Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
  • B01J27/14—Phosphorus; Compounds thereof
  • B01J27/186—Phosphorus; Compounds thereof with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
  • B01J27/195—Phosphorus; Compounds thereof with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium with vanadium, niobium or tantalum
  • B01J27/198—Vanadium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/04—Mixing
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
  • C07B61/00—Other general methods
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
  • C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
  • C07C51/23—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of oxygen-containing groups to carboxyl groups
  • C07C51/235—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of oxygen-containing groups to carboxyl groups of —CHO groups or primary alcohol groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C57/00—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms
  • C07C57/02—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms with only carbon-to-carbon double bonds as unsaturation
  • C07C57/03—Monocarboxylic acids
  • C07C57/04—Acrylic acid; Methacrylic acid
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
  • C07C69/52—Esters of acyclic unsaturated carboxylic acids having the esterified carboxyl group bound to an acyclic carbon atom
  • C07C69/533—Monocarboxylic acid esters having only one carbon-to-carbon double bond
  • C07C69/54—Acrylic acid esters; Methacrylic acid esters

Definitions

• the present invention relates to a method for producing a catalyst for producing methacrylic acid, and a method for producing methacrylic acid and methacrylic acid esters using the catalyst.
• Heteropolyacid catalysts containing molybdenum and phosphorus are known as catalysts for producing methacrylic acid (hereinafter simply referred to as "catalysts") used in producing methacrylic acid by oxidizing methacrolein.
• Heteropolyacids are condensed oxygen acids formed by the coordination atoms (hereinafter referred to as polyatoms) that form the basic skeleton of a polyacid and oxides of the heteroatoms.
• Heteropolyacid catalysts include proton-type heteropolyacids in which the counter cation is a proton, and heteropolyacid salts in which some of the protons are replaced with cations other than protons (hereinafter, proton-type heteropolyacids are simply referred to as “heteropolyacids", and at least one selected from proton-type heteropolyacids and heteropolyacid salts are simply referred to as “heteropolyacids (salts)").
• Non-Patent Document 1 describes that phosphorus, silicon, arsenic, germanium, titanium, antimony, etc. can be heteroatoms, and tungsten, molybdenum, vanadium, niobium, tantalum, etc. can be polyatoms of heteropolyacids (salts).
• the basic structures of heteropolyacids (salts) include Keggin type, Dawson type, Preysler type, etc.
• Heteropolyacid catalysts are known as catalysts used in the production of methacrylic acid by oxidizing methacrolein.
• Patent Document 1 discloses a heteropolyacid catalyst for the production of methacrylic acid, which contains molybdenum, vanadium, phosphorus, and an alkali metal, and is composed of a poorly water-soluble component and a water-soluble component, and 60 mol % or more of the total vanadium atoms contained in the catalyst are contained in the water-soluble component.
• a method for producing a heteropolyacid catalyst for the production of methacrylic acid which includes the following steps (i) to (v), is disclosed.
• An object of the present invention is to provide a method for producing a catalyst capable of producing methacrylic acid with high selectivity by oxidation of methacrolein, and a method for producing methacrylic acid using the catalyst.
• the present inventors have conducted intensive research in view of the above problems and have found that the above problems can be solved by producing a catalyst by a method using a slurry having a specific liquid phase component, thereby completing the present invention. That is, the present invention includes the following. [1]: A method for producing a catalyst used in producing methacrylic acid by oxidation of methacrolein, comprising the following steps (i) to (iii): (i) A step of mixing a phosphorus source, a molybdenum source, and a vanadium source with a solvent to prepare a slurry A. (ii) A step of drying the slurry A to obtain a dried product.
• step (iii) Calcining the dried product.
• M2/M1 is 7.5 or less.
• the M2/M1 is 1.4 to 3.5.
• the vanadium concentration in the liquid phase of the slurry A is 0.005 to 0.1 mass%.
• the vanadium concentration in the liquid phase of the slurry A is 0.01 to 0.08 mass%.
