Abstract: An object of the present invention is to suppress performance deterioration of a molybdenum composite oxide-based catalyst at the time of performing gas-phase catalytic partial oxidation with molecular oxygen by using a tubular reactor. The present invention relates to a catalytic oxidation method using a tubular reactor in which a Mo compound layer containing a Mo compound and a composite oxide catalyst layer containing a Mo composite oxide catalyst are arranged in this order from a reaction raw material supply port side and under a flow of a mixed gas containing 75 vol % of air and 25 vol % of water vapor at 440° C., a Mo sublimation amount of the Mo compound is larger than a Mo sublimation amount of the Mo composite oxide catalyst under the same conditions.

Abstract: An object of the present invention is to suppress performance deterioration of a molybdenum composite oxide-based catalyst at the time of performing gas-phase catalytic partial oxidation with molecular oxygen by using a tubular reactor. The present invention relates to a catalytic oxidation method using a tubular reactor in which a Mo compound layer containing a Mo compound and a composite oxide catalyst layer containing a Mo composite oxide catalyst are arranged in this order from a reaction raw material supply port side and under a flow of a mixed gas containing 75 vol % of air and 25 vol % of water vapor at 440° C., a Mo sublimation amount of the Mo compound is larger than a Mo sublimation amount of the Mo composite oxide catalyst under the same conditions.

Abstract: The invention is concerned with a method for producing a conjugated diene including a reaction step of subjecting a raw material gas containing a monoolefin having a carbon atom number of 4 or more to an oxidative dehydrogenation reaction with a gas containing molecular oxygen in the presence of a catalyst, to obtain a reaction product gas containing a conjugated diene; and a cooling step of cooling the reaction product gas, wherein in the cooling step, a cooling agent is supplied into a cooling column and brought into contact with the reaction product gas; the cooling agent discharged from the cooling column is then cooled by a heat exchanger; a precipitate dissolved in the cooling agent is precipitated within the heat exchanger and recovered; and the cooling agent from which the precipitate has been recovered is circulated into the cooling column.

Abstract: The invention is concerned with a method for producing a conjugated diene including a reaction step of subjecting a raw material gas containing a monoolefin having a carbon atom number of 4 or more to an oxidative dehydrogenation reaction with a gas containing molecular oxygen in the presence of a catalyst, to obtain a reaction product gas containing a conjugated diene; and a cooling step of cooling the reaction product gas, wherein in the cooling step, a cooling agent is supplied into a cooling column and brought into contact with the reaction product gas; the cooling agent discharged from the cooling column is then cooled by a heat exchanger; a precipitate dissolved in the cooling agent is precipitated within the heat exchanger and recovered; and the cooling agent from which the precipitate has been recovered is circulated into the cooling column.

Abstract: Disclosed is a method for producing a conjugated diene by subjecting a monoolefin having a carbon atom number of 4 or more and an oxygen gas to an oxidative dehydrogenation reaction by using a molybdenum-containing metal oxide catalyst under heat removal with a coolant, wherein an amount of molybdenum adhered onto a cooling heat transfer surface within a reactor is kept at not more than 20 mg/m2, or not only a surface roughness Ra of a cooling heat transfer surface within a reactor is not more than 3 ?m, but a temperature difference between a reaction temperature and a coolant temperature is in the range of from 5 to 220° C.

Abstract: Disclosed is a method for producing a conjugated diene by subjecting a monoolefin having a carbon atom number of 4 or more and an oxygen gas to an oxidative dehydrogenation reaction by using a molybdenum-containing metal oxide catalyst under heat removal with a coolant, wherein an amount of molybdenum adhered onto a cooling heat transfer surface within a reactor is kept at not more than 20 mg/m2, or not only a surface roughness Ra of a cooling heat transfer surface within a reactor is not more than 3 ?m, but a temperature difference between a reaction temperature and a coolant temperature is in the range of from 5 to 220° C.