Abstract: A method for producing fluorenone including a pretreatment step of heating fluorene in the presence of a lower aliphatic carboxylic acid, a bromine compound, and a metal catalyst, and an oxidation step of continuously supplying fluorene and oxygen to perform an oxidation reaction, in the order indicated.

Abstract: Provided is a method for producing fluorenone comprising an oxidation step of oxidizing fluorene in the presence of an aliphatic carboxylic acid having 2 to 3 carbon atoms, a metal catalyst, a bromine compound, and oxygen, a solvent removal step of removing the aliphatic carboxylic acid, a heating step at 120 to 350° C., and a distillation step in the order indicated.

Abstract: Disclosed herein is a method for producing high-purity terephthalic acid, including steps of dissolving crude terephthalic acid crystal in water and performing catalytic hydrogenation treatment, depressurizing and cooling a reaction liquid after the catalytic hydrogenation treatment in stages with two or more stages of crystallization vessels, to crystallize terephthalic acid to obtain a terephthalic acid slurry, introducing the terephthalic acid slurry into an upper portion of a mother liquor replacement tower, bringing the terephthalic acid crystal into contact with an upward flow of replacement water introduced from a tower lower compartment of the mother liquor replacement tower while making the terephthalic acid crystal settled down in the tower, withdrawing the terephthalic acid crystal as slurry with the replacement water from the tower lower compartment, subjecting the slurry withdrawn from the tower lower compartment to solid-liquid separation into water and the terephthalic acid crystal, and drying

Abstract: A method of terephthalic acid production in which slurry of crude terephthalic acid obtained through liquid-phase oxidation of a p-phenylene compound or a terephthalic acid slurry resulting from catalytic hydrogenation of the crude terephthalic acid is introduced into an upper part of a dispersion medium replacement tower while a second dispersion medium for replacement is introduced from a lower part of the dispersion medium replacement tower to perform dispersion medium replacement. The method is capable of enabling the dispersion medium replacement tower to continue stable operation while maintaining an extremely high efficiency of dispersion medium replacement.

Abstract: A method for producing high-purity terephthalic acid, comprising following steps (a) to (e): (a) a step of obtaining a crude terephthalic acid crystal by liquid-phase oxidizing a p-phenylene compound, (b) a step of dissolving the crude terephthalic acid crystal in water and then subjecting to catalytic hydrogenation treatment, (c) a step of depressurizing and cooling a reaction liquid after the catalytic hydrogenation treatment in stages with two or more stages of crystallization vessels, to crystallize terephthalic acid to obtain a terephthalic acid slurry, (d) a step of introducing the terephthalic acid slurry into an upper portion of a mother liquor replacement tower, bringing the terephthalic acid crystal into contact with an upward flow of replacement water introduced from a tower lower compartment of the mother liquor replacement tower while making the terephthalic acid crystal settled down in the tower, and withdrawing the terephthalic acid crystal as slurry with the replacement water from the tower

Abstract: A method of terephthalic acid production in which slurry of crude terephthalic acid obtained through liquid-phase oxidation of a p-phenylene compound or a terephthalic acid slurry resulting from catalytic hydrogenation of the crude terephthalic acid is introduced into an upper part of a dispersion medium replacement tower while a second dispersion medium for replacement is introduced from a lower part of the dispersion medium replacement tower to perform dispersion medium replacement. The method is capable of enabling the dispersion medium replacement tower to continue stable operation while maintaining an extremely high efficiency of dispersion medium replacement.

Abstract: A method for producing high-purity terephthalic acid, comprising following steps (a) to (c): the step (a); obtaining crude terephthalic acid crystal by liquid phase-oxidizing a p-phenylene compound; the step (b); obtaining a terephthalic acid crystal slurry by a catalytic hydrogenation treatment of the crude terephthalic acid crystal; and the step (c); introducing the terephthalic acid crystal slurry into an upper portion of a mother liquor replacement tower, and bringing the slurry into contact with an upward flow of replacement water introduced from a bottom portion of the mother liquor replacement tower while making the terephthalic acid crystal settled down in the tower, and extracting the terephthalic acid crystal as a slurry with the replacement water from the tower bottom portion, wherein (1) a stirring blade unit is disposed in a slurry layer in the bottom portion of the mother liquor replacement tower, and fluidity of the slurry layer is maintained by rotating the stirring blade unit in such a way

Abstract: A method for producing high-purity terephthalic acid, comprising following steps (a) to (c): the step (a); obtaining crude terephthalic acid crystal by liquid phase-oxidizing a p-phenylene compound; the step (b); obtaining a terephthalic acid crystal slurry by a catalytic hydrogenation treatment of the crude terephthalic acid crystal; and the step (c); introducing the terephthalic acid crystal slurry into an upper portion of a mother liquor replacement tower, and bringing the slurry into contact with an upward flow of replacement water introduced from a bottom portion of the mother liquor replacement tower while making the terephthalic acid crystal settled down in the tower, and extracting the terephthalic acid crystal as a slurry with the replacement water from the tower bottom portion, wherein (1) a stirring blade unit is disposed in a slurry layer in the bottom portion of the mother liquor replacement tower, and fluidity of the slurry layer is maintained by rotating the stirring blade unit in such a way

Abstract: The present invention can provide a 1,3-bis(hydroxyphenyl)-5-ethyladamantane compound represented by Formula (1) below and a method for producing the same, as well as an aromatic polycarbonate resin comprising said compound and a method for producing the same. (wherein, R represents an alkyl group with a carbon number of 1-6, a cycloalkyl group with a carbon number of 3-6, or a phenyl group, and n represents an integer of 0-2).