JP5797545B2 - Heat treatment method for catalyst precursor, method for producing catalyst, and method for producing propylene - Google Patents

Description

  The present invention relates to a heat treatment method for a catalyst precursor, a method for producing a catalyst, and a method for producing propylene using the catalyst.

  Many techniques using zeolite as a hydrocarbon conversion reaction catalyst are known. In addition, the treatment for stabilizing the zeolite structure by contacting the zeolite and the gas containing water vapor at a relatively high temperature and desorbing the framework aluminum of the zeolite before being subjected to the conversion reaction has been widely used as a preferred treatment. Has been done. Such steam treatment is often carried out batchwise at 400 to 900 ° C. for several hours under the condition that zeolite is charged in a rotary furnace and closed in a gas phase. On the other hand, from the viewpoint of increasing the efficiency of the water vapor treatment, a method of continuous treatment is also disclosed.

  In Patent Document 1, when ammonium-exchanged faujasite-type zeolite is continuously calcined in the form of powder in a rotary calciner, ammonia generated from the zeolite while maintaining the partial pressure of water vapor in the calciner at 10% or more. A method is described in which gas and water vapor are exhausted in the same direction (cocurrent) as the zeolite flow in the rotary calciner.

  In Patent Document 2, when the zeolite is in a powder form as in Patent Document 1, the size of the zeolite particles is small, so that a uniform distribution of the zeolite particles flowing in the calcining furnace while in contact with steam can be obtained. It is described that it becomes difficult. Therefore, in this document, a Y-type zeolite having a reduced Na content is mixed with a porous inorganic oxide, extruded, and then fired in the form of a molded body under conditions higher than a water vapor partial pressure of 2.0 p.sia. Is described.

Japanese Patent Publication No. 5-66324 Japanese Patent No. 2563910

  In Patent Documents 1 and 2, the water vapor treatment is performed while maintaining the water vapor partial pressure. However, even when the steam treatment is performed while maintaining the steam partial pressure, the resulting catalyst does not have a uniform quality, and some of them do not have a sufficient steam treatment. For this reason, the steam treatment effect may not be sufficiently obtained as a whole catalyst.

  Furthermore, although the above-mentioned patent document describes a steam treatment for zeolite powder or an extrusion-molded catalyst, it has not been studied what treatment should be performed when the catalyst is substantially spherical. . At first glance, it is considered that a spherical catalyst is easier to process uniformly than a molded catalyst. However, according to the study by the present inventors, even when the substantially spherical catalyst is continuously heat-treated even with reference to the conditions described in the above-mentioned patent document, the state of the steam-treated catalyst is It turns out that there is a problem that becomes uneven.

  Therefore, the present invention has been made in view of the above circumstances, and is a heat treatment method in which a substantially spherical catalyst precursor containing a zeolite and a binder is continuously steam-treated in a rotary furnace, and the heat treatment is performed. It is an object of the present invention to provide a catalyst precursor heat treatment method, a catalyst production method, and a propylene production method using the catalyst, in which the catalyst obtained through the above process can have a more uniform quality than conventional catalysts.

  Since the present inventors have a relatively high fluidity of the substantially spherical catalyst precursor, a difference in the moving speed of the catalyst precursor occurs depending on the location in the rotary furnace, and the processing state is likely to be uneven. We thought that it would be difficult for the catalyst to have uniform quality. As a result of further earnest research, the catalyst has a more uniform quality by maintaining a high ratio of the mass of the catalyst precursor present in the heating area to the volume of the heating area in the rotary furnace. As a result, the present invention has been completed.

That is, the present invention is as follows.
[1] A method of continuously heat-treating a substantially spherical catalyst precursor containing a zeolite and a binder in a rotary furnace under a water vapor atmosphere, wherein the precursor core volume (v) in the heating zone of the rotary furnace is A method for heat treating a catalyst precursor, wherein the catalyst precursor is heat-treated while maintaining a ratio (w / v) of mass (w) of the catalyst precursor existing in the heating region to 0.10 g / cm ³ or more.
[2] The heat treatment method according to [1], wherein the catalyst precursor is obtained through a spray drying process.
[3] The heat treatment method according to [1] or [2], wherein the zeolite is MFI type zeolite.
[4] A method for producing a catalyst, comprising a step by the heat treatment method according to any one of [1] to [3].
[5] A catalyst obtained by the production method according to [4], having a step of contacting a hydrocarbon raw material containing at least one compound selected from the group consisting of ethylene, methanol, ethanol and dimethyl ether. Production method.

  According to the present invention, there is provided a heat treatment method in which a substantially spherical catalyst precursor containing zeolite and a binder is continuously steam-treated in a rotary furnace, and the catalyst obtained through the heat treatment has a more uniform quality than before. It is possible to provide a method for heat treatment of a catalyst precursor that can have a catalyst, a method for producing a catalyst, and a method for producing propylene using the catalyst.

It is a schematic diagram which shows an example of the spray dryer which concerns on this invention. It is a schematic diagram which shows an example of the heat processing apparatus containing the rotary furnace which concerns on this invention. It is an electron micrograph (50 times) of the catalyst precursor which concerns on an Example. It is an electron micrograph (100 times) of the catalyst precursor which concerns on an Example. It is an electron micrograph (350 times) of the catalyst precursor which concerns on an Example. It is an electron micrograph (150 times) of the catalyst precursor which concerns on an Example. It is an electron micrograph (100 times) of the catalyst which concerns on an Example.

  Hereinafter, an embodiment for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. The present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

The heat treatment method of the catalyst precursor of the present embodiment is a method of continuously heat-treating a substantially spherical catalyst precursor containing a zeolite and a binder in a rotary furnace under a steam atmosphere, and the heating region of the rotary furnace The catalyst precursor is heat-treated while maintaining the ratio (w / v) of the mass (w) of the catalyst precursor existing in the heating region to the core tube volume (v) of 0.10 g / cm ³ or more. .
Here, the “catalyst precursor” refers to a material before undergoing the treatment when the catalyst is obtained through a treatment that causes some chemical change.

(1) Zeolite Zeolite is crystalline porous aluminosilicate or metallosilicate (a part or all of aluminum atoms constituting the skeleton of crystalline porous aluminosilicate is gallium (Ga) atom, iron (Fe) Phosphoric porous crystals having a structure similar to or similar to those of atoms, boron (B) atoms, chromium (Cr) atoms, titanium (Ti) atoms and the like, which can be substituted with substitutable elements) Is also included, and silicalite described later is also included.

Specifically, as a zeolite having a small pore diameter (structure having an oxygen 8-membered ring or less), for example, chabazite (CHA: notation by a code that classifies zeolite defined by the International Zeolite Society. The same applies hereinafter) SAPO-. 34 (CHA), erionite (ERI), and type A (LHA). As zeolite intermediate pore size (10-membered oxygen ring structures), for example, ferrierite (FER), ZSM-11 ( MEL), ZSM-5 (MFI), silicalite (MFI) and AlPO ₄ -11 (AEL) is Can be mentioned. Moreover, as a zeolite with a large pore diameter (oxygen 12-membered ring structure), for example, X type (FAU), Y type (FAU), faujasite (FAU), β type (BEA), mordenite (MOR), ZSM- 12 (MTW), and ALPO ₄ -5 (AFI) and the like. Furthermore, examples of the zeolite having an ultra-large pore diameter (structure having an oxygen 14-membered ring or more) include UTD-1 (DON), CIT-5 (CFI), and VPI-5 (VFI). These zeolites are used alone or in combination of two or more.

  Of these, MFI type and CHA type zeolites are preferred. More preferred are MFI type ZSM-5, MFI type silicalite, and CHA type SAPO-34. More preferred are MFI type ZSM-5 and MFI type silicalite, and particularly preferred is MFI type ZSM-5. MFI type ZSM-5 has high heat resistance and is preferable in terms of shape selectivity and solid acidity.