• the pH of the slurry A is 1.1 to 2.0.
• an organic carboxylic acid is further mixed to prepare slurry A, The method for producing a catalyst for methacrylic acid production according to any one of [1] to [5].
• the organic carboxylic acid is mixed in an amount such that the carboxyl group of the organic carboxylic acid is 0.011 to 0.46 mol per mol of molybdenum in the slurry A.
• the method for producing a catalyst for producing methacrylic acid [8]: The method for producing a catalyst for producing methacrylic acid according to [6] or [7], wherein the organic carboxylic acid contains oxalic acid or oxalic acid dihydrate.
• step (i) comprises the following steps (i-1) to (i-3): (i-1) mixing a phosphorus raw material, a molybdenum raw material, and a vanadium raw material with a solvent to prepare a solution or slurry A1; (i-2) mixing a raw material of an alkali metal element with the solution or slurry A1 to prepare a slurry A2; and (i-3) mixing an organic carboxylic acid with the slurry A2 to prepare a slurry A.
• E represents at least one element selected from the group consisting of iron, zinc, chromium, tantalum, cobalt, nickel, manganese, titanium, and niobium.
• G represents at least one element selected from the group consisting of potassium, rubidium, and cesium.
• [11] A method for producing methacrylic acid, comprising a step of oxidizing methacrolein to produce methacrylic acid using a catalyst for producing methacrylic acid produced by the method according to any one of [1] to [10].
• [12] A method for producing a methacrylic acid ester, comprising esterifying the methacrylic acid produced by the method according to [11].
• the present invention provides a catalyst that can produce methacrylic acid with high selectivity.
• a numerical range expressed using “to” means a range including the numerical values before and after “to” as the lower and upper limits, and "A to B” means A or more and B or less.
• the catalyst for producing methacrylic acid produced by the production method according to this embodiment is used when producing methacrylic acid by oxidizing methacrolein. From the viewpoint of improving the yield of methacrylic acid, the catalyst preferably has a composition represented by the following formula (I).
• the catalyst may contain a small amount of elements not described in the following formula (I).
• P, Mo, V, Cu, and O represent phosphorus, molybdenum, vanadium, copper, and oxygen, respectively.
• A represents at least one element selected from the group consisting of antimony, bismuth, arsenic, germanium, tellurium, selenium, silicon, and tungsten.
• E represents at least one element selected from the group consisting of iron, zinc, chromium, tantalum, cobalt, nickel, manganese, titanium, and niobium.
• G represents at least one element selected from the group consisting of potassium, rubidium, and cesium.
• g is 0.1 to 2.8, and more preferably, g is 0.3 to 2.5.
• the lower limit of a is preferably 0.6 or more, and more preferably 0.7 or more.
• the upper limit of a is preferably 2.5 or less, and more preferably 2 or less.
• the lower limit of c is preferably 0.1 or more, more preferably 0.15 or more, and even more preferably 0.2 or more.
• the upper limit of c is preferably 2.5 or less, more preferably 2 or less, and even more preferably 1.5 or less.
• the lower limit of d is preferably 0.03 or more, and more preferably 0.05 or more.
• the upper limit of d is preferably 2.5 or less, and more preferably 2 or less.
• the lower limit of e is preferably 0.01 or more, and more preferably 0.1 or more.
• the upper limit of e is preferably 2.5 or less, and more preferably 2 or less.
• the upper limit of f is preferably 2 or less, more preferably 1.5 or less, and even more preferably 1 or less.
• the lower limit of g is preferably 0.1 or more, and more preferably 0.3 or more.
• the upper limit of g is preferably 2.8 or less, and more preferably 2.5 or less.
• the molar ratio of each component is determined by dissolving the catalyst in ammonia water and analyzing the components using ICP emission spectrometry.
