The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 27, 2017
Filed:
Oct. 22, 2014
Basf SE, Ludwigshafen, DE;
Josef Meissner Gmbh & Co. KG, Köln, DE;
Samuel Neto, Manila, PH;
Rüdiger Fritz, Bernsdorf, DE;
Renate Hempel, Ruhland, DE;
Holger Allardt, Schwarzheide, DE;
Yuan Shen Dai, Mannheim, DE;
Barbara Becker, Moerlenbach, DE;
Sebastian Ahrens, Weisenheim am Sand, DE;
Julia Leschinski, Weiterstadt, DE;
Henrich Hermann, Köln, DE;
Mirko Haendel, Neunkirchen-Seelscheid, DE;
Jürgen Pöhlmann, Köln, DE;
BASF SE, , DE;
Josef Meissner GmbH & Co. KG, , DE;
Abstract
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.