cyclones. A trickle valve (catalyst discharge amount adjusting facility) and the like are installed at the lower end portion of the dipreg provided in the housing.

  In the catalyst filling method according to the present invention, the timing for increasing the gas flow rate U [m / s] in the fluidized bed reactor is preferably based on the amount of catalyst in the dipreg. It is preferable to set the time based on the amount of catalyst in the dipreg (the bottom is open, or a reversing plate or the like is installed and there is no trickle valve). It is also preferable to increase the gas flow rate U in the fluidized bed reactor when the amount of catalyst in the dipleg reaches a predetermined value. As said value, it is preferable to set it as 0.1 volume% or more, for example, More preferably, it is 0.3 volume% or more. When there is no catalyst in the dipreg, the gas and catalyst introduced into the fluidized bed reactor enter from the open end of the dipleg (back flow), and it reaches the cyclone and reaches the cyclone, and the catalyst scatters out of the system. There is. If the lower end of the dipreg is sealed with a catalyst, the gas and the catalyst can be prevented from entering. The minimum value of the catalyst amount of the first stage dipreg that can be confirmed by the differential pressure is preferably 0.1% by volume or more, more preferably 0.3% by volume or more. That is, after confirming that the lower end portion of the dipreg is sealed, the gas flow rate U is increased, so that the scattering of the catalyst can be suppressed more efficiently and the filling time can be shortened.

  For example, the total gas flow rate F is kept constant, and the temperature and pressure that change with time are kept unchanged. In this state, it is confirmed that the lower end of the dipreg is covered with the catalyst, the total gas flow rate F is increased, and the gas flow rate U is increased. The total gas flow rate F may be adjusted for purposes other than increasing the gas flow rate U. For example, the adjustment for suppressing the influence of the flow meter device performance (characteristic) or the flow characteristic of the catalyst may be appropriately performed.

  The method for measuring the amount of catalyst in the dipreg is not particularly limited, but in the dipreg, two places with different heights (vertical positions), for example, the vicinity of the connection with the cyclone and the return of the catalyst at the bottom It can be calculated from the difference in pressure from the vicinity of the mouth.

(Amount to increase the gas flow rate U [m / s] in the fluidized bed reactor)
The amount by which the gas flow rate U is increased can be appropriately set according to the target filling time, how much catalyst scattering is suppressed, and the like.

  After starting the packing, if the gas flow rate U in the fluidized bed reactor is increased even a little, the catalyst can be initially charged while suppressing scattering, and the gas flow rate U in the fluidized bed reactor is increased. Later, the filling can be completed in a shorter time.

  The specific value of the amount to be increased is preferably 2% or more, more preferably 4% or more, relative to the value at the start of filling, for example, from the standpoint of producing a clear effect by increasing the gas flow rate. Moreover, from a viewpoint of catalyst scattering suppression, 200% or less is preferable and 150% or less is more preferable.

(Method of increasing the gas flow rate U [m / s] in the fluidized bed reactor)
The method for increasing the gas flow rate U is not particularly limited, but it is more preferable to perform an operation for increasing the total flow rate F of the introduced gas. This is because the gas flow rate U can be easily increased.

  However, it should be noted that it is necessary to increase the total flow rate F of the introduced gas until the gas flow rate U increases. That is, even if the operation for increasing the total flow rate F of the introduced gas is performed, the temperature T and the top pressure P change due to the increase, and as a result, the gas flow rate U may not increase. However, it is necessary to increase the gas flow rate U in the catalyst filling method according to the present invention. Therefore, when an operation for increasing the total flow rate F of the introduced gas is performed, it is preferable to measure the temperature T and the tower top pressure P and operate them in the direction in which the gas flow rate U increases as necessary. It is more preferable to calculate the gas flow rate U according to the formula (1) and confirm that it has increased.

