Sumitomo Chemical Company, Limited

Taisei Kiko Co., Ltd.

Masaru Kitamura

Hiroshi Ichihashi

Hideto Tojima

Keisuke Sugita

Hiroshi Kajikuri

Hiroshi Sato

Masahiro Hoshino

Yasumoto Shimazu

Gohfu Suzukamo

Yasuhiko Higashio

Kenichi Hirose

Norio Ishii

Youichi Umada

Yasushi Fujita

Shinkichi Shimizu

Masato Mizutani

Yasuo Nakamura

Makoto Yako

Nobuyuki Abe

Akira Iguchi

Masanori Doba

Yoshinori Kobayashi

Kazuya Tsuchimoto

Tomokazu Nakamura

Shuzo Murata

Masashi Yokota

Takayasu Niwa

Eiji Tasaka

Yukio Oguri

Masao Sirosita

Shigeko Kimura

Kenji Kitani

Kanji Kuwahara

The present invention provides a process for regenerating a catalyst for producing e-caprolactam comprising the steps of adsorbing a silicon compound on a zeolite catalyst that had been used for a Beckmann rearrangement reaction of cyclohexanone oxime and contacting the catalyst with an aqueous solution containing a compound selected from a quaternary ammonium compound, lower alkylamines and ammonia. The present invention also provides a process for producing e-caprolactam comprising subjecting cyclohexanone oxime to the Beckmann rearrangement reaction in the presence of the catalyst thus regenerated.

Process for regenerating catalyst for producing e-caprolactam and process for producing e-caprolactam

&#x3b5;-Caprolactam is produced by the method comprising the step of introducing a gas comprising cyclohexanone oxime into a layer of solid catalyst particles through a plurality of holes of a gas diffusion plate so that the solid catalyst particles are brought into contact with the gas, while fluidizing the catalyst layer, wherein the holes have an average diameter of about 3 mm or smaller. In accordance with the production method, &#x3b5;-caprolactam can be produced from a raw material gas comprising cyclohexanone oxime with a high conversion of cyclohexanone oxime and a high selectivity to &#x3b5;-caprolactam.

Method for producing epsilon-caprolactam

The invention provides a method for producing &#x3b5;-caprolactam comprising the steps of: a reaction process which subjects cyclohexanone oxime to a Beckmann rearrangement reaction in the presence of a solid catalyst; and a catalyst regeneration process which regenerates the solid catalyst used in the reaction process by heat treatment under an atmosphere comprising an oxygen-containing gas, wherein the solid catalyst heat-treated in the catalyst regeneration process is used in the reaction process, the carbon contents in the solid catalyst in the reaction process and the catalyst regeneration process are maintained in a range of 0.5 to 2% by weight, and the nitrogen contents in the solid catalyst in the reaction process and the catalyst regeneration process are maintained in a range of 0.01 to 0.2% by weight. According to the invention, &#x3b5;-caprolactam can be produced in a high production yield for a long period of time by enhancing persistence of the catalytic activity for producing &#x3b5;-caprolactam.

Method for producing &#x3b5;-caprolactam

A method is provided for evaporating cyclohexanone oxime in which cyclohexanone oxime is evaporated using a falling-film evaporator with wetting the evaporation surface of the evaporator well with the cyclohexanone oxime at a pressure of less than about 1060 Torr with a falling rate of the cyclohexanone oxime of about 170 kg/hour or more per one meter around the circumference of evaporation surface at the lowest part of the evaporator. In this method, the cyclohexanone oxime is evaporated efficiently with little decomposition thereof, while preventing the plugging of the pipes of the evaporator and continuously carrying out the operation of the evaporator for a long period of time.

Method for evaporating cyclohexanone oxime

The present invention provides a method for manufacturing a zeolite comprising following steps of: According to the present invention, a method is also provided wherein &#x3b5;-caprolactam is manufactured by Beckmann rearrangement reaction of cyclohexanone oxime in a gaseous phase in the presence of the zeolite manufactured by the above-described method.

Method for manufacturing zeolite and method for manufacturing &#x3b5;-caprolactam

A method for producing &#x3b5;-caprolactam and a method for reactivating a zeolite catalyst for the production are provided. In the reactivation step, a zeolite catalyst is allowed to contact a gas containing a carboxylic acid, water and a compound selected from ammonia and amines. In accordance with the present invention, the catalytic activities of a zeolite catalyst used for the Beckmann rearrangement reaction of cyclohexanone oxime can be effectively restored. Consequently, &#x3b5;-caprolactam may be produced with a high production yield for a long period of time by reusing the catalyst by the method described above.

