KR20170093913A - Method for packing catalyst into fluidized bed reactor, and process for producing nitrile compound - Google Patents

Abstract

The catalyst filling method of the present invention is characterized in that the effective cross-sectional area of the fluidized bed reactor is B [m ² ], the temperature in the fluidized bed reactor is T [° C], the total flow rate of the gas introducing the fluidized bed reactor is F [Nm ³ / (m / s) in the fluidized bed reactor obtained by substituting the top pressure in the fluidized bed reactor for P [kPa] into the following equation (1) , And thereafter increasing the U.
U = (F / B × (273 + T) / 273) / ((101 + P) / 101)) / 3600

Description

FIELD OF THE INVENTION The present invention relates to a process for preparing a nitrile compound,

The present invention relates to a method for filling a fluidized bed catalyst and a method for producing a nitrile compound, for example, in a fluidized bed (fluidized bed) reactor used for the gas phase oxidation reaction of hydrocarbons.

Various methods for producing a nitrogen-containing compound by a gas phase oxidation reaction using a hydrocarbon, ammonia, and an oxygen-containing gas as raw materials have been known. Particularly, a method of 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 the ammoxidation reaction of propylene is widely practiced industrially.

In general, a liquid phase catalyst is used for the ammoxidation reaction. In the ammoxidation reaction of a large scale industrial scale, an optimized composition, manufacturing method, shape, particle size, density and activity have been developed so that the performance of the fluidized bed catalyst can be sufficiently exhibited.

Various methods have been proposed for the composition of the catalyst and the production method thereof. With respect to the physical properties of the fluidized-bed commercial catalyst, preferable physical properties such as particle density, shape and particle diameter have been proposed. In particular, it is known that the flow state of the catalyst becomes good by keeping the differential ratio of 44 탆 or less within a certain range with respect to the particle diameter distribution (Non-Patent Document 1), whereby the reaction results are also changed.

The method of filling the fluidized-bed catalyst may be a method of raising the temperature in an atmosphere substantially not containing oxygen and / or a combustible gas (Patent Documents 1 and 2), a method of utilizing the gas discharged from the reactor after the reactor Patent Document 3) and the like are known.

In addition, in the fluidized bed reactor, since the reaction is carried out by setting the gas flow rate in the reactor to a state higher than the terminal velocity of the fluidized bed catalyst, part of the fine particles of the fluidized bed catalyst from the fluidized bed reactor is accompanied with gas in the reaction bed, do. For this reason, a reaction method of maintaining a good catalyst flow state over a long period of time by keeping the particle size distribution of the catalyst in the reactor within a preferable range while supplying a catalyst containing a large amount of fine particles during the reaction is usually employed (Patent Document 4) .

Japanese Patent Laid-Open No. 2001-55355 International Publication No. 2012/096367 Pamphlet Japanese Patent Laid-Open No. 2002-53519 Japanese Patent Application Laid-Open No. 63-36831

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

In the production of a desired product using a fluidized bed, improvement of the final reaction performance can not be achieved unless the optimal operating conditions are employed in order not only to optimize the catalyst but also to sufficiently exhibit the ability of the catalyst. Particularly, in order to achieve an improvement in the reaction performance, selection of conditions for charging the catalyst is an important factor.

All of the methods of Patent Documents 1 to 3 are aimed at reducing oxygen and combustible gases that adversely affect catalyst, apparatus, and safety. Further, Patent Document 4 aims at maintaining a good flow state of the catalyst after initiating the reaction. There is a case in which a gas for introduction into the reactor is used when the catalyst is filled in the fluidized bed reactor, but 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, optimization of the flow rate of the gas in the reactor when the catalyst is filled in the fluidized bed reactor has not been studied.

The inventors of the present invention have studied the flow rate of gas in the reactor and found the following.

That is, by increasing the flow rate of the gas in the reactor during the charging of the catalyst, the charging of the catalyst can be completed in a short period of time. However, the scattering amount of the catalyst (particularly, the fine powder) increases, and there is a high possibility that plant operation trouble such as clogging of piping due to the scattered catalyst occurs.

When the catalyst is filled and the reaction is carried out after filling the catalyst while the catalyst is being scattered in a large amount, the flow state of the catalyst deteriorates and the reaction becomes unstable. As a result, the yield of the desired product and the partial catalyst deterioration .

