Abstract: A system of coal gasification and direct ironmaking attains both heat recovery in a coal-based direct ironmaking process and a reduction in equipment investment in a coal gasification process. A waste heat boiler in the system recovers heat of gas exhausted from a coal gasification furnace. A heater in exhaust gas lines of a heat reduction furnace in the coal-based direct ironmaking process superheats the steam generated by and exhausted from the waste heat boiler. A superheated steam line supplies the steam superheated by the heater as an oxidant to the coal gasification furnace.

Abstract: A system of coal gasification and direct ironmaking attains both heat recovery in a coal-based direct ironmaking process and a reduction in equipment investment in a coal gasification process. A waste heat boiler in the system recovers heat of gas exhausted from a coal gasification furnace. A heater in exhaust gas lines of a heat reduction furnace in the coal-based direct ironmaking process superheats the steam generated by and exhausted from the waste heat boiler. A superheated steam line supplies the steam superheated by the heater as an oxidant to the coal gasification furnace.

Abstract: A system of coal gasification and direct ironmaking which is effective in attaining both heat recovery in a coal-based direct ironmaking process and a reduction in equipment investment in a coal gasification process. The system is characterized by being equipped with: a waste heat boiler (16) for recovering heat of gas exhausted from a coal gasification furnace; a heater (7) provided in exhaust gas lines (1a and 1b) of a heat reduction furnace (1) in the coal-based direct ironmaking process and superheating the steam generated by and exhausted from the waste heat boiler (16); and a superheated steam line (23) for supplying the steam superheated by the heater (7) as an oxidant to the coal gasification furnace (10).

Abstract: An object of the present invention is to provide a method for manufacturing 2,6-DMN, in which even when a mixture containing DMN isomers which includes 5 wt % or more of 2,7-DMN is used, a highly pure 2,6-DMN can be obtained. The method for manufacturing the highly pure 2,6-dimethylnaphthalene of the present invention comprises performing cooling crystallization of a mixture containing dimethylnaphthalenes which includes 2,6-dimethylnaphthalene, performing solid-liquid separation to obtain a solid component, and washing the solid component using a solvent, wherein the solid-liquid separation performed after the cooling crystallization includes press filtration.

Abstract: A high-purity naphthalenedicarboxylic acid is produced by a method including Steps [1] and [2]: In Step [I], a raw mixture of crude terephthalic acid and crude naphthalenedicarboxylic acid is dissolved into high-temperature high-pressure water to form a dibasic acid solution wherein the crude naphthalenedicarboxylic acid content is 0.1 to 10 mass percent of the crude terephthalic acid content, the dibasic acid solution is brought into contact with hydrogen in the presence of a catalyst. In Step [II], the resultant in the dibasic acid solution is crystallized by multiple stages while the temperature and the pressure are reduced for each stage, and acid mixtures containing enriched naphthalenedicarboxylic acid or enriched terephthalic acid are obtained by solid-liquid separation.

Abstract: A method for concentrating 2,6-dimethylnaphthalene in a dimethylnaphthalene isomer mixture includes supplying the dimethylnaphthalene isomer mixture to an adsorption column packed with Y-type zeolite. In this instance, by setting the value derived from the expression (u1/3/&egr;)d−5/3 at 14 (m5/3 s−1/3 kg−1) or more, the concentration ratio of 2,6-dimethylnaphthalene to 2,7-dimethylnaphthalene can be 2.0 or more. u here represents the linear velocity (m/s) of the dimethylnaphthalene isomer mixture supplied to an adsorption column, &egr; represents the packing density (kg/m3) of Y-type zeolite, and d represents the grain size (m) of the Y-type zeolite.

Abstract: A high-purity naphthalenedicarboxylic acid is produced by a method including Steps [1] and [2]: In Step [I], a raw mixture of crude terephthalic acid and crude naphthalenedicarboxylic acid is dissolved into high-temperature high-pressure water to form a dibasic acid solution wherein the crude naphthalenedicarboxylic acid content is 0.1 to 10 mass percent of the crude terephthalic acid content, the dibasic acid solution is brought into contact with hydrogen in the presence of a catalyst. In Step [II], the resultant in the dibasic acid solution is crystallized by multiple stages while the temperature and the pressure are reduced for each stage, and acid mixtures containing enriched naphthalenedicarboxylic acid or enriched terephthalic acid are obtained by solid-liquid separation.

