JPWO2018110126A1 - Method for producing catalyst precursor for producing α, β-unsaturated carboxylic acid, method for producing catalyst for producing α, β-unsaturated carboxylic acid, method for producing α, β-unsaturated carboxylic acid, and α, β-unsaturated Method for producing carboxylic acid ester - Google Patents

Abstract

Provided is a catalyst precursor for producing an α, β-unsaturated carboxylic acid capable of producing an α, β-unsaturated carboxylic acid with a high yield. A method for producing a precursor of a catalyst used for producing an α, β-unsaturated carboxylic acid by vapor-phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen, wherein the precursor is ammonium (I) preparing an aqueous slurry or aqueous solution (I) containing a molybdenum-containing heteropolyacid, and (ii) adding an ammonium compound to the aqueous slurry or aqueous solution (I) to form an ammonium salt of the heteropolyacid. And (iii) drying the slurry (II) from which the ammonium salt of the heteropolyacid is precipitated to obtain the precursor, and the ammonium in the step (ii). Catalyst precursor for production of α, β-unsaturated carboxylic acid using an ammonium compound containing 30% by mass or more of ammonium carbamate as the compound Manufacturing method.

Description

  The present invention relates to a method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid, a method for producing a catalyst for producing an α, β-unsaturated carboxylic acid, a method for producing an α, β-unsaturated carboxylic acid, and α, The present invention relates to a method for producing a β-unsaturated carboxylic acid ester.

  As a catalyst used for producing α, β-unsaturated carboxylic acid by vapor phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen, heteropolyacid such as phosphomolybdic acid, phosphomolybdate or the like Catalysts based on such salts are known. Numerous studies have been made on the method for producing the catalyst, and many of them are prepared by first preparing an aqueous solution or slurry containing each element constituting the catalyst, then drying and calcining the catalyst. Yes.

  The basic performance of such a catalyst depends mainly on the elemental composition, crystal structure, particle size, etc., but the conditions for the preparation process of the aqueous slurry, especially the conditions such as pH and temperature, are controlled. Is required. As a catalyst having a heteropolyacid or a salt thereof as a main component, a partially neutralized salt of an alkali metal such as potassium, rubidium or cesium is generally used as a main component. However, in actual catalyst preparation, it may be difficult to form an optimal crystal structure for producing an α, β-unsaturated carboxylic acid simply by forming a partially neutralized alkali metal salt. Therefore, in actual catalyst preparation, a composite salt such as an alkali metal salt and an ammonium salt may be formed, and the ammonium salt or the like may be decomposed by calcination to form a partially neutralized alkali metal salt. Here, ammonia water, ammonium nitrate, ammonium bicarbonate, or the like is used as the ammonium raw material. However, each said ammonium raw material has a subject, respectively. In general, ammonium salts of heteropolyacids are known to have a larger particle size than alkali metal salts. When the particle size is large, the specific surface area is small, so that the catalytic activity for producing an α, β-unsaturated carboxylic acid is low.

  Patent Document 1 describes using ammonium nitrate as an ammonium raw material. When ammonium nitrate is used as an ammonium raw material, it is possible to form a preferable crystal structure for producing an α, β-unsaturated carboxylic acid by suppressing the pH of the heteropolyacid (salt) slurry to a low value (Non-patent Document 1). ). However, it is known that when an organic forming aid is added, if ammonium nitrate coexists, a large amount of heat may be generated during firing (Patent Document 2).

  Patent Document 3 describes using ammonium bicarbonate as an ammonium raw material. However, when ammonium bicarbonate is used, the catalytic activity is low and a sufficient yield of α, β-unsaturated carboxylic acid cannot be obtained.

JP 2014-226614 A Japanese Patent Laid-Open No. 6-86933 JP2013-128878A

T.A. OKUHARA, N.M. MIZUNO, M.M. MISONO ADVANCES IN CATALYSIS, 1996, VOLUME 41, 113-252.

  An object of the present invention is to provide a catalyst precursor for producing an α, β-unsaturated carboxylic acid capable of producing an α, β-unsaturated carboxylic acid with a high yield.

  The present invention includes the following [1] to [13].

[1] A method for producing a precursor of a catalyst used in producing α, β-unsaturated carboxylic acid by vapor-phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen, wherein the precursor The body contains ammonium roots,
(I) preparing an aqueous slurry or aqueous solution (I) containing a molybdenum-containing heteropolyacid,
(Ii) adding an ammonium compound to the aqueous slurry or aqueous solution (I) to obtain a slurry (II) in which an ammonium salt of a heteropolyacid is precipitated;
(Iii) drying the slurry (II) on which the ammonium salt of the heteropolyacid is deposited to obtain the precursor;
Have
A method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid, wherein an ammonium compound containing 30% by mass or more of ammonium carbamate is used as the ammonium compound in the step (ii).

[2] A method for producing a precursor of a catalyst used in producing α, β-unsaturated carboxylic acid by vapor-phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen, wherein the precursor The body contains ammonium roots,
(I) preparing an aqueous slurry or aqueous solution (I) containing a molybdenum-containing heteropolyacid,
(Ii) adding an ammonium compound to the aqueous slurry or aqueous solution (I) to obtain a slurry (II) in which an ammonium salt of a heteropolyacid is precipitated;
(Iii) drying the slurry (II) on which the ammonium salt of the heteropolyacid is deposited to obtain the precursor;
Have
A method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid, wherein the ammonium compound in the step (ii) satisfies the following formula (1).