Further, by slowing the flow rate of the gas and lengthening the charging time of the catalyst, the scattering amount of the catalyst can be suppressed. However, it takes a long time to complete the filling of the catalyst, and the energy cost for the combustible gas used for preheating the gas introduced into the reactor is also excessive.

All of the methods described in Patent Documents 1 to 4 are not considered to optimize the flow rate of the gas in the reactor when the catalyst is filled in the fluidized bed reactor, The reaction performance could not be improved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to suppress the amount of catalyst scattered out of the reactor and to charge the catalyst in a shorter time, thereby achieving a higher yield of reaction with higher efficiency.

The inventors of the present invention have extensively studied a method of filling a fluidized bed catalyst into a fluidized bed reactor. As a result, it is found that by performing the operation of increasing the gas flow rate after the start of the catalyst charging, the amount of the catalyst scattered out of the reactor is suppressed, and the reaction can be performed at a high target product yield without causing deterioration of the flow state of the catalyst The present invention has been reached. It has also been found that the increase in the gas flow rate is preferable after a certain amount of catalyst is filled in the dip leg which is the catalyst introduction pipe of the cyclone (catalyst collector).

That is, in order to solve the above problems, a method for filling a fluidized bed reactor according to the present invention with a catalyst (hereinafter referred to as " catalyst filling method according to the present invention & ² ], the temperature in the fluidized bed reactor is T [캜], the total flow rate of the gas to be introduced into the fluidized bed reactor is F [Nm ³ / h] and the top pressure in the fluidized bed reactor is P [kPa] Initiating the charging of the catalyst into the fluidized bed reactor with a gas flow rate U in the fluidized bed reactor obtained by substituting into equation (1), and thereafter increasing the U.

U = (F / B × (273 + T) / 273) / ((101 + P) / 101)) / 3600

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 the above-mentioned U is increased by increasing F.

In the catalyst charging method according to the present invention, the catalyst transporting section is provided in the fluidized bed reactor, and the catalyst returning section transports the catalyst recovered in the fluidized bed reactor from a vertically lower position than the recovered position, It is more preferable to calculate the amount of catalyst from at least two pressure differences in the vertical direction in the catalyst carrying section and to increase the U when the amount of catalyst reaches a predetermined value Do.

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

The method for producing a nitrile compound according to the present invention is characterized by including the step of carrying out the catalyst charging method according to the present invention described above.

According to the present invention, it is possible to suppress the amount of catalyst scattered out of the reactor and further to charge the catalyst in a shorter time, thereby keeping the flow state of the catalyst satisfactorily, without generating hot spots, The effect of enabling a reaction with a high yield to be performed with higher efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a schematic configuration of an embodiment of a fluidized bed reactor used in a catalyst charging method according to the present invention. Fig.

(Catalyst charging method)

The catalyst filling method according to the present invention is characterized in that the effective cross sectional area of the fluidized bed reactor is B [m ² ], the temperature in the fluidized bed reactor is T [° C], the total flow rate of the gas introducing the fluidized bed reactor is F [Nm ³ / h], initiating the charging of the catalyst into the fluidized bed reactor with the gas flow rate U in the fluidized bed reactor obtained by substituting P [kPa] for the top pressure in the fluidized bed reactor into the following equation (1) And then increasing the U.

U = (F / B × (273 + T) / 273) / ((101 + P) / 101)) / 3600

Hereinafter, the gas flow rate U [m / s] in the fluidized bed reactor is referred to as "gas flow rate U", effective sectional area B [m ² ] of the fluidized bed reactor is defined as "effective sectional area B" The total gas flow F [Nm ³ / h] of the inlet gas is referred to as the "total flow F of the inlet 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 charged catalyst from being scattered out of the fluidized bed reactor by increasing the gas flow rate U in the fluidized bed reactor during the charging of the catalyst, after initiating the charging of the catalyst. As the particle diameter of the catalyst is smaller, it tends to scatter out of the fluidized bed reactor. If the catalyst to be scattered is biased to have a small particle diameter in the whole catalyst, the particle size distribution is changed compared to that before charging, resulting in deterioration of the flow state of the catalyst. However, according to the present invention, it is possible to prevent the deterioration of the flow state of the catalyst, so that the objective product can be obtained in a high yield in the subsequent reaction. Further, since charging can be completed in a short time, the catalyst can be efficiently filled in the fluidized bed reactor. Further, it is possible to prevent scattering of the catalyst having a small particle diameter, thereby preventing deterioration of the flow state of the catalyst. From this, the flow of the catalyst is maintained well. Further, since the flow state is maintained favorably, the occurrence of temperature unevenness (hot spot) is suppressed even in the subsequent reaction of producing the target product. Further, charging can be completed in a short time, so that the energy cost can be reduced.

