Method for producing shaped catalyst and halogen

Abstract

A molding catalyst which satisfies formula (1). (1): 0.800 ≤ WAV / WC ≤ 0.875 In formula (1), WAV is obtained by formula (2), and WC is obtained by formula (3). (2): WAV = Wtot / n (3): WC = (VAV·ρ) / (1 + VP·ρ) In formula (2), Wtot represents the total weight of arbitrarily selected n molding catalysts. In formula (3), VAV represents the average of the volumes of virtual cylinders respectively having the lengths (L) of the arbitrarily selected n molding catalysts as the heights, while having the breadths (D) of the n molding catalysts as the diameters; ρ represents the true density of the molding catalysts; and VP represents the pore volume per unit weight of the molding catalysts.

Description

Technical Field

[0001] The present invention relates to a method for producing a shaped catalyst and a halogen.

Background Art

[0002] As an apparatus for producing a product by supplying a reaction raw material to a reaction tube provided with a plurality of reaction tubes filled with a catalyst, a fixed bed multitubular reactor is known. For example, Patent Document 1 describes a method for producing chlorine by oxidizing hydrogen chloride using a fixed bed multitubular reactor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique of Patent Document 1, as a catalyst filled in the reaction tubes of a fixed bed multitubular reactor, a shaped catalyst formed into a cylindrical shape or the like is used. When a shaped catalyst formed into a cylindrical shape is filled in a reaction tube, there may be variations in the filling state. That is, among the plurality of reaction tubes of a multitubular reactor, there may be a reaction tube filled densely with the shaped catalyst and a reaction tube filled coarsely with the shaped catalyst. Further, when replacing the shaped catalyst filled in the reaction tube, the degree of coarseness and density of the shaped catalyst filled in the reaction tube may be different for each replacement. Such variations in the filling state of the shaped catalyst filled in the reaction tube may occur not only in a multitubular reactor but also in a single-tube reactor. Such variations in the filling state of the shaped catalyst result in reaction tubes with easy flow of the reaction raw material and reaction tubes with difficult flow, causing uneven contact time between the reaction raw material and the shaped catalyst. As a result, differences may occur between the reaction tubes of a multitubular reactor or fluctuations may occur each time the catalyst in a single-tube reactor is replaced, in terms of catalyst activity, reaction selectivity, etc.

[0005] Therefore, there is a need for a shaped catalyst capable of reducing the degree of variation in the filling state when filling the reaction tubes, and a method for producing a halogen using the shaped catalyst.

Means for Solving the Problems

[0006] As a result of intensive studies to solve the above problems, the present inventor has found that the problem can be solved by setting the ratio (also referred to as value A) of the average weight (W AV ) of the shaped catalyst to the virtual cylindrical weight (W C ) obtained from the shaped catalyst within a predetermined range, and has completed the present invention. AV / W C (also referred to as value A) within a predetermined range, and has completed the present invention. That is, the present invention provides the following.

[0007] [1] A shaped catalyst satisfying the following formula (1): 0.800 ≦ W AV / W C ≦ 0.875 (1) In formula (1), W AV is obtained from the following formula (2), and W C is obtained by the following formula (3). W AV = W tot / n (2) W C = (V AV · ρ) / (1 + V P · ρ) (3) In formula (2), W tot represents the total weight of arbitrarily selected n shaped catalysts. In formula (3), V AVrepresents the average of the volumes obtained for each of the arbitrarily selected n shaped catalysts, with the major axis (L) as the height and the minor axis (D) as the diameter of each individual virtual cylinder, ρ represents the true density of the shaped catalyst, V P represents the pore volume per unit weight of the shaped catalyst. [2] The shaped catalyst according to [1], which is for a multitubular reactor. [3] The shaped catalyst according to [1] or [2] for oxidizing hydrogen halide with oxygen. [4] A method for producing halogen, which includes obtaining halogen using the shaped catalyst according to any one of [1] to [3]. [Advantages of the Invention]

[0008] According to the present invention, there can be provided a shaped catalyst capable of reducing the degree of variation in the filling state when filling a reaction tube; and a method for producing halogen using the shaped catalyst. [Brief Description of the Drawings]

[0009]

Figure 1

Figure 2

[0010] Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and its equivalent scope.

[0011] [1. Shaped Catalyst] [1.1. Conditions Satisfied by the Shaped Catalyst] The shaped catalyst according to an embodiment of the present invention satisfies the following formula (1). By satisfying the following formula (1), the variation in the filling state when filling the shaped catalyst into the reaction tube is reduced. The variation in the filling state can be evaluated by evaluating the variation in apparent specific gravity by the method described in the examples.

[0012] 0.800 ≦ W AV / W C ≦ 0.875 (1) W AV / W C is the ratio of the average weight (W AV ) of the shaped catalyst to the virtual cylindrical weight (W C ) of the shaped catalyst. In this specification, the ratio W AV / W C may be described as the value A. The value A is an index indicating the degree to which the corners of the cylindrical shaped catalyst are rounded. The smaller the value A, the more rounded the corners of the cylindrical shaped catalyst and the smaller the dimensions compared to the cylinder. The value A can be adjusted, for example, by manufacturing the shaped catalyst by adjusting the degree of corner rounding of the catalyst shaped into a cylindrical shape. For example, the value A can be adjusted by treating the catalyst shaped into a cylindrical shape with a kneader such as a non-bubbling kneader for an appropriate time. For example, when the treatment time with the kneader is increased, the value A tends to become smaller. When the treatment time with the kneader is decreased, the value A tends to become larger.