0.048 ≦ W1 / W2 ≦ 0.2 (1)
(In Formula (1), W1 represents the mass of ammonium carbamate in the ammonium compound, and W2 represents the mass of molybdenum element contained in the aqueous slurry or aqueous solution (I)).

  [3] The method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid according to [1], wherein the ammonium compound in the step (ii) satisfies the following formula (1).

0.048 ≦ W1 / W2 ≦ 0.2 (1)
(In Formula (1), W1 represents the mass of ammonium carbamate in the ammonium compound, and W2 represents the mass of molybdenum element contained in the aqueous slurry or aqueous solution (I)).

  [4] The method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid according to any one of [1] to [3], which has a composition represented by the following formula (2).

_{P a Mo b V c Cu d} A e E f G g (NH 4) h O i (2)
(In the formula (2), P, Mo, V, Cu, NH ₄ and O represent phosphorus, molybdenum, vanadium, copper, ammonium ion and oxygen, respectively. A represents antimony, bismuth, arsenic, germanium, zirconium. Represents at least one element selected from the group consisting of nickel, tellurium, silver, selenium, silicon, tungsten and boron, where E represents iron, zinc, chromium, calcium, strontium, tantalum, cobalt, nickel, manganese, titanium, tin And at least one element selected from the group consisting of lead, niobium, indium, sulfur, palladium, gallium, cerium and lanthanum, G is selected from the group consisting of potassium, rubidium, cesium, thallium, magnesium and barium A to h are molar ratios of the respective components. When b = 12, a = 0.5-3, c = 0.01-3, d = 0.01-2, e = 0-3, f = 0-3, g = 0. 01 to 3 and h = 0.1 to 20, i is a molar ratio of oxygen necessary to satisfy the valence of each of the above components).

  [5] In the step (ii), the ammonium compound is added to the aqueous slurry or the aqueous solution (I) having a temperature higher than 90 ° C. and lower than or equal to 105 ° C. α according to any one of [1] to [4] , Β-unsaturated carboxylic acid production catalyst precursor production method.

  [6] The catalyst for producing an α, β-unsaturated carboxylic acid according to any one of [1] to [5], wherein the ammonium compound in the step (ii) is a mixture of ammonium carbamate and ammonium bicarbonate. A method for producing a precursor.

  [7] The α, β-unsaturated aldehyde is (meth) acrolein, and the α, β-unsaturated carboxylic acid is (meth) acrylic acid, according to any one of [1] to [6] A method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid.

  [8] A catalyst for producing an α, β-unsaturated carboxylic acid comprising a step of heat-treating a catalyst precursor for producing an α, β-unsaturated carboxylic acid produced by the method according to any one of [1] to [7] Manufacturing method.

  [9] The method for producing a catalyst for producing an α, β-unsaturated carboxylic acid according to [8], wherein the temperature of the heat treatment is 200 to 500 ° C.

  [10] Gas phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen in the presence of the catalyst for producing α, β-unsaturated carboxylic acid produced by the method according to [8] or [9] A process for producing an α, β-unsaturated carboxylic acid.

  [11] A catalyst for producing an α, β-unsaturated carboxylic acid is produced by the method according to [8] or [9], and an α, β-unsaturated aldehyde is vapor-phased with molecular oxygen using the catalyst. A method for producing an α, β-unsaturated carboxylic acid which undergoes catalytic oxidation.

  [12] A method for producing an α, β-unsaturated carboxylic acid ester, wherein the α, β-unsaturated carboxylic acid produced by the method according to [10] or [11] is esterified.

  [13] An α, β-unsaturated carboxylic acid ester produced by producing an α, β-unsaturated carboxylic acid by the method described in [10] or [11] and esterifying the α, β-unsaturated carboxylic acid Production method.

  According to the present invention, it is possible to provide a catalyst precursor for producing an α, β-unsaturated carboxylic acid capable of producing an α, β-unsaturated carboxylic acid with a high yield.

[Method for Producing Catalyst Precursor for Production of α, β-Unsaturated Carboxylic Acid]
The method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid (hereinafter also referred to as a catalyst precursor) according to the present invention comprises α, β-unsaturated aldehyde by vapor-phase catalytic oxidation with molecular oxygen and α , Β-unsaturated carboxylic acid, a catalyst used for producing a precursor, wherein the precursor contains an ammonium radical. The method includes the following steps (i) to (iii).
(I) A step of preparing an aqueous slurry or an aqueous solution (I) containing a molybdenum-containing heteropolyacid.
(Ii) A step of adding an ammonium compound to the aqueous slurry or the aqueous solution (I) to obtain a slurry (II) in which an ammonium salt of a heteropolyacid is deposited.
(Iii) A step of drying the slurry (II) on which the ammonium salt of the heteropolyacid is deposited to obtain the precursor.

  The ammonium compound in the step (ii) contains 30% by mass or more of ammonium carbamate or satisfies the following formula (1).

0.048 ≦ W1 / W2 ≦ 0.2 (1)
(In Formula (1), W1 represents the mass of ammonium carbamate in the ammonium compound, and W2 represents the mass of molybdenum element contained in the aqueous slurry or aqueous solution (I)).

