Process for preparing lactams
AssigneeRhodia Operations
InventorPhilippe Leconte
Life of this patent
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Abstract
A method for preparing lactams by cyclizing hydrolysis of a corresponding aminonitrile is described. A method for manufacturing a lactam by reacting an aminonitrile with water in the presence of a catalyst involving placing the water and the aminonitrile in contact in vapor phase, passing the mixture of vapors through a bed of catalyst arranged in at least one tube forming a reaction chamber and recovering the lactam at the outlet of the tube is also described.
Claims4
A process for manufacturing a lactam from a linear or branched aliphatic aminonitrile having from 3 to 12 carbon atoms, the process comprising reacting said aminonitrile with water by forming a mixture of vapors of said aminonitrile and water by bringing into contact, in a vapor phase, water and said aminonitrile, passing said mixture of vapors through a catalyst bed positioned in at least one tube that forms a reactor and recovering the lactam at a tube outlet,
- wherein the aminonitrile is aminocapronitrile and the lactam is ε-caprolactam, and
- wherein the temperature in the tube is controlled by cooling means to maintain the temperature throughout the length of the tube at a value between 280° C. and 340° C., said cooling means comprising at least two distinct means, a first cooling means which controls the temperature in an upstream part of the tube in order to maintain the temperature at a value below 340° C., and a second cooling means positioned around a downstream part of the tube in order to maintain the temperature of the tube at a value above 280° C. and below 340° C.
Dependencies are inferred from the claim text.