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terephthalic acid crystal as slurry with the replacement water from the tower lower compartment, subjecting the slurry withdrawn from the tower lower compartment to solid-liquid separation into water and the terephthalic acid crystal, and drying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: The invention provides a process for producing xylylenediamine, including supplying a solution of phthalonitrile dissolved in a solvent to a reactor filled with a catalyst and hydrogenating the phthalonitrile to produce xylylenediamine, characterized in that the process includes halting supply of the solution; (2) bringing a washing liquid into contact with the catalyst, the washing liquid having a phthalonitrile content of 3 mass % or less and a xylylenediamine content of 1 mass % or more; and after completion of the contact, resuming supply of the solution, and employing the catalyst continuously in hydrogenation. Through the production process of the invention, the catalyst can be employed continuously for a long period of time, and the catalyst-related cost can be considerably reduced.

Abstract: The invention provides a process for producing xylylenediamine, including supplying a solution of phthalonitrile dissolved in a solvent to a reactor filled with a catalyst and hydrogenating the phthalonitrile to produce xylylenediamine, characterized in that the process includes halting supply of the solution; (2) bringing a washing liquid into contact with the catalyst, the washing liquid having a phthalonitrile content of 3 mass % or less and a xylylenediamine content of 1 mass % or more; and after completion of the contact, resuming supply of the solution, and employing the catalyst continuously in hydrogenation. Through the production process of the invention, the catalyst can be employed continuously for a long period of time, and the catalyst-related cost can be considerably reduced.

Abstract: A method of producing xylylenediamine by a two-stage hydrogenation of a starting phthalonitrile in a solvent. The main steps of the method are a hydrogenation step 1 and a hydrogenation step 2. In the hydrogenation step 1, a solution of the starting phthalonitrile in the solvent containing liquid ammonia is fed to an inlet of a first reaction zone and the hydrogenation is carried out in the first reaction zone in the presence of a heterogeneous catalyst, to hydrogenate nitrile groups in the starting phthalonitrile to aminomethyl groups. A part of the hydrogenation product solution from the first reaction zone is circulated to the inlet of the first reaction zone and the rest is introduced into the hydrogenation step 2 where further undergoes the hydrogenation.

Abstract: Provided is a production process for a carbonized product characterized by comprising the following steps (a) to (b): (a) a step in which metal-made or ceramic-made plural granular matters are charged into a heat treating apparatus which is maintained at a temperature of 400° C. or higher and 700° C. or lower and allowed to move therein and in which a carbonized product precursor is fed into the above apparatus and subjected to heat treatment, whereby the carbonized product is adhered on the surface of the above granular matters and (b) a step in which the carbonized product adhered on the surface of the granular matters is heated at a higher temperature than the heat treating temperature in the step (a) and 900° C. or lower, whereby the carbonized product is separated from the granular matters. The present invention provides a production process for an inexpensive and useful carbonized product by simple apparatus and steps.

Abstract: A method of producing xylylenediamine by a two-stage hydrogenation of a starting phthalonitrile in a solvent. The main steps of the method are a hydrogenation step 1 and a hydrogenation step 2. In the hydrogenation step 1, a solution of the starting phthalonitrile in the solvent containing liquid ammonia is fed to an inlet of a first reaction zone and the hydrogenation is carried out in the first reaction zone in the presence of a heterogeneous catalyst, to hydrogenate nitrile groups in the starting phthalonitrile to aminomethyl groups. A part of the hydrogenation product solution from the first reaction zone is circulated to the inlet of the first reaction zone and the rest is introduced into the hydrogenation step 2 where further undergoes the hydrogenation.

Abstract: Provided is a production process for a carbonized product characterized by comprising the following steps (a) to (b): (a) a step in which metal-made or ceramic-made plural granular matters are charged into a heat treating apparatus which is maintained at a temperature of 400° C. or higher and 700° C. or lower and allowed to move therein and in which a carbonized product precursor is fed into the above apparatus and subjected to heat treatment, whereby the carbonized product is adhered on the surface of the above granular matters and (b) a step in which the carbonized product adhered on the surface of the granular matters is heated at a higher temperature than the heat treating temperature in the step (a) and 900° C. or lower, whereby the carbonized product is separated from the granular matters. The present invention provides a production process for an inexpensive and useful carbonized product by simple apparatus and steps.

Abstract: A carbon material for an electric double layer capacitor in which a ratio of hydrogen atoms to carbon atoms, H/C, is not less than 0.2 and a true specific gravity is not less than 1.50 g/ml, is provided. Furthermore, a process for production of an activated carbon for an electric double layer capacitor in which a carbon material having a ratio of hydrogen atoms to carbon atoms, H/C, not less than 0.2, and a true specific gravity not less than 1.5 g/ml is activated, is provided.