  There is no particular limitation on the composition of the zeolite. When used as a catalyst in a reaction for producing propylene from a hydrocarbon raw material containing at least one compound selected from the group consisting of ethylene, methanol, ethanol and dimethyl ether (hereinafter also referred to as “propylene production reaction”), From the viewpoint of propylene selectivity, for example, in the case of Y-type zeolite, a preferable Si / Al ratio is 1 to 20 in terms of atomic ratio. In the case of MFI-type zeolite, the preferable Si / Al ratio is 10 to 20000 in terms of atomic ratio, more preferably 10 to 1000. When the MFI-type zeolite is a metallosilicate, the total amount of substituted elements and Al is used instead of the amount of Al, and is considered in the same manner as the Si / Al ratio. In the case of a silicoaluminophosphate such as SAPO-34, the (Al + P) / Si ratio is used instead of the Si / Al ratio, and the preferred (Al + P) / Si ratio is 2 to 20000 in atomic ratio. In the case of propylene production reaction, if the composition of the zeolite (Si / Al ratio, (Al + P) / Si ratio, etc.) is equal to or more than the lower limit of the above preferred range, it tends to be able to suppress the promotion of side reactions due to too high activity. When the amount is not more than the upper limit of the above preferable range, there is a tendency that a decrease in activity due to a decrease in the number of active points can be suppressed.

The cation of the zeolite may be NH ₄ ⁺ , H ⁺ , or may contain ions of the following elements from the viewpoint of increasing the propylene selectivity in the above reaction. Examples of such elements include at least one alkali metal selected from the group consisting of Li, Na, K and Rb, and at least one alkaline earth metal selected from the group consisting of Mg, Ca, Sr and Ba. At least one transition metal selected from the group consisting of Ti, Zr, V, Nb, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Ag, Au, Y, La and Ce, and Zn , B, Ga, Sn and Sb. Moreover, the form in which a zeolite contains P may be sufficient from a viewpoint of suppressing dealumination. These may be used singly or in combination of two or more, and may be included in the zeolite by ion exchange or impregnation support, or may be included after molding with a binder.

  The content of zeolite in the catalyst is preferably 15 to 65% by mass, more preferably 30 to 60% by mass, based on the mass of the whole catalyst, from the viewpoint of easily obtaining sufficient activity for the reaction.

(2) Binder The binder is not particularly limited as long as it functions as a binder for the zeolite, and may be a known one.

  A preferred binder is a porous inorganic oxide having high heat resistance. Specific examples include silica, alumina, silica alumina, silica titania, titania, silica zirconia, zirconia, kaolin clay, and diatomaceous earth. The binder is not limited to a porous material. An example of the binder other than the porous body is aluminum phosphate. A binder is used individually by 1 type or in combination of 2 or more types. When a catalyst is used in the above reaction, the binder is preferably silica and / or kaolin clay, more preferably silica, from the viewpoint of not having excessive acidity that promotes coke formation by the reaction.

  When the catalyst is used for a propylene production reaction, the content of the binder in the catalyst is preferably 35 to 85% by mass, more preferably 40 to 70% by mass, based on the mass of the entire catalyst, from the viewpoint of catalyst strength. is there.

(3) Shape and particle diameter of catalyst precursor and catalyst In the present embodiment, the catalyst precursor has a substantially spherical outer shape, and the catalyst preferably has a substantially spherical outer diameter. In this specification, “substantially spherical” means a shape excluding a columnar shape and a weight-like shape. From the viewpoint of rolling properties in the heat treatment step described below, some polyhedrons and flake shapes are allowed, but from the viewpoint of industrially efficient production, they are not shapes that require molding like polyhedrons. Is preferred. From the viewpoint of production efficiency, spray drying is a preferred drying method in the production method of the catalyst precursor. The particles obtained by the spray drying process are all substantially spherical, and the particles obtained by the spray drying process are included in the “substantially spherical” particles. The particles obtained by spray drying have a spherical shape, a substantially spherical shape, and an elliptical shape. Furthermore, the shape of the surface is depressed, or a hollow solid having such shape is opened. However, these are shapes similar to spheres in the present specification, and are all included in “substantially spherical” including spherical shapes. It is considered that the catalyst particles having a spherical shape that is depressed or opened are inferior in fluidity in a fluidized bed reactor as compared with spherical catalyst particles that are not depressed or opened. However, in the present specification, it is essential that the catalyst precursor is “substantially spherical” because the movement of the catalyst precursor particles during the heat treatment affects the uniformity of heating with respect to the particles, and finally It also affects the uniformity of the catalyst quality obtained. In the process in which the catalyst precursors flow while being rolled while being in contact with each other and are heated, the depressions and the spherical shape are distorted compared to the case where the shape is columnar or weight-like. The effect on the rolling of particles is much smaller. Therefore, “substantially spherical” means a shape excluding a columnar shape and a weight-like shape. The ratio of the minor axis to the major axis of the ellipse is preferably 0.5 to 1.0 because the closer to a sphere can make the quality of the catalyst more uniform, 0.7 to 1.0 Is more preferable. As for the state of the particle surface, the influence of the heat treatment on the movement of the particle is small compared to the shape factor, so that the surface may be smooth or uneven.

  Whether or not the catalyst precursor and the catalyst are substantially spherical can be confirmed by observing with an electron microscope at a magnification such that 100 to 200 catalysts or catalyst precursors are included in the visual field.

  The average particle diameter of the catalyst precursor and the catalyst is preferably 10 to 500 μm, more preferably 20 to 300 μm, from the viewpoint of obtaining good reactivity in the case of fluidized bed catalyst use for propylene production reaction. Preferably it is 20-100 micrometers, Most preferably, it is 30-60 micrometers. The average particle diameter of the catalyst precursor and the catalyst can be measured by a laser diffraction / scattering particle size analyzer. The average particle diameter is a point where the particle size distribution of the catalyst (the ratio of particles in a certain particle size interval) is measured by the above analyzer and the accumulation of the particle size distribution is obtained by taking the total volume as 100% and the accumulation becomes 50%. Mean particle diameter, that is, cumulative average diameter (center diameter, median diameter).

[Method for producing catalyst]
The catalyst and the catalyst precursor can be produced by subjecting a raw material mixture containing zeolite and a raw material forming a binder (hereinafter also referred to as “binder raw material”) to spray drying.

(1) Raw material mixture preparation step The raw material mixture is preferably prepared by mixing zeolite and a binder raw material.

  When the primary particles of zeolite form agglomerated particles of several μm to several tens of μm by secondary aggregation, it is preferable to deaggregate by mechanical treatment or chemical treatment and then mix with the binder. From the viewpoint of simplicity, mechanical pulverization is preferred. When the pulverization is performed until the zeolite has a particle diameter of about 0.01 to 5 μm, the wear strength of the resulting catalyst tends to increase.

  There is no limitation in particular in a binder raw material, The binder raw material used in order to manufacture the catalyst containing a well-known zeolite may be sufficient. Examples of the binder raw material include silica sol, silica gel, sodium silicate, fumed silica, alumina sol, alumina gel, silica alumina sol, silica alumina gel, silica titania sol, titania sol, silica zirconia sol, zirconia sol, kaolin clay, and diatomaceous earth. And aluminum phosphate. Of these, silica sol and kaolin clay are preferable, and silica sol is more preferable. In particular, it is preferable to use a silica sol having an average particle diameter of 4 to 30 nm from the viewpoint of increasing the catalyst strength. A binder raw material is used individually by 1 type or in combination of 2 or more types.

  The raw material mixture is preferably stirred after mixing the zeolite and the binder raw material with sufficient time and strength to mix them together. Usually, when it stirs at 5-95 degreeC for 0.5 to 48 hours, both will be in the state fully mixed. The solid content concentration of the raw material mixture is preferably adjusted to 5 to 60% by mass. When silica sol is used as the binder raw material, it is also preferable to add an inorganic salt as a molding aid to the raw material mixture. By adding an inorganic salt, solid particles having no pores are easily formed. Examples of the inorganic salt include ammonium nitrate, sodium nitrate, calcium nitrate, zirconium nitrate, ammonium chloride, ammonium sulfate, and ammonium acetate. Furthermore, it is also preferable to add an inorganic acid and / or alkali for the purpose of adjusting the pH and / or viscosity of the raw material mixture. Examples of the inorganic acid include nitric acid, hydrochloric acid, and sulfuric acid, and examples of the alkali include aqueous ammonia. The viscosity of the raw material mixture is preferably in the range of about 1-1000 cps at 25 ° C., and the pH is preferably in the range of about 0.1-10. The above-mentioned molding aid, inorganic acid and alkali are used singly or in combination of two or more.

(2) Spray drying step A method for spray drying (hereinafter also referred to as “spray drying”) of the raw material mixture will be described. Spray drying is a method of spraying a raw material liquid containing a solute and a solvent to form minute droplets of the raw material liquid, and evaporating the solvent from the droplets by contacting the liquid droplets with a heated gas fluid. And drying to obtain a dried solute. In this embodiment, by spraying the raw material mixture, fine droplets of the raw material mixture are formed, and by contacting the droplets with a heated gas fluid, volatile components are removed from the droplets and dried. This is a method for obtaining a catalyst precursor (dried product).

