Process for the production of nitrobenzene by adiabatic nitration

US9284256B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Thomas Knauf · Dormagen, DE
• Michael Merkel · Hof, DE

Key dates

• Filing date: Jul 23, 2013
• Grant date: Mar 15, 2016
• Expiry date: Jul 23, 2033

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C201/16
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention provides a continuous process for the production of nitrobenzene by nitration of benzene with mixtures of sulfuric and nitric acid using a stoichiometric excess of benzene, in which the content of aliphatic organic compounds in the feed benzene during the start-up period of the production plant is always maintained at less than 1.5 wt. %, based on the total mass of the feed benzene. This is achieved either by mixing the feed benzene comprising recycled unreacted benzene (recycled benzene) and benzene newly supplied to the reaction (fresh benzene) in appropriate quantitative ratios during the start-up period, depending on the purity of the two streams, or by completely omitting the recycling of unreacted benzene during the start-up period, i.e. the feed benzene consists only of benzene newly supplied to the reaction.