  It should also be noted that if the gas flow rate U increases, it is not always necessary to increase the total flow rate F of the introduced gas. If the gas flow rate U increases by intentionally controlling the total flow rate F of the introduced gas to be within a certain range, it is within the category of the catalyst filling method according to the present invention. For example, by making the total gas flow rate F constant, the gas flow rate U repeatedly increases and decreases within a certain range by hunting. Thus, by making the total gas flow rate F constant within a predetermined range, the catalyst can be charged while suppressing scattering to a desired degree in a desired time. Such an operation is also a category of the catalyst filling method according to the present invention.

  The operation for increasing the gas flow rate U may be performed once or twice or more. For example, it may be increased by a single operation up to the target value of the increased gas flow rate U, or may be increased stepwise over a plurality of times. The number of times can be appropriately set according to the flow state of the target catalyst, the filling time and the like.

  Further, the gas flow rate U may be increased in a short time or may be increased gradually.

(Fluidized bed reactor)
As the fluidized bed reactor used in the catalyst filling method according to the present invention, a conventionally known fluidized bed reactor used for fluidized bed reaction can be arbitrarily selected and employed. Here, an embodiment of a fluidized bed reactor used in the catalyst filling method according to the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a fluidized bed reactor 1 including a fluidized bed reactor 10.

  In this embodiment, the fluidized bed reactor 1 is an apparatus for producing acrylonitrile by ammoxidizing hydrocarbons.

  The fluidized bed reactor 10 is a vertical cylindrical fluidized bed reactor. A gas supply conduit 16 is connected to the fluidized bed reactor 10. In the fluidized bed reactor 10, a cyclone 12 and a gas dispersion plate 19 are provided. The fluidized bed reactor 10 is provided with a gas supply port 20. A catalyst hopper 2 is connected to the fluidized bed reactor 10. The fluidized bed reactor 10 is provided with a plurality of pressure measurement points (not shown), and the total amount of catalyst present in the fluidized bed reactor 10 is calculated from the measured pressure difference. can do.

(Catalyst Hopper 2)
The catalyst hopper 2 is for storing a catalyst for filling the fluidized bed reactor. The catalyst x1 delivered from the catalyst hopper 2 is carried by the catalyst carrying gas x2. That is, the catalyst-containing gas X obtained by joining the catalyst x1 and the catalyst transport gas x2 is supplied into the fluidized bed reactor 10.

(catalyst)
Although it does not specifically limit as a catalyst which applies the catalyst filling method which concerns on this invention, The said method is suitable for the catalyst etc. which are used for the ammoxidation reaction and / or oxidation reaction of the C1-C6 hydrocarbon. Can be applied. Examples of such catalysts include metal oxide catalysts containing molybdenum and bismuth, metal oxide catalysts containing iron and antimony, metal oxide catalysts containing molybdenum and vanadium, metal oxides containing uranium and antimony. And physical catalysts. Especially, it can apply suitably with the catalyst for manufacture of a nitrile compound.

  The shape of the catalyst is not particularly limited, but it is more preferably a powder. Further, the particle diameter is preferably 5 μm or more, more preferably 10 μm or more, and preferably 200 μm or less, more preferably 180 μm or less.

(Gas supply conduit 16)
The gas supply conduit 16 is used to supply the raw material gas Z to the fluidized bed reactor 10 when a reaction for producing a target product is performed after filling the catalyst. The raw material gas Z contains a gaseous hydrocarbon compound, gaseous ammonia and water vapor. It is provided below the fluidized bed reactor 10 and branches into a plurality of branch pipe portions 17. A nipple portion (raw material spray nozzle) 18 that opens toward the bottom surface of the fluidized bed reactor 10 is connected to the end of each branch pipe portion 17.

(Raw gas Z)
As the source gas Z, hydrocarbon having 1 to 6 carbon atoms, for example, butanes such as methane, ethane, ethylene, propane, propylene, n-butane, and isobutane, butylenes such as n-butylene and isobutylene, n- Examples thereof include pentanes such as pentane and isopentane, pentenes such as n-pentene and isopentene, hexanes such as n-hexane and isohexane, and hexenes such as n-hexene and isohexene.