  Spray drying can be generally performed using a spray dryer. As a spray dryer, what was conventionally known as a spray dryer used for manufacture of a catalyst can also be used. FIG. 1 is a schematic view showing a typical example of a spray dryer. The spray dryer 10 includes a raw material liquid tank 1 for storing the raw material mixture, a liquid feeding device 2, a blower device 3, a heating device 4, a spraying device 5, a drying chamber 6, a dry matter recovery device 7, This is a drying device mainly including a cyclone 8 and a wind exhaust device 9.

  The raw material liquid tank 1 may not only store the raw material mixture, but may be used as a container for preparing a raw material mixture by adding zeolite, a binder raw material, and other substances as required. Moreover, the raw material liquid tank 1 may be provided with a stirrer, and by appropriately stirring with the stirrer, it is possible to prevent the solid content in the raw material mixture from being precipitated or aggregated. . When the raw material mixture is prepared in the raw material liquid tank 1, the stirrer may be used for stirring and mixing the zeolite, the binder raw material, and various substances added as necessary. The liquid feeding device 2 is provided in a line connecting the raw material liquid tank 1 and the spraying device 5, and is a device for feeding the raw material mixture from the raw material liquid tank 1 to the spraying device 5. As the liquid delivery device 2, a pump is usually used.

  The blower 3 is a device for introducing a gas fluid used for drying droplets into the drying chamber 6. As the blower 3, for example, an electric blower can be used. Examples of the gas fluid include air, nitrogen, and helium, and preferably air. The heating device 4 is provided in a line connecting the blower 3 and the drying chamber 6, and is a device for heating the gas fluid sent from the blower 3. For example, an electric heater can be used as the heating device. In the heating device 4, the gas fluid may be heated so that the gas fluid temperature at the inlet of the drying chamber 6 becomes a desired temperature. The gas fluid temperature at the inlet of the drying chamber 6 is preferably 100 to 400 ° C, more preferably 150 to 300 ° C.

  The spraying device 5 is a device for spraying the droplets of the raw material mixture sent from the raw material liquid tank 1 through the liquid feeding device 2 into the drying chamber 6. Spraying of the raw material mixture in the spraying device 5 can be performed by, for example, a rotating disk method, a two-fluid nozzle method, and a high-pressure nozzle method. As the spraying device 5, an apparatus suitable for such a method may be used. From the viewpoint of narrowing the particle size distribution of the catalyst, the rotating disk method and the two-fluid nozzle method are preferable, and the rotating disk method is more preferable.

  In the drying chamber 6, the liquid droplets of the raw material mixture sprayed by the spraying device 5 are brought into contact with the gas fluid heated and introduced from the blower device 3 via the heating device 4, so that the liquid For removing volatile components from the droplets, that is, for drying the droplets. As the drying chamber 6, those conventionally provided in a catalyst spray dryer can be used. The gas fluid temperature at the outlet of the drying chamber 6 (exit to the cyclone 8 described later) is preferably 80 to 200 ° C, more preferably 90 to 150 ° C. The pressure in the drying chamber 6 may be normal pressure, reduced pressure, or increased pressure. The dry matter recovery apparatus 7 is an apparatus for recovering a dry body obtained by drying droplets. As the dry matter recovery device 7, a catalyst spray dryer conventionally provided can be used. In addition, the said dry body is one aspect | mode of the catalyst precursor which concerns on this embodiment.

  The cyclone 8 is a device for separating and recovering a dry body accompanying the gas fluid discharged from the drying chamber 6 from the gas fluid. As the cyclone 8, a catalyst spray dryer conventionally provided can be used. The air exhaust device 9 is a device for discharging the gas fluid from the drying chamber 6. As the air exhaust device 9, for example, an electric exhaust fan can be used.

  In order to control the average particle diameter of the catalyst and the catalyst precursor within a preferable range, the number of rotations of the disk in the spray dryer 10, the amount of spray gas from the two-fluid nozzle, the amount of raw material mixture, the amount of gas fluid, the drying temperature Can be adjusted.

  The shape and average particle size of the dried body thus obtained (one aspect of the catalyst precursor) are substantially unchanged after calcination and contact with an acidic solution described later.

(3) Firing step In the firing step, a dried product or a product obtained by subjecting the dried product to the heat treatment described below (hereinafter referred to as "dried product") is fired to obtain a fired product. This calcined body can be another embodiment of the catalyst precursor and can also be one embodiment of the catalyst. The furnace used for firing the dried body is not particularly limited, and may be a known one, for example, firing in a stationary furnace, a rotary furnace, a fluidized firing furnace, or the like. The firing temperature is preferably 400 to 1000 ° C, more preferably 600 to 800 ° C. The gas in the firing atmosphere is preferably air, nitrogen, water vapor, carbon dioxide or the like, and more preferably air. These gases are used alone or in combination of two or more.

  It is also preferable to contact the fired body thus obtained with an acidic solution. Thereby, the trace amount alkali metal etc. which are contained in a binder can be removed from a sintered body. As the acidic solution, nitric acid, hydrochloric acid, and aqueous sulfuric acid are preferable, and nitric acid is more preferable. The concentration of the acidic solution is preferably 0.01 to 2 molar, more preferably 0.1 to 1 molar. The contact time between the fired product and the acidic solution is preferably 0.5 to 48 hours, more preferably 0.5 to 2 hours. The temperature of the acidic solution at the time of contact is preferably 5 to 95 ° C., more preferably room temperature.

  After contacting with the acidic solution, the fired body is preferably filtered, washed with water, or dried. Moreover, you may ion-exchange with respect to a sintered body as needed, Furthermore, it is also possible to bake a sintered body again as needed.

  Furthermore, in order to obtain a catalyst having a desired particle size, it is also preferable to classify the fired body with a sieve.

[Method of heat treatment of catalyst precursor]
The heat treatment method of the catalyst precursor in the present embodiment is a method of continuously heat-treating the catalyst precursor, which is a dry body or a fired body, obtained as described above in a rotary furnace in a steam atmosphere. This heat treatment can also be employed as the above-described firing step. That is, the above baking step may be omitted, and this heat treatment may be performed on the dried body instead. In addition, the fired body subjected to heat treatment may be in contact with the acidic solution or not, or may be obtained by firing the fired body again. Also by these, the effect of heat treatment can be obtained. Of course, after the heat treatment is performed on the dried body, the above baking step, contact with an acidic solution, or baking again may be performed.

In the heat treatment method of the present embodiment, when a substantially spherical catalyst precursor is continuously heat-treated in a rotary furnace under a steam atmosphere, the catalyst precursor present in the heating region with respect to the core tube volume (v) in the heating region is reduced. Heat treatment is performed while maintaining the mass (w) ratio (w / v) at 0.10 (g / cm ³ ) or more. As a result, the catalyst precursor during the heat treatment flows stably, and the catalyst precursor can be uniformly heat-treated. As a result, it becomes possible to obtain a catalyst having a more uniform quality than conventional.

  A rotary furnace means an apparatus that heats an internal catalyst precursor while uniaxially rotating in a state where the catalyst precursor is accommodated in the furnace. FIG. 2 shows an example of a heat treatment apparatus including a rotary furnace according to this embodiment. As shown in FIG. 2, the rotary furnace is typically a horizontal cylindrical shape that rotates in the axial direction, while the catalyst precursor circulates in the cylinder from one end side to the other end side. It is supposed to be heated.

  A heat treatment apparatus 20 that is a rotary furnace shown in FIG. 2 has a reactor core tube 11 having both ends opened, and a feeder capable of supplying a catalyst precursor into the reactor core tube 11 through an opening that communicates with one end of the reactor core tube 11. 12, and a container 13 having an opening leading from the other end of the core tube 11 to the inside thereof and capable of recovering the catalyst and / or catalyst precursor from the core tube 11. Most of the core tube 11 is covered with a heater 14, and the space region in the core tube 11 covered with the heater 14 is a heating region, and the volume thereof is the core tube volume (v). Since the core tube 11 is heated while rotating around the axis of the tube, the catalyst precursor supplied from the feeder 12 to the core tube 11 is also heated in the core tube 11. Since the reactor core tube 11 is slightly lower on the container 13 side, the catalyst precursor moves from the feeder 12 side to the container 13 side while flowing as the reactor core tube 11 rotates.

