Bayer Materialscience Ag

Covestro Deutschland Ag

Bayer Materialscience, LLC

Juergen Muennig

Bernd Pennemann

Thomas Knauf

Wolfgang Lorenz

Dietmar Wastian

Volker Michele

Fritz Pohl

Gerhard Wiechers

Denise Chan

Jesse Caravaggio

John F Gisch, Jr

The invention relates to a method for continuous production of nitrobenzene by means of nitration of benzene with nitric acid and sulfuric acid, in which load change (i.e. a reduction or increase in the quantity of nitric acid supplied to the process per time interval) is particularly advantageously developed. The invention particularly relates to a method in which, in the case of a load reduction, the ratio of the masses of benzene and nitric acid supplied per time interval is significantly increased compared to said ratio before the load change and/or the ratio of the masses of nitric acid and sulfuric acid supplied per time interval is significantly reduced compared to said ratio before the load change. In the event of a load increase, the reverse is carried out.

Method for producing nitrobenzene

Dinitrotoluene is produced by nitration of toluene with nitrating acid (mixture of nitric acid and sulfuric acid) in which, in a first stage, the toluene is converted to mononitrotoluene (MNT) and then the mononitrotoluene is converted in a second stage to dinitrotoluene (DNT). Control of the weight ratio of the aqueous to organic phases, dispersion of the organic phase in the aqueous phase and use of less than 2.06 moles of nitric acid per mole of toluene are key features of this process.

Process for the production of dinitrotoluene

The present invention is directed to a process for the isothermal nitration of aromatic organic compounds, wherein an aromatic organic compound is brought into contact and reacted with a mixture of sulfuric acid and nitric acid. The mixture of sulfuric acid and nitric acid, and the aromatic organic compound are brought into contact with each other through a mixing nozzle which comprises a substantially cylindrical tubular reactor and an annular gap which surrounds the tubular reactor. The aromatic organic compound flows through the tubular reactor, and the mixture of sulfuric acid and nitric acid flows through the annular gap, and they are mixed together upon emerging from the tubular reactor and the annular gap, wherein the ratio of the average rates of flow of the aromatic organic compound in the tubular reactor, and of the mixture of sulphuric acid and nitric acid in the annular gap ranges from 0.5:1 to 10:1.

Growing community of inventors

Kaarst, Germany

Juergen Muennig