An object of the present invention is to provide a method for production of a high purity conjugated diolefin. The method for production of a conjugated diolefin of the present invention comprises steps of supplying a source gas containing a C4 or higher monoolefin and an oxygen-containing gas into a reactor, bringing a catalyst into contact with the gas mixture, compressing a gas containing a conjugated diolefin produced by an oxidative dehydrogenation reaction to obtain a liquefied gas and rinsing the liquefied gas with water.

An object of the present invention is to provide a method for production of a high purity conjugated diolefin. The method for production of a conjugated diolefin of the present invention comprises steps of supplying a source gas containing a C4 or higher monoolefin and an oxygen-containing gas into a reactor, bringing a catalyst into contact with the gas mixture, compressing a gas containing a conjugated diolefin produced by an oxidative dehydrogenation reaction to obtain a liquefied gas and rinsing the liquefied gas with water.

A method for producing a catalyst according to the present invention includes: a preparation step of preparing a precursor slurry comprising molybdenum, bismuth, iron, silica, and a carboxylic acid; a drying step of spray-drying the precursor slurry and thereby obtaining a dried particle; and a calcination step of calcining the dried particle, wherein the preparation step comprises: a step (I) of mixing a starting material for silica with the carboxylic acid and thereby preparing a silica-carboxylic acid mixed liquid; and a step (II) of mixing the silica-carboxylic acid mixed liquid, molybdenum, bismuth, and iron.

A method for producing a catalyst according to the present invention includes: a preparation step of preparing a precursor slurry comprising molybdenum, bismuth, iron, silica, and a carboxylic acid; a drying step of spray-drying the precursor slurry and thereby obtaining a dried particle; and a calcination step of calcining the dried particle, wherein the preparation step comprises: a step (I) of mixing a starting material for silica with the carboxylic acid and thereby preparing a silica-carboxylic acid mixed liquid; and a step (II) of mixing the silica-carboxylic acid mixed liquid, molybdenum, bismuth, and iron.

A method for producing a catalyst according to the present invention includes: a preparation step of preparing a precursor slurry comprising molybdenum, bismuth, iron, silica, and a carboxylic acid; a drying step of spray-drying the precursor slurry and thereby obtaining a dried particle; and a calcination step of calcining the dried particle, wherein the preparation step comprises: a step (I) of mixing a starting material for silica with the carboxylic acid and thereby preparing a silica-carboxylic acid mixed liquid; and a step (II) of mixing the silica-carboxylic acid mixed liquid, molybdenum, bismuth, and iron.

A method for producing a catalyst according to the present invention includes: a preparation step of preparing a precursor slurry comprising molybdenum, bismuth, iron, silica, and a carboxylic acid; a drying step of spray-drying the precursor slurry and thereby obtaining a dried particle; and a calcination step of calcining the dried particle, wherein the preparation step comprises: a step (I) of mixing a starting material for silica with the carboxylic acid and thereby preparing a silica-carboxylic acid mixed liquid; and a step (II) of mixing the silica-carboxylic acid mixed liquid, molybdenum, bismuth, and iron.

A method for producing an ammoxidation catalyst, the method including: a step (i) of preparing a starting material slurry comprising molybdenum, bismuth, iron, and a carboxylic acid compound; a step (ii) of stirring the starting material slurry in a temperature range of 30 to 50 C. for 20 minutes to 8 hours, thereby preparing a precursor slurry; a step of spray-drying the precursor slurry, thereby obtaining a dried particle; and a step of calcining the dried particle.

A method for producing an ammoxidation catalyst, the method including: a step (i) of preparing a starting material slurry comprising molybdenum, bismuth, iron, and a carboxylic acid compound; a step (ii) of stirring the starting material slurry in a temperature range of 30 to 50 C. for 20 minutes to 8 hours, thereby preparing a precursor slurry; a step of spray-drying the precursor slurry, thereby obtaining a dried particle; and a step of calcining the dried particle.

A method for producing an ammoxidation catalyst, comprising: a step of preparing a precursor slurry that is a precursor of the catalyst; a drying step of obtaining a dry particle from the precursor slurry; and a calcination step of calcining the dry particle, wherein the step of preparing the precursor slurry is a step of mixing a first solution or slurry having a first pH and a second solution or slurry to obtain a solution or slurry having a second pH after completion of mixing, a time during which a pH of a mixture passes through a particular range having an upper limit and a lower limit while the second solution or slurry is mixed is 1-70 seconds, he upper limit and the lower limit being designated as a third pH and a fourth pH respectively, and the third pH and the fourth pH are set between the first pH and the second pH.

A method for producing an ammoxidation catalyst, comprising: a step of preparing a precursor slurry that is a precursor of the catalyst; a drying step of obtaining a dry particle from the precursor slurry; and a calcination step of calcining the dry particle, wherein the step of preparing the precursor slurry is a step of mixing a first solution or slurry having a first pH and a second solution or slurry to obtain a solution or slurry having a second pH after completion of mixing, a time during which a pH of a mixture passes through a particular range having an upper limit and a lower limit while the second solution or slurry is mixed is 1-70 seconds, he upper limit and the lower limit being designated as a third pH and a fourth pH respectively, and the third pH and the fourth pH are set between the first pH and the second pH.