  A water supply pipe 15 is inserted from the end of the core tube 11 on the container 13 side, and extends to the heating region in the core tube 11 covered with the heater 14 so as to open. The water supplied from the water supply pipe 15 into the core tube 11 is vaporized by the heat of the heater 14, moves toward the feeder 12 while contacting the catalyst precursor in the core pipe 11, and from the exhaust port 17. leak. When water and / or steam is supplied from the end of the core tube 11 not covered with the heater 14, water and / or steam is mixed into the container 13 to condense the catalyst and / or catalyst precursor. Is likely to occur. On the other hand, in this embodiment, since water is supplied from the heating region in the core tube 11 and is immediately vaporized and supplied to a sufficiently high-temperature portion in the state of water vapor, the catalyst and / or catalyst precursor is used. It is difficult to condense the body, and the supply location is away from the container 13, so that mixing into the container 13 is unlikely to occur. The air supply pipe 16 is also inserted from the open end of the reactor core tube 11 on the container 13 side. However, since air does not cause problems such as condensation, it is supplied from the heating region as long as a sufficient amount of air can be supplied into the pipe. Or you may supply from an edge part.

  In this specification, “continuous” means that the process from the supply of the catalyst precursor to the recovery of the catalyst and / or catalyst precursor through the heat treatment is performed without interruption or intermittently. In this case, after a certain catalyst precursor is supplied to the rotary furnace, it moves in the heating region in the rotary furnace while flowing from the supply side to the recovery side, and is discharged from the recovery side. The so-called batch method (batch method) in which the catalyst is retained in a closed container and heat-treated, and part or all of the treated catalyst is taken out of the container many times is not “continuous”. That is, the batch type is an operation of repeating the same processing in a plurality of batches when processing a large amount of objects to be processed. On the other hand, the continuous type is an operation in which a large amount of objects to be processed are successively processed without being divided into a plurality of batches. In the batch system, since the apparatus is opened every time the workpiece is charged, the loss of the workpiece and energy is unavoidable, and the continuous method is superior from the viewpoint of efficiency.

The ratio w / v is preferably 0.10 to 0.70 g / cm ³ , more preferably 0.10 to 0.50 g / cm ³ , still more preferably 0.10 to 0.40 g / cm ^3. And particularly preferably 0.10 to 0.30 g / cm ³ . By setting the ratio w / v to 0.10 g / cm ³ or more, the catalyst precursor easily flows at a uniform speed in the furnace core tube. In addition, by setting the ratio w / v to 0.70 g / cm ³ or less, a space is generated in the upper part of the core tube, and clogging by the catalyst precursor hardly occurs in the core tube. In addition, an effect is obtained that the catalyst precursor easily comes into contact with water vapor in the gas phase.

  Usually, since the core tube is a cylinder having a circular cross section or a polygonal cross section, the volume of the core tube in the heating region can be obtained by multiplying the cross section area of the core tube by the length of the heating region. The mass of the catalyst precursor present in the heating region can be measured as follows. In other words, the catalyst precursor was supplied under the same conditions as the conditions for determining the mass of the catalyst precursor existing in the heating zone, and the supply amount and discharge amount of the catalyst precursor became the same level. The supply of the catalyst precursor is stopped when the flow rate of the catalyst precursor to be reached becomes steady. Then, the catalyst precursor remaining in the reactor core tube is discharged from the reactor core tube, and its mass is measured to obtain the mass of the catalyst precursor existing in the heating region. In addition, for mass measurement, it is not essential to measure the catalyst precursor that is not heat-treated by aligning the conditions and conditions to be grasped, and if possible, measure the throughput when heat-treating. Also good.

In order to maintain the ratio w / v at 0.10 g / cm ³ or more, for example, the supply amount of the catalyst precursor, the inclination angle of the core tube, and the rotational speed of the core tube may be adjusted.

  Although the supply amount of the catalyst precursor per hour depends on the core tube volume and the residence time, it is preferably 0.1 to 1000 kg / hr, more preferably 0.5 to 500 kg / hr, still more preferably. Is 1 to 300 kg / hr. As a supply method, a method of continuously supplying the powder into the furnace core tube by a powder feeder is preferable.

  The inclination angle from the horizontal of the core tube is preferably 0 to 10 °, more preferably 0.1 to 5 °, still more preferably 0.5 to 3 °, and particularly preferably 0.5 to 3. 1.5 °.

  The number of rotations of the core tube is preferably 5 rpm (rotation / minute) or less, more preferably 0.1 to 5 rpm, and still more preferably 0.5 to 3 rpm. The rotation of the reactor core tube is effective for mixing the catalyst precursor at the bottom of the reactor core tube and the catalyst precursor at the top of the reactor core tube, but if the rotational speed is too high, the flow of the catalyst precursor in the axial direction of the reactor core tube is accelerated. The residence time of the catalyst precursor in the heating region is shortened and the ratio w / v tends to be small.

For example, in the case of a rotary furnace with a furnace core tube volume of 5000 cm ³ in the heating zone and a tilt angle of 1 ° from the horizontal of the core tube, the rotational speed of the core tube is 1 rpm, and the supply amount of the catalyst precursor is 3000 g / hr. Thus, the ratio w / v can be set to 0.10 g / cm ³ or more. When implemented in an industrial scale rotary furnace, the supply amount of the catalyst precursor may be increased in proportion to the core tube volume.

By maintaining the ratio w / v at 0.10 g / cm ³ or more, it is considered that the rate at which the catalyst precursor passes through the core tube is likely to be uniform, and the heat treatment of the catalyst precursor can be made uniform. It is speculated that the catalyst obtained through the heat treatment can have a more uniform quality than the conventional one. Although the cause is unknown in detail, the mechanism which the present inventors presume is described below. However, the factor is not limited to this. Conventionally, when heat treatment is performed on substantially spherical catalyst precursor particles in a core tube, the catalyst precursor at the bottom of the catalyst precursor layer in the heating region in the core tube tends to flow quickly in the axial direction of the core tube. On the other hand, the catalyst precursor in the upper part of the catalyst precursor layer has a slow flow. As a result, non-uniformity in the flow of the catalyst precursor in the heating region occurs, which is presumed to be a factor that makes uniform heat treatment difficult. In particular, when producing a catalyst used in a fluidized bed reaction, it is natural to adjust the shape and particle size so as to exhibit high fluidity, and this tendency is considered to be more remarkable. On the other hand, when the amount of the catalyst precursor is more than a certain amount with respect to the core tube volume in the heating region, the inventors of the present invention have a catalyst at the bottom of the core tube that easily flows in the axial direction of the core tube due to its own weight. We thought that the flow of the precursor could be suppressed, the difference from the flow rate of the catalyst precursor above the catalyst precursor layer could be reduced, and the entire catalyst precursor layer could flow uniformly. Specifically, by setting the ratio (w / v) of the mass (w) of the catalyst precursor existing in the heating region to the core tube volume (v) in the heating region to be a certain level or more, the catalyst precursor in the core tube. It has been found that heat treatment can be uniformly performed on the upper and bottom portions of the body layer, whereby the catalyst obtained through the heat treatment can have a more uniform quality than conventional.

  Moreover, the catalyst obtained through the heat treatment method of the present embodiment has an unexpected effect that the propylene yield is higher in the propylene production reaction than the catalyst with a different treatment method. Although the factor is also unknown in detail, the present inventors consider as follows. However, the factor is not limited to this. The heterogeneously heat-treated catalyst contains a catalyst with insufficient dealumination of the zeolite, that is, a catalyst with a high acid point density, so that the produced propylene is further converted to other compounds such as aromas. Conversion easily. On the other hand, in the case of a uniformly heat-treated catalyst, it is presumed that the sequential reaction is suppressed because the dealumination of zeolite is uniform in any part of the catalyst and the acid point density is not biased.

  From the viewpoint of controlling the degree of dealumination, the temperature of the catalyst precursor existing in the heating region in the furnace core tube is preferably 400 to 1000 ° C, more preferably 500 to 900 ° C, and particularly preferably 600 to 900. ° C. The temperature of the catalyst precursor can be measured by installing a thermocouple in the furnace core tube.