In the method according to the present invention, an ammonium compound comprising the steps (i) to (iii) and containing 30% by mass or more of ammonium carbamate in the step (ii) or satisfying the formula (1) Can be used to reduce only the particle size of the catalyst particles in the aqueous slurry without changing the chemical properties such as the elemental composition and crystal structure of the catalyst, the pH of the aqueous slurry and the residual counteranion, and the specific surface area. Can be improved. As a result, the catalytic activity is improved, and when α, β-unsaturated carboxylic acid is produced by vapor-phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen, The yield can be improved. That is, the present inventors have found that a high yield can be achieved by using a predetermined content ratio of ammonium carbamate as an ammonium raw material used for producing a catalyst, and completed the present invention. In the present invention, the “ammonium root” is a general term for ammonium (NH ₃ ) that can be an ammonium ion (NH ₄ ⁺ ) and ammonium contained in an ammonium-containing compound such as an ammonium salt. In the method according to the present invention, in the step (ii), an ammonium compound containing 30% by mass or more of ammonium carbamate and satisfying the formula (1) may be used.

  The catalyst precursor for producing an α, β-unsaturated carboxylic acid produced by the method according to the present invention preferably contains at least phosphorus and molybdenum, and has a composition represented by the following formula (2). , Β-unsaturated carboxylic acid is more preferable from the viewpoint of producing α, β-unsaturated carboxylic acid in high yield. In addition, let the molar ratio of each element in a catalyst precursor be the value calculated | required by analyzing the component which melt | dissolved the catalyst precursor in ammonia water by ICP emission spectrometry. The molar ratio of ammonium ions is a value determined by analyzing the catalyst precursor by the Kjeldahl method.

_{P a Mo b V c Cu d} A e E f G g (NH 4) h O i (2)
In the formula (2), P, Mo, V, Cu, NH ₄ and O represent phosphorus, molybdenum, vanadium, copper, ammonium ion and oxygen, respectively. A represents at least one element selected from the group consisting of antimony, bismuth, arsenic, germanium, zirconium, tellurium, silver, selenium, silicon, tungsten and boron. E is at least one selected from the group consisting of iron, zinc, chromium, calcium, strontium, tantalum, cobalt, nickel, manganese, titanium, tin, lead, niobium, indium, sulfur, palladium, gallium, cerium and lanthanum Indicates an element. G represents at least one element selected from the group consisting of potassium, rubidium, cesium, thallium, magnesium and barium. a to h represent the molar ratio of each component. When b = 12, a = 0.5 to 3, c = 0.01 to 3, d = 0.01 to 2, e = 0 to 3, f = 0 to 3, g = 0.01 to 3, h = 0.1 to 20, i is a molar ratio of oxygen necessary to satisfy the valence of each component.

  The method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid according to the present invention includes the following steps (i) to (iii). (I) A step of preparing an aqueous slurry or an aqueous solution (I) containing a molybdenum-containing heteropolyacid. (Ii) A step of adding an ammonium compound to the aqueous slurry or the aqueous solution (I) to obtain a slurry (II) in which an ammonium salt of a heteropolyacid is deposited. (Iii) A step of drying the slurry (II) on which the ammonium salt of the heteropolyacid is deposited to obtain a catalyst precursor. Here, as the ammonium compound in the step (ii), an ammonium compound containing 30% by mass or more of ammonium carbamate or satisfying the formula (1) is used. Moreover, the manufacturing method of the catalyst precursor for methacrylic acid manufacture which concerns on this invention may further have the shaping | molding process mentioned later.

(Process (i))
In step (i), an aqueous slurry or aqueous solution (I) containing a molybdenum-containing heteropolyacid is prepared. For example, an aqueous slurry or aqueous solution (I) can be obtained by dissolving or suspending the raw material compound of the catalyst component in a solvent using a preparation container. The aqueous slurry or aqueous solution (I) preferably contains at least phosphorus and molybdenum, and more preferably contains an element contained in the composition represented by the formula (2).

  As raw material compounds to be used, nitrates, carbonates, acetates, ammonium salts, oxides, halides, oxoacids, oxoacid salts, etc. of each catalytic element may be used alone or in combination of two or more. it can. Examples of the molybdenum raw material include ammonium paramolybdate, molybdenum trioxide, molybdic acid, and molybdenum chloride. Examples of the phosphorus raw material include orthophosphoric acid, phosphorus pentoxide, or phosphates such as ammonium phosphate and cesium phosphate. Examples of the copper raw material include copper sulfate, copper nitrate, copper oxide, copper carbonate, copper acetate, and copper chloride. Examples of the vanadium raw material include ammonium vanadate, ammonium metavanadate, vanadium pentoxide, vanadium chloride, and the like. These may use only 1 type and may use 2 or more types together.

  Further, as a raw material for molybdenum, phosphorus, and vanadium, a heteropolyacid containing at least one element of molybdenum, phosphorus, and vanadium may be used. Examples of the heteropolyacid include phosphomolybdic acid, phosphovanadmolybdic acid, and silicomolybdic acid. These may use only 1 type and may use 2 or more types together.

