TW201707781A - Method for packing catalyst into fluidized bed reactor, and process for producing nitrile compound - Google Patents

Abstract

This catalyst packing method includes a step in which the packing of a catalyst into a fluidized bed reactor is initiated while introducing a gas into the fluidized bed reactor so as to result in a gas flow velocity inside the fluidized bed reactor of U [m/s], and thereafter the U is increased, the U being obtained by substituting the effective cross-sectional area of the fluidized bed reactor as B [m2], the temperature inside the fluidized bed reactor as T [DEG C], the total amount of the gas introduced into the fluidized bed reactor as F [Nm3/h], and the top pressure inside the fluidized bed reactor as P [kPa] into the following equation (1). U=(F/B x ((273+T)/273)/((101+P)/101))/3600 equation (1).

Description

Method for filling catalyst in fluidized bed reactor and method for producing nitrile compound

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

Various methods for producing a nitrogen-containing compound by gas phase oxidation reaction using a hydrocarbon, ammonia, and a gas containing oxygen as a raw material are known. In particular, a method of producing an unsaturated nitrile by reacting a hydrocarbon, ammonia, and a gas containing oxygen as a raw material by a gas phase fluid bed reaction is known as an ammoxidation reaction. Among them, the production of acrylonitrile by the ammoxidation reaction of propylene is widely practiced in the industry.

Typically, the ammoxidation reaction uses a fluid bed catalyst. In a large-scale industrial-scale ammoxidation reaction, a catalyst that optimizes the composition, preparation method, shape, particle size, density, activity, and the like is developed so that the performance of the fluid bed catalyst can be sufficiently exhibited.

Various proposals have been made regarding the composition and preparation method of the catalyst. Regarding the physical properties of the fluid bed catalyst, physical properties such as particle density, shape, and particle size are proposed. Particularly, regarding the particle size distribution, it is known that the ratio of the fine powder of 44 μm or less is maintained in a fixed range. The flow state of the medium becomes good (Non-Patent Document 1), whereby the reaction results also change.

Further, a method of filling a fluid bed catalyst is known as a method of raising the temperature in an environment containing substantially no oxygen gas and/or a combustible gas (Patent Document 1 and Patent Document 2); A method of discharging a gas in a process (Patent Document 3).

Further, in the fluidized bed reactor, the gas flow rate in the reactor is set to be equal to or higher than the final velocity of the fluid bed catalyst, and therefore a part of the fine powder of the fluid bed catalyst is accompanied by the gas in the reaction column from the fluid bed. The reactor scatters outside the reactor. Therefore, the following reaction method is generally employed: while the catalyst containing a large amount of fine powder is replenished in the reaction, the particle size distribution of the catalyst in the reactor is maintained in a preferable range, thereby maintaining good flow of the catalyst for a long period of time. State (Patent Document 4). [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2001-55355 [Patent Document 2] International Publication No. 2012/096367 [Patent Document 3] Japanese Patent Laid-Open Publication No. 2002-53519 (Patent Document 4) Japanese Patent Laid-Open Publication No. 63-36831 [Non-Patent Document]

[Non-Patent Document 1] Chemical Engineering [10] p.1013-1019, Vol.34 (1970)

[Problems to be solved by the invention]

In the production of the target product using the fluid bed, not only the optimization of the catalyst is required, but also the optimum operating conditions must be employed in order to fully utilize the catalyst, so that the final reaction performance can be improved. In particular, in order to achieve an improvement in the reaction performance, the selection of conditions at the time of catalyst filling becomes an important factor.

The methods of Patent Document 1 to Patent Document 3 all aim to reduce oxygen and flammable gases which adversely affect the catalyst, device, and safety. Further, Patent Document 4 aims to maintain the flow state of the catalyst well after starting the reaction. When the fluid bed reactor is filled with a catalyst, a gas to be introduced into the reactor may be used. However, Patent Documents 1 to 4 do not describe the flow rate of the gas. That is, in order to improve the reaction performance of the catalyst, the flow velocity of the gas in the reactor when the fluid bed reactor was filled with the catalyst was optimized, and no investigation was conducted.

The inventors of the present application have studied the flow rate of the gas in the reactor, and the results are as follows.

That is, the filling of the catalyst can be completed in a short time by accelerating the flow rate of the gas in the reactor in the catalyst filling. However, the amount of scattering of the catalyst (especially fine powder) increases, and the possibility of malfunction of equipment such as clogging of the piping due to the scattered catalyst increases.

When the catalyst is filled in a state in which the catalyst (especially the fine powder) is largely dispersed, the catalyst is filled and the reaction after the filling is performed, whereby the flow state of the catalyst is deteriorated and the reaction becomes unstable, resulting in the yield of the target product. Industrial problems such as deterioration of part of the catalyst are lowered.

Further, by shortening the filling time of the catalyst by slowing down the flow rate of the gas, the amount of scattering of the catalyst can be suppressed. However, it takes a long time before the completion of the filling of the catalyst, and the energy cost of the combustible gas or the like used when the introduction gas introduced into the reactor is preheated is also excessively large.