(Cyclone 12)
The cyclone 12 is for separating gas and catalyst. The cyclone 12 has an inlet 13 for taking gas and catalyst into the cyclone 12, a gas outflow pipe 15 for leading the separated gas out of the fluidized bed reactor 10, and the separated catalyst flowing through the catalyst in the reactor. A dipleg 14 to be returned to the floor 11 is provided.

  As shown in FIG. 1, the fluidized bed reactor has a series of three cyclones 12 connected to each other inside the reactor (however, in FIG. Only one series is shown.) Further, as shown in FIG. 1, two cyclones 12 are connected by one gas outflow pipe 15, and another one gas outflow pipe 15 leads gas out of the fluidized bed reactor 10.

(Gas dispersion plate 19)
The gas dispersion plate 19 is for dispersing the oxygen-containing gas Y supplied from the gas supply port 20 in the fluidized bed reactor 10. The gas dispersion plate 19 is provided between the gas supply port 20 and the gas supply conduit 16.

(Gas supply port 20)
The gas supply port 20 is for supplying the oxygen-containing gas Y to the fluidized bed reactor 10. The gas supply port 20 is provided at the bottom of the fluidized bed reactor 10.

(Oxygen-containing gas Y)
The oxygen-containing gas Y is a fluid gas for causing the catalyst to flow in the fluidized bed reactor 10 at the time of catalyst filling, and is a gas for supplying oxygen to be used for the reaction at the time of reaction.

  The oxygen-containing gas Y as a flowing gas at the time of catalyst filling and the oxygen-containing gas Y as a gas for supplying oxygen at the time of reaction may be the same gas or different gases. The specific type of the oxygen-containing gas Y conforms to the above description of the flow gas.

(Method for producing nitrile compound)
The manufacturing method of the nitrile compound which concerns on this invention includes the process of performing the catalyst filling method which concerns on this invention mentioned above. By adopting the catalyst filling method according to the present invention, the flow state of the catalyst in the fluidized bed reactor is good, and there are many fine catalyst particles in the fluidized bed reactor without scattering. . Therefore, a nitrile compound can be obtained with a high yield.

  After performing the catalyst filling method according to the present invention, a reaction for producing a nitrile compound may be started at any time of the user. For example, the reaction may be started after confirming that the flow state of the catalyst in the fluidized bed reactor has reached a steady state. When the reaction starts, the reaction temperature rises due to heat generation, the pressure fluctuates, and the flow state of the catalyst may change. In the case where the fluctuations in these states are large and unstable before the reaction starts, it is preferable from the safety aspect that the reaction is started when the fluctuations in the respective states are within a predetermined range and the state is stabilized. Further, before the reaction for producing the nitrile compound, the temperature rise due to the reaction may be predicted, and the temperature may be lowered before the reaction starts.

  The raw material gas supplied to the fluidized bed reactor may be diluted with an inert gas such as nitrogen or carbon dioxide, saturated hydrocarbons, alcohols, or the like, or may be used with an increased oxygen concentration.

  In the method for producing a nitrile compound according to the present invention, the composition ratio of the raw material gas used for the gas phase oxidation reaction is not particularly limited. However, since the yield of the target product is increased, the carbonization having 1 to 6 carbon atoms described above is performed. More preferably, the molar ratio of at least one compound selected from hydrogen / ammonia / oxygen is in the range of 1 / 0.5 to 2.0 / 1.0 to 5.0.

  The gas phase oxidation reaction conditions applied in the method for producing a nitrile compound according to the present invention are not particularly limited, but in general, the reaction temperature is 350 to 500 ° C., and the reaction pressure is normal pressure to 500 kPa.

  In the present invention, the method for supplying at least one compound selected from the hydrocarbons having 1 to 6 carbon atoms, ammonia, and an oxygen-containing gas into the reactor is not particularly limited. Commonly used methods such as a method and a method of supplying through a dispersion plate can be used.