• the method for producing a catalyst for producing methacrylic acid is a method for producing a catalyst used in producing methacrylic acid by an oxidation reaction of methacrolein, and has the following steps. (i) mixing a phosphorus raw material, a molybdenum raw material, and a vanadium raw material with a solvent to prepare a slurry A; (ii) drying the slurry A to obtain a dried product; and (iii) firing the dried product.
• step (i) when the number of moles of molybdenum in the liquid phase of the slurry A is M1 and the number of moles of vanadium in the liquid phase of the slurry A is M2, M2/M1 is 7.5 or less.
• step (i) the phosphorus raw material, the molybdenum raw material, and the vanadium raw material are mixed with a solvent to prepare a slurry A.
• the slurry A may be mixed with raw materials of catalyst components other than the phosphorus raw material, the molybdenum raw material, and the vanadium raw material, and preferably has a raw material of an element represented by the formula (I).
• the metal element or ion in the slurry A and the carboxylate ion form a complex, and the proportion of the solid phase in the slurry A increases. Therefore, by mixing the organic carboxylic acid in step (i), the value of M2/M1 of the slurry A can be easily adjusted.
• the organic carboxylic acid is an organic acid having a carboxyl group, and examples thereof include oxalic acid, oxalic acid dihydrate, acetic acid, citric acid, and formic acid. Among these, it is preferable to use oxalic acid or oxalic acid dihydrate, which has a low carbon content and is stable as a compound.
• a catalyst with stable performance can be obtained regardless of the preparation scale of slurry A. It is preferable to mix the organic carboxylic acid so that the carboxyl group is 0.011 to 0.46 moles, more preferably 0.023 to 0.27 moles, per mole of molybdenum in slurry A.
• the step (i) preferably includes the following steps (i-1) to (i-3).
• (i-1) A step of mixing a phosphorus source, a molybdenum source, and a vanadium source with a solvent to prepare a solution or slurry A1.
• (i-2) A step of mixing a raw material of an alkali metal element with the solution or slurry A1 to prepare a slurry A2.
• (i-3) A step of mixing an organic carboxylic acid with the slurry A2 to prepare a slurry A.
• a phosphorus source, a molybdenum source, and a vanadium source are mixed with a solvent to prepare a solution or slurry A1.
• the solution or slurry A1 contains the source materials of elements other than the G element in the formula (I). It is preferable to have
• the raw materials for the catalyst components are not particularly limited, and nitrates, carbonates, acetates, ammonium salts, oxides, halides, oxoacids, oxoacid salts, and the like of each of the constituent elements of the catalyst can be used alone or in combination of two or more kinds.
• Examples of phosphorus raw materials include phosphoric acid, phosphorus pentoxide, ammonium phosphate, etc.
• Examples of molybdenum raw materials include molybdenum oxides such as molybdenum trioxide, ammonium molybdates such as ammonium paramolybdate and ammonium dimolybdate, molybdenum chloride, etc.
• vanadium raw materials include ammonium metavanadate, vanadium pentoxide, vanadium chloride, vanadyl oxalate, etc.
• copper raw materials include copper sulfate, copper nitrate, copper oxide, copper carbonate, copper acetate, copper chloride, etc.
• the concentration of the raw catalyst components in the slurry A1 is not particularly limited, but is preferably within the range of 5 to 90 mass%.
• solvent examples include water, ethyl alcohol, acetone, etc. These may be used alone or in combination of two or more. Among these, it is preferable to use water from an industrial viewpoint.
• the solution or slurry A1 is preferably prepared by adding raw materials of the catalyst components to a solvent in a preparation vessel and stirring the mixture while heating, thereby producing a sufficient amount of heteropolyacid suitable for the production of methacrylic acid.
• the heating temperature is usually in the range of 30 to 150°C, but is preferably in the range of 60 to 150°C.
• the lower limit of the heating temperature is more preferably 80°C or higher, and even more preferably 90°C or higher.
• the upper limit of the heating temperature is more preferably 130°C or lower, and even more preferably 110°C or lower.