Method for producing &#x3b5;-caprolactam and method for reactivating catalyst for production of &#x3b5;-caprolactam

A process for producing &egr;-caprolactam is provided which comprises the steps of subjecting cyclohexanone oxime to a gaseous phase Beckmann rearrangement reaction in a fluidized bed system using a solid catalyst and re-generating the catalyst, wherein said process comprises a step of treating the catalyst with an oxygen-containing gas at an elevated temperature in a re-generation step so that the nitrogen content of the catalyst falls within a range of 10 ppm to 2,500 ppm on its way to the reaction step from the re-generating step. According to the present invention, &egr;-caprolactam is produced with a high conversion or a high selectivity without interrupting the rearrangement reaction or the re-generation step.

Process for producing &egr;-caprolactam

An apparatus for the production of &egr;-caprolactam is provided which comprises (i) a fluidized bed reactor having a solid catalyst therein for subjecting cyclohexanone oxime to a rearrangement reaction to obtain a reaction product containing unreacted cyclohexanone oxime and (ii) a fixed bed reactor packed with a solid catalyst for subjecting the unreacted cyclohexanone oxime to a rearrangement reaction to obtain &egr;-caprolactam. Using the apparatus, &egr;-caprolactam is obtained with a high yield.

Apparatus and process for producing &egr;-caprolactam

A flexible joint comprises: first cylindrical bodies comprising a pair of spherical ring members; a second cylindrical body comprising a sleeve relatively movably inserted in the first cylindrical bodies from an axial direction X of the second cylindrical body; third cylindrical bodies comprising a pair of casing tubes which are fitted around outer peripheral surfaces of the first cylindrical bodies and are provided with mutually slidable spherical inner peripheral surfaces, the casings being formed at their opposite ends with connecting portions, and being provided at their outer peripheral surfaces of large diameter portions with projections having through holes; and rods capable of being inserted into the through holes formed in the outer peripheral surfaces of the large diameter portions, each of the rods being provided and fixed between the projections of the pair of third cylindrical bodies for restricting the telescopic movement of the tube joint, wherein the rods comprise a pair of rods connected to each other in the vicinity of a substantially central portion between the opposed projections, the pair of rods being threadedly connected to at least one of bottomed holes opened and formed on opposite ends of a long nut which is provided at its substantially central portion with a notched portion so that when excessive external force is applied, the notched portion is preferentially broken to restore telescopic flexible effect of the tube joint.

Flexible joint and long nut for flexible joint

The invention provides a process for producing high quality .epsilon.-caprolactam which comprises allowing crude .epsilon.-caprolactam obtained by gas phase Beckmann rearrangement of cyclohexanone oxime to contact with hydrogen at 100.degree.-200.degree. C. in the presence of a hydrogenation catalyst.

Process for producing .epsilon. -caprolactam

A process is disclosed wherein a zeolite molding having a high mechanical strength is produced by contacting a pentasil type zeolite molding with water.

Process for increasing the strength of a zeolite molding

In the production of .epsilon.-caprolactam from cyclohexanon oxime in gaseous phase in the presence of solid catalysts, the catalysts, no matter whether they may have worked, are brought into contact with either aqueous solution of ammonium salts and at least one basic material or ammonia water.

Process for producing .epsilon.-caprolactam and activating solid

.epsilon.-Caprolactam is prepared by bringing cyclohexanone oxime into contact in gas phase with solid catalysts such as a zeolite catalyst in the presence of at least one nitrogen-containing compound selected from the group consisting of ammonia, methylamines and .epsilon.-caprolactam.

.epsilon.-caprolactam

Thermal decomposition of cycloalkanone oximes is inhibited by allowing nitrogen-containing compounds represented by the following formula (1) to coexist with the cycloalkanone oximes:

Method for inhibiting thermal decomposition of cycloalkanone oximes

.epsilon.-Caprolactam is prepared by subjecting cyclohexanone oxime in a gas phase to a catalytic reaction using zeolite catalysts in the presence of water and at least one compound selected from alcohols and ether compounds.

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Niihama, Japan

Masaru Kitamura