  In addition, at least one compound selected from hydrocarbons having 1 to 6 carbon atoms, ammonia, and oxygen-containing gas may be divided and supplied to the fluidized bed reactor, or may be mixed in whole or in part. You may supply. In consideration of safety and the like, a method in which at least one compound selected from hydrocarbons having 1 to 6 carbon atoms, ammonia, and an oxygen-containing gas are divided and supplied into the fluidized bed reactor is common. .

  Moreover, after filling the catalyst as described above from the viewpoint of efficiency, the nitrile compound may be subsequently produced.

  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 the embodiments. Is also included in the technical scope of the present invention. EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated in detail, this invention is not limited by the following description, unless the summary is exceeded.

[Example 1]
(Charging the reactor with fluid bed catalyst)
Fluidized bed catalyst (catalyst _{composition, Fe 10 Sb 20 Mo 0.5 W} 0.4 Te 1.4 Cu 3 Ni 1 P 0.5 B 1.8 Cr 0.3 Mn 0.1 K 0.1 O x (SiO ₂ ) ₆₀ ; where x is the number of oxygen atoms necessary to satisfy the valence of each of the above components excluding silica) 110 tons from the catalyst hopper to an inner diameter of 8.0 m (effective sectional area B47 m ² ) Was charged into the vertical cylindrical fluidized bed reactor.

  As the fluidized bed reactor, the fluidized bed reactor equipped with this, and the catalyst hopper, the one shown in FIG. 1 was used.

Air is used as the gas for flowing into the fluidized bed reactor and the gas for transporting the catalyst, and the reaction is performed under the conditions of the total gas flow rate F12 × 10 ³ Nm ³ / h, the reactor internal temperature T420 ° C., and the reactor top pressure P8 kPa. Filling of the vessel with catalyst was started. The gas flow rate U in the reactor at the start of filling (filling time 0 hour) was 0.17 m / s. The flow rate of the catalyst transport gas may be any flow rate that can transport the catalyst. However, in the examples and comparative examples, the flow rate of the flow gas is extremely large compared to the flow rate of the catalyst transport gas. The total flow rate F was set to be substantially the same as the flow rate of the flow gas (the same applies to the following examples and comparative examples).

11.5 hours after the start of catalyst filling, when the catalyst charge in the dipreg reached 1.6% by volume, when the catalyst charge in the fluidized bed reactor reached 64 tons, the fluidized bed reactor was The total gas flow rate F was set to 37 × 10 ³ Nm ³ / h.

  After the increase of the flow gas (11.7 hours), the temperature T in the reactor was 345 ° C., the top pressure P was 21 kPa, and the gas flow rate U was 0.41 m / s.

  Finally, the catalyst filling could be completed with a catalyst filling time of 12.9 hours. The catalyst filling amount was 110 tons, and it was confirmed that almost the entire amount of catalyst was filled in the reactor. The catalyst charge after completion of catalyst charge was determined from the difference in pressure measured at the bottom of the fluidized bed reactor and the position where the reaction was performed above the position where the raw material gas was introduced.

  Table 1 shows each value from the start of filling to the completion of filling.

(Ammoxidation reaction after catalyst filling)
The ammoxidation reaction was carried out using a fluidized bed reactor in which the catalyst charge was completed. Air was used as an oxygen source, and a raw material gas having a composition of propylene: ammonia: oxygen = 1: 1.1: 2.3 (molar ratio) was fed into the reaction tower. The reaction pressure was 180 to 220 kPa, the reaction temperature was 455 to 465 ° C., and the gas flow rate in the reactor was 50 to 70 cm / sec.

  During the reaction under the above conditions, the reaction temperature was detected with thermocouple thermometers installed at a plurality of locations, but no temperature spots (hot spots) were observed during the reaction, and the catalyst was in a good fluid state. The average yield of acrylonitrile was 77.4%.