• the solvent may be concentrated or refluxed during heating, or the solvent may be heated under pressurized conditions by operating in a closed container.
• the heating rate is not particularly limited, but is preferably 0.8 to 15°C/min. By setting the heating rate to 0.8°C/min or more, the time required for step (i) can be shortened. Furthermore, by setting the heating rate to 15°C/min or less, heating can be performed using ordinary heating equipment.
• the stirring is preferably performed with a stirring power of 0.01 kW/m 3 or more, more preferably 0.05 kW/m 3 or more.
• a stirring power 0.01 kW/m 3 or more, more preferably 0.05 kW/m 3 or more.
• the stirring power is preferably performed with a stirring power of 3.5 kW/m 3 or less.
• an alkali metal element is mixed with the solution or slurry A1 obtained in step (i-1) to prepare a slurry A2.
• the alkali metal may be lithium, sodium, potassium, rubidium, Cesium is an example, and it is preferable that the element contains at least one selected from the group consisting of potassium and cesium, and it is more preferable that the element contains cesium.
• an organic carboxylic acid is mixed with the slurry A2 obtained in the step (i-2) to prepare a slurry A.
• the pH of the resulting slurry A is preferably 1.1 to 2.0, more preferably 1.3 to 2.0. This allows the production of a heteropolyacid suitable for the production of an ⁇ , ⁇ -unsaturated carboxylic acid.
• the pH of the slurry A is adjusted to the above range by, for example, using molybdenum trioxide as a molybdenum raw material, or by appropriately selecting a raw material compound to adjust the content of nitrate ions or oxalate ions.
• the pH of the slurry A can be measured using a commercially available pH meter.
• vanadium when vanadium is present on the solid phase side of the slurry A so as to obtain the specified M2/M1, vanadium is suitably distributed in the heteropolyacid formed in the solid phase, forming a chemical structure suitable for the production of methacrylic acid. Therefore, it is considered that a catalyst with a high methacrylic acid selectivity can be obtained.
• the lower limit of M2/M1 is more preferably 1.4 or more, and the upper limit is more preferably 3.5 or less.
• Preferred ranges of M2/M1 include 0 to 7.5, 0.5 to 7.5, 0 to 3.5, 0.5 to 3.5, 1.4 to 7.5, and 1.4 to 3.5.
• the ratio M2/M1 can be adjusted, for example, by changing the amount of the organic carboxylic acid used. By increasing the amount of the organic carboxylic acid used, the ratio M2/M1 tends to decrease.
• the vanadium concentration in the liquid phase of slurry A is preferably 0.005 to 0.1 mass% from the viewpoint of methacrylic acid selectivity.
• the vanadium concentration in the liquid phase of slurry A is more preferably 0.01 to 0.08 mass%.
• Methods for adjusting the vanadium concentration in the liquid phase of slurry A include, for example, changing the amount of the organic carboxylic acid used and changing the pH of slurry A. By increasing the amount of the organic carboxylic acid used or lowering the pH of slurry A, the vanadium concentration in the liquid phase of slurry A tends to decrease.
• the number of moles and molar concentration of each element in the liquid phase of Slurry A are values determined by elemental analysis of the liquid phase of Slurry A using ICP atomic emission spectrometry.
• the number of moles of each element in the solid phase of Slurry A is the value obtained by subtracting the number of moles of each element in the liquid phase determined by ICP atomic emission spectrometry from the amount of each raw material charged.
• step (ii) the slurry A obtained in step (i) is dried to obtain a dried product.
• the method for drying the slurry A includes a method of drying using a box dryer, a method of drying using a spray dryer, a method of drying using a slurry dryer, a method of drying using a drum dryer, and a method of pulverizing the lumpy solid obtained by evaporation to dryness.
• the drying conditions there is no particular limitation on the drying conditions, and for example, when using a box dryer, it is preferable to dry at a temperature of 30 to 150 ° C. Furthermore, when using a spray dryer, it is preferable to set the inlet temperature to 100 to 500 ° C. and the outlet temperature to 100 to 300 ° C.
