Dsm N.v.

Other

Frank P W Agterberg

Rudolf P M Guit

Nicolaas F Haasen

Otto E Sielcken

Wim Buijs

Imre Toth

Henk Oevering

Henricus F W Wolters

Paulus F A Buijsen

Matthias R J Offermanns

A process for the preparation of &egr;-caprolactam starting from 6-aminocaproic acid, 6-aminocaproamide, 6-aminocaproic ester, 6-aminocapronitrile, oligomers or polymers of these compounds or mixtures comprising at least two of these compounds, which process is performed in the presence of N-(5-carboxypentyl)-&egr;-caprolactam and/or derivative thereof in an amount of less than 50 wt. % and more than 0.1 wt. % (based on the total reaction mixture).

Process for the preparation of &egr;-caprolactam

Process for the preparation of &egr;-caprolactam comprising treating 6-aminocaproic acid 6-aminocaproate ester, 6-aminocaproamide, oligomers or polymers of these compounds or mixtures comprising at least two of these compounds in a cyclisation reactor in the presence of superheated steam in which a gaseous product stream comprising &egr;-caprolactam, lights and heavies is obtained, wherein the product stream, after condensation and at least partial removal of water and lights, is split into a &egr;-caprolactam stream and a heavies stream containing heavies and &egr;-caprolactam and the heavies stream is recycled to a cyclisation reactor.

The invention relates to a process for the purification of crude &egr;-caprolactam, wherein crude &egr;-caprolactam prepared by cyclization of alkyl 6-aminocaproate, 6-aminocapronitrile, 6-aminocaproic acid, 6-aminocaproic amide and/or oligomers thereof, is subjected to a crystallization process.

Process for the continuous purification of crude &egr;-caprolactam

Catalyst system comprising a palladium compound, an acid compound having a pKa>2 measured in water of 18&deg; C. and an non-symmetrical bidentate phosphorous ligand according to:

Carbonylation catalyst system

Process to prepare &egr;-caprolactam by treating 6-aminocaproic acid, 6-aminocaproate ester or 6-aminocaproamide or mixtures comprising at least two of these compounds in the presence of superheated steam in which a gaseous mixture comprising &egr;-caprolactam and steam is obtained, wherein the process is carried out in the absence of a catalyst at a temperature between 250 and 400&deg; C. and at a pressure of between 0.5 and 2 MPa. The invention also encompasses a process to prepare &egr;-caprolactam starting from 6-aminocapronitrile by performing a hydrolysis and a subsequent step as described above.

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Nieuwstadt, Netherlands

Frank P W Agterberg