  From the viewpoint of controlling the degree of dealumination, the residence time of the catalyst precursor in the heating region is preferably 1 minute to 48 hours, more preferably 30 minutes to 24 hours, and particularly preferably 30 minutes to 6 hours. It is. In order to control the residence time, it is also preferable to provide a baffle plate in the core tube perpendicular to the axial direction of the core tube to control the flow of the catalyst precursor. In order to promote a more uniform heat treatment of the catalyst precursor, it is also preferable to provide a scraping blade for the catalyst precursor in the axial direction in the core tube.

  The water vapor concentration in the furnace core tube is preferably 1 to 100% by volume, more preferably 10 to 80% by volume. From the viewpoint of avoiding clogging in the apparatus due to the catalyst precursor accompanying the condensation of water vapor, it is more preferably 30 to 70% by volume. Examples of the gas phase portion other than water vapor include air, nitrogen and oxygen, and mixtures thereof. The pressure in the furnace core tube may be increased or reduced. Formation of the water vapor atmosphere can be performed by supplying water through the tube into the core tube.

  The flow direction of the gas containing the water vapor in the core tube and the catalyst precursor may be cocurrent or counterflow. The counter current is preferably a counter current from the viewpoint of high contact efficiency between the gas containing water vapor and the catalyst.

In addition, the catalyst precursor that has undergone the heat treatment may be subjected to ion exchange as necessary to obtain a catalyst.
In particular, when the zeolite is of the MFI type, it tends to be difficult to dealumination compared to other zeolites, and therefore it is preferable to perform heat treatment under somewhat severe conditions. That is, when heat-treating a catalyst precursor containing MFI-type zeolite, the temperature of the catalyst precursor in the heat treatment is preferably 800 to 900 ° C., the residence time in the heating region is preferably 1 to 6 hours, and the water vapor concentration in the core tube is 50 -70 volume% is preferable.

[Method for measuring acid amount of catalyst after heat treatment]
The uniformity of the catalyst quality can be evaluated by measuring the degree of dealumination of the zeolite contained in the catalyst as an acid amount. The amount of acid can be measured by a TPD (Templeature Programmed Desorption) NH ₃ adsorption / desorption method.

  The acid amount of a suitable catalyst varies depending on the type of zeolite. For example, when a catalyst containing ZSM-5 is used as a catalyst for the propylene production reaction, the acid amount is preferably 0.1 to 500 μmol, more preferably 1 to 100 μmol, per unit mass (g) of the catalyst. When the acid amount is 500 μmol or less, it becomes easy to suppress the formation of by-products in the above reaction, and when it is 0.1 μmol or more, it becomes easy to prevent a decrease in activity.

Specifically, the acid amount can be measured using TPD-1-ATw (manufactured by Nippon Bell Co., Ltd.) as a measuring device. In the measurement method, about 100 mg of catalyst is filled in a measurement cell, and heated at 500 ° C. for 1 hour while flowing He gas into the measurement cell at 50 cc / min. Next, after cooling to 100 ° C., NH ₃ gas is introduced into the measurement cell and held at an NH ₃ pressure of 100 mmHg for 30 minutes to adsorb NH ₃ on the catalyst. After stopping the introduction of NH ₃ gas, the temperature was raised to 600 ° C. at 10 ° C./min while flowing He gas into the measurement cell, and NH ₃ desorbed during the temperature rise (that is, adsorbed on the catalyst). The amount is measured with a mass spectrometer. As shown in the following formula, the amount of acid is derived by dividing the amount of NH ₃ desorbed at 180 ° C. or higher by the amount of catalyst used for the measurement. The reason is the NH ₃ was NH ₃ is mainly physical adsorption to desorption at less than 180 ° C., NH ₃ chemisorbed on the catalyst acid site is for desorbing at 180 ° C. or higher.
Catalytic acid amount (μmol / g) = desorbed NH ₃ amount (μmol) / catalyst amount (g) at 180 ° C. or higher

[Propylene production method]
Next, a method for producing propylene will be described.

  Propylene can be produced by bringing the catalyst that has undergone the heat treatment method of this embodiment into contact with the reaction raw material. A preferable reaction raw material contains a hydrocarbon containing a lower olefin and / or an oxygen-containing compound having 1 to 4 carbon atoms. The lower olefin is preferably an olefin having 1 to 6 carbon atoms, such as ethylene, 2-methyl-propene, 1-butene, cis-2-butene, trans-2-butene, 1-pentene, 2-pentene, 2 -Methyl-1-butene, 3-methyl-1-butene, 1-hexene and 2-hexene. The oxygen-containing compound having 1 to 4 carbon atoms is preferably an alcohol having 1 to 4 carbon atoms or an ether having 1 to 4 carbon atoms, and examples thereof include methanol, ethanol, propanol and butanol, dimethyl ether, diethyl ether and ethyl methyl ether. It is done. The hydrocarbon raw material more preferably contains at least one compound selected from the group consisting of lower olefins, alcohols having 1 to 4 carbon atoms and ethers having 1 to 4 carbon atoms, and more preferably ethylene, methanol, ethanol , At least one compound selected from the group consisting of dimethyl ether and diethyl ether, and particularly preferably at least one compound selected from the group consisting of ethylene, methanol, ethanol and dimethyl ether.

  The reaction system of the propylene production reaction may be any of a fixed bed reaction, a moving bed reaction, a fluidized bed reaction, and a riser reaction system, for example. The reaction has a tendency that coke is generated on the catalyst with the progress of the reaction and the activity tends to deteriorate, and the fluidized bed reaction method is preferable from the viewpoint of easily extracting the catalyst having deteriorated activity from the reactor.

  When selecting what contains 1 or more types of ethylene, methanol, ethanol, and dimethyl ether as a hydrocarbon raw material, what contains 20 mass% or more of ethylene with respect to the mass of the whole reaction raw material is preferable, More preferably It is contained in an amount of 25% by mass or more, more preferably more than 50% by mass. When the ethylene concentration in the reaction raw material is 20% by mass or more, the propylene production reaction rate tends to be improved. When the hydrocarbon raw material contains one or more of methanol, ethanol and dimethyl ether, it is assumed that each of these compounds decomposes into ethylene and water by a dehydration reaction, and it is considered as ethylene and falls within the above range. It is preferable.

  From the viewpoint of suppressing coke formation on the catalyst, it is also preferable that water be present in the reaction raw material. The water content is preferably 1% by mass or more, more preferably 10 to 80% by mass, based on the mass of the whole reaction raw material.

  The hydrocarbon raw material may contain at least one of olefins other than the above and paraffin. Examples of paraffin include methane, ethane, propane, butane, pentane, hexane, heptane, octane and nonane. Examples of the olefin include propylene, pentene other than the above, hexene other than the above, heptene, octene, and nonene. The olefin and paraffin may be cyclic or diene, such as cycloparaffins such as cyclopentane, methylcyclopentane and cyclohexane; cycloolefins such as cyclopentene, methylcyclopentene and cyclohexene; cyclohexadiene, Examples include dienes such as butadiene, pentadiene and cyclopentadiene. Further, the hydrocarbon raw material may contain acetylene such as acetylene and methylacetylene, or may contain oxygen-containing compounds such as t-butyl alcohol, methyl-t-butyl ether, diethyl ether and methyl ethyl ether. The reaction raw material may usually contain a carrier gas or other gas. Examples of the carrier gas and other gas include at least one of hydrogen, nitrogen, carbon dioxide, carbon monoxide and sulfur compounds. The above is mentioned.

  Ethanol (biomass ethanol) obtained from plant resources can also be used as the raw material ethanol. Specific examples include ethanol obtained by fermentation of sugarcane, corn, and the like, and ethanol obtained from woody resources such as waste wood, thinned wood, rice straw, and agricultural crops.

  The reaction temperature of the propylene production reaction is preferably 300 to 650 ° C, more preferably 400 to 600 ° C. The reaction pressure is preferably 0.1 to 30 atm, more preferably 0.5 to 10 atm.

The feed rate of the reaction raw material, at a weight hourly space velocity of the catalyst reference (WHSV), preferably 0.1 to 20 ^-1, more preferably 0.2~5hr ^-1.

  When a hydrocarbon raw material containing ethylene and / or ethanol is used, it is preferable to control the ethylene conversion rate in the range of 45 to 85%, preferably 50 to 80% by adjusting the reaction conditions. A high propylene yield can be obtained within the above ethylene conversion range.

  In the method for producing propylene of the present embodiment, it is also preferable to separate propylene from the reaction product and to recycle at least a part of the remaining low-boiling components containing ethylene and / or high-boiling components containing butene as raw materials.