[0013] Here, W AV is obtained by the following formula (2). W AV = W tot / n (2) In formula (2), W tot represents the total weight of arbitrarily selected n shaped catalysts. Therefore, W AV means the average weight of arbitrarily selected n shaped catalysts.

[0014] W C is obtained by the following formula (3). W C =(V AV·ρ) / (1 + V P ·ρ) (3) In formula (3), V AV represents the average of the volumes obtained for each of the n arbitrarily selected shaped catalysts, where the major axis (L) of each is taken as the height and the minor axis (D) is taken as the diameter of an individual virtual cylinder. ρ represents the true density of the shaped catalyst. V P represents the pore volume per unit weight of the shaped catalyst. W C is the weight of a cylindrical catalyst having the same volume as the average volume of the n virtual cylinders assumed from the n arbitrarily selected shaped catalysts. Formula (3) is derived from the following formula. (V AV - V P ·W C )·ρ = W C

[0015] The shaped catalyst of this embodiment has a substantially cylindrical shape and has a shape with the corners of the cylindrical shape rounded off. The minor axis (D) of the shaped catalyst means the maximum diameter of the shaped catalyst in a cross-section perpendicular to the height direction (axial direction) of the substantially cylindrical shape.

[0016] The major axis (L) of the shaped catalyst means the longest diameter of the shaped catalyst in the height direction (axial direction) of the substantially cylindrical shape.

[0017] For measuring the major axis (L) and minor axis (D) of the shaped catalyst, conventionally known calipers, digital indicators, etc. can be used. The measurement is performed on n arbitrarily extracted samples (usually, n is 50 or more).

[0018] A virtual cylinder is a cylinder assumed with the major axis (L) of the shaped catalyst as the height and the minor axis (D) as the diameter of the bottom surface. V AV is the average volume of the individual virtual cylinders obtained with the major axis (L) of each arbitrarily selected shaped catalyst as the height and the minor axis (D) as the diameter.

[0019] The true density of the shaped catalyst is the density obtained by dividing the weight of the shaped catalyst by the true volume (the volume obtained by subtracting the pore volume from the apparent volume of the shaped catalyst). The true density (ρ) of the shaped catalyst can be measured by the liquid phase displacement method or the gas phase displacement method. Specifically, it can be measured by the liquid phase displacement method under the conditions described in the examples.

[0020] The pore volume (Vp) per unit weight of the shaped catalyst can be measured by a pore volume measuring device (e.g., "AutoPore III 9420" manufactured by MICROMERITICS).

[0021] [1.2. Size of the Shaped Catalyst] The size of the shaped catalyst is not particularly limited. However, from the viewpoint of further promoting the reaction by increasing the catalytic activity, usually, the minor axis (D) of the shaped catalyst is preferably 5 mm or less. On the other hand, from the viewpoint of reducing the pressure loss in the packed bed, the shaped catalyst used in the present invention preferably has an appropriate size, and usually, its minor axis (D) is preferably 1 mm or more. The major axis (L) of the shaped catalyst is usually 1 mm or more and 10 mm or less, preferably 3 mm or more and 7 mm or less.

[0022] [1.3. Shaping Method of the Shaped Catalyst] As an example of the method for producing the shaped catalyst of the present invention, a method of forming a cylindrical catalyst and then chamfering the corner portions of the cylindrical shape can be mentioned. Examples of the method for forming the cylindrical catalyst include methods by extrusion molding or tableting. In the case of extrusion molding, the extrudate may be cut to an appropriate length and used. The cylindrical catalyst obtained here has corner portions. The corner portions of the cylindrical shape are the corner portions formed by the bottom surface and the side surface of the cylinder. Next, a process of chamfering (also referred to as corner chamfering) the corner portions of the cylindrical catalyst is performed using a rotating device or the like. The rounding of the catalyst can be carried out, for example, by processing with a non-bubbling kneader (manufactured by Nippon Seiki Co., Ltd., NBK-1) at any time and rotation speed. The operating time of the non-bubbling kneader is preferably in the time range of 10 minutes or more and 150 minutes or less, more preferably in the time range of 50 minutes or more and 130 minutes or less, from the viewpoints of production efficiency and rounding effect. The rotation speed of the non-bubbling kneader is preferably in the range of 100 revolutions per minute or more and 2000 revolutions per minute or less, more preferably in the range of 200 revolutions per minute or more and 1000 revolutions per minute or less, from the viewpoints of maintaining the catalyst strength and rounding effect.

[0023] [1.4. Catalyst material for forming the shaped catalyst] The shaped catalyst may be formed from any catalyst material. The catalyst material to be formed into the shaped catalyst of the present invention may be a material consisting only of a catalyst active component, or may be a material containing a catalyst active component and a carrier for supporting the same.

[0024] (Example (1) of catalyst material) Examples of the catalyst active component that can be included in the catalyst material are not particularly limited, but include (1) known catalyst active components for producing chlorine by oxidizing hydrogen chloride with oxygen by a gas-phase oxidation method (for example, catalyst active components containing elements such as copper element, chromium element, ruthenium element, etc.).

[0025] Examples of the catalyst containing copper element include Deacon catalyst (a catalyst containing copper chloride and potassium chloride and further containing various compounds). Examples of the catalyst containing chromium element include catalysts containing chromium oxide (for example, the catalysts described in JP-A-61-136902, JP-A-61-275104, JP-A-62-113701, JP-A-62-270405, etc.). Examples of the catalyst containing ruthenium element include catalysts containing ruthenium oxide (for example, the catalysts described in JP-A-9-67103, JP-A-10-338502, JP-A-2000-281314, JP-A-2002-79093, JP-A-2002-292279, etc.).