• the drying is preferably carried out so that the moisture content of the resulting dried product is 4.5% by mass or less, and more preferably 0.1 to 4.5% by mass.
• the dried product obtained in step (ii) may be molded as described below, if necessary.
• the molding step the dried product obtained in the step (ii) is molded as necessary.
• the molding may be performed after the step (iii) described below.
• the molding method is not particularly limited, and known dry and wet molding methods can be applied, such as tablet molding, press molding, extrusion molding, and granulation molding.
• the shape of the molded product is not particularly limited, and examples include cylindrical, ring-like, and spherical shapes.
• a carrier is used, the carrier is not particularly limited, but silica is preferred.
• Step (iii)> the dried product obtained in the step (ii) or the shaped dried product obtained in the shaping step is fired to obtain a fired product.
• the calcination can be carried out under a flow of at least one of an oxygen-containing gas such as air and an inert gas, and it is preferable to carry out the calcination under a flow of an oxygen-containing gas such as air.
• an oxygen-containing gas such as air
• the inert gas refers to a gas that does not reduce the catalytic activity, and examples of such gas include nitrogen, carbon dioxide, helium, and argon. These may be used alone or in combination of two or more.
• the shape of the firing vessel is not particularly limited, but a box-shaped, tubular, or other vessel can be used.
• the mixture can be divided and filled into multiple vessels and fired. Among them, it is preferable to use a tubular vessel with a cross-sectional area of 1 to 100 cm2 .
• the firing temperature (maximum temperature during firing) is preferably 200 to 700°C, and more preferably 320 to 450°C.
• the calcined product obtained in the above manner can be used as a catalyst for producing methacrylic acid.
• the calcined product may also be molded as described in the molding step.
• the calcined product and the calcined product after molding are collectively referred to as the catalyst.
• methacrolein is oxidized using the catalyst for producing methacrylic acid produced by the production method according to the present embodiment. According to these methods, methacrylic acid can be produced in high yield.
• the method for producing methacrylic acid according to this embodiment can be carried out by contacting a catalyst for producing methacrylic acid produced by the production method according to this embodiment with a raw material gas containing methacrolein.
• a fixed-bed type reactor can be used for this reaction.
• the reactor is filled with the catalyst, and the raw material gas is supplied to the reactor to carry out the reaction.
• the catalyst layer may be a single layer, or multiple catalysts with different activities may be packed separately in multiple layers. Also, the catalyst may be diluted with an inert carrier and packed to control activity.
• the methacrolein concentration in the raw material gas is preferably 1 to 20% by volume, more preferably 3 to 10% by volume.
• the raw material methacrolein may contain small amounts of impurities such as lower saturated aldehydes that do not substantially affect this reaction.
• the oxygen source for the raw gas is not particularly limited, but it is industrially advantageous to use air. If necessary, a gas in which pure oxygen is mixed with air or the like can also be used.
• the ratio of oxygen in the raw gas is not particularly limited, but is preferably 0.4 to 4 moles per mole of methacrolein, and more preferably 0.5 to 3 moles.
• the raw material gas may be diluted with an inert gas such as nitrogen or carbon dioxide gas from an economical point of view. Furthermore, water vapor may be added to the raw material gas. By carrying out the reaction in the presence of water vapor, methacrylic acid can be obtained in a higher yield.
• concentration of water vapor in the raw material gas is preferably 0.1 to 50% by volume, more preferably 1 to 40% by volume.
• the contact time between the raw material gas and the catalyst for producing methacrylic acid is preferably 1.5 to 15 seconds, more preferably 2 to 10 seconds.
• the reaction pressure is preferably 0.1 to 1 MPa (G), where (G) means gauge pressure.
• the reaction temperature is preferably 200 to 450°C, more preferably 250 to 400°C.
• the position of the catalyst in the reactor and the proportion of the catalyst in the reactor are not particularly limited, and commonly used forms can be applied.