  In the method for producing propylene of the present embodiment, when a catalyst is used for a long-term reaction, a carbonaceous compound (coke) is generated on the catalyst, and the catalytic activity tends to decrease. In that case, the coke on the catalyst may be removed and regenerated by contacting the catalyst with an oxygen-containing gas at 400 to 700 ° C. Thereafter, the regenerated catalyst is preferably used again for the reaction.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples.

[Catalyst precursor preparation example 1]
First, 30 kg of H-type beta zeolite (manufactured by PQ, BEA-type zeolite, Si / Al ratio (atomic ratio) = 14), silica sol (manufactured by Nalco, trade name “NalcoDVSZN002”, silica content: 34 mass%) 88 kg, A raw material mixture was prepared by thoroughly mixing 10 kg of ammonium nitrate (Wako Pure Chemicals, special grade reagent) and 4 kg of nitric acid (Wako Pure Chemicals, special grade reagent). The obtained raw material mixture was spray-dried by a spray dryer (model: OC-16, manufactured by Okawara Chemical Co., Ltd.) having the same configuration as shown in FIG. 1 to obtain a dried product. In spray drying, the raw material mixture was supplied at 15 kg / hr, and the raw material mixture was sprayed by a rotating disk method under the condition of a rotational speed of 8000 rpm. Air was used as the gas fluid, the gas fluid temperature at the inlet of the drying chamber was 230 ° C., and the gas fluid temperature at the outlet of the drying chamber was 130 ° C. The recovered dried body was baked at 600 ° C. for 1 hour in a static electric furnace in an air atmosphere to obtain a baked body.

The obtained fired body was put into a 1N ammonium nitrate aqueous solution, subjected to ion exchange at 25 ° C. for 1 hour, and then dried. The catalyst precursor thus obtained contained 50% by mass of NH ₄ type beta zeolite and 50% by mass of silica. This was classified with a sieve to obtain a catalyst precursor having an average particle diameter (laser diffraction / scattering particle size analyzer manufactured by Microtrac, model: measured with MT3000, the same applies hereinafter) of 95 μm. FIG. 3 shows an electron micrograph of the catalyst precursor (manufactured by KEYENCE, model: measured by VE-9800, the same applies hereinafter).
As can be seen from FIG. 3, the obtained catalyst precursor was substantially spherical.

[Catalyst precursor preparation example 2]
First, H-type ZSM-5 zeolite (manufactured by Zude Chemie, MFI-type zeolite, Si / Al ratio (atomic ratio) = 14) 30 kg, silica sol (manufactured by Nalco, trade name “Nalco2326”, silica content: 15 mass%) 200 kg, ammonium nitrate (manufactured by Wako Pure Chemicals, special grade reagent) 10 kg, and nitric acid (manufactured by Wako Pure Chemicals, special grade reagent) 4 kg were sufficiently mixed to prepare a raw material mixture. The obtained raw material mixture was spray-dried with a spray drier under the same conditions as in Catalyst Precursor Preparation Example 1 except that the rotational speed of the rotating disk was changed to 12000 rpm, to obtain a dried product. The collected dried body was fired at 700 ° C. for 1 hour in a static electric furnace in an air atmosphere to obtain a fired body. The obtained fired body was put into a 0.1N nitric acid aqueous solution, subjected to ion exchange at 25 ° C. for 1 hour, and then dried. The catalyst precursor thus obtained contained 50% by mass of H-type ZSM-5 zeolite and 50% by mass of silica. The average particle diameter of this catalyst precursor was 52 μm. FIG. 4 shows an electron micrograph of the catalyst precursor.
As can be seen from FIG. 4, the obtained catalyst precursor was substantially spherical.

[Catalyst precursor preparation example 3]
First, phosphorus-modified H-type ZSM-5 zeolite (MFI-type zeolite manufactured by Zude Chemie (Si / Al ratio (atomic ratio) = 120, phosphorus element content = 0.5 mass%) pulverized) 30 kg, Silica sol (Nalco, trade name “Nalco 2326”, silica content: 15% by mass) 200 kg, ammonium nitrate (Wako Pure Chemicals, special grade reagent) 10 kg, and nitric acid (Wako Pure Chemicals, special grade reagent) 4 kg are mixed thoroughly. Thus, a raw material mixture was prepared. The obtained raw material mixture was spray-dried with a spray dryer under the same conditions as in Catalyst Precursor Preparation Example 1 except that the rotational speed of the rotating disk was changed to 16000 rpm, to obtain a dried product. The collected dried body was fired at 700 ° C. for 1 hour in a static electric furnace in an air atmosphere to obtain a fired body. The obtained fired body was put into a 0.1N nitric acid aqueous solution, subjected to ion exchange at 25 ° C. for 1 hour, and then dried. The catalyst precursor thus obtained contained 50% by mass of phosphorus-modified H-type ZSM-5 zeolite and 50% by mass of silica. This was classified with a sieve to obtain a catalyst precursor having an average particle size of 25 μm. FIG. 5 shows an electron micrograph of the catalyst precursor.
As can be seen from FIG. 5, the obtained catalyst precursor was substantially spherical.

[Catalyst precursor preparation example 4]
First, H-type ZSM-5 zeolite (manufactured by Zude Chemie, MFI-type zeolite, Si / Al ratio (atomic ratio) = 14) 30 kg, silica sol (manufactured by Nalco, trade name “Nalco2326”, silica content: 15 mass%) 100 kg, kaolin clay (product of ENGELHARD, trade name “ASP-600”) 15 kg, ammonium nitrate (product of Wako Pure Chemicals, special grade reagent) 5 kg, and nitric acid (product of Wako Pure Chemicals, special grade reagent) 2 kg are mixed thoroughly to prepare raw materials A mixture was obtained. The obtained raw material mixture was spray-dried with a spray dryer under the same conditions as in Catalyst Precursor Preparation Example 2 to obtain a dried product. The collected dried body was fired at 700 ° C. for 1 hour in a static electric furnace in an air atmosphere to obtain a fired body. The obtained fired body was put into a 0.1N nitric acid aqueous solution, subjected to ion exchange at 25 ° C. for 1 hour, and then dried. The catalyst precursor thus obtained contained 50% by mass of H-type ZSM-5 zeolite, 25% by mass of silica, and 25% by mass of kaolin clay. The average particle size of this catalyst precursor was 49 μm. FIG. 6 shows an electron micrograph of the catalyst precursor.
As can be seen from FIG. 6, the obtained catalyst precursor was substantially spherical. Some of the particles had an elliptical shape, and included particles having an open surface. “A” in FIG. 6 shows an example of an elliptical particle, and “b” shows an example of a particle having an opening on the surface (a hole appears black in the figure).

[Catalyst precursor preparation example 5]
H-type ZSM-5 zeolite (manufactured by Zude Chemie, MFI-type zeolite, Si / Al ratio (atomic ratio) = 14) 500 kg, silica sol (manufactured by Nalco, trade name “Nalco 2326”, silica content: 15 mass%) 2667 kg, A raw material mixture was prepared by sufficiently mixing 1000 kg of alumina sol (manufactured by Nissan Chemical Co., Ltd., trade name “Alumina 200”, alumina content: 10 mass%) and 2000 kg of pure water. The obtained raw material mixture was spray-dried by a spray dryer having a spray device of a two-fluid nozzle method (spraying the raw material mixture in the form of a mist with a spray gas) to obtain a dried product. The supply amount of the raw material mixture was 80 kg / hr, and the spray gas pressure was 0.1 MPa. The gas fluid temperature at the drying chamber inlet was 300 ° C, and the gas fluid temperature at the drying chamber outlet was 150 ° C. The collected dried body was fired at 700 ° C. for 1 hour in a static electric furnace in an air atmosphere to obtain a fired body. The obtained fired body was put into a 0.1N nitric acid aqueous solution, subjected to ion exchange at 25 ° C. for 1 hour, and then dried. The catalyst precursor thus obtained contained 50% by mass of H-type ZSM-5 zeolite, 40% by mass of silica, and 10% by mass of alumina. The average particle diameter of this catalyst precursor was 42 μm. FIG. 7 shows an electron micrograph of the catalyst precursor.
As can be seen from FIG. 7, the obtained catalyst precursor was substantially spherical.