[0026] In one embodiment, as the catalyst material to be formed into a shaped catalyst, a catalyst containing ruthenium element is preferred, and a catalyst containing ruthenium oxide is more preferred. Here, as ruthenium oxide, ruthenium dioxide (RuO2) with an oxidation number of +4 and ruthenium oxide with other oxidation numbers exist. The catalyst may contain ruthenium oxide in various forms with various oxidation numbers as ruthenium oxide. The catalyst containing ruthenium oxide preferably contains ruthenium dioxide (RuO2) with an oxidation number of +4.

[0027] The catalyst may be a catalyst consisting essentially of only ruthenium oxide, or may be a supported ruthenium oxide catalyst containing ruthenium oxide and a carrier on which it is supported. Since high activity can be obtained even when the content of ruthenium oxide is relatively small, the supported ruthenium oxide catalyst is more preferred.

[0028] As an example of a method for producing a supported ruthenium oxide catalyst, there is a method of obtaining a catalyst by supporting a ruthenium compound on a carrier and then firing it in an atmosphere of an oxygen-containing gas.

[0029] Examples of the carrier include oxides of elements selected from the group consisting of aluminum, silicon, titanium, zirconium, and niobium (which may be composite oxides), and one or more combinations of carriers such as activated carbon. Among these, as the carrier, one or more selected from the group consisting of alumina, silica, titanium oxide, and zirconium oxide are preferred, and titanium oxide having a rutile-type crystal structure is more preferred.

[0030] In the supported ruthenium oxide catalyst, the weight ratio of ruthenium oxide to the carrier is not particularly limited, but is preferably 0.1 / 99.9 to 20 / 80, more preferably 0.5 / 99.5 to 15 / 85. Such a weight ratio can be adjusted by adjusting the usage ratio of the ruthenium compound and the carrier in the production of the supported ruthenium oxide catalyst. When the weight ratio is equal to or higher than the lower limit value, the catalyst activity can be made sufficient. On the other hand, when the weight ratio is equal to or lower than the upper limit value, the catalyst cost can be reduced.

[0031] The above-mentioned supported ruthenium oxide catalyst can be suitably used in the gas-phase oxidation method for obtaining chlorine from hydrogen chloride and oxygen.

[0032] By forming a shaped catalyst from a catalyst material containing a catalyst active component for oxidizing hydrogen halide with oxygen, such as a ruthenium oxide catalyst, the shaped catalyst can be used as a shaped catalyst for oxidizing hydrogen halide with oxygen.

[0033] (Particularly preferred example of ruthenium oxide catalyst) Hereinafter, an example of a ruthenium oxide catalyst in which ruthenium oxide is supported on a titania carrier, which is particularly preferred as a material for a shaped catalyst for oxidizing hydrogen halide with oxygen, will be described in detail.

[0034] The titania carrier may be a titania carrier composed of rutile-type titania (titania having a rutile-type crystal structure), anatase-type titania (titania having an anatase-type crystal structure), amorphous titania, etc., or may be a titania carrier composed of a mixture thereof. A titania carrier composed of rutile-type titania and / or anatase-type titania is preferred. Among them, a titania carrier having a ratio of rutile-type titania to rutile-type titania and anatase-type titania in the titania carrier (hereinafter sometimes referred to as rutile-type titania ratio) of 50% or more is preferred, a titania carrier of 70% or more is more preferred, and a titania carrier of 90% or more is even more preferred. The higher the rutile-type titania ratio, the more the thermal stability of the supported ruthenium oxide obtained tends to improve, and the better the catalytic activity becomes. The above rutile-type titania ratio can be measured by the X-ray diffraction method (hereinafter referred to as the XRD method) and is represented by the following formula (a).

[0035] Rutile-type titania ratio [%] = 〔IR / (IA + IR)〕×100 (a)

[0036] IR: Intensity of the diffraction line indicating the (110) plane of rutile-type titania IA: Intensity of the diffraction line indicating the (101) plane of anatase-type titania

[0037] Incidentally, the sodium content in the titania carrier is preferably 200 ppm by weight or less, and the calcium content is preferably 200 ppm by weight or less. Further, the content of all alkali metal elements in the titania carrier is more preferably 200 ppm by weight or less, and the content of all alkaline earth metal elements in the titania carrier is more preferably 200 ppm by weight or less. The contents of these alkali metal elements and alkaline earth metal elements can be measured by, for example, inductively coupled plasma optical emission spectrometry (hereinafter sometimes referred to as ICP analysis), atomic absorption spectrometry, ion chromatography analysis, etc., and preferably measured by ICP analysis. Incidentally, the titania carrier may contain oxides such as α-alumina, silica, zirconia, niobium oxide, etc. in addition to titania. The titania carrier preferably does not substantially contain alumina having a high specific surface area. When alumina having a high specific surface area is present in the titania carrier, sulfur components and oxidized sulfur components are likely to be adsorbed and / or absorbed by the supported ruthenium oxide, and the activity of the catalyst may decrease. Since α-alumina has a low BET specific surface area, adsorption and / or absorption of sulfur components and oxidized sulfur components are less likely to occur. That is, even if the carrier contains α-alumina, the above problem is less likely to occur. Examples of alumina having a high specific surface area include those having a specific surface area of 10 to 500 m 2 / g, preferably 20 to 350 m 2 / g. The specific surface area of alumina can be measured by the nitrogen adsorption method (BET method), and is usually measured by the BET one-point method.