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

(A step of increasing the gas flow rate U [m / s] in the reactor)

The catalyst charging method according to the present invention includes a step of increasing the gas flow rate U expressed by the above-mentioned formula (1).

The gas flow rate in the fluidized bed reactor is a value obtained by dividing the flow rate of the introduced gas by the effective cross-sectional area by temperature correction and pressure correction. The specific value of U is preferably 0.07 m / s or more, more preferably 0.10 m / s or more, further preferably 0.46 m / s or less, and more preferably 0.43 m / s or less. Within the above range, the larger the gas flow rate in the reactor, the shorter the catalyst filling time in the reactor, the higher the productivity of the reaction. Within the above range, the smaller the gas flow rate in the reactor, the more suppressed scattering of the catalyst during the charging of the catalyst, 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 cross-sectional area B is the area obtained by subtracting the cross-sectional area of the viscous material from the cross-sectional area when the fluid-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 rich layer) above a position (height) at which a raw material gas is introduced, Sectional area obtained by subtracting the sectional area of a built-in object such as a leg.

The size of the fluidized bed reactor used in the catalyst filling method according to the present invention is not particularly limited, but it is usually within the range of 10 to 200 m ² as an effective cross-sectional area of the reactor for industrial production. Within this range, the larger the effective cross-sectional area, the higher the productivity of the desired product. Further, within the above-mentioned range, the smaller the effective sectional area, the better the operability of the apparatus such as the temperature control.

(Temperature T [° C] in the fluidized bed reactor)

The temperature T is determined by measuring the temperature in the fluidized bed reactor. The measurement portion may be a portion (reaction portion or rich layer) where the reaction with the catalyst occurs above the position (height) at which the material gas is introduced, which will be described 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 above equation (1) is obtained by multiplying the flow rate (F / B) of the introduced gas per unit effective cross-sectional area, which is obtained by dividing the total flow rate F of the introduced gas by the effective cross-sectional area B, by (273 + T) / 273, The influence due to the change of the temperature is corrected. The influence of the change in temperature means, for example, a change in the volume of the gas caused by a change in the temperature, and a change in the flow rate. Therefore, it is also possible to increase the gas flow rate U by changing the temperature T. For example, it is possible to increase the gas flow rate U by increasing the temperature T. Also, " 273 " is an approximate value for calculating the Celsius temperature (占 폚) by the thermodynamic temperature (K).

The temperature T in the fluidized bed reactor at the time of charging the catalyst in the fluidized bed commercial catalyst charging method of the present invention is usually in the range of 100 to 500 ° C. Within the above range, the higher the temperature, the faster the reaction can start after charging, and the better the flow state of the catalyst. Also, within this range, the lower the temperature, the lower the fuel cost per unit time used for heating the gas introduced into the fluidized bed reactor during the catalyst charging.

(Top pressure P [kPa] in the fluidized bed reactor)

The overhead pressure P is obtained by measuring the pressure at the top of the fluidized bed reactor. The top pressure P is the top pressure after the change if the temperature is changed by performing the process of increasing the gas flow velocity U. The above equation (1) corrects the influence of the pressure change by dividing the flow rate (F / B) of the introduced gas per unit effective cross-sectional area by (101 + P) / 101. The effect of the change in pressure means, for example, a change in the volume of the gas caused by the change in pressure, and a change in the flow rate. Therefore, it is also possible to increase the gas flow rate U by changing the top pressure P. For example, it is possible to increase the gas flow rate U by reducing the top pressure P. Also, " 101 " is an approximation of a value for calculating the value of the unit of PASCAL as the standard atmospheric pressure.

