Patent ID: 6254789
Filing Date: 2001-07-03
Classification: C07C,Y10S

Abstract:
A process for treating an aqueous solution originating from washing mononitro- or dinitro-aromatic compounds obtained by a nitration step comprising the reaction of a corresponding aromatic compound with a nitrating acid comprising at least nitric acid, said mononitro- or dinitro-aromatic compounds having been separated from the aqueous phase prior to said washing, said washing being carried out with water, optionally comprising traces of nitrating acid, said process comprising the following steps:(a) mixing said aqueous solution with said aromatic compound to obtain an aqueous phase and an organic phase;(b) recycling said organic phase to the nitration step;(c) distilling said aqueous phase to obtain a concentrated acid;(d) recycling the concentrated acid obtained in step (c) to the nitration step;and(e) recycling or eliminating the water recovered in step (c).