[0038] The specific surface area of the titania carrier can be measured by the nitrogen adsorption method (BET method), and is usually measured by the BET one-point method. The specific surface area obtained by this measurement is preferably 5 to 300 m 2 / g, more preferably 5 to 50 m 2 / g. If the specific surface area is too high, the titania carrier and ruthenium oxide in the obtained supported ruthenium oxide are likely to sinter, and the thermal stability may decrease. On the other hand, if the specific surface area is too low, the ruthenium oxide in the obtained supported ruthenium oxide is difficult to disperse, and the catalytic activity may decrease.

[0039] Ruthenium oxide is supported on the above-mentioned titania carrier. The support of ruthenium oxide on the titania carrier is carried out, for example, by contacting the titania carrier with a solution containing a ruthenium compound and a solvent, then drying until the content of the solvent becomes 0.10 to 15% by weight based on the weight of the titania carrier, and then holding the obtained dried product in a state containing 1.0 to 15% by weight of the solvent based on the weight of the titania carrier, and then firing in an oxidizing gas atmosphere.

[0040] Examples of the ruthenium compound include halides such as RuCl3 and RuBr3, halogenoacid salts such as K3RuCl6 and K2RuCl6, oxoacid salts such as K2RuO4 and Na2RuO4, oxohalides such as Ru2OCl4, Ru2OCl5, and Ru2OCl6, 10 halogeno complexes such as K2[RuCl5(H2O)4], [RuCl2(H2O)4]Cl, K2[Ru2OCl 12 , Cs2[Ru2OCl4], ammine complexes such as [Ru(NH3)5H2O]Cl2, [Ru(NH3)5Cl]Cl2, [Ru(NH3)6]Cl2, [Ru(NH3)6]Cl3, [Ru(NH3)6]Br3, carbonyl complexes such as Ru(CO)5 and Ru3(CO) 1 , carboxylato complexes such as [Ru3O(OCOCH3)6(H2O)3]OCOCH3 and [Ru2(OCOR 1 )(R

[0041] = alkyl group having 1 to 3 carbon atoms), nitrosyl complexes such as K2[RuCl5(NO)], [Ru(NH3)5(NO)]Cl3, [Ru(OH)(NH3)4(NO)](NO3)2, and [Ru(NO)](NO3)3, phosphine complexes, amine complexes, acetylacetonato complexes, etc. Among them, halides are preferably used, and chlorides are particularly preferably used. In addition, as the ruthenium compound, its hydrate may be used as necessary, or two or more of them may be used.The usage ratio of the titania carrier and the ruthenium compound can be adjusted as appropriate. For example, the weight ratio of ruthenium oxide / titania carrier in the supported ruthenium oxide obtained after firing described later is preferably 0.1 / 99.9 to 20.0 / 80.0, more preferably 0.3 / 99.7 to 10.0 / 90.0, and even more preferably 0.5 / 99.5 to 5.0 / 95.0, and can be adjusted as appropriate. If there is too little ruthenium oxide, the catalytic activity may not be sufficient, and if there is too much, it will be disadvantageous in terms of cost.

[0042] The ruthenium compound is supported on the titania carrier by contact treatment of the titania carrier with a solution containing the ruthenium compound and a solvent. In this contact treatment, examples of the solvent include water, alcohol, nitrile, etc., and if necessary, two or more of them may be used. As the water, highly pure water such as distilled water, ion-exchanged water, and ultrapure water is preferred. If the water used contains a large amount of impurities, such impurities may adhere to the catalyst and reduce the activity of the catalyst. Examples of the alcohol include alcohols having 1 to 6 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, hexanol, and cyclohexanol. Examples of the nitrile include nitriles having 1 to 6 carbon atoms such as acetonitrile, propionitrile, and benzonitrile. The amount of the solvent contained in the solution is preferably 70% by volume or more of the amount obtained by subtracting the volume of the ruthenium compound to be supported from the total pore volume of the titania carrier used. The upper limit is not particularly limited, but if the amount of the solvent used is too large, it tends to take a long time for drying, so it is preferably about 120% by volume or less. In this contact treatment, the temperature during the treatment is usually 0 to 100°C, preferably 0 to 50°C, and the pressure during the treatment is usually 0.1 to 1 MPa, preferably atmospheric pressure. Further, such contact treatment can be carried out in an air atmosphere or in an inert gas atmosphere such as nitrogen, helium, argon, and carbon dioxide, and at this time, it may be carried out in an atmosphere containing water vapor.

[0043] Examples of the contact treatment include impregnation and dipping. Examples of the method for subjecting the titania support to a contact treatment with a solution containing a ruthenium compound and a solvent include, for example, (A) a method of impregnating the titania support with a solution containing a ruthenium compound and a solvent, (B) a method of dipping the titania support in a solution containing a ruthenium compound and a solvent, etc. Among them, the method (A) is preferred. By this contact treatment, the ruthenium compound is supported on the titania support. In the contact treatment, in the titania support containing the ruthenium compound and the solvent obtained after the contact treatment, the amount of the solvent used for the titania support is adjusted so that the content of the solvent is usually more than 15% by weight based on the weight of the titania support.