The methods described in Patent Documents 1 to 4 do not consider that the flow rate of the gas in the reactor is optimized when the fluid bed reactor is filled with the catalyst, so that the reaction performance of the catalyst cannot be improved until the industrial demand is satisfied. level.

The present invention has been made in view of the above circumstances, and an object thereof is to perform a higher-yield reaction more efficiently by suppressing the amount of catalyst scattered to the outside of the reactor and charging the catalyst in a shorter period of time. [Means for solving the problem]

The inventors of the present application have conducted an effort to study a method of filling a fluid bed catalyst in a fluidized bed reactor. As a result, it has been found that the operation of increasing the gas flow rate after the start of the catalyst filling can suppress the amount of the catalyst that scatters outside the reactor, and the flow state of the catalyst does not deteriorate, resulting in a high target product. The reaction was carried out to complete the present invention. Further, it has been found that the gas flow rate can be increased by filling a certain amount of catalyst in the dip tube of the cyclone (catalyst trap) as a catalyst introduction pipe.

That is, in order to solve the above problems, the method of filling a catalyst in a fluidized bed reactor of the present invention (hereinafter, referred to as "catalyst filling method of the present invention") is characterized by comprising the steps of: the fluidized bed reactor The effective sectional area is set to B [m ² ], the temperature in the fluidized bed reactor is set to T [° C.], and the total flow rate of the gas introduced into the fluid bed reactor is set to F [Nm ³ / h], the overhead pressure in the fluidized bed reactor is set to P [kPa], and is substituted into the following formula (1) to start with the gas flow rate U in the obtained fluidized bed reactor. The catalyst is filled into the fluid bed reactor and then the U is increased.

U=(F/B×((273+T)/273)/((101+P)/101))/3600·(1) In the catalyst filling method of the present invention, it is more preferable The value of T is from 100 ° C to 500 ° C. Further, in the catalyst filling method of the present invention, it is more preferable to increase the F and increase the U.

In the catalyst filling method of the present invention, it is more preferred that a catalyst returning portion is provided in the fluidized bed reactor, and the catalyst returning portion is a unit to be recovered in the fluidized bed reactor. The position at which the catalyst is recovered from the relatively lower position is returned to the portion in the fluidized bed reactor, and the pressure is at least two locations different in position in the vertical direction inside the catalyst returning portion. The amount of the catalyst is calculated by the difference, and when the amount of the catalyst becomes a predetermined value, the U is increased.

The catalyst filling method of the present invention can be preferably used in the form of a catalyst for producing a nitrile compound.

Further, the method for producing a nitrile compound of the present invention is characterized by comprising the step of carrying out the catalyst filling method of the present invention. [Effects of the Invention]

According to the present invention, by suppressing the amount of the catalyst scattered outside the reactor and filling the catalyst in a shorter time, the flow state of the catalyst can be favorably maintained, and hot spots are not generated. And, reducing energy costs, and performing higher yield reactions more efficiently.

(Catalyst Filling Method) The catalyst filling method of the present invention comprises the steps of setting the effective sectional area of the fluidized bed reactor to B [m ² ], and setting the temperature in the fluidized bed reactor to T [ °C], the total flow rate of the gas introduced into the fluidized bed reactor is F [Nm ³ /h], and the pressure at the top of the fluidized bed reactor is set to P [kPa], and is substituted into the lower portion. In the above formula (1), the catalyst is filled into the fluidized bed reactor at the gas flow rate U in the fluid bed reactor obtained, and then the U is increased.

U = (F / B × ((273 + T) / 273) / ((101 + P) / 101)) / 3600 · · · (1) In addition, the following may also be the gas in the fluid bed reactor The flow rate U[m/s] is called "gas flow rate U", and the effective sectional area B[m ² ] of the fluidized bed reactor is referred to as "effective sectional area B", and the temperature inside the fluidized bed reactor T [°C] The temperature is referred to as "temperature T", and the gas introduced into the fluidized bed reactor is referred to as "introduced gas", and the total flow rate F [Nm ³ /h] of the introduced gas is referred to as "the total flow rate F of the introduced gas", and the fluid bed is referred to. The column top pressure P [kPa] in the reactor is referred to as "tower pressure P".

For example, after the start of the filling of the catalyst, the gas flow rate U in the fluidized bed reactor is increased in the middle of filling the catalyst, whereby the filled catalyst can be prevented from scattering outside the fluidized bed reactor. The smaller the particle size of the catalyst, the easier it is to scatter outside the fluid bed reactor. If the catalyst scattered in the entire catalyst is biased toward a catalyst having a small particle size, the particle size distribution changes as compared with that before filling, and the flow state of the catalyst is deteriorated. However, according to the present invention, the flow state of the catalyst can be prevented from being deteriorated, so that the target product can be obtained in a high yield by the reaction which is carried out thereafter. In addition, since the filling can be completed in a short time, it is possible to efficiently fill the fluidized bed reactor with the catalyst. Further, scattering of the catalyst having a small particle diameter can be prevented, and the flow state of the catalyst can be prevented from being deteriorated. Therefore, the flow state of the catalyst is well maintained. Further, since the flow state is favorably maintained, the occurrence of temperature unevenness (hot spots) can also be suppressed in the formation reaction of the target object which is subsequently performed. In addition, since the filling can be completed in a short time, the energy cost can be reduced.

