Abstract: The present invention provides a process for producing acrylic acid from glycerin with a catalyst having a prolonged life. In the process for producing acrylic acid from glycerin, a molar ratio of oxygen to glycerin in a raw material gas is set to be not lower than 0.8 and not higher than 20.

Abstract: The present invention provides a process for producing acrolein, which exhibits a prolonged catalyst life, low energy consumption, and excellent efficiency, and which is earth-conscious, and a glycerin-containing composition which can preferably be used even in this process. The process for producing acrolein is one which includes bringing a raw material gas containing glycerin gas into contact with a solid acid catalyst in a reactor, and the partial pressure of the glycerin gas in the raw material gas is set to be from 0.01 to 30 kPa. The glycerin-containing composition is for use in a process for producing acrolein using a solid catalyst and includes a fatty acid and/or a fatty acid ester, and a total mass of the fatty acid and the fatty acid ester is from 0.001% to 5% by mass, relative to the glycerin.

Abstract: In order to realize, while preventing gelatification of a monomer not yet to be polymerized, a water-absorbent resin which is more stable in color over time and has a significant enhancement in a problem concerning surface color and an excellent absorption property, a method for producing a polyacrylic acid-based water-absorbent resin includes: a preparation step in which a monomer is prepared from acrylic acid including hydroxyacetone in an amount not larger than 300 mass ppm; a polymerization step in which the monomer is polymerized so that a hydrogel is obtained; and a drying step in which the hydrogel is dried. Also, a method of the present invention for producing polyacrylic acid-based water-absorbent resin includes: a preparation step in which a monomer is prepared from acrylic acid; a polymerization step in which the monomer is polymerized in presence of phenol so that a hydrogel is obtained; and a drying step in which the hydrogel is dried.

Abstract: There is provided a process for producing acrolein from glycerin, exhibiting a suppressed decrease in the yield of acrolein with time. In the process for producing acrolein by dehydrating glycerin in the presence of a catalyst containing a metal phosphate, one, or two or more, metal phosphates are used, which are selected from aluminum salts, zirconium salts, manganese salts, alkali metal salts (provided that the alkali metal is sodium, potassium, or cesium, and the ratio between the mole number (M) of the alkali metal and the mole number (P) of phosphoric acid (i.e., M/P ratio) in the metal phosphate is 2.0 or lower), alkali earth metal salts (provided that the ratio between the mole number (M) of the alkali earth metal and the mole number (P) of phosphoric acid (i.e., M/P ratio) in the metal phosphate is 1.0 or lower), and the like.

Abstract: There are provided a process, an apparatus, and an acrolein-containing composition, for producing acrylic acid from the acrolein-containing composition at a high yield. The process for producing acrylic acid includes a refinement step of removing phenol and/or 1-hydroxyacetone from an acrolein-containing composition and an oxidation step of oxidizing acrolein in the acrolein-containing composition after the refinement step to produce acrylic acid, and the apparatus to be used in the process includes a refiner to be used in the refinement step and an oxidation reactor for oxidizing acrolein to produce acrylic acid. The acrolein-containing composition is a composition having a (mass of phenol)/(mass of acrolein) ratio of 0.020 or lower and a (mass of 1-hydroxyacetone)/(mass of acrolein) ratio of 0.020 or lower.

Abstract: The present invention provides a process for producing acrylic acid from glycerin with a catalyst having a prolonged life. In the process for producing acrylic acid from glycerin, a molar ratio of oxygen to glycerin in a raw material gas is set to be not lower than 0.8 and not higher than 20.

Abstract: There is provided a process for producing acrolein from glycerin, exhibiting a suppressed decrease in the yield of acrolein with time. In the process for producing acrolein by dehydrating glycerin in the presence of a catalyst containing a metal phosphate, one, or two or more, metal phosphates are used, which are selected from aluminum salts, zirconium salts, manganese salts, alkali metal salts (provided that the alkali metal is sodium, potassium, or cesium, and the ratio between the mole number (M) of the alkali metal and the mole number (P) of phosphoric acid (i.e., M/P ratio) in the metal phosphate is 2.0 or lower), alkali earth metal salts (provided that the ratio between the mole number (M) of the alkali earth metal and the mole number (P) of phosphoric acid (i.e., M/P ratio) in the metal phosphate is 1.0 or lower), and the like.

Abstract: This invention provides a method of reactivating a catalyst for methacrylic acid production, which catalyst is used in production of methacrylic acid through vapor-phase oxidation of methacrolein or vapor-phase oxidative dehydrogenation of isobutyric acid, contains P and Mo, and exhibits reduced activity. The process comprises treating the catalyst, whose activity level has dropped (deteriorated catalyst), with a gas containing a nitrogen-containing heterocyclic compound (e.g., pyridine, piperidine, piperazine, quinoline).

Abstract: A catalyst useful for catalytic vapor-phase oxidation of isobutylene, t-butanol or propylene to produce respectively corresponding unsaturated aldehyde and unsaturated carboxylic acid is provided. The catalyst consists of ring-formed shaped bodies composed of (i) a catalyst composition containing at least molybdenum and bismuth as the active ingredients and (ii) inorganic fibers. The catalyst excels in mechanical strength, can give the object products at high yield and shows little activity degradation with time.

Abstract: A catalyst suited for catalytic vapor-phase oxidation of isobutylene, t-butanol or propylene to produce respectively corresponding unsaturated aldehyde and unsaturated carboxylic acid is provided. Said catalyst consists of ring-formed shaped bodies composed of (i) a catalyst composition containing at least molybdenum and bismuth as the active ingredients and (ii) inorganic fibers. The catalyst excels in mechanical strength, can give the object products at high yield and shows little activity degradation with time.

