Abstract: The present invention clarifies the characteristic of the hygroscopicity of the catalyst for producing acrylic acid and finds out a relationship between the water amount of the catalyst and the catalytic performance as the catalyst for producing acrylic acid, and provides an excellent catalyst. Provided is a catalyst for producing acrylic acid, which contains molybdenum and vanadium as essential active components, in which the amount of water contained in the catalyst is 0.01 mass % or more and 0.53 mass % or less.

Abstract: A method for producing at least one oxidation product selected from the group consisting of acrolein and acrylic acid is provided. This method can alleviate concerns about deterioration of a gas-phase oxidation catalyst and reaction runaway in a restart period after a shutdown, and can allow the reaction to proceed in a stable state. Using a fixed-bed reactor filled with a gas-phase oxidation catalyst, at least one source gas selected from the group consisting of propylene and acrolein is subjected to a gas-phase contact oxidation reaction while a heating medium is caused to contact with or circulate through the fixed-bed reactor and thereby to heat the fixed-bed reactor. The temperature of the heating medium when the load is maximum in the restart period after the shutdown is controlled to be lower than the temperature of the heating medium when the load is maximum in an initial start-up period.

Abstract: A method for producing at least one oxidation product selected from the group consisting of acrolein and acrylic acid is provided. This method can alleviate concerns about deterioration of a gas-phase oxidation catalyst and reaction runaway in a restart period after a shutdown, and can allow the reaction to proceed in a stable state. Using a fixed-bed reactor filled with a gas-phase oxidation catalyst, at least one source gas selected from the group consisting of propylene and acrolein is subjected to a gas-phase contact oxidation reaction while a heating medium is caused to contact with or circulate through the fixed-bed reactor and thereby to heat the fixed-bed reactor. The temperature of the heating medium when the load is maximum in the restart period after the shutdown is controlled to be lower than the temperature of the heating medium when the load is maximum in an initial start-up period.

Abstract: The present invention clarifies the characteristic of the hygroscopicity of the catalyst for producing acrylic acid and finds out a relationship between the water amount of the catalyst and the catalytic performance as the catalyst for producing acrylic acid, and provides an excellent catalyst. Provided is a catalyst for producing acrylic acid, which contains molybdenum and vanadium as essential active components, in which the amount of water contained in the catalyst is 0.01 mass % or more and 0.53 mass % or less.

Abstract: The present invention relates to a method for producing an unsaturated carboxylic acid using a catalyst having both a high catalytic performance and a high mechanical strength, and in the method, a supported catalyst obtained by feeding a liquid binder component and a catalytic active component containing molybdenum and vanadium and/or a precursor thereof into a rolling granulator and conducting granulation at a relative centrifugal acceleration of 0.5 G or more and 30 G or less is used.

Abstract: Provided is a catalyst having high activity and yield of a target product for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid and further having high mechanical strength. The catalyst is a catalyst prepared by a method in which a catalyst formulation satisfies specified atomic ratios; and in the preparation thereof, a molybdenum component raw material is an ammonium molybdate, a solvent for dissolving the ammonium molybdate is water, a bismuth component raw material is bismuth nitrate, and a solvent for dissolving bismuth nitrate is a nitric acid aqueous solution, and the weight of water for dissolving the ammonium molybdate, the weight of the nitric acid aqueous solution for dissolving the bismuth nitrate, and the acid concentration of the nitric acid aqueous solution are satisfied with specified ranges, respectively.

Abstract: Provided is a method of subjecting an alkene to partial oxidation by using a fixed bed multitubular reactor, thereby producing an unsaturated aldehyde and/or an unsaturated carboxylic acid each corresponding to the alkene, wherein a plurality of catalyst layers formed by N division (N is N?2) with respect to a gas flow direction of a reaction tube are provided, and when a change (° C.) of hot spot temperature per 1° C. change of reaction bath temperature in the catalyst layer is designated as Sn, at least one of the plurality of catalyst layers is regulated to Sn?6.

Abstract: Provided is a method capable of producing acrolein and/or acrylic acid, or methacrolein and/or methacrylic acid, stably in a high yield over a long period of time advantageously even in a high-load reaction, and the method is a method in which when preparing two or more kinds of catalysts having different formulations and stacking two or more layers in the axial direction of the tube, the catalysts are filled in such a manner that not only the component amount of bismuth relative to molybdenum decreases from the gas inlet side toward the gas outlet side, but also the component amount of iron relative to molybdenum increases from the gas inlet side toward the gas outlet side.

Abstract: The present invention relates to a method for producing an unsaturated carboxylic acid using a catalyst having both a high catalytic performance and a high mechanical strength, and in the method, a supported catalyst obtained by feeding a liquid binder component and a catalytic active component containing molybdenum and vanadium and/or a precursor thereof into a rolling granulator and conducting granulation at a relative centrifugal acceleration of 0.5 G or more and 30 G or less is used.

Abstract: Provided is a method of subjecting an alkene to partial oxidation by using a fixed bed multitubular reactor, thereby producing an unsaturated aldehyde and/or an unsaturated carboxylic acid each corresponding to the alkene, wherein a plurality of catalyst layers formed by N division (N is N?2) with respect to a gas flow direction of a reaction tube are provided, and when a change (° C.) of hot spot temperature per 1° C. change of reaction bath temperature in the catalyst layer is designated as Sn, at least one of the plurality of catalyst layers is regulated to Sn?6.