• the methacrylic acid produced by the method for producing the methacrylic acid ester according to the present embodiment is esterified. That is, the method for producing a methacrylic acid ester according to the present embodiment includes a step of producing methacrylic acid by the method for producing the methacrylic acid ester according to the present embodiment and a step of esterifying the methacrylic acid.
• the alcohol to be reacted with methacrylic acid is not particularly limited, and examples thereof include methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol.
• examples of the methacrylic acid ester obtained include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, and isobutyl methacrylate.
• the esterification reaction can be carried out in the presence of an acid catalyst such as a sulfonic acid type cation exchange resin.
• the temperature during the esterification reaction is preferably 50 to 200°C.
• the pressure during the esterification reaction, the position of the catalyst in the reactor, the proportion of the catalyst in the reactor, etc. are not particularly limited, and commonly used forms can be applied.
• Catalyst composition ratio The molar ratio of each component was determined by dissolving the catalyst in ammonia water and subjecting the resulting solution to elemental analysis by ICP emission spectrometry.
• Methacrylic acid selectivity (%) (N3/N2) x 100
• N1 is the number of moles of methacrolein supplied
• N2 is the number of moles of methacrolein reacted
• N3 is the number of moles of methacrylic acid produced.
• pH of slurry A The pH of the slurry A was measured using a portable pH meter LAQUAact D-71 manufactured by HORIBA.
• Example 1 300 parts of molybdenum trioxide, 10.2 parts of ammonium metavanadate, a dilution of 30.0 parts of 85% by mass phosphoric acid aqueous solution with 36 parts of pure water, and a solution of 6.3 parts of copper (II) nitrate trihydrate dissolved in 9.0 parts of pure water were mixed into 1200 parts of room temperature pure water. Then, 13.5 parts of oxalic acid dihydrate were mixed so that the carboxyl group was 0.10 mole per mole of molybdenum. The obtained slurry was heated to 95°C at 2°C/min and stirred for 2 hours to obtain slurry A1.
• the obtained slurry A1 was mixed with a solution of 40.4 parts of cesium bicarbonate dissolved in 60 parts of pure water at room temperature, and stirred for 15 minutes at 95° C. Then, a solution of 27.5 parts of ammonium carbonate dissolved in 78 parts of pure water was mixed with the solution, and stirred for 15 minutes at 95° C. to obtain a slurry A.
• the pH of the slurry A was 1.65.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the obtained slurry A was evaporated to dryness, and the obtained solid mass was pulverized to obtain a dry product.
• the resulting dried product was calcined at 380° C. for 5 hours in an air stream to obtain a catalyst, which had a composition excluding oxygen of P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• the obtained catalyst was diluted to a weight ratio of catalyst to silicon carbide of 4:5, and packed into a fixed-bed reactor.
• a raw material gas consisting of 5% methacrolein by volume, 10% oxygen by volume, 30% steam by volume, and 55% nitrogen by volume was passed through the reactor at a contact time of 178 h ⁇ g/mol, and the oxidation reaction of methacrolein was carried out at a reaction temperature of 300° C.
• the amount of catalyst packed was adjusted so that the conversion rate of methacrolein in the oxidation reaction was 70%.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 2 A catalyst was obtained in the same manner as in Example 1, except that the amount of oxalic acid dihydrate was 21.0 parts.
• the pH of the slurry A was 1.43.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the charged amount of water. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 3 A catalyst was obtained in the same manner as in Example 1, except that the amount of oxalic acid dihydrate was 30.0 parts.
• the pH of the slurry A was 1.25.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 4 300 parts of molybdenum trioxide, 10.2 parts of ammonium metavanadate, a dilution of 30.0 parts of an 85% by mass aqueous phosphoric acid solution with 36 parts of pure water, and a solution of 6.3 parts of copper (II) nitrate trihydrate in 9.0 parts of pure water were mixed into 1200 parts of room temperature pure water.