[0044] After the titania support is subjected to a contact treatment with a solution containing a ruthenium compound and a solvent, the obtained titania support containing the ruthenium compound and the solvent is usually dried until the content of the solvent becomes 0.10 to 15% by weight based on the weight of the titania support. In such drying, the temperature is preferably 10°C to 100°C, the pressure in the drying is preferably 0.01 to 1 MPa, more preferably atmospheric pressure. The drying time is set as appropriate. Such drying can be carried out in an air atmosphere or in an inert gas atmosphere such as nitrogen, helium, argon, and oxygen dioxide. At this time, it may also be carried out in an atmosphere containing water vapor. Further, drying may be carried out under the flow of air, an inert gas, or a mixed gas of air and an inert gas. At this time, the gas to be circulated may contain water vapor. When drying is carried out under the flow of a water vapor-containing gas, the concentration of water vapor in the water vapor-containing gas is usually set in a range less than the saturated water vapor amount under the drying conditions. In the above drying, when drying is carried out under the flow of a gas, the flow rate of the gas is preferably 10 to 10,000 / h, more preferably 100 to 5,000 / h, as the space velocity (GHSV) of the gas in the titania support under standard conditions (0°C, 0.1 MPa conversion). The space velocity can be obtained by dividing the amount of gas (L / h) passing through the apparatus for the drying treatment per hour by the volume (L) of the titania support in the apparatus for the drying treatment.

[0045] The drying rate in the drying is appropriately set. From the perspective of productivity, the evaporation rate of the solvent per 1 g of the titania carrier is preferably 0.01 g / h or more, more preferably 0.02 g / h or more, and even more preferably 0.03 g / h or more. The upper limit of the drying rate is appropriately set, but the evaporation rate of the solvent per 1 g of the titania carrier is preferably 0.50 g / h or less. Such a drying rate can be controlled by adjusting conditions such as temperature, pressure, time, and the flow rate of the gas. However, during drying, these conditions may be changed to vary the drying rate.

[0046] The content of the solvent contained in the dried product obtained after the drying is usually 0.10 to 15% by weight, preferably 1.0 to 13% by weight, and more preferably 2.0 to 7.0% by weight based on the weight of the titania carrier. The content of the solvent based on the weight of the titania carrier in the dried product is calculated by the following formula (b).

[0047] Content of solvent based on weight of titania carrier in dried product (% by weight) = [Residual solvent amount in dried product (g)] / [Content of titania carrier in dried product (g)] × 100 (b)

[0048] In addition, when the contact treatment between the titania carrier and the solution containing the ruthenium compound and the solvent is performed by impregnation, the amount of the residual solvent in the dried product can be determined by subtracting the weight change amount before and after drying from the amount of the solvent used in the contact treatment.

[0049] The drying is preferably carried out with stirring. Note that drying with stirring means drying the titania carrier containing the ruthenium compound and the solvent in a flowing state rather than a stationary state. Examples of the stirring method include a method of rotating the drying container itself, a method of vibrating the drying container itself, and a method of stirring with a stirrer provided in the drying container.

[0050] The dried product thus obtained is maintained in a state containing 1.0 to 15% by weight of a solvent, usually based on the weight of the titania carrier. This maintenance is carried out in a state where the evaporation of the solvent contained in the dried product is suppressed, and the evaporation rate of the solvent is preferably less than 0.01 g / h per 1 g of the titania carrier, more preferably 0.001 g / h or less. In such maintenance, the temperature is preferably 0 to 80°C, more preferably 5 to 50°C. The maintenance time is appropriately set depending on the solvent content and the maintenance temperature, but is preferably 10 hours or more, more preferably 15 hours or more. This maintenance is preferably carried out in a state containing 1.0 to 15% by weight of a solvent based on the weight of the titania carrier, and may be carried out under sealed conditions, open conditions, or gas flow conditions. Also, it may be maintained in the same apparatus as during drying, or may be transferred to another container after drying and then maintained.

[0051] When, during the drying, the content of the solvent based on the weight of the titania carrier is 0.10% by weight or more and less than 1.0% by weight, before the above-mentioned maintenance, a method of passing a gas containing the vaporized solvent into contact with the dried product, or when the solvent is water, a method of leaving it in the atmosphere, etc. are used so that the solvent content in the dried product is within the range of 1.0 to 15% by weight based on the weight of the titania carrier, and then it is preferably subjected to the above-mentioned maintenance.

[0052] After the above-mentioned maintenance, firing is usually carried out in an atmosphere of an oxidizing gas. By such firing, the supported ruthenium compound is converted into ruthenium oxide, and a supported ruthenium oxide in which ruthenium oxide is supported on a titania carrier is obtained. The oxidizing gas is a gas containing an oxidizing substance, and examples thereof include oxygen-containing gases. The oxygen concentration is usually about 1 to 30% by volume. As this oxygen source, air or pure oxygen is usually used and is diluted with an inert gas or steam as necessary. Among them, air is preferably used as the oxidizing gas. The firing temperature is usually 100 to 500°C, preferably 200 to 400°C.

[0053] After the holding, the firing may be carried out after further drying until the solvent content in the dried product is less than 1.0% by weight based on the weight of the titania support, or may be carried out after a reduction treatment after the holding, or may be carried out after further drying until the solvent content in the dried product is less than 1.0% by weight based on the weight of the titania support after the holding and then carrying out a reduction treatment. As such a drying method, a conventionally known method can be adopted. The temperature is usually about from room temperature to 100°C, and the pressure is usually 0.001 to 1 MPa, preferably atmospheric pressure. Such drying can be carried out in an air atmosphere or in an inert gas atmosphere such as nitrogen, helium, argon, or carbon dioxide, and at this time, it may be carried out in an inert gas atmosphere containing water vapor. As such a reduction treatment, for example, the reduction treatments described in JP-A-2000-229239, JP-A-2000-254502, JP-A-2000-281314, JP-A-2002-79093, etc. can be mentioned.

[0054] In the supported ruthenium oxide obtained by the firing, the oxidation number of ruthenium in the supported ruthenium oxide is usually +4, and usually the ruthenium oxide is in the form of ruthenium dioxide (RuO2), but ruthenium with other oxidation numbers or other forms of ruthenium oxide may be included.