Abstract: Provided is a method capable of producing acrolein and/or acrylic acid, or methacrolein and/or methacrylic acid, stably in a high yield over a long period of time advantageously even in a high-load reaction, and the method is a method in which when preparing two or more kinds of catalysts having different formulations and stacking two or more layers in the axial direction of the tube, the catalysts are filled in such a manner that not only the component amount of bismuth relative to molybdenum decreases from the gas inlet side toward the gas outlet side, but also the component amount of iron relative to molybdenum increases from the gas inlet side toward the gas outlet side.

Abstract: Provided is a catalyst having high activity and yield of a target product for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid and further having high mechanical strength. The catalyst is a catalyst prepared by a method in which a catalyst formulation satisfies specified atomic ratios; and in the preparation thereof, a molybdenum component raw material is an ammonium molybdate, a solvent for dissolving the ammonium molybdate is water, a bismuth component raw material is bismuth nitrate, and a solvent for dissolving bismuth nitrate is a nitric acid aqueous solution, and the weight of water for dissolving the ammonium molybdate, the weight of the nitric acid aqueous solution for dissolving the bismuth nitrate, and the acid concentration of the nitric acid aqueous solution are satisfied with specified ranges, respectively.

Abstract: There is provided a hetero polyacid-based catalyst for methacrylic acid production, which is more excellent in performance, life and moisture absorption during storage, the catalyst being a catalyst for methacrylic acid production, wherein a proton is replaced so as to satisfy conditions of ?=A+(B×C) and 0.5???1.4 when the atomic ratio of the alkali metal atom relative to 10 atoms of Mo is taken as A and the atomic ratio of the copper atom relative to 10 atoms of Mo is taken as B in MoaPbVcCudYeZfOg where Y represents cesium or the like; Z represents iron or the like; and a to g represent each an atomic ratio of each element relative to 10 atoms of Mo.

Abstract: A catalyst and a catalyst packing schedule are designed so that a relation between the raw material conversion rate at which the yield of the objective product becomes maximum and the raw material conversion rate at which a high and low correlation between maximum temperature of the catalyst layer present closest to a reaction gas inlet side Zin and maximum temperature of the catalyst layer present closest to a reaction gas outlet side Zout is reversed satisfies a specific condition of 0.5?Cmax?Ccrs?5, in which Cmax: a raw material conversion rate at which yield of the objective products becomes maximum; and Ccrs: a raw material conversion rate at which, when maximum temperature of the catalyst layer Zin is regarded as Tin, maximum temperature of the catalyst layer Zout is regarded as Tout, and the raw material conversion rate is changed, a high and low correlation between Tin and Tout is reversed.

Abstract: The present invention relates to a method for producing acrylic acid through vapor-phase contact oxidation of acrolein, wherein a reactor tube is divided into at least two catalyst layers, and catalysts having a higher activity are charged in the reactor tube sequentially toward an outlet port side from a material source gas inlet port side for a reaction therein to give acrylic acid, and wherein a catalyst activity-controlling method is a method comprising: a step of mixing a molybdenum-containing compound, a vanadium-containing compound, a copper-containing compound and an antimony-containing compound with water, then drying and calcining a resulting mixture, in which a catalytically-active element composition is kept constant but material source compounds are made to vary in type to give composite metal oxides having a different activity.

Abstract: There is provided a hetero polyacid-based catalyst for methacrylic acid production, which is more excellent in performance, life and moisture absorption during storage, the catalyst being a catalyst for methacrylic acid production, wherein a proton is replaced so as to satisfy conditions of ?=A+(B×C) and 0.5???1.4 when the atomic ratio of the alkali metal atom relative to 10 atoms of Mo is taken as A and the atomic ratio of the copper atom relative to 10 atoms of Mo is taken as B in MoaPbVcCudYeZfOg where Y represents cesium or the like; Z represents iron or the like; and a to g represent each an atomic ratio of each element relative to 10 atoms of Mo.

Abstract: A method for manufacturing a catalyst of which active components are partly neutralized salt of heteropoly acid comprising molybdenum, phosphorus, vanadium, cesium, antimony, and ammonia as essential components, wherein the method is characterized in mixing an antimony compound with a complex oxide of the essential active components in the catalyst containing active components other than antimony, wherein the antimony compound may be added during slurry preparation.

Abstract: There is provided a process for producing aerolein, acrylic acid, methacrolein, methacrylic acid in a safe and steady manner and in high yields, which avoids a phenomenon of occurrence of an abnormal reaction attributable to the fact that the temperature at a raw material gas outlet side becomes considerably higher than the temperature at a raw material gas inlet side, with regard to the temperature of a catalyst packed in a reaction tube at vapor-phase catalytic oxidation of propylene, isobutylene, or the like.

Abstract: An object of the present invention is to provide a process for stably producing a catalyst for methacrylic acid production exhibiting high activity and high performance. The process for producing a catalyst for methacrylic acid production of the invention is characterized in that the water content of the catalyst ingredient powder for use in molding, temperature and humidity of a molding step, humidity and temperature of a baking step are individually controlled in the case where molding is performed by a coating method using an Mo—V—P—Cu-based hetero polyacid as an active ingredient and water or an alcohol and/or an aqueous solution of an alcohol as a binder.

Abstract: The present invention relates to a method for producing acrylic acid through vapor-phase contact oxidation of acrolein, wherein a reactor tube is divided into at least two catalyst layers, and catalysts having a higher activity are charged in the reactor tube sequentially toward an outlet port side from a material source gas inlet port side for a reaction therein to give acrylic acid, and wherein a catalyst activity-controlling method is a method comprising: a step of mixing a molybdenum-containing compound, a vanadium-containing compound, a copper-containing compound and an antimony-containing compound with water, then drying and calcining a resulting mixture, in which a catalytically-active element composition is kept constant but material source compounds are made to vary in type to give composite metal oxides having a different activity.