  When an ammonium salt is used as the raw material compound of the catalyst component in step (i), the amount of the ammonium radical derived from the raw material compound contained in the catalyst precursor is 3 mol or less when the amount of molybdenum is 12 mol. Preferably, 1.5 mol or less is more preferable, 1 mol or less is more preferable, and 0.6 mol or less is particularly preferable. The effect of the present invention can be sufficiently obtained when the amount of the ammonium root derived from the raw material compound is 3 mol or less when the amount of molybdenum is 12 mol.

  The aqueous slurry or aqueous solution (I) is preferably prepared by a method in which a part or all of the raw materials of each element constituting the catalyst precursor is added to water and stirred while heating. An aqueous solution, an aqueous slurry, or an aqueous sol of raw materials for each element constituting the catalyst precursor may be added to water. The heating temperature of the aqueous slurry or aqueous solution (I) is preferably 80 to 130 ° C, more preferably 90 to 130 ° C. By setting the heating temperature of the aqueous slurry or aqueous solution (I) to 80 ° C. or higher, the production rate of the molybdenum-containing heteropolyacid can be sufficiently increased. Moreover, evaporation of water in the aqueous slurry or aqueous solution (I) can be suppressed by setting the heating temperature of the aqueous slurry or aqueous solution (I) to 130 ° C. or lower. The aqueous slurry or aqueous solution (I) to be prepared has a pH of preferably 4 or less, and more preferably 2 or less. By making the pH of the aqueous slurry or aqueous solution (I) sufficiently low, a molybdenum-containing heteropolyacid having a preferred structure can be formed. The pH of the aqueous slurry or aqueous solution (I) can be measured with a pH meter (trade name: D-21, manufactured by Horiba, Ltd.). Whether or not the molybdenum-containing heteropolyacid is formed can be determined by infrared absorption analysis using NICOLET6700FT-IR (product name, manufactured by Thermo Electron).

(Step (ii))
In the step (ii), an ammonium compound is added to the aqueous slurry or the aqueous solution (I) to obtain a slurry (II) in which the ammonium salt of the heteropolyacid is precipitated.

  As the ammonium compound, an ammonium compound containing 30% by mass or more of ammonium carbamate or satisfying the following formula (1) is used.

0.048 ≦ W1 / W2 ≦ 0.2 (1)
In the formula (1), W1 represents the mass of ammonium carbamate in the ammonium compound, and W2 represents the mass of molybdenum element contained in the aqueous slurry or aqueous solution (I).

  Thereby, the specific surface area of the catalyst obtained increases, the catalytic activity in the production of α, β-unsaturated carboxylic acid can be increased, and the yield of α, β-unsaturated carboxylic acid can be improved. The content of ammonium carbamate in the ammonium compound is preferably 40% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass or more. The higher the content of ammonium carbamate, the more the yield of α, β-unsaturated carboxylic acid can be improved. From the viewpoint of production cost, the upper limit of the content of ammonium carbamate is preferably 95% by mass or less. The lower limit of W1 / W2 is preferably 0.055 or more, more preferably 0.078 or more, further preferably 0.085 or more, and particularly preferably 0.092 or more. Further, the upper limit of W1 / W2 is preferably 0.15 or less, more preferably 0.13 or less, and further preferably 0.12 or less.

  When the ammonium compound is used in combination with an ammonium compound other than ammonium carbamate, examples of the other ammonium compound include ammonium bicarbonate, ammonium nitrate, and aqueous ammonia. From the viewpoint of the yield of the target product, bicarbonate is used. It is preferable to use ammonium together. That is, the ammonium compound is preferably a mixture of ammonium carbamate and ammonium bicarbonate. These other ammonium compounds may be used alone or in combination. The ammonium compound preferably contains 80 to 100% by mass in total of ammonium carbamate and ammonium bicarbonate, and more preferably 90 to 100% by mass. The “ammonium compound” in the present invention refers to an ammonium compound that does not contain the catalyst element.

  The temperature of the aqueous slurry or aqueous solution (I) to which the ammonium compound is added is lower than 90 ° C. and the upper limit is 105 ° C. or lower from the viewpoint of suppressing hot spots when producing α, β-unsaturated carboxylic acid. It is preferable. The lower limit is more preferably 93 ° C. or higher.

  In this step, in addition to the ammonium compound, a G element raw material in the formula (2) may be added to precipitate at least a part of the heteropolyacid as a salt of the G element.

  It is preferable to add the ammonium compound and the elemental G raw material added as necessary, dissolved or suspended in a solvent. Examples of the solvent include water, ethyl alcohol, acetone and the like, but it is preferable to use the same water as the aqueous slurry or aqueous solution (I) obtained in the step (i) as a solvent. The stirring time of the slurry (II) after adding the ammonium compound and the G element raw material added as necessary is preferably 5 to 60 minutes, the lower limit is 10 minutes or more, and the upper limit is more preferably 30 minutes or less. The temperature of the slurry (II) during stirring is preferably 80 to 100 ° C. By setting the stirring time to 5 minutes or more and the temperature to 80 ° C. or more, the ammonium salt of the heteropolyacid and the salt of the G element can be sufficiently formed. On the other hand, by setting the stirring time to 60 minutes or less and the temperature to 100 ° C. or less, side reactions other than the formation of the target ammonium salt of the heteropolyacid and the salt of the G element can be suppressed.