[0055] (Examples of catalyst materials (2)) Another example of the catalytically active component that can be included in the catalyst material is (2) a catalytically active component for obtaining methacrolein and further methacrylic acid from isobutylene and oxygen by a gas-phase oxidation method (for example, a catalytically active component containing an element such as molybdenum element). Examples of the catalyst containing such a catalytically active component include the oxidation catalysts described in JP-A-2000-351744, JP-A-2010-188276, JP-A-2003-10690, and JP-A-2007-260588, and these catalysts can be produced by a conventionally known method (for example, the method described in the above-mentioned publications).

[0056] [2. Usage modes of shaped catalysts] [2.1. Suitable Reactor] The shaped catalyst can be placed in and used in any reactor. However, since the effects of the shaped catalyst of the present invention are significantly exhibited, it is preferably filled and used in the reaction tubes of a multitubular reactor. Therefore, the shaped catalyst is suitable for use in a multitubular reactor, particularly a fixed-bed multitubular reactor.

[0057] Here, as the fixed-bed multitubular reactor, any previously known reactor having a plurality of reaction tubes can be used. Hereinafter, an example of the fixed-bed multitubular reactor will be described with reference to the drawings. FIG. 1 is a schematic view schematically showing an example of the fixed-bed multitubular reactor.

[0058] As shown in FIG. 1, the fixed-bed multitubular reactor 100 includes a plurality of reaction tubes 101, a cylindrical shell 102 that houses the reaction tubes 101 therein, a raw material introduction part 103 that is connected to the lower end part of the shell 102 for introducing raw materials, a product recovery part 104 that is connected to the upper end part of the shell 102 for recovering products, a fixing member 105a that fixes the reaction tubes 101 to the shell 102 at its lower end part, and a fixing member 105b that fixes the reaction tubes 101 to the shell 102 at its upper end part. The fixed-bed multitubular reactor 100 is usually installed and used such that the axis of the shell 102 is substantially parallel to the vertical direction.

[0059] The plurality of reaction tubes 101 are fixed to the shell 102 such that their axial directions are substantially parallel to the axial direction of the shell 102, and the shaped catalyst 10 is filled and used inside the reaction tubes 101.

[0060] A heat medium is introduced outside the reaction tubes 101 inside the shell 102 so that the reaction heat generated in the reaction tubes 101 can be removed by the heat medium. The fixed-bed multitubular reactor 100 can be of a type such as a disk-and-donut type or a non-circular baffle type.

[0061] The plurality of reaction tubes 101 are straight tubes having substantially the same length and inner diameter as each other. The upper ends of the reaction tubes 101 are open, and the shaped catalyst 10 is filled and used through this opening. In another embodiment, the plurality of reaction tubes may be coiled.

[0062] An example of the method of using the fixed bed multitubular reactor 100 will be described below. The reaction tube 101 is filled with a shaped catalyst 10 (for example, a catalyst formed using a supported ruthenium oxide catalyst as a material). A raw material (for example, a gas containing hydrogen chloride and oxygen) is introduced from the raw material introduction section 103 and passed through the inside of the reaction tube 101 filled with the shaped catalyst 10. Inside the reaction tube 101, the raw material comes into contact with the shaped catalyst 10 and reacts to be converted into a product (for example, chlorine gas). The obtained product is collected in the product recovery section 104 and taken out of the fixed bed multitubular reactor 100.

[0063] [2.2. Preferred applications] The shaped catalyst can be used in any production method depending on the catalyst active component contained therein. In particular, the shaped catalyst formed using the supported ruthenium oxide catalyst as a material can be preferably used as a catalyst for oxidizing hydrogen halide with oxygen to obtain a halogen.

[0064] [3. Method for producing halogen using a shaped catalyst] The shaped catalyst can be used in a method for producing a halogen (preferably chlorine). In the method for producing a halogen, it is preferable to use, as the shaped catalyst, a shaped catalyst having a catalytic activity for generating a halogen from hydrogen halide and oxygen, and it is more preferable to use a shaped catalyst formed from the catalyst materials listed in the above item [1. Shaped catalyst] (example of catalyst material (1)).

[0065] The method for producing a halogen according to an embodiment of the present invention includes a step of obtaining a halogen using the shaped catalyst. Hereinafter, the production method of this embodiment will be described by taking, as an example, a method for producing chlorine as the halogen.

[0066] In the production method of the present embodiment, hydrogen chloride is oxidized by supplying hydrogen chloride and oxygen to each reaction tube of a fixed-bed multitubular reactor. The fixed-bed multitubular reactor is not particularly limited, but the fixed-bed multitubular reactor described in [2. Mode of use of the shaped catalyst] can be used. Each reaction tube is filled with the shaped catalyst, and hydrogen chloride is oxidized by flowing a gas containing hydrogen chloride and a gas containing oxygen through the layer of the shaped catalyst (catalyst-filled layer) filled in each reaction tube.

[0067] Examples of the gas containing hydrogen chloride are not particularly limited, and include any gas containing hydrogen chloride, such as a gas generated by the reaction of hydrogen and chlorine; a gas generated by heating hydrochloric acid; a gas generated by a thermal decomposition reaction or a combustion reaction of a chlorine compound; a gas by-produced in the production of various compounds (for example, a carbonylation reaction of an organic compound with phosgene, a chlorination reaction of an organic compound with chlorine, a production reaction of chlorofluorocarbon); and a combustion exhaust gas generated from an incinerator.

[0068] The concentration of hydrogen chloride in the gas containing hydrogen chloride is preferably 10% by volume or more, more preferably 50% by volume or more, still more preferably 80% by volume or more, and usually 100% by volume or less. When the concentration of hydrogen chloride is at least the above lower limit value, the production efficiency is improved, and the reaction operation such as the separation of the produced chlorine and the recycling operation when recycling unreacted oxygen can be simplified.

