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US 6,583,327 B2Granted
Continuous isothermal process for preparing mononitrotoluenes
AssigneeBayer Aktiengesellschaft
InventorsRalf Demuth, Frank Döbert, Harald Petersen, Georg Ronge, Hans-Martin Weber, Thomas Würminghausen, Eberhard Zirngiebl
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Abstract
The present invention relates to a process for the continuous isothermal preparation of mononitrotoluenes with concentration of the resultant waste sulfuric acid and recycling of the concentrated waste sulfuric acid to the process.
Claims11
A continuous process for preparing mononitrotoluenes by reacting toluene with nitric acid and sulfuric acid under isothermal reaction conditions comprising
- (a) feeding 75 to 93% strength sulfuric acid, 60 to 70% strength nitric acid, and toluene into a reactor,
- (b) separating the crude nitrotoluene from the waste sulfuric acid at the reactor outlet,
- (c) concentrating the waste sulfuric acid in a single-stage concentration to 75 to 93%, and
- (d) recycling the concentrated waste sulfuric acid in a circulation back to the nitration reaction.
1 more element
Dependencies are inferred from the claim text.