(Total flow F [Nm ³ / h] of the gas introduced into the fluidized bed reactor)

As the gas to be introduced into the fluidized bed reactor, for example, a flowing gas for flowing the catalyst packed in the fluidized bed reactor 10, and a catalyst carrying gas for transporting the catalyst to the fluidized bed reactor. Since the flow rate of this gas is set by the user, the total flow rate F of the introduced gas is obtained by adding up the flow rates of the gas set by the user.

The kind of the flowing gas and the catalyst carrying gas is not particularly limited, and examples thereof include pure oxygen, air, and a mixed gas of pure oxygen and air. These gases may be diluted with another gas. The gas for dilution is not particularly limited, but it may be any gas which does not adversely affect the catalytic performance and the gas phase oxidation reaction, and examples thereof include air, nitrogen and helium. Generally, an oxygen-containing gas diluted to an arbitrary concentration by air, oxygen gas, or inert gas may be used.

The total flow rate F of the introduced gas includes the flow rate of the gas introduced into the fluidized bed reactor other than the flowing gas and the catalyst carrying gas. Examples of such gases include a feed gas line or a purge gas to a line for measuring differential pressure.

(A preferred combination of temperature T, top pressure P and total flow F of the inlet gas)

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

(Time to increase the gas flow rate U [m / s] in the fluidized bed reactor)

The timing at which the gas flow rate U is increased can be appropriately set in accordance with the aimed charging time and the degree of suppression of scattering of the catalyst and the like. .

Further, in the fluidized bed reactor, in order to increase the collection efficiency of the catalyst, a plurality of cyclones are often connected and installed. Normally, a dip leg is provided in the cyclone. The deep leg is a device that transports the catalyst recovered in the fluidized bed reactor from the lower portion of the fluidized bed reactor (vertically below the recovered position) into the fluidized bed reactor.

Generally, since the first stage of the deep leg has a large amount of circulation of the catalyst, the lowermost portion is opened into the reactor (or the inverted plate or the like is provided), and the deep legs installed in the second and third stage cyclones And a trickle valve (catalyst emission control device) is installed at the lower end.

In the catalyst filling method according to the present invention, the time for increasing the gas flow rate U [m / s] in the fluidized bed reactor is preferably based on the amount of catalyst in the deep leg, and in the deep leg, It is preferable to set the timing based on the amount of catalyst in the catalyst (the lowest part is open, or the reverse plate is provided, 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 deep leg reaches a predetermined value. The above value is preferably 0.1% by volume or more, more preferably 0.3% by volume or more. In the case where there is no catalyst in the deep leg, the gas and the catalyst introduced into the fluidized bed reactor from the lower end of the deep leg enter (upflow) and reach the cyclone part, and the catalyst may be scattered out of the system. When the bottom of the deep leg is sealed with the catalyst, entry of this gas and catalyst can be prevented. The minimum value of the catalytic amount of the first-stage deep leg which can confirm the sealed state by differential pressure is preferably 0.1% by volume or more, and more preferably 0.3% by volume or more. In other words, by increasing the gas flow rate U after confirming that the lower end of the deep leg is sealed, scattering of the catalyst can be suppressed more efficiently and the charging time can be shortened.

For example, the total flow rate F of the gas is kept constant, and the temperature and pressure vary with time. In this state, it is confirmed that the bottom of the deep leg is covered with the catalyst, and the gas flow rate U is increased by increasing the total flow rate F of the gas. 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 may be appropriately made to suppress influences such as flow meter performance (characteristics) or flow characteristics of the catalyst.

The method of measuring the amount of the catalyst in the deep leg is not particularly limited. However, the method of measuring the amount of the catalyst in the deep leg is not particularly limited, Can be calculated from the pressure difference.

(The amount by which the gas flow rate U [m / s] in the fluidized bed reactor is increased)

The amount by which the gas flow rate U is increased can be appropriately set in accordance with the aimed charging time, to what extent the scattering of the catalyst is suppressed, and the like.

If the gas flow rate U in the fluidized bed reactor is slightly increased after the start of charging, the catalyst can be initially charged while suppressing scattering, and the gas flow rate U in the fluidized bed reactor can be increased, .

As a concrete numerical value for increasing the amount, for example, it is preferably not less than 2%, more preferably not less than 4%, from the viewpoint of manifesting a clear effect by increasing the gas flow rate. From the viewpoint of suppressing the scattering of the catalyst, it is preferably 200% or less, more preferably 150% or less.