[Example 2]
(Charging the reactor with fluid bed catalyst)
By the same operation as in Example 1, the fluidized bed catalyst was charged into the fluidized bed reactor shown in FIG. Air was used as the gas for flowing into the fluidized bed reactor and the gas for transporting the catalyst, and the total flow rate F of these gases was 23 × 10 ³ Nm ³ / h. The gas flow rate U in the reactor at the start of filling (filling time 0 hour) was 0.30 m / s. Filling of the fluidized bed reactor with the catalyst was started under the conditions of a temperature T420 ° C. in the fluidized bed reactor and a top pressure P15 kPa in the fluidized bed reactor.

After 4.6 hours from the start of catalyst filling, when the catalyst charge in the dipreg reached 1.7 vol%, when the catalyst charge in the fluidized bed reactor reached 66 tons, the flow to the reactor The working gas was increased so that the total flow rate F was 30 × 10 ³ Nm ³ / h.

  After the increase of the flow gas (5.3 hours), the temperature T in the reactor was 280 ° C., the top pressure P was 15 kPa, and the gas flow rate U was 0.31 m / s.

  Finally, the catalyst filling could be completed with a catalyst filling time of 6.1 hours. The catalyst filling amount after completion of catalyst filling was 109 tons, and it was confirmed that almost the entire amount of catalyst was filled in the reactor.

(Ammoxidation reaction after catalyst filling)
An ammoxidation reaction was carried out under the same conditions as in Example 1 using a fluidized bed reactor (see FIG. 1) after charging the fluidized bed catalyst. During the reaction, the reaction temperature was detected by thermocouple thermometers installed at a plurality of locations, but no temperature spots (hot spots) were observed during the reaction, and the catalyst was in a good fluid state. The average yield of acrylonitrile was 77.1%.

[Comparative Example 1]
(Charging the reactor with fluid bed catalyst)
In the same manner as in Example 1, charging of the fluidized bed catalyst into the fluidized bed reactor (see FIG. 1) was started. Air was used as the gas for flowing into the fluidized bed reactor and the gas for transporting the catalyst, and the total flow rate F of these gases was 40 × 10 ³ Nm ³ / h. The gas flow rate U in the reactor at the start of filling (filling time 0 hour) was 0.48 m / s. Filling of the fluidized bed reactor with the catalyst was started under conditions of a fluidized bed reactor temperature T420 ° C. and a fluidized bed reactor top pressure P26 kPa.

  The total flow rate F of the introduced gas was constant and no increase was made. The catalyst loading in the dipreg after 1.1 hours was 1.3% by volume. Finally, the catalyst loading was completed with a 2.1 hour catalyst loading time. The catalyst filling amount after completion of catalyst filling was 105 tons, and it was found that about 5% by mass of the catalyst used for filling was scattered outside the reactor.

(Ammoxidation reaction after catalyst filling)
An ammoxidation reaction was carried out under the same conditions as in Example 1 using a fluidized bed reactor (see FIG. 1) after charging the fluidized bed catalyst. During the reaction, when the reaction temperature was detected by thermocouple thermometers installed at a plurality of locations, temperature spots (hot spots) were observed in the reactor, and it was found that the flow state of the catalyst was deteriorated. The average yield of acrylonitrile was 73.4%. From the reactor stopped after the reaction, a catalyst that was reduced and deteriorated (discolored) was observed.

[Comparative Example 2]
(Charging the reactor with fluid bed catalyst)
In the same manner as in Example 1, charging of the fluidized bed catalyst into the fluidized bed reactor (see FIG. 1) was started. Air was used as the gas for flowing into the fluidized bed reactor and the gas for transporting the catalyst, and the total flow rate F of these gases was 3 × 10 ³ Nm ³ / h. The gas flow rate U in the reactor at the start of filling (filling time 0 hour) was 0.04 m / s. Filling of the fluidized bed reactor with the catalyst was started under the conditions of a fluidized bed reactor temperature T420 ° C. and a fluidized bed reactor top pressure P2 kPa.