The catalyst filling method of the present invention can be preferably applied to the filling of a catalyst when a nitrile is synthesized by an ammoxidation reaction of a hydrocarbon having 1 to 6 carbon atoms. Among them, the catalyst charging method of the present invention can be more preferably used for synthesizing acrylonitrile by ammoxidation of propylene and/or propane, and synthesizing methyl propylene by ammoxidation of isobutylene and/or isobutane. A method of filling a nitrile catalyst.

(Step of increasing the gas flow rate U [m/s] in the reactor) The catalyst filling method of the present invention comprises the step of increasing the gas flow rate U shown by the formula (1).

The gas flow rate in the fluidized bed reactor is a value for temperature correction and pressure correction for dividing the flow rate of the introduced gas by the effective sectional area. The range of the specific value of U is preferably 0.07 m/s or more, more preferably 0.10 m/s or more, and further preferably 0.46 m/s or less, more preferably 0.43 m/s or less. If it is in the above range, the larger the gas flow rate in the reactor, the more the catalyst can be filled in the reactor in a short time, and the productivity of the reaction can be improved. Further, in the range described above, the smaller the gas flow rate in the reactor, the more the scattering of the catalyst during the filling of the catalyst can be suppressed, and the lowering of the temperature in the reactor can be suppressed.

(effective sectional area B [m ² ] of the fluidized bed reactor) The effective sectional area B is the area obtained by subtracting the sectional area of the contents from the sectional area when the fluidized bed reactor is cut in the horizontal direction. . Specifically, the effective sectional area is, for example, a cross-sectional area of a portion (reaction portion or thick layer) that causes a reaction between the source gas and the catalyst above the position (height) at which the source gas is introduced, which is described later. The cross-sectional area of the cross-sectional area of the contents of the dipid or the like.

The size of the fluidized bed reactor used in the catalyst charging method of the present invention is not particularly limited, and in the case of industrial production, the effective sectional area of the reactor is usually in the range of 10 m ² to 200 m ² . If it is within the above range, the larger the effective sectional area, the more the productivity of the target product can be improved. Further, when the range is within the above range, the smaller the effective sectional area, the better the operability of the device such as temperature control.

(Temperature T [°C] in Fluidized Bed Reactor) The temperature T is determined by measuring the temperature in the fluidized bed reactor. For example, the measurement site may be a portion (reaction portion or thick layer) that causes a reaction with the catalyst to be higher than the position (height) at which the source gas is introduced, which will be described later. Regarding the temperature T, if there is a case where the temperature changes by performing the step of increasing the gas flow rate U, the temperature after the change is the temperature. The formula (1) corrects the influence due to the change in temperature by dividing the total flow rate F of the introduced gas by the effective sectional area B to obtain the flow rate of the introduced gas per unit effective sectional area ( F/B), multiplied by (273+T)/273. The influence due to the change in temperature is considered to mean, for example, a change in the volume of the gas due to a change in temperature, and a change in the flow velocity. Therefore, by changing the temperature T, the gas flow rate U can also be increased. For example, the gas flow rate U can be increased by increasing the temperature T. Further, "273" is an approximate value for calculating the value of the Celsius temperature (°C) at the thermodynamic temperature (K).

The temperature T in the fluidized bed reactor at the time of catalyst charging in the method for filling a fluid bed catalyst according to the present invention is usually in the range of 100 ° C to 500 ° C. If it is in the above range, the higher the temperature, the faster the reaction can be started after the filling, and the better the flow state of the catalyst becomes. Further, if it is within the above range, the lower the temperature, the more the fuel cost per unit time used for heating the gas introduced into the fluidized bed reactor during the catalyst charging can be suppressed to a low level.

(Tower pressure P [kPa] in the fluidized bed reactor) The column top pressure P was determined by measuring the pressure at the top of the fluidized bed reactor. Regarding the peak pressure P, if there is a case where the temperature changes by the step of increasing the gas flow rate U, the peak pressure after the change is used. The formula (1) corrects the influence due to the change in pressure by dividing the flow rate (F/B) of the introduction gas per unit effective sectional area by (101 + P) / 101. The influence due to the change in pressure is considered to mean, for example, a change in the volume of the gas due to a change in pressure, and a change in the flow velocity. Therefore, by changing the top pressure P, the gas flow rate U can also be increased. The gas flow rate U can be increased, for example, by reducing the overhead pressure P. Further, "101" is an approximate value of a value for calculating a value of Pascal according to a standard atmospheric pressure.

(Total flow rate of gas introduced into the fluidized bed reactor F [Nm ³ /h]) As the gas introduced into the fluidized bed reactor, for example, a catalyst for filling the fluidized bed reactor 10 is used. A flow gas, a catalyst transport gas for transporting the catalyst to the fluidized bed reactor. Since the flow rate of the gas is the flow rate set by the user, the total flow rate F of the introduced gas is obtained by totaling the flow rate of the gas set by the user.