[0069] The gas containing hydrogen chloride may contain impurities such as unreacted raw materials and reaction products in the reaction for generating the gas. However, the concentration of the impurities is preferably such that the concentration of hydrogen chloride in the gas is within the above preferred range.

[0070] The gas containing hydrogen chloride may contain other gases such as water vapor and an inert gas. However, other gases such as water vapor and an inert gas are preferably such that the concentration of hydrogen chloride in the gas is within the above preferred range. The gas containing hydrogen chloride preferably contains water vapor because it can smooth the temperature distribution in the catalyst-filled layer.

[0071] As the gas containing oxygen, air may be used or pure oxygen may be used.

[0072] The method for producing halogen according to this embodiment may include an arbitrary process in addition to the process of obtaining halogen using the shaped catalyst. For example, the method for producing halogen according to this embodiment may include a process of filling a reactor with the shaped catalyst, a process of transferring the halogen generated in the reactor, and the like.

Examples

[0073] Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto. In the following description, "parts" means "parts by weight". The physical properties, etc. of the shaped catalyst used were measured and calculated by the following methods.

[0074] <Major axis (L) of the shaped catalyst> The major axis (L) of 50 arbitrarily extracted shaped catalysts was measured with a digital caliper.

[0075] <Minor axis (D) of the shaped catalyst> The minor axis (D) of 50 arbitrarily extracted shaped catalysts was measured with a digital caliper.

[0076] <Average weight (W AV ) of the shaped catalyst> Fifty arbitrarily extracted shaped catalysts were precisely weighed and divided by 50 to calculate W AV .

[0077] <Average volume (V AV ) of the virtual cylinder> For each of the 50 arbitrarily extracted shaped catalysts, the volume V of each virtual cylinder was obtained from the major axis (L) and the minor axis (D) by the following formula, and the sum of the volumes of the individual virtual cylinders (= W tot ) was divided by 50 to calculate V AV . Formula: V = (D / 2) 2 ·π·L

[0078] <True density (ρ) of the shaped catalyst> It was measured by the liquid phase displacement method using a pycnometer. Butanol was used as the dispersion medium. Before measurement, the shaped catalyst was dried at 105 °C for 2 hours in an air atmosphere. The measurement was carried out at 25 °C using a pycnometer (specific gravity bottle with side tube, 40 mL). As a result of the measurement, the true density of the shaped catalysts used in the examples and comparative examples was ρ = 4.193 g / cm 3 It was.

[0079] <Pore volume per unit weight of the shaped catalyst (V P )> Weigh out 0.6 - 1.2 g of the catalyst to be measured, dry it at 110 °C for 4 hours in a dryer, and accurately weigh the weight after drying to obtain a sample. This sample was placed in a cell of a pore volume measuring device ("AutoPore III 9420" manufactured by MICROMERITICS). After making the inside of the cell system 50 μmHg or less, the cell was filled with mercury. Then, pressure was gradually applied to the cell, and with a mercury intrusion equilibrium waiting time of 10 seconds, the mercury intrusion amount at each pressure was measured. Then, by dividing the total mercury intrusion amount (mL) when the pressure was applied from 0.007 MPa to 207 MPa by the sample weight (g), the mercury intrusion amount per 1 g of the sample was obtained, and this was taken as the pore volume per unit weight (mL / g). The shaped catalysts used in the examples and comparative examples had V P = 0.20 mL / g.

[0080] <Variation in apparent specific gravity> Accurately weigh about 80 - 100 g of the shaped catalyst to be measured to obtain a sample, and drop the entire amount onto the center of a graduated cylinder within 3 seconds from above a funnel placed on a 100 cc graduated cylinder. Then, level the upper surface of the catalyst in the graduated cylinder and read the volume, and calculate the value obtained by dividing the sample weight (g) by the read volume (cc) to obtain the apparent specific gravity (g / cc). For the results of repeating the measurement of the apparent specific gravity 10 times, the unbiased variance was obtained and taken as the variation in the apparent specific gravity.

[0081] <Angularity of the catalyst> The chamfering of the catalyst was carried out by processing it for a predetermined time and at a predetermined rotation speed using a non-bubbling kneader (manufactured by Nippon Seiki Co., Ltd., NBK-1).

[0082] [Example 1] [Preparation of Titanium Oxide Molded Body] 100 parts of titania powder [F-1R manufactured by Showa Titanium Co., Ltd., rutile-type titania ratio 93%] and 2 parts of an organic binder [YB-152A manufactured by Yuken Kogyo Co., Ltd.] were mixed, and then 29 parts of pure water and 12.5 parts of titania sol [CSB manufactured by Sakai Chemical Industry Co., Ltd., titania content 40%] were added and kneaded. This mixture was extruded into a noodle shape with a diameter of 3.0 mmφ, dried at 60°C for 2 hours, and then crushed into pieces about 3 to 5 mm in length. The obtained molded body was heated from room temperature to 600°C in air over 1.7 hours and then held at the same temperature for 3 hours for firing to obtain a white titanium oxide (titania) molded body.

