Mitsubishi Gas Chemical Company, Inc.

Mitsubishi Gas Chemical, Inc.

Akio Hashimoto

Makoto Takagawa

Ryusuke Shigematsu

Masayoshi Hayashi

Kenichi Nakamura

Shinichi Nagao

Katsumi Higuchi

Jitsuo Oishi

Toshihiro Nomura

Takayo Sasaki

Sachiko Arie

Norio Fushimi

Takashi Kojima

Kinji Kato

Kenji Inamasa

Takuo Ohshida

Hideharu Kurashima

Ryuusuke Shigematsu

According to the present invention, a method for producing a catalyst for use in the production of a methylamine compound can be provided, wherein the catalyst comprises a modified crystalline silicoaluminophosphate salt molecular sieve. The method comprises: a moisture control step of adsorbing moisture onto a crystalline silicoaluminophosphate salt molecular sieve in an amount of 5 to 30 wt % of the crystalline silicoaluminophosphate salt molecular sieve; and a step of heating the crystalline silicoaluminophosphate salt molecular sieve having moisture adsorbed thereon under a pressure of 0.1 MPa or more and at a temperature of 130 to 350&#xb0; C. for 5 to 40 hours.

Method for producing catalyst for use in production of methylamine compound, and method for producing methylamine compound

A method for producing a purified naphthalenedicarboxylic acid includes steps of mixing a naphthalenedicarboxylic acid-containing material and an amine in a mixed liquid of water and an organic solvent to give a crystal of a naphthalenedicarboxylic acid amine salt; and obtaining a purified naphthalenedicarboxylic acid from the crystal of the naphthalenedicarboxylic acid amine salt, wherein (1) in the step of forming the naphthalenedicarboxylic acid amine salt by adding an amine to the slurry that contains water, an organic solvent and a naphthalenedicarboxylic acid, the amine addition rate is from 0.002 to 0.4 mol/min relative to one mol of the naphthalenedicarboxylic acid, or (2) an amine is added to the aqueous solution prepared by dissolving the naphthalenedicarboxylic acid amine salt in water, or to the liquid prepared through solid-liquid separation of the aqueous solution to insolubilize and precipitate the metal component, and the precipitated metal component is removed through solid-liquid separation.

Method for producing a purified naphthalene dicarboxylic acid

Problems on catalyst production and catalyst performance with respect to conventional 8-oxygen-membered ring micropore-containing crystalline silicoaluminophosphate molecular sieves as non-equilibrium methylamine synthesis catalysts, are resolved. A chabazite type crystalline silicoaluminophosphate molecular sieve having high purity and high crystallinity and having, on a crystal grain surface, an amorphous oxide layer whose Si/Al atomic ratio is greater than that of the whole crystal grain can be stably produced with high yield with the use of a small amount of structure directing agents by the present method characterized in that hydrothermal treatment conducted in the production of 8-oxygen-membered ring micropore-containing crystalline silicoaluminophosphate sieves is controlled under specified treating conditions. The thickness and composition of the amorphous oxide layer, which exert marked influence on the yield of dimethylamine synthesis, can be easily controlled and reproduced under the conditions of catalyst synthesis according to the invention. Thus, the catalyst of high performance can be stably supplied by the present invention at a low cost with reduced output of waste.

Crystalline silicoaluminophosphate salt molecular sieve having octaoxygen-membered ring pore, process for producing the same and process for producing methylamine with the molecular sieve as catalyst

Process for producing a high purity aromatic polycarboxylic acid

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. A high purity aromatic polycarboxylic acid having excellent hue and large particle diameters can be produced from a crude aromatic polycarboxylic acid industrially with stability at a low cost of production in accordance with a process having a simple construction.

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.

Process for producing highly pure aromatic polycarboxylic acid

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.

Process for the production of high-purity naphthalenedicarboxylic acid

Their is disclosed a process for producing a monoalkenyl aromatic hydrocarbon compound (e.g. 5-(o-tolyl)-2-pentene) which comprises the steps of alkenylating a side chain of an aromatic hydrocarbon compound having at lease one hydrogen atom bonded to .alpha.-position of the side chain (e.g. alkylbenzene) by the use of a conjugated diene having 4 to 5 carbon atoms (e.g. 1-3 butadiene) in the presence an alkali metal-based catalyst supported on a carrier; removing at least part of the catalyst from the resultant reaction product by separating the same; inactivating and optionally removing the catalyst contained in the reaction product; and thereafter distilling the reaction produce in liquid form to separate and recover the objective monoalkenyl aromatic hydrocarbon compound. By virtue of using the above specific method, the process can prevent the change in quality and properly of the objective product even during atmospheric distillation, produce the objective product with high purity in high recovery race and operate a distillation column during a long stable period of time.

Process for producing monoalkenyl aromatic hydrocarbon compound

There is disclosed a process for producing a monoalkenylbenzene which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst produced by calcining the mixture of a basic potassium compound and alumina and then heat treating the calcined product together with metallic sodium in an atmosphere of an inert gas. According to the aforesaid process, an industrially useful monoalkenylbenzene can be produced in high yield at a low cost with enhanced safety.

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Ibaraki-ken, Japan

Akio Hashimoto