[Example 1]
The catalyst precursor produced in Catalyst Precursor Preparation Example 1 was continuously supplied to a heat treatment apparatus (rotary furnace) having the same configuration as shown in FIG. 2 and heat-treated to obtain a catalyst. As the core tube in the rotary furnace, a circular core (inner diameter) of 8 cmφ and a heating region length of 100 cm was used. The core tube volume (v) in the heating region was 5024 cm ³ ((8/2) ² × π × 100). The supply amount of the catalyst precursor was 2000 g / hr, and the atmosphere in the furnace core tube was a steam atmosphere. Heat treatment was performed under the conditions of the catalyst precursor temperature of 600 ° C., the core tube rotation speed of 0.5 rpm, the core tube tilt angle from 1 °, and the water vapor concentration of 50% by volume (the balance being air). . The mass (w) of the catalyst precursor present in the heating region at this time was 1350 g. Therefore, the ratio of the mass of the catalyst precursor present in the heating region to the core tube volume of the heating area (w / v) was ^{1350g / 5024cm 3 = 0.27g / cm} 3.

  The amount of catalyst precursor supplied and the amount of catalyst discharged are stable. After 3 hours have passed since the catalyst precursor was supplied, the catalyst discharged from the reactor core tube outlet was sampled every hour and the acid amount was measured. . Table 1 shows the amount of catalyst acid for 3 to 8 hours after the supply of the catalyst precursor. The standard deviations shown in Tables 1 and 2 were derived by the following formula (A) as an index representing the variation in the amount of catalytic acid at each time. The closer the standard deviation is to zero, the smaller the variation of the catalyst acid amount, which means that the catalyst has a uniform quality. The catalyst composition, average particle diameter, and particle shape after the heat treatment were unchanged from the catalyst precursor before the heat treatment.

[Example 2]
The catalyst precursor produced in Catalyst Precursor Preparation Example 2 was continuously supplied to the same heat treatment apparatus (rotary furnace) as used in Example 1 and heat treated to obtain a catalyst. The supply amount of the catalyst precursor was 600 g / hr, and the atmosphere in the core tube was a steam atmosphere. Heat treatment was performed under the conditions of the catalyst precursor temperature of 900 ° C., the core tube rotation speed of 1 rpm, the core tube inclination angle from 1 °, and the water vapor concentration of 50% by volume (the balance being air). The mass (w) of the catalyst precursor present in the heating region at this time was 520 g. Therefore, the ratio of the mass of the catalyst precursor present in the heating region to the core tube volume of the heating area (w / v) was ^{520g / 5024cm 3 = 0.10g / cm} 3.

  The catalyst was collected in the same manner as in Example 1, and the amount of catalyst acid was measured. The results are shown in Table 1. The catalyst composition, average particle diameter, and particle shape after the heat treatment were unchanged from the catalyst precursor before the heat treatment.

[Example 3]
The catalyst precursor produced in Catalyst Precursor Preparation Example 3 was continuously supplied to the same heat treatment apparatus (rotary furnace) as used in Example 1 and heat treated to obtain a catalyst. The supply amount of the catalyst precursor was 4500 g / hr, and the atmosphere in the furnace core tube was a steam atmosphere. Heat treatment was performed under the conditions of the catalyst precursor temperature of 800 ° C., the core tube rotation speed of 2 rpm, the core tube inclination angle from 1 °, and the water vapor concentration of 50% by volume (the balance being air). The mass (w) of the catalyst present in the heating region at this time was 2500 g. Therefore, the ratio of the mass of the catalyst precursor present in the heating region to the core tube volume of the heating area (w / v) was ^{2500g / 5024cm 3 = 0.50g / cm} 3.

  The catalyst was collected in the same manner as in Example 1, and the amount of catalyst acid was measured. The results are shown in Table 1. The catalyst composition, average particle diameter, and particle shape after the heat treatment were unchanged from the catalyst precursor before the heat treatment.

[Example 4]
The catalyst precursor produced in Catalyst Precursor Preparation Example 4 was continuously supplied to the same heat treatment apparatus (rotary furnace) as used in Example 1 and heat treated to obtain a catalyst. The supply amount of the catalyst precursor was 2000 g / hr, and the atmosphere in the furnace core tube was a steam atmosphere. The heat treatment was performed under the conditions of the catalyst precursor temperature of 700 ° C., the core tube rotation speed of 1 rpm, the core tube tilt angle from the horizontal of 0.5 °, and the water vapor concentration of 60% by volume (the balance being air). . The mass (w) of the catalyst precursor present in the heating region at this time was 1450 g. Therefore, the ratio of the mass of the catalyst precursor present in the heating region to the core tube volume of the heating area (w / v) was ^{1450g / 5024cm 3 = 0.29g / cm} 3.

  The catalyst was collected in the same manner as in Example 1, and the amount of catalyst acid was measured. The results are shown in Table 1. The catalyst composition, average particle diameter, and particle shape after the heat treatment were unchanged from the catalyst precursor before the heat treatment.

[Example 5]
In order to confirm reproducibility, the catalyst precursor produced in Catalyst Precursor Preparation Example 2 was heat-treated under the same conditions as in Example 2. The mass (w) of the catalyst precursor present in the heating region at this time was 600 g. Therefore, the ratio of the mass of catalyst present in the heating region to the core tube volume of the heating area (w / v) was ^{600g / 5024cm 3 = 0.12g / cm} 3.

  The catalyst was collected in the same manner as in Example 1, and the amount of catalyst acid was measured. The results are shown in Table 1. The catalyst composition, average particle diameter, and particle shape after the heat treatment were unchanged from the catalyst precursor before the heat treatment.

[Example 6]
In the same manner as in Catalyst Precursor Preparation Example 2, drying was performed to obtain a dried product as a catalyst precursor. The average particle diameter of the obtained dried product was 52 μm. Next, this dried body was continuously supplied to the same heat treatment apparatus (rotary furnace) as used in Example 1 and subjected to heat treatment to obtain a catalyst. The supply amount of the dried body was 4000 g / hr, and the atmosphere in the furnace core tube was a steam atmosphere. Heat treatment was performed under conditions of a dry body temperature of 800 ° C., a core tube rotation speed of 0.5 rpm, a core tube inclination angle of 0.5 °, and a water vapor concentration of 30% by volume (the balance being air). The mass (w) of the catalyst precursor (dry body) present in the heating region at this time was 3500 g. Therefore, the ratio of the mass of the catalyst precursor present in the heating region to the core tube volume of the heating area (w / v) was ^{3500g / 5024cm 3 = 0.70g / cm} 3.

  A catalyst precursor was collected in the same manner as the catalyst was collected in Example 1, and it was put into a 0.1N nitric acid aqueous solution and subjected to ion exchange at 25 ° C. for 1 hour to obtain a catalyst. And the acid amount of the obtained catalyst was measured. The results are shown in Table 1. The average particle diameter and particle shape of the catalyst precursor after the heat treatment did not change from the dry body before the heat treatment.

[Example 7]
The catalyst precursor produced in Catalyst Precursor Preparation Example 5 was continuously supplied to a heat treatment apparatus (rotary furnace) having the same configuration as shown in FIG. 2 and heat-treated to obtain a catalyst. As the core tube in the rotary furnace, a circular core (inner diameter) of 50 cmφ and a heating region length of 400 cm was used. The core tube volume (v) in the heating region was 785000 cm ³ ((50/2) ² × π × 400). The supply amount of the catalyst precursor was 86000 g / hr, and the atmosphere in the furnace core tube was a steam atmosphere. Heat treatment was performed under the conditions of the catalyst precursor temperature of 800 ° C., the core tube rotation speed of 1.0 rpm, the core tube tilt angle from 1 °, and the water vapor concentration of 50% by volume (the balance being air). . The mass (w) of the catalyst precursor present in the heating region at this time was 172700 g. Therefore, the ratio of the mass of the catalyst precursor present in the heating region to the core tube volume of the heating area (w / v) was ^{172700g / 785000cm 3 = 0.22g / cm} 3.
The catalyst was collected in the same manner as in Example 1, and the amount of catalyst acid was measured. The results are shown in Table 1. The catalyst composition, average particle diameter, and particle shape after the heat treatment were unchanged from the catalyst precursor before the heat treatment.
[Example 8]
The catalyst obtained in Example 2 was classified with a sieve having an opening of 32 μm, and 25.0 g of the catalyst remaining on the sieve was charged into a stainless steel fluidized bed reaction tube having an inner diameter of 24 mm. Next, a raw material gas of ethylene / H ₂ / H ₂ O / N ₂ = 24/24/33/19 (volume ratio) was circulated in the reaction tube, the reaction temperature was 550 ° C., and the reaction pressure was 0.14 MPa (gauge). The reaction was performed for 90 hours under the conditions of WHSV 0.4 hr ⁻¹ . The gas analysis after the reaction was performed by gas chromatography directly connected to the reaction tube. The ethylene conversion after 3 hours was 82%, and the propylene yield at 70% ethylene conversion after 60 hours was 26.0% by mass.

