Basf Se Corporation

Josef Meissner Gmbh & Co. Kg

Basf Aktiengesellschaft

Verein Für Kernverfahrenstechnik Und Analytik Rossendorf E.v.

Holger Allardt

Renate Hempel

Ruediger Fritz

Reiner Reetz

Sebastian Ahrens

Samuel Neto

Julia Leschinski

Barbara Becker

Michael Zoellinger

Anne-Kathrin Merten

Mirko Haendel

Rüdiger Fritz

Andreas Raichle

Ulrich Penzel

Heinrich Hermann

Michael Reichelt

Mirko Händel

Johannes Buettner

Jürgen Pöhlmann

Stefanie Haase

Johannes Adam

Yuan Shen Dai

Yuanshen Dai

Henrich Hermann

Juergen Poehlmann

Johannes Büttner

Michael Zöllinger

Doris Zschieschang

Ina Homann

Annett Gersdorf

Elvira Flegel

Reinhard Tonder

Process for scrubbing a crude mixture which is obtained in the nitration of toluene after separating off the nitrating acid and comprises dinitrotoluene, nitric acid, nitrogen oxides and sulfuric acid, which comprises two scrubbing steps (WS-I) and (WS-II), wherein i) in a first scrubbing step (WS-I), the crude mixture is extracted with a scrubbing acid I comprising nitric acid, nitrogen oxides and sulfuric acid in a scrub comprising at least one extraction stage, where the scrubbing acid discharged from the first extraction stage (WS-I-1) of the first scrubbing step (WS-I) has a total acid content of from 10 to 40% by weight and a content of from 80 to 350 ppm of hydrocyanic acid, giving a prescrubbed crude mixture, ii) in a second scrubbing step (WS-II), the prescrubbed crude mixture comprising dinitrotoluene is extracted with a scrubbing acid II in a scrub comprising at least one, preferably at least 2, extraction stage(s), where the scrubbing acid discharged from the first extraction stage (WS-II-1) of the second scrubbing step (WS-II) has a pH of less than or equal to 4, giving a dinitrotoluene-comprising mixture which is essentially free of nitric acid, sulfuric acid, nitrogen oxides and hydrocyanic acid and has a content of not more than 300 ppm of nitric acid and nitrogen oxides, not more than 3 ppm of sulfate and not more than 50 ppm of hydrocyanic acid.

Process for acidic scrubbing of dinitrotoluene in the presence of hydrocyanic acid

The present invention relates to a process for workup of nitrite-comprising alkaline process wastewaters from the nitration of aromatic compounds, wherein the alkaline process wastewater is acidified by addition of acids and the offgas which comprises nitrogen oxides and escapes from the acidified process wastewater is worked up, comprising the steps of

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The invention relates to a process for scrubbing a crude mixture comprising dinitrotoluene, nitric acid, nitrogen oxides and sulfuric acid obtained in the nitration of toluene after the nitrating acid has been separated off, which comprises two scrubbing steps (SS-I) and (SS-II), wherein

Process for scrubbing dinitrotoluene

Precipitations of nitrohydroxyaromatic salts out of the nitrated crude products obtained in the nitration of aromatic compounds after alkaline scrubbing, for example mononitrotoluenes, are prevented by contacting the nitrated crude products with an acidic ion exchanger. The nitrated crude products are preferably selected from a feedstream to a distillation column, a bottoms circulation stream of a distillation column and a feedstream to a vaporizer.

Prevention of precipitation from nitrated aromatic crude products

A process for working up alkaline process wastewater from the nitration of aromatic compounds to mono-, di- and trinitroaromatics, said alkaline process wastewater having a pH of 7.5 to 13, comprising the steps of

Acidic sludge adsorption of DNT wastewaters

A process is proposed for distillatively removing dinitrotoluene from process wastewater from the preparation of dinitrotoluene by nitrating toluene with nitrating acid, which comprises

Process for distillatively removing dinitrotoluene from process wastewater from the preparation of dinitrotoluene by nitrating of toluene with nitrating acid

The invention provides a process for removing nitrocresols from wastewater of mononitrotoluene preparation, which comprises acidifying the alkaline wastewater of mononitrotoluene preparation with acids to a pH of at most 3 and treating the nitrocresols with an extractant. The invention further provides the preparation of dinitrotoluene by use of the nitrocresol-containing extracts as a feedstock.

Method for extracting nitrocresols from waste water produced in the manufacture of mononitrotoluene and use of said extract

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Schwarzheide, Germany

Holger Allardt