Fuji Oil Company Limited

Fuji Oil Company Limited and Petroleum Energy Center

Osamu Kubota

Toshio Tsutsui

Shinichi Okada

Toshihito Nakamura

Masaki Fujii

Masataka Wakabayashi

Masaharu Tashiro

Shu Bin Pu

Yoshitaka Satou

Tomoyuki Inui

Takumi Sasaki

A process for producing 2,6-dimethylnaphthalene by subjecting 2,7-dimethylnaphthalene to an isomerization reaction, wherein the isomerization reaction is carried out by the use of a metallosilicate catalyst that comprises a metallosilicate having a main cavity defined by a ten-oxygen-membered ring, that is in the form of aggregates of fine crystals of the metallosilicate, the external surface area of the aggregate as calculated from t-plot analysis made in the nitrogen adsorption method being 25 m /g or more, and that has been treated to inactivate acid centers present on the external surfaces of the fine crystals until the rate constant basic value N becomes 0.5 or less.

Process for producing dimetylnaphthalene and alkylnaphthalene with methallosilicate catalyst

A rational technical process for producing dialkylnaphthalenes from petroleum-derived starting materials which exist in abundance is established. The process for producing dialkylnaphthalenes contains the steps (1), (2), (3), and (4): (1) 1,step which is for catalytically hydrodealkylating a stock oil containing a substantial amount of naphthalene and/or alkylnapthalenes, separating a product oil form a product gas, and separating and recovering a fraction composed mainly of naphthalene and/or methylnaphthalene from the product oil; (2) 2,step which is for catalytically alkylating or catalytically transalkylating the fraction, recovered in the 1,step, composed mainly of naphthalene and/or methylnaphthalene directly without pretreatment for purification, with an alkylating agent or transalkylating agent to prepare alkylnaphthalenes; (3) 3,step which is for separating and recovering dialkylnaphthalenes from the alkylnaphthalenes obtained in the 2,step; and (4) 4,step which is for returning at least a part of the residual fraction, after the separation and recovery of dialkylnaphthalenes in the 3,step, as at least a part of the stock oil in the 1,step and/or at least part of the alkylating agent or transalkylating agent in the 2,step to the corresponding step.

Process for producing dialklylnaphthalenes

The present invention provides a method for producing .beta.-methylnaphthalene from an inexpensive and easily available feed oil. According to the invention, highly pure .beta.-methylnaphthalene adequate for industrial use can be mass-produced at reduced costs. The method comprises catalytic hydrodealkylation of a feed oil containing an alkyl naphthalene having at least two methyl groups in the presence of a catalyst having at least one metal species of selected from the group consisting of vanadium (V), chromium (Cr), nickel (Ni), rhodium (Rh), platinum (Pt), iridium (Ir), and compounds of these metals as an active component and a carrier therefor containing at least one of alumina and silica as its primary component, with a hydrogen partial pressure of 1 to 50 kgf/cm.sup.2, at a temperature of 450.degree. C. to 650.degree. C., and for a contact time of 3 to 35 seconds. The method of the invention is excellent in that it affords .beta.-methylnaphthalene of a chemical grade with a high yield.

Method for producing .beta.-methylnaphthalene

Catalytic hydrodealkylation by means of a catalyst which comprises microporous particles having a catalytic species carried thereon. Particulars of the microporous particles are disclosed.

Hydrodealkylation process

A catalyst for hydrodealkylation of alkylaromatic compounds which comprises porous alumina particles with coke deposited thereon in the pores, said alumina particles having a pore volume of 0.1 to 1.5 cm.sup.3 /g and a specific surface area of 5 to 500 m.sup.2 /g, the quantity of said coke being 1 to 30% by weight of said alumina particles, and the pore volume and the specific surface area of said catalyst being 0.05 to 1.5 cm.sup.3 /g and 1 to 500 m.sup.2 /g, respectively.

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Chiba-ken, Japan

Osamu Kubota