Abstract: A process for obtaining pure aniline contains catalytically hydrogenating nitrobenzene, to obtain a reaction mixture, separating the reaction mixture into a gas phase containing hydrogen and a liquid phase, liquid/liquid phase separating the liquid phase to obtain an aqueous phase and also crude aniline containing water as an organic phase, distillatively pre-purifying the crude aniline by removing the water via an overhead stream of a first distillation column to obtain a first bottom stream, feeding the first bottom stream as a feed stream to a pure column from which a pure aniline stream is taken off at the top and a second bottom stream containing high boilers is taken off, and passing the second bottom stream to incineration, by pumping the second bottom stream through heated pipelines and by adding methanol, ethanol, propanol, and/or acetone to the second bottom stream.

Abstract: A process for obtaining pure aniline contains catalytically hydrogenating nitrobenzene, to obtain a reaction mixture, separating the reaction mixture into a gas phase containing hydrogen and a liquid phase, liquid/liquid phase separating the liquid phase to obtain an aqueous phase and also crude aniline containing water as an organic phase, distillatively pre-purifying the crude aniline by removing the water via an overhead stream of a first distillation column to obtain a first bottom stream, feeding the first bottom stream as a feed stream to a pure column from which a pure aniline stream is taken off at the top and a second bottom stream containing high boilers is taken off, and passing the second bottom stream to incineration, by pumping the second bottom stream through heated pipelines and by adding methanol, ethanol, propanol, and/or acetone to the second bottom stream.

Abstract: The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the single or multiple performance of the following wash stage (a): (a) contacting the crude aromatic nitro compound (N-in) with an aqueous phase (W-res) and then separating the phases to obtain an organic phase (N-res) and an aqueous phase (W-res), wherein at least one demulsifier (D) is present in one or more of the wash stages (a).

Abstract: The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the single or multiple performance of the following wash stage (a): (a) contacting the crude aromatic nitro compound (N-in) with an aqueous phase (W-res) and then separating the phases to obtain an organic phase (N-res) and an aqueous phase (W-res), wherein at least one demulsifier (D) is present in one or more of the wash stages (a).

Abstract: The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the following wash stages (a1) and (a2), where each of stages (a1) and (a2) may be performed once or more than once in succession: (a1) contacting the crude aromatic nitro compound (N1-in) with a first aqueous phase (W1-in) comprising at least one base (B) and then separating the phases to obtain an organic phase (N1-res)and an aqueous phase (W1-res); and then (a2) contacting the organic phase (N1-res) obtained in stage (a1) with a second aqueous phase (W2-in) and then separating the phases to obtain a purified organic phase (N2-res) and at least one aqueous phase (W2-res), the aqueous phase used (W2-in) having a pH of 6 to 9.

Abstract: The invention relates to a process for working up wastewaters which are obtained in the purification of crude aromatic nitro compounds after the nitration of aromatic compounds, comprising the following steps: (a) single-stage or multistage washing of the crude aromatic nitro compound to obtain at least one organic phase and at least one aqueous phase, and removal of the aqueous phase or of the aqueous phases, step (a) comprising the addition of a base other than ammonia, and then (b) optional removal of organic constituents from at least a portion of the aqueous phase or aqueous phases obtained in step (a) by stripping, preferably with steam, then (c) removal of organic compounds from at least a portion of the aqueous phase or aqueous phases resulting from step (a) or step (b) by thermal and/or oxidative degradation, then (d) distillative depletion of ammonia from at least a portion of the aqueous phase or aqueous phases resulting from step (c), and then (e) optional supply of at least a portion of the aq