Abstract: A process for producing a high purity aromatic polycarboxylic acid by purifying a crude aromatic polycarboxylic acid in accordance with the steps of (I) forming an amine salt of an aromatic polycarboxylic acid from the crude polycarboxylic acid and an amine, (II) continuously decomposing the salt in a salt decomposition reactor in operations of (i) supplying an aqueous solution of the amine salt of an organic polycarboxylic acid formed in the step of forming a salt, (ii) removing the amine and water by distillation under heating and (iii) taking out a slurry containing crystallized aromatic polycarboxylic acid, and (III) separating and recovering crystals of the aromatic polycarboxylic acid from the slurry which is taken out in the step of decomposing the salt.

Abstract: A process for producing a high purity aromatic polycarboxylic acid by purifying a crude aromatic polycarboxylic acid in accordance with the steps of (I) forming an amine salt of an aromatic polycarboxylic acid from the crude polycarboxylic acid and an amine, (II) continuously decomposing the salt in a salt decomposition reactor in operations of (i) supplying an aqueous solution of the amine salt of an organic polycarboxylic acid formed in the step of forming a salt, (ii) removing the amine and water by distillation under heating and (iii) taking out a slurry containing crystallized aromatic polycarboxylic acid, and (III) separating and recovering crystals of the aromatic polycarboxylic acid from the slurry which is taken out in the step of decomposing the salt.

Abstract: A process for producing a high purity aromatic polycarboxylic acid by purify a crude aromatic polycarboxylic acid in accordance with the steps of (I) forming an amine salt of an aromatic polycarboxylic acid from the crude polycarboxylic acid and an amine, (II) continuously decomposing the salt in a salt decomposition reactor in operations of (i) supplying an aqueous solution of the amine salt of an organic polycarboxylic acid formed in the step of forming a salt, (ii) removing the amine and water by distillation under heating and (iii) taking out a slurry containing crystallized aromatic polycarboxylic acid, and (III) separating and recovering crystals of the aromatic polycarboxylic acid from the slurry which is taken out in the step of decomposing the salt.

Abstract: Highly pure, less colored aromatic polycarboxylic acids are produced from crude aromatic polycarboxylic acids by simple procedures at low production costs. The crude aromatic polycarboxylic acid is mixed with aliphatic amine or alicyclic amine in the presence of a solvent to precipitate crystals of amine salt of aromatic polycarboxylic acid. The crystals are dissolved in water and decomposed, thereby obtaining the highly pure aromatic polycarboxylic acids.

Abstract: A process for producing a high purity aromatic polycarboxylic acid by purifying a crude aromatic polycarboxylic acid in accordance with the steps of (I) forming an amine salt of an aromatic polycarboxylic acid from the crude polycarboxylic acid and an amine, (II) continuously decomposing the salt in a salt decomposition reactor in operations of (i) supplying an aqueous solution of the amine salt of an organic polycarboxylic acid formed in the step of forming a salt, (ii) removing the amine and water by distillation under heating and (iii) taking out a slurry containing crystallized aromatic polycarboxylic acid, and (III) separating and recovering crystals of the aromatic polycarboxylic acid from the slurry which is taken out in the step of decomposing the salt.

Abstract: There are disclosed an industrially advantageous process for efficiently producing highly pure 2,6-dimethylnaphthalene (DMN) in high yield from a mixture of DMN by carrying out in turn, the steps of isomerizing a mixture of DMN in the presence of a catalyst; crystallizing the isomerization reaction product in the presence of a solvent (e.g.

Abstract: A process for producing highly pure 2,6-dimethylnaphthalene in a high yield from a mixture of dimethylnaphthalene isomers in the presence of a solvent, such as an aliphatic or alicyclic saturated hydrocarbon. Highly pure 2,6-dimethylnaphthalene can be produced steadily for a long time by filtering the 2,6-dimethylnaphthalene crystal precipitated by the crystallizing by using a filtration apparatus, such as a rotary vacuum filter, peeling-off the filtered cake from a filter cloth and cleaning the filter cloth with a solvent, at a temperature not lower than a filtration temperature.

Abstract: A process for producing a high-purity naphthalenedicarboxylic acid having an improved hue or an excellent hue from a crude naphthalenedicarboxylic acid obtained by the oxidation of dialkyl naphthalene, industrially advantageously at high yields, which comprises dissolving a crude naphthalenedicarboxylic acid obtained by the oxidation of dialkyl naphthalene in an aqueous solution containing an aliphatic amine, an alicyclic amine or acetonitrile, removing heavy metal components contained as impurities until the content of the heavy metal components based on the crude naphthalenedicarboxylic acid is 100 ppm or less, and heating the aqueous solution containing a naphthalenedicarboxylic acid amine salt to distill off the amine.

Abstract: There is disclosed a method for isomerizing dimethylnaphthalene (DMN) in liquid phase under atmospheric pressure by using a catalyst comprising hydrogen-form mordenite which has a molar ratio of silica to alumina (SiO.sub.2 /Al.sub.2 O.sub.3 ratio) of at least 100 and is molded by incorporating alumina as the molding aid therein. According to the above method, the objective 2,6-DMN minimized in the contents of impurities can stably be produced in high selectivity and high yield under mild reaction conditions for a long period of time, while side reactions and deterioration of the catalyst are suppressed to a minimum.