Teijin Petrochemical Industries, Ltd.

Teijin Limited

Teijin Limied

Koji Sumitani

Tamio Onodera

Tokuji Sakai

Yasuo Yamasaki

Kimihiko Sato

Kazuhiro Sato

Keizo Shimada

Seiji Itoh

Akio Namatame

Risuke Suzuki

Yukio Kuninobu

Hisasi Shono

Minekazu Sueoka

A method for recovering dimethyl naphthalene-2,6-dicarboxylate (DMN) from a mixture of dimethyl naphthalene-2,6-dicarboxylate (DMN) and dimethyl terephthalate (DMT), which comprises recrystallizing said mixture in a mixed medium of ethylene glycol and methanol, said mixed medium containing 10 to 60% by weight of ethylene glycol, and separating precipitated dimethyl naphthalene-2,6-dicarboxylate (DMN). According to this invention, DMN can be recovered with high yield from a mixture of DMN and DMT which is obtained from depolymerization of a mixed polymer of polyethylene-2,6-naphthalenedicarboxylate and polyethylene terephthalate.

Method for recovering dimethyl naphthalene-2,6-dicarboxylate

Method for preparing dialkylnaphthalene

In a process for producing an alkenylbenzene by the reaction of an alkylbenzene having 8 or more carbon atoms and a conjugated diolefin, the improvement in which the reaction is performed in the presence of a catalyst obtained by dispersing (a) an alkali metal and (b) potassium carbonate and/or potassium hydroxide in the presence of (c) an aromatic hydrocarbon having at least a substituent with a double bond.

Process for producing alkenylbenzene

A process for producing a crystalline aluminosilicate zeolite characterized by having (a) a silica/alumina mole ratio of from 10 to 100, (b) X-ray lattice distances d shown in Table A of the specification, and (c) a specific n-hexane adsorption, under limited measuring conditions, of at least 0.07 g/g, which comprises maintaining a silica source, an alumina source, and a zeolite selected from zeolites ZSM-5 and zeolites having said characteristics, in an aqueous solution containing 1 to 200 millimoles, per gram of said zeolite, of an alkali metal hydroxide under such temperature, pressure and time conditions as to produce a crystalline aluminosilicate zeolite; and a crystalline aluminosilicate zeolite characterized by having aforesaid properties (a) to (c) and (d) a (2-methylpentane/cyclohexane) adsorption ratio of from 1.1 to 1.6.

Preparation of crystalline aluminosilicate zeolite, and its product

A process for continuously isomerizing xylene, which comprises subjecting a hydrocarbon feed material comprising a major proportion of a xylene isomer mixture and a minor proportion of non-aromatic hydrocarbons to xylene isomerization reaction, isolating a specific xylene isomer from the resulting isomerization reaction mixture, and recycling the remaining hydrocarbon mixture to the xylene isomerization reaction; wherein the hydrocarbon feed material or the xylene isomerization reaction mixture is treated with hydrogen in the presence of a cracking catalyst comprising

Process for isomerizing xylene

A novel crystalline aluminosilicate zeolite characterized by having a composition of the following general formula expressed in terms of the mole ratios of oxides in the anhydrous state

Novel crystalline aluminosilicate zeolites and process for production

A process for producing a crystalline zeolite TPZ-12, which comprises maintaining a starting mixture at a temperature of at least 80.degree. C. for a period sufficient to produce zeolite crystals, said starting mixture consisting of

Production of crystalline zeolites

A novel crystalline aluminosilicate zeolite characterized by having

Crystalline aluminosilicate zeolite and process for production thereof

A catalyst composition comprising (i) a crystalline aluminosilicate selected from the group consisting of zeolite ZSM-5, zeolite ZSM-11, zeolite ZSM-12, zeolite ZSM-35 and zeolite ZSM-38 and having a silica/alumina mole ratio of 20 to 1,000; and (ii) at least two metals which are (a) platinum and (b) at least one other metal selected from the group consisting of titanium, chromium, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, palladium, tin, barium, cerium, tungsten, osmium, lead, cadmium, mercury, indium, lanthanum and beryllium. This catalyst composition is useful particularly for the isomerization of aromatic hydrocarbons and reforming of naphtha.

Catalyst composition

In a process for producing p-xylene which comprises catalytically methylating toluene with a methylating agent in the gaseous phase, the improvement wherein (a) said methylation is carried out continuously in a multi-stage reaction system consisting of a plurality of separate series-connected fixed catalyst layers without separating the resulting xylenes in an intermediate stage, (b) said toluene is fed together with hydrogen gas into only the first-stage fixed catalyst layer and passed successively through the subsequent fixed catalyst layers, the amount of toluene fed being such that the total weight hourly space velocity of toluene is from 1 to 300 hr.sup.-1, (c) said methylating agent is fed into each of said fixed catalyst layers, if desired together with hydrogen gas, the amount of the methylating agent fed into each catalyst layer being 0.01/t moles to 1/t moles, in which t is the number of methyl groups in the methylating agent, per mole of toluene fed into the first-stage catalyst layer, and the total amount of the methylating agent fed into all of the catalyst layers being within the range of 0.1/t moles to 2/t moles, in which t is as defined, per mole of toluene fed into the first-stage catalyst layer, and (d) each fixed catalyst layer is filled with a catalyst composed of a crystalline aluminosilicate containing magnesium oxide or lanthanide oxide.

Process for producing p-xylene

In a process for isomerization of xylenes which comprises contactng an aromatic hydrocarbon stock mainly containing xylene isomers not attaining a thermodynamic equilibrium composition with a catalyst composition containing a crystalline aluminosilicate at an elevated temperature in the vapor phase in the presence of hydrogen, the improvement wherein said catalyst composition comprises a crystalline aluminosilicate having a silica/alumina mole ratio of at least 10 and contains at least two metals which are (a) platinum and (b) at least one metal selected from the group consisting of titanium, chromium, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, palladium, tin, barium, cesium, cerium, tungsten, osmium, lead, cadmium, mercury, indium, lanthanum, beryllium, lithium and rubidium.

Isomerization of xylene

In a process for dealkylating a hydrocarbon material containing at least one alkyl-substituted aromatic hydrocarbon having bonded to the aromatic ring at least one alkyl group with at least 2 carbon atoms in the gaseous phase in the presence of hydrogen using a hydro-dealkylation catalyst, the improvement wherein (a) said hydro-dealkylation catalyst is composed of a crystalline aluminosilicate having a silica/alumina mole ratio of from 20 to 200 and containing a noble metal selected from platinum, palladium, rhodium and iridium, and (b) said dealkylation is carried out at a temperature of 250.degree. C. to 420.degree. C. and a pressure of not more than 100 psig, thereby selectively removing said alkyl group containing at least 2 carbon atoms from said alkyl-substituted aromatic hydrocarbon.

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Matsuyama, Japan

Koji Sumitani