Removal of light impurities from caprolactam by distillation with water
AssigneeAllied Corporation
InventorsLamberto Crescentini, Joseph D. DeCaprio, William B. Fisher, Roy J. Lilley, Jr.
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Abstract
This invention is a method of purifying crude caprolactam. The improved method comprises taking a portion of a process stream of crude caprolactam having low boiling impurities and distilling the stream in the presence of water by fractional distillation into an overhead containing water and low boiling impurities and bottoms of caprolactam having improved purity and low water content. The improvement also comprises taking a low water content stream of crude caprolactam having low boiling impurities and adding water to the stream and distilling the stream by fractional distillation as described above.
Claims7
In a method to purify crude caprolactam, the improvement consisting essentially of
- (a) taking a water content below 10% stream of crude caprolactam having impurities,
- (b) adding water to said stream, and
- (c) distilling said stream by fractional distillation into an overhead containing water and low boiling impurities and a bottoms of caprolactam with water content below 10%.
In a method to purify crude caprolactam the improvement consisting essentially of
- a. taking a portion of a water content below 10% stream of caprolactam having low boiling impurities,
- b. adding water to said stream, and
- c. distilling said stream by fractional distillation into an overhead containing water and low boiling impurities and bottoms of caprolactam with water content below 10%.
Dependencies are inferred from the claim text.