  The ammonium salt of the heteropoly acid to be deposited and the salt of the G element may have a Keggin type structure or a non-Keggin type structure such as a Dawson type structure, but have a Keggin type structure. Is preferred. When the ammonium salt of heteropolyacid to precipitate and the salt of G element have a Keggin type structure, the yield of (alpha), (beta)-unsaturated carboxylic acid improves more. As a method for precipitating the ammonium salt of heteropolyacid having a Keggin structure and the salt of element G, for example, using molybdenum trioxide as a molybdenum raw material, the pH of slurry (II) in step (ii) is adjusted to 3 or less. The method of doing is mentioned. The structures of the ammonium salt of the heteropoly acid and the salt of the element G were determined by infrared absorption analysis and X-ray diffractometer X'Pert PRO MPD (product name) using NICOLET6700FT-IR (product name, manufactured by Thermoelectron). (Manufactured by PANaltical).

(Process (iii))
In step (iii), the slurry (II) on which the ammonium salt of the heteropolyacid is deposited is dried to obtain a catalyst precursor. Examples of drying methods include drum drying, airflow drying, evaporation to dryness, and spray drying. The drying temperature is preferably 120 to 500 ° C, the lower limit is 140 ° C or higher, and the upper limit is more preferably 350 ° C or lower. Drying can be performed until the slurry (II) is solidified. The water content of the catalyst precursor is preferably 0.1 to 4.5% by mass. These conditions can be appropriately selected depending on the shape and size of the desired catalyst precursor.

(Molding process)
In the forming step, the catalyst precursor or the catalyst after heat treatment obtained in the heat treatment step described later is formed. The molding method is not particularly limited, and a known dry or wet molding method can be applied. For example, tableting molding, extrusion molding, pressure molding, rolling granulation and the like can be mentioned. There is no restriction | limiting in particular as a shape of a molded article, Arbitrary shapes, such as a spherical granular form, a ring shape, a cylindrical pellet shape, a star shape, and the granule shape classified by grinding | pulverization after shaping | molding, are mentioned. As the size of the catalyst, the catalyst diameter is preferably 0.1 to 10 mm. When the catalyst diameter is 0.1 mm or more, the pressure loss in the reaction tube can be reduced. Moreover, a catalyst activity improves more because a catalyst diameter is 10 mm or less. When molding, it may be supported on a carrier or other additives may be mixed.

[Method for producing catalyst for producing α, β-unsaturated carboxylic acid]
The method for producing a catalyst for producing an α, β-unsaturated carboxylic acid according to the present invention comprises a catalyst precursor obtained in the step (iii) or a molded product of the catalyst precursor obtained in the molding step (hereinafter referred to as “the catalyst precursor”). It is preferable to include a step (hereinafter also referred to as a heat treatment step) of heat-treating (also collectively referred to as a catalyst precursor).

(Heat treatment process)
In the heat treatment step, the catalyst precursor is heat treated to obtain a catalyst for producing an α, β-unsaturated carboxylic acid. The heat treatment conditions are not particularly limited, but can be performed under the flow of at least one of an oxygen-containing gas such as air and an inert gas, for example. The heat treatment is preferably performed under a flow of oxygen-containing gas such as air. The “inert gas” refers to a gas that does not decrease the catalytic activity, and examples thereof include nitrogen, carbon dioxide gas, helium, and argon. These may use 1 type and may mix and use 2 or more types. The heat treatment temperature is preferably 200 to 500 ° C, the lower limit is 300 ° C or higher, and the upper limit is more preferably 450 ° C or lower. Further, the lower limit of the heat treatment time is preferably 0.5 hours or more, and more preferably 1 hour or more. The upper limit of the heat treatment time is preferably 40 hours or less. The specific surface area of the obtained catalyst is preferably 4.6 m ² / g or more. In addition, the specific surface area of a catalyst is a value calculated | required using a nitrogen adsorption method, and is a value calculated | required by the method mentioned later specifically.

[Production method of α, β-unsaturated carboxylic acid]
The method for producing an α, β-unsaturated carboxylic acid according to the present invention comprises an α, β-unsaturated aldehyde in the presence of a catalyst for producing an α, β-unsaturated carboxylic acid produced by the method according to the present invention. Gas phase catalytic oxidation with molecular oxygen. Moreover, the manufacturing method of the (alpha), (beta)-unsaturated carboxylic acid which concerns on this invention manufactures the catalyst for (alpha), (beta) -unsaturated carboxylic acid manufacture by the method based on this invention, Gas phase catalytic oxidation of unsaturated aldehyde with molecular oxygen.

  In the method according to the present invention, examples of the α, β-unsaturated aldehyde include (meth) acrolein, crotonaldehyde (β-methylacrolein), cinnamaldehyde (β-phenylacrolein) and the like. Among these, (meth) acrolein is preferable from the viewpoint of the yield of the target product, and methacrolein is more preferable. The α, β-unsaturated carboxylic acid produced is an α, β-unsaturated carboxylic acid in which the aldehyde group of the α, β-unsaturated aldehyde is changed to a carboxyl group. Specifically, when the α, β-unsaturated aldehyde is (meth) acrolein, (meth) acrylic acid is obtained. “(Meth) acrolein” indicates acrolein and methacrolein, and “(meth) acrylic acid” indicates acrylic acid and methacrylic acid.

