Process for workup of mixed acid and wastewater from the nitration of aromatics and apparatus for performing the process

Abstract

In a process for workup of mixed acid and wastewater from the nitration of aromatics in which the nitric acid present is converted by reaction with an aromatic under adiabatic conditions, a. at least one waste stream component selected from waste acid (mixed acid) generated in the nitration, acidic washing water from the workup of crude nitroaromatics and dilute nitric acid generated in an off-gas treatment in the course of the nitration is provided, b. the at least one waste stream component is mixed with re-concentrated sulfuric acid, c. an aromatic is added to the mixture in stoichiometric excess based on the nitric acid, d. the obtained reaction mixture is reacted in an adiabatically operated reactor, e. the obtained organic phase is separated from the sulfuric-acid-containing phase in a separator, f. the sulfuric-acid-containing phase is concentrated under vacuum and g. at least one substream of the re-concentrated sulfuric acid from step g) is employed in step b).

Dependencies are inferred from the claim text.