Abstract: A catalyst suited for catalytic vapor-phase oxidation of isobutylene, t-butanol or propylene to produce respectively corresponding unsaturated aldehyde and unsaturated carboxylic acid is provided. Said catalyst consists of ring-formed shaped bodies composed of (i) a catalyst composition containing at least molybdenum and bismuth as the active ingredients and (ii) inorganic fibers. The catalyst excels in mechanical strength, can give the object products at high yield and shows little activity degradation with time.

Abstract: This invention provides a method of reactivating a catalyst for methacrylic acid production, which catalyst is used in production of methacrylic acid through vapor-phase oxidation of methacrolein or vapor-phase oxidative dehydrogenation of isobutyric acid, contains P and Mo, and exhibits reduced activity. The process comprises treating the catalyst, whose activity level has dropped (deteriorated catalyst), with a gas containing a nitrogen-containing heterocyclic compound (e.g., pyridine, piperidine, piperazine, quinoline).

Abstract: The invention provides a method for regenerating with high efficiency a deteriorated catalyst of reduced activity, said catalyst originating from a heteropolyacid catalyst containing heteropolyacid formed of molybdophosphoric acid and/or molybdovanadophosphoric acid, or a salt thereof, to a heteropolyacid catalyst which exhibits approximately equivalent activity level to that of the fresh catalyst. Said method comprises mixing a deteriorated catalyst and a nitrogen-containing heterocyclic compound under the conditions whereunder ammonium ions and nitrate anions are present at such ratio that the amount of total ammonium ions per mol of total nitrate anions does not exceed 1.7 mols, drying the mixture and calcining the same.

Abstract: The present invention produces (meth)acrylic acid in a high yield in a process for producing (meth)acrylic acid by subjecting at least one member selected from the group consisting of (meth)acrolein, propane, and isobutane to catalytic gas phase oxidation with molecular oxygen or a molecular-oxygen-containing gas. In addition, the present invention makes it possible to produce (meth)acrylic acid in a high yield and stably for a long time. The present invention provides a process for producing (meth)acrylic acid by catalytic gas phase oxidation reaction, which is characterized by allowing a reaction gas to contain a reducible compound.

Abstract: This invention provides a method of reactivating a catalyst for methacrylic acid production, which catalyst is used in production of methacrylic acid through vapor-phase oxidation of methacrolein or vapor-phase oxidative dehydrogenation of isobutyric acid, contains P and Mo, and exhibits reduced activity. The process comprises treating the catalyst, whose activity level has dropped (deteriorated catalyst), with a gas containing a nitrogen-containing heterocyclic compound (e.g., pyridine, piperidine, piperazine, quinoline).

Abstract: A novel method for preparing a heteropolyacid catalyst containing a heteropolyacid composed of molybdophosphoric acid and/or molybdovanadophosphoric acid, or a salt of the heteropolyacid, is provided. The method comprises preparing an aqueous solution or aqueous dispersion which (1) contains the nitrogen-containing heterocyclic compound, nitrate anions and ammonium ions, (2) the ammonium ion content not exceeding 1.7 mols per mol of the nitrate anion content, and (3) the ammonium ion content not exceeding 10 mols per 12 mols of the molybdenum atom content by mixing raw materials containing the catalyst-constituting elements with the nitrogen-containing heterocyclic compound in the presence of water, drying and calcining the same. This heteropolyacid catalyst excels over conventional catalysts in performance, life and strength.

Abstract: A catalyst suited for catalytic vapor-phase oxidation of isobutylene, t-butanol or propylene to produce respectively corresponding unsaturated aldehyde and unsaturated carboxylic acid is provided. Said catalyst consists of ring-formed shaped bodies composed of (i) a catalyst composition containing at least molybdenum and bismuth as the active ingredients and (ii) inorganic fibers. The catalyst excels in mechanical strength, can give the object products at high yield and shows little activity degradation with time.

Abstract: A novel method for preparing a heteropolyacid catalyst containing a heteropolyacid composed of molybdophosphoric acid and/or molybdovanadophosphoric acid, or a salt of the heteropolyacid, is provided.

Abstract: The present invention produces (meth)acrylic acid in a high yield in a process for producing (meth)acrylic acid by subjecting at least one member selected from the group consisting of (meth)acrolein, propane, and isobutane to catalytic gas phase oxidation with molecular oxygen or a molecular-oxygen-containing gas. In addition, the present invention makes it possible to produce (meth)acrylic acid in a high yield and stably for a long time. The present invention provides a process for producing (meth)acrylic acid by catalytic gas phase oxidation reaction, which is characterized by allowing a reaction gas to contain a reducible compound.

Abstract: A novel method for preparing a heteropolyacid catalyst containing a heteropolyacid composed of molybdophosphoric acid and/or molybdovanadophosphoric acid, or a salt of the heteropolyacid, is provided. The method comprises preparing an aqueous solution or aqueous dispersion which (1) contains the nitrogen-containing heterocyclic compound, nitrate anions and ammonium ions, (2) the ammonium ion content not exceeding 1.7 mols per mol of the nitrate anion content, and (3) the ammonium ion content not exceeding 10 mols per 12 mols of the molybdenum atom content by mixing raw materials containing the catalyst-constituting elements with the nitrogen-containing heterocyclic compound in the presence of water, drying and calcining the same. This heteropolyacid catalyst excels over conventional catalysts in performance, life and strength.