Bayer Materialscience Ag

Bayer Intellectual Property Gmbh

Covestro Deutschland Ag

Alexandre Racoes

Thomas Knauf

Andreas Karl Rausch

Wolfgang Dohmen

Antoni Mairata

Jeffrey Bolton

Christian Drumm

Murat Kalem

Dietrich Wulf

Andreas Rausch

The invention relates to a continuously operating process for producing nitrobenzene, comprising the following steps: a) nitriding benzene in adiabatic conditions with sulfuric acid and nitric acid, using a stoichiometric excess of benzene in relation to the nitric acid; b) first separating a gaseous phase containing benzene and gaseous secondary components from the raw process product of the nitridation in a gas separator provided specifically for this purpose, then separating, in a downstream phase-separating apparatus, the resulting liquid phase, which is depleted in gaseous components and contains nitrobenzene and sulfuric acid, into a sulfuric acid phase and a nitrobenzene phase; and c) processing the nitrobenzene phase, obtaining nitrobenzene. The invention also relates to a production plant suitable for carrying out the claimed process.

Process for the continuous production of nitrobenzene

The invention relates to an adiabatic process for producing nitrobenzene by nitrating benzene with sulphuric acid mixtures and nitric acid mixtures using a stoichiometric excess of benzene and reusing non-reacted benzene, the content of the aliphatic organic compounds in the feed benzene being limited, by the targeted evacuation of aliphatic organic compounds to at least one step in the process, to a content of less than 1.5 mass-%, in relation to the total amount of feed benzene.

Method for producing nitrobenzene by adiabatic nitriding

The invention relates to a process for the continuous production of nitrobenzene by nitration of benzene with a mixture of nitric acid and sulfuric acid under adiabatic conditions, in which unreacted benzene is separated from the crude product obtained after phase separation before washing thereof, using the adiabatic heat of reaction.

This invention relates to a process for the continuous preparation of nitrobenzene. This process comprises the adiabatic nitration of benzene with a mixture of sulfuric acid and nitric acid, in which the sum of the concentrations in the reaction zone of the metal ions which form sparingly soluble metal sulfates is less than 900 mg/l, based on the volume of the aqueous phase which contains sulfuric acid.

Process for the preparation of nitrobenzene by adiabatic nitration

The invention relates to a continuous process for the manufacture of nitrobenzene. This process comprises the nitration of benzene with nitrating acid that contains at least 3.0 wt. % of nitric acid and at least 67.0 wt. % of sulfuric acid, in a reaction space in which the start temperature of the reaction is above 100.0&#xb0; C. but below 102.0&#xb0; C. In addition, this process requires that the benzene and the nitrating acid are dispersed in one another several times.

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Krefeld, Germany

Alexandre Racoes