The type of the gas for flow and the gas for catalyst transport is not particularly limited, and examples thereof include pure oxygen, air, and a mixed gas of pure oxygen and air. In addition, the gases may be diluted with other gases. The gas to be used for the dilution is not particularly limited as long as it is a gas which does not adversely affect the catalyst performance and the gas phase oxidation reaction, and examples thereof include air, nitrogen gas, and helium gas. It is usually the case that air, oxygen, or an oxygen-containing gas diluted to an arbitrary concentration by an inert gas is used.

Further, in the total flow rate F of the introduced gas, the flow rate is also included in the gas to be introduced into the fluidized bed reactor in addition to the flow gas and the catalyst transport gas. Examples of such a gas include a purge gas for a raw material gas line or a differential pressure measurement line.

(A preferred combination of the temperature T, the column top pressure P, and the total flow rate F of the introduced gas) The values of the temperature T, the column top pressure P, and the total flow rate F of the introduced gas vary depending on the size and structure of the fluidized bed reactor, Therefore, it is not particularly limited. The gas flow rate U is calculated by combining the three values of the temperature T, the column top pressure P, and the total flow rate F of the introduced gas after the effective sectional area B is defined.

(Period of increasing the gas flow rate U [m/s] in the fluidized bed reactor) The period during which the gas flow rate U is increased can be appropriately set according to the target filling time, the amount of scattering of the catalyst, and the like, as long as it is started. The catalyst is filled and a portion of the filled catalyst is introduced into the fluid bed reactor.

Further, in order to improve the capture efficiency of the catalyst, the fluidized bed reactor is often connected and provided with a plurality of cyclones. A dip tube is usually provided in the cyclone. The dip tube is a device that returns the catalyst recovered in the fluid bed reactor from the lower portion of the fluid bed reactor (the position at which the recovery position is vertically lower) to the fluid bed reactor.

Usually, in the first stage of the immersion tube, since the circulation amount of the catalyst is large, the lowermost portion is opened in the reactor (or a reversal plate or the like is provided), and is disposed in the cyclone provided in the second stage and the third stage. A trickle valve (catalyst discharge amount adjusting device) or the like is provided at a lower end portion of the dip tube.

In the catalyst charging method of the present invention, the period of increasing the gas flow rate U [m/s] in the fluidized bed reactor is preferably based on the amount of the catalyst in the immersion tube, and is preferably in accordance with the immersion tube. The amount of the catalyst in the first stage of the dip tube (the lowermost portion, or the reversing plate or the like, without the trickle valve) is set for the period. Further, it is more preferable that the gas flow rate U in the fluidized bed reactor is increased when the amount of the catalyst in the immersion tube becomes a predetermined value. The value is, for example, preferably 0.1% by volume or more, and more preferably 0.3% by volume or more. When there is no catalyst in the immersion tube, there is a case where the gas from the lower end of the immersion tube enters the gas and the catalyst (countercurrent) introduced into the fluid bed reactor, and the rise reaches the cyclone portion, and In the state, the catalyst flies out of the system. If the lower end of the dip tube is sealed by a catalyst, the entry of the gas and the catalyst can be prevented. The minimum value of the amount of the catalyst in the first stage of the dip tube which can be confirmed by the differential pressure is preferably 0.1% by volume or more, and more preferably 0.3% by volume or more. In other words, after confirming that the lower end portion of the dip tube is sealed, by increasing the gas flow velocity U, the scattering of the catalyst can be more effectively suppressed, and the filling time can be made short.

For example, the total flow rate F of the gas is set to be fixed in advance, and the temperature and pressure that change with time are set to be in a state of constant change in advance. As long as it is confirmed in the state that the lower end of the dip tube is covered by the catalyst, the total flow rate F of the gas is increased, and the gas flow rate U is increased. Further, in addition to the purpose of increasing the gas flow rate U, the total flow rate F of the gas may be adjusted. For example, adjustment for suppressing the influence of the performance (characteristics) of the flowmeter device or the flow characteristics of the catalyst can be appropriately performed.

The method for measuring the amount of the catalyst to be immersed in the tube is not particularly limited, and it is possible to contact two places having different heights (positions in the vertical direction) in the dip tube, for example, in the vicinity of the connection portion of the cyclone and in the lowermost portion. The pressure difference near the return port of the medium is calculated.

(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 depending on the target filling time, the amount of scattering of the catalyst, and the like.

After the start of the filling, even if the gas flow rate U in the fluidized bed reactor is slightly increased, the catalyst can be filled at the initial stage while suppressing the scattering, and the gas flow rate U in the fluidized bed reactor can be increased in a shorter time. The fill is completed inside.

The specific value of the increased amount is, for example, 2% or more, and more preferably 4% or more, from the viewpoint of the performance of the clear effect due to an increase in the gas flow rate. Further, from the viewpoint of suppressing scattering of the catalyst, it is preferably 200% or less, more preferably 150% or less.

(Method of Increasing Gas Flow Rate U [m/s] in Fluid Bed Reactor) The method of increasing the gas flow rate U is not particularly limited, and it is more preferable to perform an operation of increasing the total flow rate F of the introduced gas. The reason is that this can easily increase the gas flow rate U.

