Patent ID: 6635151
Filing Date: 2003-10-21
Classification: C07D,Y10S

Abstract:
A process for separating water from an aqueous lactam solution, consisting essentially of:distilling the aqueous lactam solution in a first distillation column while maintaining a temperature at the bottom of the column less than or equal to 160Â° C. and at an absolute pressure of 50 millibars to 200 millibars, distillate recovered from the top of the column having been condensed at a temperature of 30Â° C. to 60Â° C. using a coolant; forwarding the lactam solution remaining at the bottom of the first distillation column to a second distillation column and maintaining a temperature at the bottom of the second distillation column less than or equal to 160Â° C. and at a pressure of 10 millibars to 45 millibars; recovering water, containing traces of lactam, at the top of the second column, as vapor at a temperature greater than or equal to 70Â° C.