[0083] [Chamfering Treatment and Apparent Specific Gravity Measurement] 100 g of the titanium oxide molded body was precisely weighed as a sample, placed in the sample container of a non-bubbling kneader, and operated at a rotation speed of 500 revolutions per minute for 52 minutes. The obtained molded body (formed catalyst) was sieved (sieve opening 1.4 mm, wire diameter 0.71 mm). When the sieved molded body (formed catalyst) was precisely weighed, it was 95.1 g. When 50 pieces were randomly extracted from the sieved molded body (formed catalyst) and precisely weighed, it was 3.2602 g, and W AV = 0.0652 g. From the results of measuring the major axis (L) and minor axis (D) of the randomly extracted 50 molded bodies, V AV , W C , A were V AV = 0.0332 mL, W C = 0.0754 g, A = 0.865, respectively. Furthermore, the apparent specific gravity of the sieved formed catalyst was measured 10 times to obtain the variation, which was 0.00002. The results are shown in Table 1.

[0084] [Example 2] The operation was carried out in the same manner as in Example 1 except that the operation time of the non-bubbling kneader was 87 minutes. As a result, the molded body (molded catalyst) after sieving was 90.1 g. The result of arbitrarily extracting 50 pieces from the molded body (molded catalyst) after sieving and precisely weighing them was 3.1650 g, W AV =0.0633 g, V AV =0.0338 mL, W C =0.0769 g, A = 0.823. The variation in the apparent specific gravity of the molded catalyst after sieving was 0.00004. The results are shown in Table 1.

[0085] [Example 3] The operation was carried out in the same manner as in Example 1 except that the operation time of the non-bubbling kneader was 127 minutes. As a result, the molded body (molded catalyst) after sieving was 84.9 g. The result of arbitrarily extracting 50 pieces from the molded body (molded catalyst) after sieving and precisely weighing them was 2.9746 g, W AV =0.0595 g, V AV =0.0320 mL, W C =0.0727 g, A = 0.818. The variation in the apparent specific gravity of the molded catalyst after sieving was 0.00001. The results are shown in Table 1.

[0086] [Example 4] The operation was carried out in the same manner as in Example 1 except that the operation time of the non-bubbling kneader was 24 minutes. As a result, the molded body (molded catalyst) after sieving was 98.0 g. The result of arbitrarily extracting 50 pieces from the molded body (molded catalyst) after sieving and precisely weighing them was 3.4262 g, W AV =0.0685 g, V AV =0.0346 mL, W C =0.0786 g, A = 0.872. The variation in the apparent specific gravity of the molded catalyst after sieving was 0.00013. The results are shown in Table 1.

[0087] [Comparative Example 1] The operation was carried out in the same manner as in Example 1 except that the operation time of the non-bubbling kneader was 20 minutes. As a result, the molded body (molded catalyst) after sieving was 98.5 g. The result of arbitrarily extracting 50 pieces from the molded body (molded catalyst) after sieving and precisely weighing them was 3.3633 g, W AV =0.0673 g, V AV =0.0337 mL, WC = 0.0766 g, A = 0.878, and the variation in the apparent specific gravity of the formed catalyst after screening was 0.00024. The results are shown in Table 1.

[0088] [Comparative Example 2] The operation time of the non-bubbling kneader was 158 minutes, and the same procedure as in Example 1 was carried out. As a result, the weight of the formed body (formed catalyst) after screening was 80.0 g. The result of randomly extracting 50 pieces from the formed body (formed catalyst) after screening and precisely weighing them was 2.8625 g, W AV = 0.0573 g, V AV = 0.0319 mL, W C = 0.0725 g, A = 0.789, and the variation in the apparent specific gravity of the formed catalyst after screening was 0.00018. The results are shown in Table 1.

[0089]

Table 1

[0090] For the examples and comparative examples, the variation in the apparent specific gravity with respect to the value A was plotted and shown in Fig. 2. Fig. 2 is a graph showing the relationship between the value A and the variation in the apparent specific gravity for the examples and comparative examples.

[0091] According to the above results, the formed catalyst of the example satisfying formula (1) has a significantly smaller variation in the apparent specific gravity compared to the formed catalyst of the comparative example.

[0092] In this example, titanium oxide (titania) was used as the material for forming the formed catalyst. However, by using a material containing various components having other catalytic activities (for example, a ruthenium oxide catalyst in which ruthenium oxide is supported on a titania carrier) as the material for forming the formed catalyst, it is possible to obtain a formed catalyst having various catalytic activities and a reduced degree of variation in the filling state when filling the reaction tube.

Explanation of Symbols

[0093] 10 Formed catalyst 100 Fixed-bed multitubular reactor 101 Reaction tube 102 Shell 103 Raw material introduction part 104 Product recovery part 105a, 105b Fixing members

Claims

1. A shaped catalyst obtained by chamfering a cylindrical catalyst for oxidizing hydrogen halide with oxygen, having the following formula (1): 0.818 ≤ W ＡＶ / W Ｃ ≤ 0.865 (1) (In formula (1), W ＡＶ is obtained from the following formula (2), and W Ｃ is obtained by the following formula (3), W ＡＶ = W ｔｏｔ / n (2) W Ｃ = (V ＡＶ · ρ) / (1 + V Ｐ · ρ) (3) In formula (2), W ｔｏｔ represents the total weight of n arbitrarily selected shaped catalysts, In formula (3), V ＡＶ represents the average of the volumes obtained for individual virtual cylinders, each having the major axis (L) of an arbitrarily selected n shaped catalysts as the height and the minor axis (D) as the diameter, ρ represents the true density of the shaped catalyst, V Ｐ satisfies (representing the pore volume per unit weight of the molding catalyst), and The major axis (L) is 1 mm or more and 10 mm or less, The minor axis (D) is 5 mm or less, The shaped catalyst.

2. The shaped catalyst according to claim 1, which is for a multitubular reactor.

3. A method for producing a halogen, comprising obtaining a halogen using the shaped catalyst according to claim 1 or 2.

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