(A 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. The gas flow rate U can be easily increased.

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

It should also be noted that it is not necessarily necessary to increase the total flow F of the introduced gas if the gas flow rate U is increased. It is a category of the catalyst filling method according to the present invention that the gas flow rate U is increased by controlling the total flow rate F of the introduced gas to be intentionally within a certain range. For example, by keeping the total flow F of the gas constant, the gas flow rate U repeats the increase and decrease in the hunting range. By making the total flow rate F of the gas constant in this predetermined range, it is possible to fill the catalyst by suppressing scattering to a desired degree at a desired time. This operation is also a category of the catalyst charging method according to the present invention.

The operation for increasing the gas flow velocity U may be performed once or two times or more. For example, it may be increased by one operation up to the target value of the gas flow rate U after the increase, or may be increased stepwise by a plurality of times. The number of times can be appropriately set in accordance with the flow state of the target catalyst, the charging time, and the like.

The gas flow rate U may be increased in a short period of time or gradually increased.

(Fluidized bed reactor)

The fluidized bed reactor used in the catalyst charging method according to the present invention can be employed by arbitrarily selecting a conventionally known fluidized bed reactor used for the fluidized bed reaction. Here, one embodiment of the 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 view showing a schematic structure of a fluidized bed reactor 1 having a fluidized bed reactor 10.

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

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

(Catalyst hopper 2)

The catalyst hopper 2 is for storing the catalyst for filling the fluidized bed reactor. The catalyst (x1) discharged from the catalyst hopper (2) is carried by the catalyst carrier gas (x2). That is, the catalyst-containing gas (X) in which the catalyst (x1) and the catalyst carrier gas (x2) are combined is supplied into the fluidized bed reactor (10).

(catalyst)

The catalyst to which the catalyst filling method according to the present invention is applied is not particularly limited, but the method can be suitably applied to a catalyst used for an ammoxidation reaction and / or oxidation reaction of hydrocarbons having 1 to 6 carbon atoms. Examples of such a catalyst include molybdenum, a metal oxide catalyst containing bismuth, a metal oxide catalyst containing iron and antimony, a metal oxide catalyst containing molybdenum and vanadium, a metal oxide catalyst containing uranium and antimony, and the like have. Among them, it is more suitably applicable to a catalyst for producing a nitrile compound.

The shape of the catalyst is not particularly limited, but a powdery form is more preferable. The particle diameter is preferably 5 mu m or more, more preferably 10 mu m or more, further preferably 200 mu m or less, and more preferably 180 mu m or less.

(Gas supply conduit 16)

The gas supply conduit 16 is for supplying the source gas Z to the fluidized bed reactor 10 when performing the reaction for preparing the desired product after filling the catalyst. The raw material gas (Z) includes a gaseous hydrocarbon compound, gaseous ammonia and water vapor. Is disposed below the fluidized bed reactor (10) and branches into a plurality of branch tubes (17). At the end of each branch pipe section 17, a nipple section (raw material spray nozzle) 18 which is opened toward the bottom surface of the fluidized bed reactor 10 is connected.

(Raw material gas (Z))

Examples of the raw material gas Z include hydrocarbons having 1 to 6 carbon atoms such as butanes such as methane, ethane, ethylene, propane, propylene, n-butane and isobutane; butanes such as n-butylene and isobutylene; , pentanes such as n-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 the gas and the catalyst. The cyclone 12 is provided with an inlet 13 for introducing gas and catalyst into the cyclone 12, a gas outlet tube 15 for drawing the separated gas out of the fluidized bed reactor 10, There is provided a deep leg 14 that conveys to the catalyst flow bed 11.

In the fluidized bed reactor, as shown in FIG. 1, three cyclones 12 are connected to one another in the reactor (however, in FIG. 1, only one series connected with three cyclones 12) Lt; / RTI > 1, the two cyclones 12 are connected to one gas outlet pipe 15, and the other gas outlet pipe 15 is connected to the outlet of the fluidized- .

(Gas distributor 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 distribution 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). A 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 flowing gas for flowing the catalyst in the fluidized bed reactor (10) during the charging of the catalyst, and a gas for supplying oxygen to the reaction during the reaction.

