Process for the preparation of ε-caprolactam
AssigneesDsm N.V., E.I. duPont de Nemours and Company
InventorsRudolf P. M. Guit, Samuel L. Lane
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Abstract
Process to prepare ε-caprolactam starting from a starting mixture containing a 6-aminocaproate ester, in which in a first step (1) the 6-aminocaproate ester is converted into 6-aminocaproic acid and 6-aminocaproamide by reaction with water in the presence of ammonia at a temperature of between 50 and 250° C., with a separate or simultaneous removal of alcohol(s), and in a subsequent step (2) the 6-aminocaproic acid and 6-aminocaproamide are cyclizised at an elevated temperature, wherein in step (1) the 6-aminocaproate ester is converted into 6-aminocaproic acid and 6-aminocaproamide in the presence of an amount higher than 2 wt. % and less than or equal to 25 wt. % NH3 (relative to the total amount of organic compounds, water and ammonia present in step (1)).
Claims8
Process to prepare ε-caprolactam from a starting mixture containing a 6-aminocaproate ester in an amount higher than 0.5 wt % calculated on the amount of organic compounds in the starting mixture, in which in a first step (1) the 6-aminocaproate ester is converted into 6-aminocaproic acid and 6-aminocaproamide by reaction with water in the presence of ammonia at a temperature of between 50 and 250° C., with a separate or simultaneous removal of alcohol(s), and in a subsequent step (2) the 6-aminocaproic acid and 6-aminocaproamide are cyclizised at an elevated temperature, characterized in that in step (1) the 6-aminocaproate ester is converted into 6-aminocaproic acid and 6-aminocaproamide in the presence of an amount higher than 3 wt. % and less than or equal to 25 wt. % NH3 (relative to the total amount of organic compounds, water and ammonia present in step (1)).
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