However, it should be noted that the total flow F of the introduced gas must be increased until the gas flow rate U is increased. That is, there is a case where even if the operation of increasing the total flow rate F of the introduced gas is performed, the temperature T and the column top pressure P change due to the influence of the increase, and as a result, the gas flow velocity U does not increase. However, in the catalyst filling method of the present invention, it is necessary to increase the gas flow rate U. Therefore, in the operation of increasing the total flow rate F of the introduced gas, it is preferable to measure the temperature T and the column top pressure P, and to operate them as needed in the direction in which the gas flow velocity U increases. Further, it is more preferable to calculate the gas flow rate U based on the above formula (1) and confirm the increase.

In addition, it should also be noted that if the gas flow rate U is increased, it is not necessary to increase the total flow rate F of the introduced gas. If the total flow rate F of the introduced gas is controlled to be concentrated in a fixed range and the gas flow rate U is increased, it is the scope of the catalyst filling method of the present invention. For example, by setting the introduction amount F of the gas to be fixed, the gas flow velocity U is repeatedly increased and decreased in a fixed range by flow rate hunting. Thus, even if the total flow rate F of the gas is set to be constant within a predetermined range, the scattering can be suppressed to a desired extent and the catalyst can be filled for a desired period of time. This operation is also within the scope of the catalyst filling method of the present invention.

The operation for increasing the gas flow rate U may be one time, or may be performed twice or more. For example, it can be increased to the target value of the increased gas flow rate U in one operation, or can be increased in stages by multiple times. The number of times can be appropriately set according to the flow state of the target catalyst, the filling time, and the like.

In addition, the gas flow rate U can be increased in a short time or slowly.

(Fluid Bed Reactor) The fluid bed reactor used in the catalyst charging method of the present invention can be arbitrarily selected to employ a previously known fluidized bed reactor for fluid bed reaction. Here, an embodiment of a fluidized bed reactor used in the catalyst charging method of the present invention will be described with reference to Fig. 1 . FIG. 1 is a view showing a schematic configuration of a fluidized bed reactor 1 including a fluidized bed reactor 10.

In the present embodiment, the fluidized bed reactor 1 is an apparatus for producing acrylonitrile by ammoxidation of a hydrocarbon.

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

(Catalyst Hopper 2) The catalyst hopper 2 is used to store a catalyst for filling into a fluid bed reactor. The catalyst x1 supplied from the catalyst hopper 2 is transported by the catalyst transport gas x2. In other words, the catalyst-containing gas X formed by the combination of the catalyst x1 and the catalyst-carrying gas x2 is supplied into the fluidized bed reactor 10.

(Catalyst) The catalyst used in the catalyst filling method of the present invention is not particularly limited, and the method can be preferably used in the ammoxidation reaction and/or the oxidation reaction of a hydrocarbon having 1 to 6 carbon atoms. The catalyst used, etc. Examples of such a catalyst include a metal oxide catalyst containing molybdenum and ruthenium, a metal oxide catalyst containing iron and ruthenium, a metal oxide catalyst containing molybdenum and vanadium, and a metal oxide containing uranium and ruthenium. Material catalyst, etc. Among them, it can be more preferably used for a catalyst for producing a nitrile compound.

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

(Gas Supply Pipe 16) The gas supply pipe 16 is a gas supply pipe for supplying the material gas Z to the fluidized bed reactor 10 when a reaction for producing a target product is performed after filling the catalyst. The material gas Z includes a gaseous hydrocarbon compound, gaseous ammonia, and water vapor. The gas supply conduit 16 is disposed below the fluid bed reactor 10 and branches into a plurality of branch portions 17. A pipe joint portion (raw material distributing nozzle) 18 that faces the bottom surface of the fluidized bed reactor 10 is connected to the front end of each branch pipe portion 17.

(Material Gas Z) Examples of the material gas Z include hydrocarbons having a carbon number of 1 to 6, such as methane, ethane, ethylene, propane, propylene, n-butane, isobutane and the like butane, n-butene and isobutylene. Examples include butenes, pentanes such as n-pentane and isopentane, pentenes such as n-pentene and isoamylene, hexanes such as n-hexane and isohexane, and hexenes such as n-hexene and isohexene.

(Cyclone 12) The cyclone 12 is used to separate the gas from the catalyst. The cyclone 12 is provided with an inflow port 13 for introducing a gas and a catalyst into the cyclone 12, a gas outflow pipe 15 for discharging the separated gas to the outside of the fluid bed reactor 10, and a separated catalyst. It is returned to the dip tube 14 of the catalytic fluid bed 11 in the reactor.

In the fluidized bed reactor, as shown in FIG. 1, a plurality of series of three cyclones 12 are connected inside the reactor (in which, in FIG. 1, only three cyclones 12 are connected) 1 series) Further, as shown in FIG. 1, the two cyclones 12 are coupled by a gas outflow pipe 15, and further, the other gas outflow pipe 15 conducts the gas out of the fluid 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 into 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 gas Y containing oxygen to the fluidized bed reactor 10. A gas supply port 20 is provided at the bottom of the fluid bed reactor 10.