  Hereinafter, as a representative example, a method for producing methacrylic acid by vapor-phase catalytic oxidation of methacrolein with molecular oxygen in the presence of a catalyst for producing methacrylic acid produced by the method according to the present invention will be described.

  In the method, methacrylic acid is produced by bringing a raw material gas containing methacrolein and molecular oxygen into contact with the catalyst according to the present invention. In this reaction, a fixed bed reactor can be used. The reaction can be carried out by filling the reaction tube with a catalyst and supplying a raw material gas to the reactor. The catalyst layer may be a single layer, or a plurality of catalysts having different activities may be divided into a plurality of layers and filled. In order to control the activity, the catalyst for producing methacrylic acid may be diluted with an inert carrier and filled.

  The concentration of methacrolein in the raw material gas is not particularly limited, but is preferably 1 to 20% by volume, the lower limit is 3% by volume or more, and the upper limit is more preferably 10% by volume or less. The raw material methacrolein may contain a small amount of impurities such as lower saturated aldehydes that do not substantially affect the present reaction.

  The concentration of molecular oxygen in the raw material gas is preferably 0.4 to 4 mol per mol of methacrolein, the lower limit is 0.5 mol or more, and the upper limit is more preferably 3 mol or less. The molecular oxygen source is preferably air from the viewpoint of economy. If necessary, a gas enriched with molecular oxygen by adding pure oxygen to air may be used.

  The source gas may be obtained by diluting methacrolein and molecular oxygen with an inert gas such as nitrogen or carbon dioxide. Further, water vapor may be added to the source gas. By performing the reaction in the presence of water vapor, methacrylic acid can be obtained in a higher yield. The concentration of water vapor in the raw material gas is preferably 0.1 to 50% by volume, the lower limit is 1% by volume or more, and the upper limit is more preferably 40% by volume.

  The contact time between the source gas and the catalyst for producing methacrylic acid is preferably 1.5 to 15 seconds. The reaction pressure is preferably 0.1 to 1 MPa (G). However, (G) means a gauge pressure. The reaction temperature is preferably 200 to 450 ° C, the lower limit is 250 ° C or higher, and the upper limit is more preferably 400 ° C or lower.

[Production method of α, β-unsaturated carboxylic acid ester]
In the method for producing an α, β-unsaturated carboxylic acid ester according to the present invention, the α, β-unsaturated carboxylic acid produced by the method according to the present invention is esterified. In addition, the method for producing an α, β-unsaturated carboxylic acid ester according to the present invention comprises producing an α, β-unsaturated carboxylic acid by the method according to the present invention and esterifying the α, β-unsaturated carboxylic acid. To do. According to these methods, an α, β-unsaturated carboxylic acid ester can be obtained using an α, β-unsaturated carboxylic acid obtained by gas phase catalytic oxidation of an α, β-unsaturated aldehyde. The alcohol to be reacted with the α, β-unsaturated carboxylic acid is not particularly limited, and examples thereof include methanol, ethanol, isopropanol, n-butanol, and isobutanol. Examples of the α, β-unsaturated carboxylic acid ester to be obtained include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. The reaction can be carried out in the presence of an acidic catalyst such as a sulfonic acid type cation exchange resin. The reaction temperature is preferably 50 to 200 ° C.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited to these Examples. “Parts” in Examples and Comparative Examples means parts by mass. The analysis of the raw material gas and the product was performed using gas chromatography. From the results of gas chromatography, the yield of methacrylic acid was determined by the following formula.

Methacrylic acid yield (%) = (B / A) × 100
In the formula, A is the number of moles of methacrolein fed to the reactor, and B is the number of moles of methacrylic acid produced.

  The specific surface area of the catalyst was determined using a nitrogen adsorption method. Specifically, it measured using Tristar 3000 (trade name, manufactured by Micrometrics). Measurement was performed using 1.5 g of the catalyst, and the specific surface area was calculated by the BET 5-point method.

Example 1
In 400 parts of pure water, 100 parts of molybdenum trioxide, 3.4 parts of ammonium metavanadate, 9.4 parts of 85% by weight phosphoric acid aqueous solution diluted with 6.0 parts of pure water, and copper (II) nitrate A dissolved material in which 2.1 parts of hydrate was dissolved in 4.5 parts of pure water was added. The obtained aqueous slurry was heated from 25 ° C. to 95 ° C. while stirring, and stirred for 2 hours while maintaining the liquid temperature at 95 ° C., to obtain an aqueous slurry (I) containing molybdenum-containing heteropolyacid. The pH of the aqueous slurry (I) was 0.6. Further, with stirring while maintaining the liquid temperature at 95 ° C., a dissolved product obtained by dissolving 13.5 parts of cesium bicarbonate in 24 parts of pure water and a dissolved product obtained by dissolving 6.9 parts of ammonium carbamate in 70 parts of pure water. The mixture was added dropwise and stirred for 15 minutes to precipitate the cesium salt and ammonium salt of the heteropolyacid. The cesium salt and ammonium salt of the heteropolyacid had a Keggin type structure. The resulting slurry (II) was heated with 140 ° C. water vapor to evaporate to dryness to obtain a catalyst precursor. The composition of the catalyst precursor other than oxygen was P _1.4 Mo ₁₂ V _0.5 Cu _0.15 Cs _1.2 (NH ₄ ) _3.6 . After the catalyst precursor was pressure-molded, the pulverized product was heat treated at 380 ° C. for 5 hours under air flow to obtain a catalyst.