The oxygen-containing gas (Y) as the flowing gas at the time of charging the catalyst and the oxygen-containing gas (Y) as the gas for supplying oxygen at the time of the reaction may be the same gas or different gases. The specific kind of the oxygen-containing gas (Y) is the same as that of the above-mentioned flowing gas.

(Method for producing nitrile compound)

The method for producing a nitrile compound according to the present invention includes a step for carrying out the catalyst charging method according to the present invention described above. By employing the catalyst charging method according to the present invention, the flow of the catalyst in the fluidized bed reactor is good, and minute catalyst particles are not scattered and exist in the fluidized bed reactor. Thus, a nitrile compound can be obtained with a high yield.

After carrying out the catalyst charging method according to the present invention, the user may initiate a reaction for producing the nitrile compound at an arbitrary timing. For example, the reaction may be started after confirming that the flow state of the catalyst in the fluidized bed reactor has become a normal state. When the reaction is initiated, the reaction temperature is raised by heat generation, the pressure is also varied, and the flow state of the catalyst sometimes changes. In the case where the fluctuation of these states is large before the start of the reaction, it is preferable from the safety standpoint that the fluctuation of each state becomes a predetermined range and the reaction is started when the state is stable. Further, before the reaction for producing the nitrile compound, the rising temperature by the reaction may be predicted, and the temperature may be lowered before the start of the reaction.

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, etc., or may be used with an increased oxygen concentration.

In the method for producing the nitrile compound according to the present invention, the composition ratio of the raw material gas used in the gas phase oxidation reaction is not particularly limited, but from the viewpoint of increasing the yield of the desired product, at least one selected from the above-mentioned hydrocarbons having 1 to 6 carbon atoms It is more preferable that the molar ratio of compound / ammonia / oxygen in the range of 1 / 0.5 to 2.0 / 1.0 to 5.0.

The gas-phase oxidation reaction conditions employed in the production method of the nitrile compound according to the present invention are not particularly limited, but generally the reaction temperature is 350 to 500 ° C and the reaction pressure is atmospheric pressure to 500 kPa.

In the present invention, the method of feeding at least one compound selected from the above-mentioned hydrocarbons having 1 to 6 carbon atoms, ammonia, and an oxygen-containing gas into the reactor is not particularly limited, and a sparger type, And a method of supplying a solution to the solution.

Further, the at least one compound selected from hydrocarbons having 1 to 6 carbon atoms, the ammonia, and the oxygen-containing gas may be divided and supplied to the fluidized bed reactor, or all or a part of them may be mixed and supplied. From the viewpoint of safety and the like, a method is generally adopted in which at least one compound selected from hydrocarbons having 1 to 6 carbon atoms, ammonia, and oxygen-containing gas are divided and fed into the fluidized bed reactor.

In addition, from the viewpoint of efficiency, after the catalyst is filled as described above, the nitrile compound may be continuously produced.

The present invention is not limited to the above-described embodiments, but various modifications may be made within the scope of the claims, and embodiments obtained by properly combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention. EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited by the following description unless it departs from the gist thereof.

Example

[Example 1]

(Filling of the liquid phase commercial catalyst into the reactor)

The 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 wherein x represents the amount of each component Of the number of atoms of oxygen required to satisfy the valence of oxygen atoms) was charged from the catalyst hopper into a cylindrical cylindrical fluidized bed reactor having an internal diameter of 8.0 m (effective cross-sectional area B 47 m ² ).

The fluidized bed reactor, the fluidized bed reactor equipped with the fluidized bed reactor, and the catalyst hopper were the ones shown in Fig.

The flow rate of the gas is F 12 × 10 ³ Nm ³ / h, the temperature in the reactor T is 420 ° C., and the top pressure P 8 kPa in the reactor is used as the gas for the flow into the fluidized bed reactor and the catalyst transporting gas. Of the catalyst. The gas flow rate U in the reactor at the start of charging (charge time 0 hour) was 0.17 m / s. The flow rate of the catalyst carrying gas may be a flow rate capable of transporting the catalyst. However, in the examples and the comparative examples, the flow rate of the flowing gas is very large compared to the flow rate of the catalyst carrying gas. F was set to be substantially equal to the flow rate of the flowing gas (the same is true in the following examples and comparative examples).