(Oxygen-Containing Gas Y) The oxygen-containing gas Y is a flowing gas for causing the catalyst to flow in the fluidized bed reactor 10 when the catalyst is filled, and is a gas which supplies oxygen for the reaction at the time of the reaction.

The oxygen-containing gas Y as a flowing gas during the catalyst filling may be the same gas or the different gas as the oxygen-containing gas Y as a gas for supplying oxygen during the reaction. The specific type of the gas Y containing oxygen is based on the description of the flow gas.

(Method for Producing Nitrile Compound) The method for producing a nitrile compound of the present invention includes the step of carrying out the above-described catalyst filling method of the present invention. By using the catalyst charging method of the present invention, the flow of the catalyst in the fluidized bed reactor is good, and the minute catalyst particles are not scattered and are present in a large amount in the fluidized bed reactor. Therefore, the nitrile compound can be obtained in a high yield.

After the catalyst filling method of the present invention is carried out, the reaction for generating a nitrile compound may be started at any time of the user. For example, it is only necessary to confirm that the flow state of the catalyst in the fluidized bed reactor becomes a constant state or the like and then start the reaction. After the reaction is started, there is a case where the reaction temperature rises due to heat generation, the pressure also changes, and the flow state of the catalyst changes. When the fluctuation of these states is large and unstable before the start of the reaction, in terms of safety, it is preferable that the fluctuation of each state becomes a predetermined range and the reaction is started after the state is stabilized. Further, before the reaction for generating the nitrile compound, the rising temperature due to the reaction can be predicted, and the temperature is lowered before the start of the reaction.

The material gas supplied to the fluidized bed reactor can be diluted with an inert gas such as nitrogen or carbon dioxide, a saturated hydrocarbon, an alcohol or the like, and can be used by increasing the oxygen concentration.

In the method for producing a nitrile compound of the present invention, the composition ratio of the material gas used for the gas phase oxidation reaction is not particularly limited, and it is more preferably selected from the carbon number 1 to improve the yield of the target product. The molar ratio of at least one compound/ammonia/oxygen of 6 hydrocarbons is in the range of 1/0.5 to 2.0/1.0 to 5.0.

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

In the present invention, the method of supplying at least one compound selected from the hydrocarbons having 1 to 6 carbon atoms, ammonia, and a gas containing oxygen into the reactor is not particularly limited, and a sprinker may be used. A method generally used, such as a method of supplying a dispersion plate, and the like.

Further, at least one compound selected from the hydrocarbons having 1 to 6 carbon atoms, ammonia, and a gas containing oxygen may be supplied separately to the fluidized bed reactor, or all or a part thereof may be mixed and supplied. In consideration of safety and the like, at least one compound selected from the group consisting of hydrocarbons having 1 to 6 carbon atoms, ammonia, and a gas containing oxygen are separately supplied to the fluidized bed reactor. [0074 ́] Further, from the viewpoint of efficiency, the nitrile compound can be subsequently produced after filling the catalyst as described above.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and embodiments in which the technical methods disclosed in the embodiments are appropriately combined are also included in the present invention. Within the technical scope of the invention. Hereinafter, the present invention will be described in detail by way of examples and comparative examples. However, the present invention is not limited to the description below unless the scope of the invention is exceeded. [Examples]

[Example 1] (filling of a fluid bed catalyst in a reactor) Starting a fluid 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 ; Here, x is the number of atoms of oxygen necessary to satisfy the valence of each component other than cerium oxide. 110 tons of self-catalyst hopper to inner diameter 8.0 A vertical cylindrical fluid bed reactor filled with m (effective sectional area B of 47 m ² ) was filled.

As shown in Fig. 1, the fluid bed reactor and the fluid bed reactor and the catalyst hopper provided therewith are used.

Air is used as the flow gas and catalyst transport gas flowing to the fluidized bed reactor, and the total flow rate F of the gas is 12 × 10 ³ Nm ³ /h, the temperature T in the reactor is 420 ° C, and the top pressure in the reactor The catalyst was initially charged to the reactor under the condition that P was 8 kPa. The gas flow rate U in the reactor at the start of filling (filling time 0 hours) was 0.17 m/s. In addition, the flow rate of the catalyst transport gas is not particularly limited as long as the flow rate of the catalyst can be transported. In the examples and the comparative examples, the flow rate of the flow gas is extremely larger than the flow rate of the catalyst transport gas. The total flow rate F is set to be substantially the same as the flow rate of the flowing gas (the same applies to the following examples and comparative examples).

After 11.5 hours from the start of the filling of the catalyst, when the catalyst filling in the immersion tube became 1.6% by volume, and when the loading amount of the catalyst in the fluidized bed reactor became 64 tons, the flow to the fluidized bed reactor was made. The flow gas was increased to set the total flow rate F of the gas to 37 × 10 ³ Nm ³ /h.

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

Finally, the catalyst fill can be completed with a catalyst fill time of 12.9 hours. The catalyst loading amount was 110 tons, and it was confirmed that almost all of the catalyst was filled into the reactor. Further, the amount of catalyst charged after completion of the catalyst filling was determined from the pressure difference measured in the portion of the fluidized bed reactor where the reaction was carried out at the bottom of the column and at a position higher than the position at which the raw material gas was introduced.