The ethylene conversion rate and the propylene yield were derived according to the following formula.
(A) Ethylene conversion rate = ((ethylene concentration in gas at reaction tube inlet) − (ethylene concentration in gas at reaction tube outlet)) / (ethylene concentration in gas at reaction tube inlet) × 100
(B) Propylene yield = (Mass of propylene produced by reaction) / (Mass of ethylene supplied to the reaction tube) × 100

[Example 9]
The catalyst obtained in Example 3 was classified by a sieve having an opening of 32 μm, and 25.0 g of the catalyst remaining on the sieve was charged into a stainless fluidized bed reaction tube having an inner diameter of 24 mm. Next, a raw material gas of ethanol / N ₂ = 80/20 (volume ratio) was passed through the reaction tube, and the reaction temperature was 550 ° C., the reaction pressure was 0.14 MPa (gauge), and WHSV was 0.5 hr ⁻¹ for 80 hours. Reaction was performed. The gas analysis after the reaction was performed by gas chromatography directly connected to the reaction tube. The ethanol conversion after 3 hours was 100%, and the propylene yield after 2 hours was 27.0% by mass.

Ethanol conversion and propylene yield were derived according to the following formula.
(A) Ethanol conversion rate = ((ethanol concentration in gas at reaction tube inlet) − (ethanol concentration in gas at reaction tube outlet)) / (ethanol concentration in gas at reaction tube inlet) × 100
(B) Propylene yield = (Mass of propylene produced by the reaction) / (Mass of ethylene supplied to the reaction tube) x 100 (However, the mass of ethylene supplied to the reaction tube is determined when ethanol is immediately decomposed into ethylene and water. Calculated assuming.)

[Example 10]
The catalyst obtained in Example 3 was classified by a sieve having an opening of 32 μm, and 25.0 g of the catalyst remaining on the sieve was charged into a stainless fluidized bed reaction tube having an inner diameter of 24 mm. Next, a raw material gas of methanol / N ₂ = 80/20 (volume ratio) was circulated in the reaction tube, and the reaction temperature was 550 ° C., the reaction pressure was 0.14 MPa (gauge), and WHSV was 0.4 hr ⁻¹ for 80 hours. Reaction was performed. Gas analysis after the reaction was performed by gas chromatography directly connected to the reactor. The methanol conversion after 3 hours was 100%, and the propylene yield after 2 hours was 29.5% by mass.

Methanol conversion and propylene yield were derived according to the following equations.
(A) Methanol conversion rate = ((Methanol concentration in gas at reaction tube inlet) − (Methanol concentration in gas at reaction tube outlet)) / (Methanol concentration in gas at reaction tube inlet) × 100
(B) Propylene yield = (Mass of propylene produced by reaction) / (Mass of ethylene supplied to the reaction tube) × 100 (However, the mass of ethylene supplied to the reaction tube is determined when methanol is immediately decomposed into ethylene and water. Calculated assuming.)

[Example 11]
The catalyst obtained in Example 3 was compressed and then crushed to a size of 6 to 16 mesh. 8.56 g of this catalyst was packed into a stainless fixed bed reaction tube having an inner diameter of 15 mm. Next, a source gas of dimethyl ether / N ₂ = 65/35 (volume ratio) was circulated in the reaction tube, and the reaction was performed under the conditions of a reaction temperature of 550 ° C., a reaction pressure of 0.14 MPa (gauge), and WHSV 0.7 hr ^−1. went. Gas analysis after the reaction was performed by gas chromatography directly connected to the reactor. The dimethyl ether conversion after 3 hours was 100%, and the propylene yield after 30 hours was 40.0%.

Dimethyl ether conversion and propylene yield were derived according to the following equations.
(A) Dimethyl ether conversion rate = ((dimethyl ether concentration in gas at reaction tube inlet) − (dimethyl ether concentration in gas at reaction tube outlet)) / (dimethyl ether concentration in gas at reaction tube inlet) × 100
(B) Propylene yield = (Mass of propylene produced by the reaction) / (Mass of ethylene supplied to the reaction tube) × 100 (However, the mass of ethylene supplied to the reaction tube is determined when dimethyl ether is immediately decomposed into ethylene and water. Calculated assuming.)

[Comparative Example 1]
The catalyst precursor produced in Catalyst Precursor Preparation Example 2 was heat-treated under the same conditions as in Example 2 except that the supply amount of the catalyst precursor was changed to 300 g / hr to obtain a catalyst. The mass (w) of the catalyst precursor present in the heating region at this time was 250 g. Therefore, the ratio of the mass of the catalyst precursor of the heating region to the core tube volume of the heating area (w / v) was ^{250g / 5024cm 3 = 0.05g / cm} 3.

  The catalyst was collected in the same manner as in Example 1, and the amount of catalyst acid was measured. The results are shown in Table 2. The catalyst composition, average particle diameter, and particle shape after the heat treatment were unchanged from the catalyst precursor before the heat treatment.

[Comparative Example 2]
The catalyst obtained in Comparative Example 1 was classified with a sieve having an opening of 32 μm, and 25.0 g of the catalyst remaining on the sieve was packed into a stainless fluidized bed reaction tube having an inner diameter of 1 inch. Next, the reaction was performed for 90 hours in the same manner as in Example 8. The gas analysis after the reaction was performed by gas chromatography directly connected to the reaction tube. The ethylene conversion after 3 hours was 85%, and the propylene yield at 70% ethylene conversion after 2 hours was 24.5% by mass.

  From the comparison of the above Examples and Comparative Examples, it can be seen that the acid amounts of the catalysts of Examples 1 to 7 all have a standard deviation of 2 or less, have little variation, and are uniformly heat-treated. Moreover, it can be seen from the comparison between Example 2 and Example 5 that the reproducibility of the heat treatment is also excellent. On the other hand, in the catalyst of Comparative Example 1, it can be seen that the standard deviation of the acid amount is 8.2, and the variation is large and non-uniform.

  Furthermore, Example 8 using the catalyst heat-treated by the method of the present invention has a higher propylene yield at the same ethylene conversion rate than Comparative Example 2 using the catalyst heat-treated by the method not satisfying the requirements of the present invention. I understand.

  INDUSTRIAL APPLICABILITY The present invention can be used when a substantially spherical catalyst precursor containing zeolite and a binder is continuously heat-treated in a steam atmosphere using a rotary furnace. The catalyst has particular industrial applicability in that it can be used for the production of propylene.

  DESCRIPTION OF SYMBOLS 1 ... Raw material liquid tank, 2 ... Liquid feeding apparatus, 3 ... Blower apparatus, 4 ... Heating apparatus, 5 ... Spraying apparatus, 6 ... Drying chamber, 7 ... Dry matter collection apparatus, 8 ... Cyclone, 9 ... Air exhaust apparatus, 10 DESCRIPTION OF SYMBOLS ... Spray dryer, 11 ... Core tube, 12 ... Feeder, 13 ... Container, 14 ... Heater, 15 ... Water supply pipe, 16 ... Air supply pipe, 17 ... Exhaust port, 20 ... Heat processing apparatus.

Claims (5)

A method of continuously heat-treating a substantially spherical catalyst precursor containing a zeolite and a binder in a rotary furnace under a steam atmosphere, wherein the heating area with respect to a core tube volume (v) of the heating area of the rotary furnace The catalyst precursor is heat-treated by heat-treating the catalyst precursor while maintaining the ratio (w / v) of the mass (w) of the catalyst precursor present in 0.10 to 0.10 g / cm ³ or more.   The heat treatment method according to claim 1, wherein the catalyst precursor is obtained through a spray drying process.   The heat treatment method according to claim 1 or 2, wherein the zeolite is MFI type zeolite.   The manufacturing method of a catalyst which has the process by the heat processing method as described in any one of Claims 1-3.   A method for producing propylene, comprising a step of contacting a catalyst obtained by the production method according to claim 4 with a hydrocarbon raw material containing at least one compound selected from the group consisting of ethylene, methanol, ethanol and dimethyl ether.