| 摘要 |
THE INVENTION RELATES TO A PROCESS FOR PURIFYING CAPROLACTAM, SAID PROCESS COMPRISING (A) SUBJECTING THE CAPROLACTAM TO A HYDROGENATION BY TREATING THE CAPROLACTAM WITH HYDROGEN IN THE PRESENCE OF A HETEROGENEOUS NICKEL CONTAINING HYDROGENATION CATALYST, (B) DISTILLING AT LEAST A PORTION OF THE HYDROGENATED CAPROLACTAM IN A DISTILLATION COLUMN CONTAINING NICKEL IN AN AMOUNT SUFFICIENTLY LOW SUCH THAT DPANNI£3, WHEREIN DPANNI,=DPAN-DPANNI=0, DPAN=INCREASE OF THE PAN NUMBER OF CAPROLACTAM DURING DISTILLING, DPANNI=0 INCREASE OF THE PAN NUMBER OF CAPROLACTAM DURING DISTILLING UNDER THE SAME CONDITIONS IN A DISTILLATION COLUMN FREE OF NICKEL. NICKEL IS REMOVED FROM THE CAPROLACTAM SOLUTION PRIOR TO THE DISTILLATION STEP.
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