In addition, each value from the start of the filling to the completion of the filling is shown in Table 1.

[Table 1]

(Ammoxidation reaction after catalyst filling) The ammoxidation reaction was carried out using a fluidized bed reactor in which the catalyst was filled. Using air as a source of oxygen, a material gas having a composition of propylene: ammonia: oxygen = 1:1.1:2.3 (mole ratio) is fed into the reaction column. The reaction pressure is set to 180 kPa to 220 kPa, the reaction temperature is set to 455 ° C to 465 ° C, and the gas flow rate in the reactor is set to 50 cm/sec to 70 cm/sec.

In the reaction under the above conditions, the reaction temperature was detected by a thermocouple thermometer provided at a plurality of locations, but the temperature unevenness (hot spot) in the reaction was not observed, and the catalyst was in a good flow state. In addition, the average yield of acrylonitrile was 77.4%.

[Example 2] (filling of fluid bed catalyst in the reactor) By the same operation as in Example 1, the fluid bed catalyst shown in Fig. 1 was started to be filled with a fluid bed catalyst. Air was used as the flow gas and the catalyst transport gas flowing to the fluidized bed reactor, and the total flow rate F of these gases was set to 23 × 10 ³ Nm ³ /h. The gas flow rate U in the reactor at the start of filling (filling time 0 hours) was 0.30 m/s. The fluid bed reactor was filled with a catalyst under the condition that the temperature T in the fluidized bed reactor was 420 ° C and the column top pressure P in the fluidized bed reactor was 15 kPa.

After 4.6 hours from the start of the filling of the catalyst, when the catalyst filling in the immersion tube became 1.7% by volume, and the flow into the reactor was made when the loading amount of the catalyst in the fluidized bed reactor became 66 tons The total flow rate F was set to 30 × 10 ³ Nm ³ /h by gas addition.

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

Finally, the catalyst fill can be completed with a 6.1 hour catalyst fill time. The amount of catalyst charged after completion of the catalyst filling was 109 tons, and it was confirmed that almost all of the catalyst was filled into the reactor.

(Ammoxidation reaction after catalyst filling) The ammoxidation reaction was carried out under the same conditions as in Example 1 using a fluid bed reactor (see Fig. 1) filled with a fluid bed catalyst. In the reaction, the reaction temperature was detected by a thermocouple thermometer provided at a plurality of locations, but no temperature unevenness (hot spot) was observed in the reaction, and the catalyst was in a good flow state. Further, the average yield of acrylonitrile was 77.1%.

[Comparative Example 1] (filling of the fluid bed catalyst in the reactor) By the same operation as in Example 1, the fluid bed catalyst (see Fig. 1) was started to be filled with the fluid bed catalyst. Air was used as the flow gas and the catalyst transport gas flowing to the fluidized bed reactor, and the total flow rate F of these gases was set to 40 × 10 ³ Nm ³ /h. The gas flow rate U in the reactor at the start of filling (filling time 0 hours) was 0.48 m/s. The fluid bed reactor was filled with a catalyst under conditions of a temperature T of 420 ° C in the fluid bed reactor and an overhead pressure P in the fluid bed reactor of 26 kPa.

The total flow rate F of the introduced gas is set to be fixed without increasing. The catalyst filling in the dip tube after 1.1 hours was 1.3% by volume. Finally, the catalyst fill was completed with a 2.1 hour catalyst fill time. Further, the amount of catalyst charged after completion of the catalyst filling was 105 tons, and it was found that about 5% by mass of the catalyst for filling was scattered outside the reactor.

(Ammoxidation reaction after catalyst filling) The ammoxidation reaction was carried out under the same conditions as in Example 1 using a fluid bed reactor (see Fig. 1) filled with a fluid bed catalyst. In the reaction, the reaction temperature was detected by a thermocouple thermometer provided at a plurality of locations, and as a result, temperature unevenness (hot spot) was observed in the reactor, and it was found that the flow state of the catalyst was deteriorated. Further, the average yield of acrylonitrile was 73.4%, and a catalyst for reducing deterioration (discoloration) was observed from the reactor which was stopped after the reaction.

[Comparative Example 2] (filling of the fluid bed catalyst in the reactor) By the same operation as in Example 1, the fluid bed catalyst (see Fig. 1) was started to be filled with the fluid bed catalyst. Air was used as the flow gas and the catalyst transport gas flowing to the fluidized bed reactor, and the total flow rate F of these gases was set to 3 × 10 ³ Nm ³ /h. The gas flow rate U in the reactor at the start of filling (filling time 0 hours) was 0.04 m/s. The fluid bed reactor was filled with a catalyst under the conditions that the temperature T in the fluidized bed reactor was 420 ° C and the overhead pressure P in the fluid bed reactor was 2 kPa.

