Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2005-08-30
2005-08-30
Parsa, J. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S927000, C568S939000, C568S940000
Reexamination Certificate
active
06936741
ABSTRACT:
The present invention relates to a process for working up or treating aqueous waste waters which are formed during the nitration of toluene to dinitrotoluene with nitrating acid. These aqueous waste waters containing acidic wash water and alkaline wash water from the dinitrotoluene washing step, and distillate from the sulfuric acid concentration step. The process comprises,a) combining the acidic and alkaline waste waters from the washing step and the aqueous distillate from the sulfuric acid concentration step such that the resulting mixture has a pH below 5,b) separating the aqueous and organic phases which are formed by phase separation,c) subjecting the aqueous phase from b) to an extraction step, whereind) the organic components contained in the aqueous phase from c) are extracted with toluene, ande) introducing the toluene phase enriched with the organic components into the toluene nitration.
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Keggenhoff Berthold
Lorenz Wolfgang
Münnig Jürgen
Wastian Dietmar
Bayer MaterialScience AG
Brown N. Denise
Gil Joseph C.
Parsa J.
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