At 11.5 hours after the start of the charge of the catalyst, when the charge of the catalyst in the deep leg reached 1.6% by volume, when the amount of the catalyst charged to the fluidized bed reactor reached 64 tons, the flowable gas to the fluidized- And the flow rate F was 37 × 10 ³ Nm ³ / h.

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

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

Table 1 shows the values from the start of charging to the completion of charging.

(Ammoxidation reaction after catalyst charging)

The ammoxidation reaction was carried out using a fluidized bed reactor in which the catalyst was charged. Using air as an oxygen source, a feed 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-described conditions, the reaction temperature was detected by a thermocouple thermometer provided at a plurality of places, but temperature unevenness (hot spot) during the reaction was not observed, and the catalyst was in a good flow state. The average yield of acrylonitrile was 77.4%.

[Example 2]

(Filling of the liquid phase commercial catalyst into the reactor)

The same procedure as in Example 1 was followed to initiate the charging of the liquid phase catalyst into the fluidized bed reactor shown in Fig. Air was used as the flow-through gas to the fluidized bed reactor and the catalyst-carrying gas, and the total flow F of these gases was 23 × 10 ³ Nm ³ / h. The gas flow rate U in the reactor at the start of charging (charge time 0 hour) was 0.30 m / s. The charging of the catalyst to the fluidized bed reactor was initiated under conditions of temperature T 420 ° C in the fluidized bed reactor and top pressure P 15kPa in the fluidized bed reactor.

4.6 hours after the start of the charge of the catalyst, when the catalyst charge in the deep leg reached 1.7% by volume, when the charged amount of the catalyst into the fluidized bed reactor reached 66 tons, the flowable gas to the reactor was increased to increase the total flow rate F to 30 × 10 ³ Nm ³ / h.

After increasing the flowable 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 charging time of 6.1 hours was able to complete the catalyst charging. The amount of the catalyst charged after completion of the catalyst charging was 109 tons, and it was confirmed that almost all of the catalyst was charged in the reactor.

(Ammoxidation reaction after catalyst charging)

Using the fluidized bed reactor (see Fig. 1) after filling with the fluidized catalyst, the ammoxidation reaction was carried out under the same conditions as in Example 1. During the reaction, the reaction temperature was detected with a thermocouple thermometer provided at a plurality of locations, but temperature unevenness (hot spot) during the reaction was not observed, and the catalyst was in a good flow state. The average yield of acrylonitrile was 77.1%.

[Comparative Example 1]

(Filling of the liquid phase commercial catalyst into the reactor)

Filling of the liquid phase catalyst into the fluidized bed reactor (see FIG. 1) was initiated by the same procedure as in Example 1. Air was used as the flow-through gas to the fluidized bed reactor and the catalyst-carrying gas, 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 charging (charge time 0 hour) was 0.48 m / s. The charging of the catalyst to the fluidized bed reactor was initiated at the temperature T 420 ° C in the fluidized bed reactor and at the top pressure P 26kPa in the fluidized bed reactor.

The total flow F of the introduced gas was kept constant, and no increase was made. The catalyst filling in the deep leg after 1.1 hours was 1.3% by volume. The catalyst was finally charged with a catalyst charge time of 2.1 hours. Further, it was found that the charged amount of the catalyst after completion of the catalyst charging was 105 tons, and that about 5 mass% of the catalyst supplied to the charging was scattered out of the reactor.

(Ammoxidation reaction after catalyst charging)

Using the fluidized bed reactor (see Fig. 1) after filling with the fluidized catalyst, the ammoxidation reaction was carried out under the same conditions as in Example 1. As a result of detecting the reaction temperature with a thermocouple thermometer provided at a plurality of locations during the reaction, it was found that temperature unevenness (hot spot) was observed in the reactor and the flow state of the catalyst deteriorated. In addition, the average yield of acrylonitrile was 73.4%, and a catalyst which was subjected to reduction deterioration (discoloration) from the reactor stopped after the reaction was observed.

[Comparative Example 2]

(Filling of the liquid phase commercial catalyst into the reactor)

Filling of the liquid phase catalyst into the fluidized bed reactor (see FIG. 1) was initiated by the same procedure as in Example 1. Air was used as the flow-through gas to the fluidized bed reactor and the catalyst-carrying gas, 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 charging (charge time 0 hour) was 0.04 m / s. The charging of the catalyst to the fluidized bed reactor was initiated at the temperature T 420 ° C in the fluidized bed reactor and at the top pressure P 2kPa in the fluidized bed reactor.

