Patent ID: 7692042
Filing Date: 2010-04-06
Classification: C07C

Abstract:
1. A process for the production of aniline comprising: a) hydrogenating nitrobenzene in the presence of a catalyst to produce crude aniline, and b) purifying the crude aniline by single- or multi-stage distillation, in which an aqueous alkali metal hydroxide solution is added to the crude aniline prior to distillation and/or during distillation of the crude aniline, and the aqueous alkali metal hydroxide solution amount is adjusted to maintain a molar ratio of alkali metal hydroxide to phenolic compounds present in the crude aniline between 0.1:1 and 10:1, c) partially discharging sump from the distillation, d) washing the sump with water or diluted alkali metal hydroxide solution to reduce phenolate salt concentration, e) separating the washed sump into an organic phase and an aqueous phase, and f) recycling the organic phase to the distillation.