During the filling of the catalyst, the total flow rate F of the introduced gas was kept constant and was not increased. The catalyst loading in the dipreg after 7.9 hours was 1.3% by volume. The catalyst filling time of 17.8 hours was finally required to complete the catalyst filling. The catalyst filling amount after completion of catalyst filling was 110 tons, and it was confirmed that almost the whole amount of catalyst was filled in the reactor, but the filling time was longer by about 5 to 12 hours than in Examples 1 and 2. The energy cost required to heat the temperature in the reactor during that time (for example, if the charging time is increased by 5 hours, the amount of propylene used as fuel is 400 Nm ³ × 5 hours = 2000 Nm ³ used) Increased.

(Ammoxidation reaction after catalyst filling)
An ammoxidation reaction was carried out under the same conditions as in Example 1 using a fluidized bed reactor (see FIG. 1) after charging the fluidized bed catalyst. During the reaction, the reaction temperature was detected by thermocouple thermometers installed at a plurality of locations, but no temperature spots (hot spots) were observed during the reaction, and the catalyst was in a good fluid state. In addition, although the average yield of acrylonitrile was 77.3%, since the filling time was required as described above, an opportunity loss in acrylonitrile production occurred during that time.

  As is clear from the above-mentioned examples and comparative examples, the catalyst filling initial stage until the catalyst amount of a certain amount is filled in the dipleg below the cyclone in the reactor is reduced by reducing the gas flow rate in the reactor. By increasing the gas flow rate in the reactor in the middle of filling and performing the reaction after filling the reactor with the catalyst, the amount of catalyst scattered outside the reactor is suppressed, and the flow state of the catalyst is not deteriorated. It was shown that the reaction can be performed with a high yield of the desired product.

DESCRIPTION OF SYMBOLS 1 Fluidized bed reactor 2 Catalytic hopper 10 Fluidized bed reactor 11 Catalytic fluidized bed 12 Cyclone 13 Inlet 14 Dipreg 15 Gas outlet pipe 16 Gas supply conduit 17 Branch pipe part 18 Nipple part 19 Gas distribution plate 20 Gas supply port X Catalyst containing Gas Y Oxygen-containing gas Z Raw material gas x1 Catalyst x2 Catalyst transport gas

Claims (11)

A method of charging a fluidized bed reactor with a catalyst, wherein the effective sectional area of the fluidized bed reactor is B [m ² ], the temperature in the fluidized bed reactor is T [° C.], and the fluidized bed reactor is supplied to the fluidized bed reactor. The total flow rate of the gas to be introduced is F [Nm ³ / h] and the top pressure in the fluidized bed reactor is substituted into P [kPa] and is obtained by substituting into the following formula (1). A method including increasing the U after starting the charging of the catalyst into the fluidized bed reactor with respect to a gas flow rate U [m / s].
U = (F / B × ((273 + T) / 273) / ((101 + P) / 101)) / 3600 (1)   The method according to claim 1, wherein the value of T is 100 to 500 ° C.   The method according to claim 1 or 2, wherein the U is increased by increasing the F.   The method according to claim 1, wherein the U is increased by changing at least one of the T and the P. A catalyst return section is provided in the fluidized bed reactor,
The catalyst return section returns the catalyst recovered in the fluidized bed reactor from the position vertically below the recovered position to the fluidized bed reactor,
2. The catalyst amount is calculated from a difference in pressure between at least two different positions in the vertical direction inside the catalyst return unit, and the U is increased when the catalyst amount reaches a predetermined value. The method of any one of -4.   The method according to any one of claims 1 to 5, wherein the gas is at least one of a fluidizing gas for fluidizing the catalyst and a catalyst transporting gas for transporting the catalyst to a fluidized bed reactor. .   The method according to claim 1, wherein in the step of increasing U, the amount is increased by 2% or more and 200% or less with respect to U at the start of filling.   The method according to claim 1, wherein in the step of increasing U, the amount is increased by 4% or more and 150% or less with respect to U at the start of filling.   The method according to claim 1, wherein the catalyst is a catalyst for producing a nitrile compound.   The manufacturing method of the nitrile compound characterized by including the process of performing the method of Claims 1-9.   A method for producing a nitrile compound, wherein the production of a nitrile compound is subsequently carried out after the method according to claim 1 is carried out.

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