Abstract: The present invention provides a method for manufacturing a highly pure 2,6-dimethylnaphthalene having a purity of 99% or more even when a mixture of dimethylnaphthalene isomers containing 5 wt % or more of 2,7-dimethylnaphthalate is used as a feedstock. The method for manufacturing 2,6-dimethylnaphthalene comprises a step of performing crystallization and solid-liquid separation of a liquid primarily containing dimethylnaphthalene isomers so that the liquid is separated into a cake containing the dimethylnaphthalene isomers and a mother liquor, and a step of performing separation/purification of the cake. In the method described above, the crystallization and the solid-liquid separation are performed under the condition in which the ratio of the content of 2,6-dimethylnaphthalene in the mother liquor to that of 2,7-dimethylnaphthalene therein is not less than 1 so that the content of 2,6-dimethylnaphthalene in the cake is 60% or more and that the content of 2,7-dimethylnaphthalene therein is 6.5% or less.

Abstract: A method for concentrating 2,6-dimethylnaphthalene in a dimethylnaphthalene isomer mixture includes supplying the dimethylnaphthalene isomer mixture to an adsorption column packed with Y-type zeolite. In this instance, by setting the value derived from the expression (u⅓/&egr;)d−5/3 at 14 (m5/3 s−⅓kg−1) or more, the concentration ratio of 2,6-dimethylnaphthalene to 2,7-dimethylnaphthalene can be 2.0 or more. u here represents the linear velocity (m/s) of the dimethylnaphthalene isomer mixture supplied to an adsorption column, &egr; represents the packing density (kg/m3) of Y-type zeolite, and d represents the grain size (m) of the Y-type zeolite.

Abstract: The present invention provides a method for manufacturing a highly pure 2,6-dimethylnaphthalene having a purity of 99% or more even when a mixture of dimethylnaphthalene isomers containing 5 wt % or more of 2,7-dimethylnaphthalate is used as a feedstock. The method for manufacturing 2,6-dimethylnaphthalene comprises a step of performing crystallization and solid-liquid separation of a liquid primarily containing dimethylnaphthalene isomers so that the liquid is separated into a cake containing the dimethylnaphthalene isomers and a mother liquor, and a step of performing separation/purification of the cake. In the method described above, the crystallization and the solid-liquid separation are performed under the condition in which the ratio of the content of 2,6-dimethylnaphthalene in the mother liquor to that of 2,7-dimethylnaphthalene therein is not less than 1 so that the content of 2,6-dimethylnaphthalene in the cake is 60% or more and that the content of 2,7-dimethylnaphthalene therein is 6.5% or less.

Abstract: In a method for separating at least one alkylnaphthalene from a stock mixture containing at least two alkylnaphthalenes selected from the group consisting of monoalkylnaphthalenes and dialkylnaphthalenes, a column packed with an optically active chromatographic packing is used for separation. The method can effectively separate a variety of alkylnaphthalenes from a mixture thereof.

Abstract: A process for producing 2,6-dialkylnaphthalene from a hydrocarbon feedstock that contains at least one component selected from the group consisting of dialkylnaphthalene isomers, monoalkylnaphthalene isomers, polyalkylnaphthalenes, and naphthalene, is provided that includes the following steps:I. separating the hydrocarbon feedstock and/or a dealkylation product fed from step III into a naphthalene fraction, a monoalkylnaphthalene fraction, a dialkylnaphthalene fraction and a remaining products fraction;II. separating and purifying 2,6-dialkylnaphthalene from the dialkylnaphthalene fraction of step I;III. dealkylating the hydrocarbon feedstock and/or the remaining products fraction of step I and feeding the dealkylation product to step I; andIV. alkylating the naphthalene and monoalkylnaphthalene fractions of step I;wherein the hydrocarbon feedstock is fed to step I or step III.