  The catalyst is filled in a reaction tube, and a raw material gas composed of 5% by volume of methacrolein, 10% by volume of oxygen, 30% by volume of water vapor and 55% by volume of nitrogen is reacted at a reaction temperature of 285 ° C. Time passed in 2.4 seconds. The product obtained from the reactor was collected and analyzed by gas chromatography to calculate the yield of methacrylic acid. Moreover, before using for a catalytic reaction, the specific surface area was computed by the nitrogen adsorption method. The results are shown in Table 1.

(Example 2)
Instead of a solution obtained by dissolving 6.9 parts of ammonium carbamate in 70 parts of pure water, a solution obtained by dissolving a mixture of 2.0 parts of ammonium bicarbonate and 5.9 parts of ammonium carbamate in 70 parts of pure water was used. A catalyst precursor was produced in the same manner as in Example 1 except that it was used. The composition of the catalyst precursor other than oxygen was P _1.4 Mo ₁₂ V _0.5 Cu _0.15 Cs _1.2 (NH ₄ ) _3.6 . The catalyst precursor was molded by the same method as in Example 1 and heat-treated to obtain a catalyst. Using this catalyst, the reaction was carried out in the same manner as in Example 1, and the methacrylic acid yield was calculated. The results are shown in Table 1.

(Example 3)
Instead of a solution obtained by dissolving 6.9 parts of ammonium carbamate in 70 parts of pure water, a solution obtained by dissolving a mixture of 4.6 parts of ammonium bicarbonate and 4.6 parts of ammonium carbamate in 70 parts of pure water was used. A catalyst precursor was produced in the same manner as in Example 1 except that it was used. The composition of the catalyst precursor other than oxygen was P _1.4 Mo ₁₂ V _0.5 Cu _0.15 Cs _1.2 (NH ₄ ) _3.6 . The catalyst precursor was molded by the same method as in Example 1 and heat-treated to obtain a catalyst. Using this catalyst, the reaction was carried out in the same manner as in Example 1, and the methacrylic acid yield was calculated. The results are shown in Table 1.

Example 4
Instead of a solution obtained by dissolving 6.9 parts of ammonium carbamate in 70 parts of pure water, a solution obtained by dissolving a mixture of 5.9 parts of ammonium bicarbonate and 4.0 parts of ammonium carbamate in 70 parts of pure water was used. A catalyst precursor was produced in the same manner as in Example 1 except that it was used. The composition of the catalyst precursor other than oxygen was P _1.4 Mo ₁₂ V _0.5 Cu _0.15 Cs _1.2 (NH ₄ ) _3.6 . The catalyst precursor was molded by the same method as in Example 1 and heat-treated to obtain a catalyst. Using this catalyst, the reaction was carried out in the same manner as in Example 1, and the methacrylic acid yield was calculated. The results are shown in Table 1.

(Comparative Example 1)
Instead of a solution obtained by dissolving 6.9 parts of ammonium carbamate in 70 parts of pure water, a solution obtained by dissolving a mixture of 8.3 parts of ammonium bicarbonate and 2.8 parts of ammonium carbamate in 70 parts of pure water was used. A catalyst precursor was produced in the same manner as in Example 1 except that it was used. The composition of the catalyst precursor other than oxygen was P _1.4 Mo ₁₂ V _0.5 Cu _0.15 Cs _1.2 (NH ₄ ) _3.6 . The catalyst precursor was molded by the same method as in Example 1 and heat-treated to obtain a catalyst. Using this catalyst, the reaction was carried out in the same manner as in Example 1, and the methacrylic acid yield was calculated. The results are shown in Table 1.

(Comparative Example 2)
The catalyst was the same as in Example 1 except that a solution obtained by dissolving 14.0 g of ammonium bicarbonate in 70 parts of pure water was used instead of a solution obtained by dissolving 6.9 parts of ammonium carbamate in 70 parts of pure water. A precursor was produced. The composition of the catalyst precursor other than oxygen was P _1.4 Mo ₁₂ V _0.5 Cu _0.15 Cs _1.2 (NH ₄ ) _3.6 . The catalyst precursor was molded by the same method as in Example 1 and heat-treated to obtain a catalyst. Using this catalyst, the reaction was carried out in the same manner as in Example 1, and the methacrylic acid yield was calculated. The results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 4, it was confirmed that the mass ratio of ammonium carbamate and the value of W1 / W2 are within the scope of the present invention, and the catalyst has a high methacrylic acid yield. . On the other hand, in Comparative Examples 1 and 2, since the mass ratio of ammonium carbamate and the value of W1 / W2 were outside the scope of the present invention, the methacrylic acid yield was low compared to the Examples. In addition, a methacrylic acid ester can be obtained by esterifying the methacrylic acid obtained in the present Example.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2016-240355 for which it applied on December 12, 2016, and takes in those the indications of all here.

  Although the present invention has been described with reference to the exemplary embodiments and examples, the present invention is not limited to the above exemplary embodiments and examples. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

  According to the present invention, it is possible to provide a catalyst precursor for producing an α, β-unsaturated carboxylic acid capable of producing an α, β-unsaturated carboxylic acid in a high yield from an α, β-unsaturated aldehyde. And industrially useful.