During the charging of the catalyst, the total flow rate F of the introduced gas was kept constant and did not increase. The catalyst filling in the deep leg after 7.9 hours was 1.3% by volume. Finally, a catalyst charging time of 17.8 hours was required to complete the catalyst charging. It was confirmed that almost all of the catalyst was charged in the reactor. However, since the charging time was long for about 5 to 12 hours as compared with Examples 1 and 2, the temperature inside the reactor (For example, the use amount of propylene 400 Nm ³ x 5 hours = 2000 Nm ³ supplied as fuel when the charging time was increased by 5 hours) was increased.

(Ammoxidation reaction after catalyst charging)

Using the fluidized bed reactor (see Fig. 1) after filling with the fluidized catalyst, the ammoxidation reaction was carried out under the same conditions as in Example 1. During the reaction, the reaction temperature was detected by a thermocouple thermometer provided at a plurality of locations, but temperature unevenness (hot spot) during the reaction was not observed, and the catalyst was in a good flow state. The average yield of acrylonitrile was 77.3%. However, since charging time was required as described above, opportunity loss in the production of acrylonitrile occurred in the meantime.

As apparent from the above-mentioned Examples and Comparative Examples, the gas flow rate in the reactor is reduced during the initial stage of the catalyst charging until a certain amount of catalyst is filled in the deep legs under the cyclone in the reactor, It is possible to suppress the amount of the catalyst scattered to the outside of the reactor and to perform the reaction at a high target product yield without causing deterioration of the flow state of the catalyst .

1 Fluid bed reactor
2 catalyst hopper
10 fluidized bed reactor
11 catalyst fluid phase
12 cyclones
13 Inlet
14 Deep legs
15 gas outlet pipe
16 gas supply conduit
17 branch tube
18 Nipples
19 gas distribution plate
20 gas supply port
X catalyst-containing gas
Y oxygen-containing gas
Z raw material gas
x1 catalyst
x2 catalyst carrier gas

Claims (11)

A method for filling a fluidized bed reactor with a catalyst, comprising the steps of: providing an effective cross sectional area of the fluidized bed reactor of B [m ² ], a temperature in the fluidized bed reactor of T [° C] (M / s) in the fluidized bed reactor obtained by substituting the top pressure in the fluidized bed reactor [Nm ³ / h] and the top pressure in the fluidized bed reactor P [kPa] into the following equation (1) Wherein said step of increasing the U comprises the step of increasing the U after initiating the charging of the catalyst into the reactor.
U = (F / B × (273 + T) / 273) / ((101 + P) / 101)) / 3600 The method of claim 1, wherein the value of T is 100 to 500 占 폚. 3. The method according to claim 1 or 2, wherein the U is increased by increasing F. 4. The method according to any one of claims 1 to 3, wherein the U is increased by changing at least one of T and P. The fluidized-bed reactor according to any one of claims 1 to 4, wherein a catalyst carrier is provided in the fluidized bed reactor,
Wherein the catalyst returning portion conveys the catalyst recovered in the fluidized bed reactor from a vertically lower position than the recovered position into the fluidized bed reactor,
Wherein the catalyst amount is calculated from at least two pressure differences in the vertical direction in the catalyst carrying section, and the U is increased when the catalyst amount reaches a predetermined value. The process according to any one of claims 1 to 5, wherein the gas is at least one of a flowing gas for flowing the catalyst and a catalyst transporting gas for transporting the catalyst to the fluidized bed reactor. The method according to any one of claims 1 to 6, wherein in the step of increasing U, the amount of U is increased to 2% or more and 200% or less at the start of charging. 7. The method according to any one of claims 1 to 6, wherein the U is increased by 4% or more and 150% or less with respect to the U at the start of charging in the step of increasing U. 9. The process according to any one of claims 1 to 8, wherein the catalyst is a catalyst for the production of a nitrile compound. A process for producing a nitrile compound, comprising the step of carrying out the process according to any one of claims 1 to 9. A process for producing a nitrile compound, characterized by carrying out the process according to any one of claims 1 to 9, followed by production of a nitrile compound.

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