Abstract: The present invention relates to a method of preparing 2,6-dimethylnaphthalene from a feed stream that contains hydrocarbons which contain dimethylnaphthalene isomers. The method includes the following steps:I. distillation and concentration of the dimethylnaphthalene isomers from the feed stream, to form a dimethylnaphthalene fraction,II. isomerization of the dimethylnaphthalene fraction to enrich the dimethylnaphthalene fraction in 2,6-dimethylnaphthalene, to form a 2,6-enriched dimethylnaphthalene fraction,III. purification of 2,6-dimethylnaphthalene from the 2,6-enriched dimethylnaphthalene fraction,wherein step II is conducted in the presence of a catalyst composition containing a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing (.ANG.)12.36.+-.10.411.03.+-.0.28.83.+-.10.146.18.+-.0.126.00.+-.0.104.06.+-.0.073.91.+-.0.013.42.+-.0.06,wherein the purification includes crystallization under pressure.

Abstract: The present invention relates to a process of preparing dialkylnaphthylenes and polyalkylenenaphthyleneates.

Abstract: 2,6-Dialkylnaphthalene is prepared from a feedstock comprising naphthalene and an alkylating agent, by a process comprising the steps:(I) transalkylating isomers of dialkylnaphthalene and naphthalene to produce monoalkylnaphthalene and isomers of dialkylnaphthalene;(II) separating the product obtained in step (I) into naphthalene, monoalkylnaphthalene, dialkylnaphthalene and other components;(III) alkylating the monoalkylnaphthalene fraction from step (II) with an alkylating agent to produce dialkylnaphthalene; and(IV) separating 2,6-dialkylnaphthalene from the dialkylnaphthalene fraction in step (II),wherein at least step (I) or step (III) is conducted in the presence of a catalyst having a composition comprising a synthetic zeolite having an X-ray diffraction pattern with an interplanar d-spacing (.ANG.)______________________________________ 12.36 .+-. 0.4 11.03 .+-. 0.2 8.83 .+-. 0.14 6.18 .+-. 0.12 6.00 .+-. 0.10 4.06 .+-. 0.07 3.91 .+-. 0.07 3.42 .+-. 0.06.

Abstract: A process for producing alkylnaphthalene from a feedstock comprising isomers of dialkylnaphthalene and naphthalene by contacting the feedstock with a catalyst composition, in which the process comprising transalkylation between isomers of dialkylnaphthalene and naphthalene to produce monoalkylnaphthalene, and isomerization of dialkylnaphthalene, wherein the catalyst composition comprising a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing as set forth in Table A of the specification.

Abstract: A process for producing alkylnaphthalene from a feedstock comprising isomers of dialkylnaphthalene and naphthalene by contacting the feedstock with a catalyst composition, in which the process comprising transalkylation between isomers of dialkylnaphthalene and naphthalene to produce monoalkylnaphthalene, and isomerization of dialkylnaphthalene, wherein the catalyst composition comprising a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing as set forth in Table A of the specification.

Abstract: A process for producing 2-methylnaphthalene from a feedstock containing 1-methylnaphthalene by contacting the feedstock with a catalyst composition, in which the process comprising isomerization of 1-methylnaphthalene,wherein the catalyst composition comprising a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing as set forth in Table A of the specification.

Abstract: A process for producing 2,6-dialkylnaphthalene from a hydrocarbon feedstock that contains at least one component selected from the group consisting of dialkylnaphthalene isomers, monoalkylnaphthalene isomers, polyalkylnaphthalenes, and naphthalene, is provided that includes the following steps: I. separating the hydrocarbon feedstock and/or a dealkylation product fed from step III into a naphthalene fraction, a monoalkylnaphthalene fraction, a dialkylnaphthalene fraction and a remaining products fraction; II. separating and purifying 2,6-dialkylnaphthalene from the dialkylnaphthalene fraction of step I; III. dealkylating the hydrocarbon feedstock and/or the remaining products fraction of step I and feeding the dealkylation product to step I; and IV. alkylating the naphthalene and monoalkylnaphthalene fractions of step I; wherein the hydrocarbon feedstock is fed to step I or step III.

Abstract: The present invention relates to a process of preparing dialkylnaphthylenes and polyalkylenenaphthyleneates dialkylnaphthalenes and polyalkylenenaphthalates.