Claims (13)

A method for producing a precursor of a catalyst used for producing an α, β-unsaturated carboxylic acid by vapor-phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen, wherein the precursor is ammonium Including roots,
(I) preparing an aqueous slurry or aqueous solution (I) containing a molybdenum-containing heteropolyacid,
(Ii) adding an ammonium compound to the aqueous slurry or aqueous solution (I) to obtain a slurry (II) in which an ammonium salt of a heteropolyacid is precipitated;
(Iii) drying the slurry (II) on which the ammonium salt of the heteropolyacid is deposited to obtain the precursor;
Have
A method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid, wherein an ammonium compound containing 30% by mass or more of ammonium carbamate is used as the ammonium compound in the step (ii). A method for producing a precursor of a catalyst used for producing an α, β-unsaturated carboxylic acid by vapor-phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen, wherein the precursor is ammonium Including roots,
(I) preparing an aqueous slurry or aqueous solution (I) containing a molybdenum-containing heteropolyacid,
(Ii) adding an ammonium compound to the aqueous slurry or aqueous solution (I) to obtain a slurry (II) in which an ammonium salt of a heteropolyacid is precipitated;
(Iii) drying the slurry (II) on which the ammonium salt of the heteropolyacid is deposited to obtain the precursor;
Have
A method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid, wherein the ammonium compound in the step (ii) satisfies the following formula (1).
0.048 ≦ W1 / W2 ≦ 0.2 (1)
(In formula (1), W1 represents the mass of ammonium carbamate in the ammonium compound, and W2 represents the mass of molybdenum element contained in the aqueous slurry or aqueous solution (I).) The method for producing a catalyst precursor for producing an α, β-unsaturated carboxylic acid according to claim 1, wherein the ammonium compound in the step (ii) satisfies the following formula (1).
0.048 ≦ W1 / W2 ≦ 0.2 (1)
(In formula (1), W1 represents the mass of ammonium carbamate in the ammonium compound, and W2 represents the mass of molybdenum element contained in the aqueous slurry or aqueous solution (I).) The manufacturing method of the catalyst precursor for alpha, beta-unsaturated carboxylic acid manufacture of any one of Claim 1 to 3 which has a composition represented by following formula (2).
_{P a Mo b V c Cu d} A e E f G g (NH 4) h O i (2)
(In the formula (2), P, Mo, V, Cu, NH ₄ and O represent phosphorus, molybdenum, vanadium, copper, ammonium ion and oxygen, respectively. A represents antimony, bismuth, arsenic, germanium, zirconium. Represents at least one element selected from the group consisting of nickel, tellurium, silver, selenium, silicon, tungsten and boron, where E represents iron, zinc, chromium, calcium, strontium, tantalum, cobalt, nickel, manganese, titanium, tin And at least one element selected from the group consisting of lead, niobium, indium, sulfur, palladium, gallium, cerium and lanthanum, G is selected from the group consisting of potassium, rubidium, cesium, thallium, magnesium and barium A to h are molar ratios of the respective components. When b = 12, a = 0.5-3, c = 0.01-3, d = 0.01-2, e = 0-3, f = 0-3, g = 0. (01-3, h = 0.1-20, i is the molar ratio of oxygen necessary to satisfy the valence of each component)   The α, β- according to any one of claims 1 to 4, wherein in the step (ii), the ammonium compound is added to the aqueous slurry or the aqueous solution (I) having a temperature higher than 90 ° C and lower than or equal to 105 ° C. A method for producing a catalyst precursor for producing an unsaturated carboxylic acid.   The catalyst precursor for producing an α, β-unsaturated carboxylic acid according to any one of claims 1 to 5, wherein the ammonium compound in the step (ii) is a mixture of ammonium carbamate and ammonium bicarbonate. Production method.   The α, β according to any one of claims 1 to 6, wherein the α, β-unsaturated aldehyde is (meth) acrolein and the α, β-unsaturated carboxylic acid is (meth) acrylic acid. -The manufacturing method of the catalyst precursor for unsaturated carboxylic acid manufacture.   A method for producing a catalyst for producing an α, β-unsaturated carboxylic acid, comprising a step of heat-treating a catalyst precursor for producing an α, β-unsaturated carboxylic acid produced by the method according to any one of claims 1 to 7. .   The method for producing a catalyst for producing an α, β-unsaturated carboxylic acid according to claim 8, wherein a temperature of the heat treatment is 200 to 500 ° C.   An α, β- that undergoes gas phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen in the presence of a catalyst for producing an α, β-unsaturated carboxylic acid produced by the method according to claim 8 or 9. A method for producing an unsaturated carboxylic acid.   An α, β-unsaturated carboxylic acid production catalyst is produced by the method according to claim 8 or 9, and α, β-unsaturated aldehyde is vapor-phase catalytically oxidized with molecular oxygen using the catalyst, α, A method for producing a β-unsaturated carboxylic acid.   A method for producing an α, β-unsaturated carboxylic acid ester, wherein the α, β-unsaturated carboxylic acid produced by the method according to claim 10 or 11 is esterified.   A method for producing an α, β-unsaturated carboxylic acid ester, wherein an α, β-unsaturated carboxylic acid is produced by the method according to claim 10 or 11, and the α, β-unsaturated carboxylic acid is esterified.