Patent · US Active

Process for the preparation of nitrobenzene by adiabatic nitration

US9302978B1 · kind B1 · utility

0Cited by

10References

7Claims

0Family size

Assignee

Covestro Deutschland AG · DE

Inventors

Antoni Mairata · Düsseldorf, DE
Thomas Knauf · Dormagen, DE

Key dates

Filing date	Apr 24, 2014
Grant date	Apr 5, 2016
Priority date	—
Expiry date	Apr 24, 2034

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C201/16
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

The present invention relates to a continuously operated adiabatic process for the preparation of nitrobenzene by nitration of benzene with nitric acid and sulfuric acid, in which the dilute sulfuric acid obtained after the nitration has taken place and the crude nitrobenzene has been separated off from the aqueous phase is concentrated for the purpose of re-use in the nitration, and after its concentration, at least one minute before it comes into contact with fresh nitric acid again an oxidizing agent is added such that a concentration of the oxidizing agent of from 10 ppm to 5,000 ppm, based on the total weight of the concentrated sulfuric acid to be recycled into the nitration, is established.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.