In the filling of the catalyst, the total flow rate F of the introduced gas is set to be fixed without increasing. The catalyst charge in the dip tube after 7.9 hours was 1.3% by volume. The final catalyst fill requires 17.8 hours of catalyst fill time. The catalyst loading amount after completion of the catalyst filling was 110 tons, and it was confirmed that almost all of the catalyst was filled into the reactor, but it was necessary to extend the length of about 5 hours to 12 hours with respect to Example 1 and Example 2. The filling time, and therefore the energy cost required to heat the temperature in the reactor (for example, when the filling time is extended by 5 hours, the amount of propylene supplied as fuel is 400 Nm ³ × 5 hours = 2000 Nm ³ ) ) increase.

(Ammoxidation reaction after catalyst filling) The ammoxidation reaction was carried out under the same conditions as in Example 1 using a fluid bed reactor (see Fig. 1) filled with a fluid bed catalyst. In the reaction, the reaction temperature was detected by a thermocouple thermometer provided at a plurality of locations, but no temperature unevenness (hot spot) was observed in the reaction, and the catalyst was in a good flow state. Further, the average yield of acrylonitrile was 77.3%, but as described above, since the filling time was required, there was a chance of loss in the production of acrylonitrile.

According to the above examples and comparative examples, it is clearly revealed that the gas flow rate in the reactor is reduced in the initial stage of catalyst charging until the amount of catalyst is filled in the dip tube in the lower portion of the cyclone in the reactor. Further, the flow rate of the gas in the reactor is increased in the middle of the catalyst charging, and the reaction between the catalyst and the filling in the reactor is performed in the reactor, whereby the amount of the catalyst scattered outside the reactor can be suppressed, and the catalyst is not caused. The flow state deteriorates and the reaction proceeds at a high target product yield.

1‧‧‧ Fluid bed reactor
2‧‧‧catalyst hopper
10‧‧‧ Fluid Bed Reactor
11‧‧‧catalyst fluid bed
12‧‧‧Cyclone
13‧‧‧Inlet
14‧‧‧Immersion tube
15‧‧‧ gas outflow tube
16‧‧‧ gas supply conduit
17‧‧‧Support Department
18‧‧‧Receipt Department
19‧‧‧ gas dispersion plate
20‧‧‧ gas supply port
X‧‧‧ gas containing catalyst
X1‧‧‧ catalyst
X2‧‧‧catalyst transport gas
Y‧‧‧Oxygen-containing gas
Z‧‧‧Material gases

Fig. 1 is a view showing a schematic configuration of an embodiment of a fluidized bed reactor used in the catalyst charging method of the present invention.

1‧‧‧ Fluid bed reactor

2‧‧‧catalyst hopper

10‧‧‧ Fluid Bed Reactor

11‧‧‧catalyst fluid bed

12‧‧‧Cyclone

13‧‧‧Inlet

14‧‧‧Immersion tube

15‧‧‧ gas outflow tube

16‧‧‧ gas supply conduit

17‧‧‧Support Department

18‧‧‧Receipt Department

19‧‧‧ gas dispersion plate

20‧‧‧ gas supply port

X‧‧‧ gas containing catalyst

X1‧‧‧ catalyst

X2‧‧‧catalyst transport gas

Y‧‧‧Oxygen-containing gas

Z‧‧‧Material gases

Claims (11)

A method for filling a catalyst in a fluidized bed reactor, comprising the steps of: setting an effective sectional area of the fluidized bed reactor to B [m ² ], and setting a temperature in the fluidized bed reactor to T [ °C], the total flow rate of the gas introduced into the fluidized bed reactor is F [Nm ³ /h], and the pressure at the top of the fluidized bed reactor is set to P [kPa], and is substituted into the lower portion. Said (1), for the gas flow rate U [m / s] in the fluid bed reactor obtained, starting to fill the fluid bed reactor with the catalyst, and then increasing the U; = (F/B × ((273 + T)) / 273) / ((101 + P) / 101)) / 3600 · · · (1). The method of claim 1, wherein the value of T is from 100 ° C to 500 ° C. The method of claim 1 or 2, wherein the U is increased by increasing the F. The method of any one of claims 1 to 3, wherein the U is increased by changing at least one of the T and the P. The method of any one of the preceding claims, wherein the fluid bed reactor is provided with a catalyst returning portion, the catalyst returning portion being to be in the fluid The catalyst recovered in the bed reactor is returned to the portion in the fluid bed reactor from a position where the recovery is relatively low, and the position in the vertical direction of the catalyst returning portion is different. The amount of catalyst is calculated from the pressure difference of at least two locations, and when the amount of the catalyst becomes a predetermined value, the U is increased. The method of any one of claims 1 to 5, wherein the gas is a flow gas for flowing the catalyst and the catalyst is transported to the fluid bed reactor At least one of the catalyst transport gases. The method according to any one of claims 1 to 6, wherein in the step of increasing the U, the U is increased by 2% or more and 200% or less with respect to the U at the start of filling. The method according to any one of claims 1 to 6, wherein in the step of increasing the U, the U is increased by 4% or more and 150% or less with respect to the U at the start of filling. The method according to any one of claims 1 to 8, wherein the catalyst is a catalyst for producing a nitrile compound. A method for producing a nitrile compound, which comprises the steps of carrying out the method according to the first to ninth aspects of the patent application. A method for producing a nitrile compound, which is characterized in that the method described in the first to ninth aspects of the patent application is carried out, followed by the production of a nitrile compound.