• the resulting slurry was heated to 95° C. at 2° C./min and stirred for 2 hours to obtain slurry A1.
• the obtained slurry A1 was mixed with a solution of 40.4 parts of cesium bicarbonate in 60 parts of pure water at room temperature, and stirred for 15 minutes at 95° C.
• a solution of 27.5 parts of ammonium carbonate in 78 parts of pure water was mixed with the mixture, and stirred for 15 minutes at 95° C. to obtain a slurry A2.
• the obtained slurry A2 was mixed with 6.0 parts of oxalic acid dihydrate so that the carboxyl group was 0.05 mol per mol of molybdenum, and the mixture was stirred for 15 minutes to obtain a slurry A.
• the pH of the slurry A was 1.71.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the resulting slurry A was dried and calcined in the same manner as in Example 1 to obtain a catalyst.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 5 A catalyst was obtained in the same manner as in Example 4, except that the amount of oxalic acid dihydrate was 3.4 parts.
• the pH of the slurry A was 1.56.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the charged amount of water. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 6 A catalyst was obtained in the same manner as in Example 4, except that the amount of oxalic acid dihydrate was 13.5 parts.
• the pH of the slurry A was 1.53.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 7 A catalyst was obtained in the same manner as in Example 4, except that the amount of oxalic acid dihydrate was 21.0.
• the pH of the slurry A was 1.47.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 8 A catalyst was obtained in the same manner as in Example 1, except that the amount of ammonium metavanadate was 11.2 parts.
• the pH of the slurry A was 1.47.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.55 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 9 A catalyst was obtained in the same manner as in Example 1, except that the amount of ammonium metavanadate was 12.2 parts.
• the pH of the slurry A was 1.49.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.6 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• Example 10 A catalyst was obtained in the same manner as in Example 1, except that the amount of ammonium carbonate was 24.8 parts.
• the pH of the slurry A was 1.30.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• slurry A1 was obtained in the same manner as in Example 4. The obtained slurry was mixed with a solution of 40.4 parts of cesium bicarbonate in 60 parts of pure water at room temperature, and stirred for 15 minutes at 95° C. Then, a solution of 36.3 parts of ammonium carbonate in 78 parts of pure water was mixed with the slurry, and stirred for 15 minutes at 95° C. to obtain Slurry A.
• the pH of Slurry A was 2.43.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the resulting slurry A was dried and calcined in the same manner as in Example 1 to obtain a catalyst.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• slurry A1 was obtained in the same manner as in Example 4. The obtained slurry was mixed with a solution of 40.4 parts of cesium bicarbonate in 60 parts of pure water at room temperature, and stirred for 15 minutes at 95° C. Then, a solution of 40.7 parts of ammonium carbonate in 78 parts of pure water was mixed with the obtained slurry, and stirred for 15 minutes at 95° C. to obtain Slurry A.
• the pH of Slurry A was 2.91.
• the vanadium concentration and M2/M1 were calculated from the elemental analysis results of the obtained slurry A and the amount of water added. The results are shown in Table 1.
• the resulting slurry A was dried and calcined in the same manner as in Example 1 to obtain a catalyst.
• the composition of the catalyst excluding oxygen was P 1.5 Mo 12 V 0.5 Cu 0.15 Cs 1.2 .
• an oxidation reaction of methacrolein was carried out in the same manner as in Example 1.
• the results of the methacrylic acid selectivity are shown in Table 1.
• the present invention provides a method for producing a catalyst capable of producing methacrylic acid with high selectivity by oxidizing methacrolein, and a method for producing methacrylic acid using the catalyst.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=93256378

Family Applications (1)

Country Status (2)

Citations (6)

• 2024
  • 2024-04-22 JP JP2025516798A patent/JPWO2024225230A1/ja active Pending
  • 2024-04-22 WO PCT/JP2024/015757 patent/WO2024225230A1/ja not_active Ceased

Patent Citations (6)

Also Published As

Similar Documents

Legal Events