Recovering/recycling nitric acid from dinitration process streams comprising HNO3/dinitro compounds
AssigneeRhodia Chimie
InventorsPhilippe Marion, Pascal Metivier
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Abstract
Dinitro aromatic compounds are improvedly prepared by reacting an aromatic compound with a nitric acid nitrating agent and thence separating the nitrating acid from the process stream thus formed, the process stream containing said at least one dinitro aromatic compound and also having a fraction of the nitrating acid dissolved therein, the subject process also comprising (a) distilling/stripping nitric acid from said process stream, (b) recovering nitric acid from the top of the distillation/stripping vessel and recycling same to the nitration reaction and (c) washing the process stream which contains the at least one dinitro aromatic compound, but having the nitric acid removed therefrom.
Claims20
A process for the preparation of at least one dinitro aromatic compound which comprises reacting an aromatic compound with a nitric acid nitrating agent, wherein said nitrating agent is a mixture of nitric acid and sulfuric acid, and thence separating the nitrating acid from the process stream thus formed, said process stream comprising said at least 80% by weight of one dinitro aromatic compound and having a fraction of said nitrating acid dissolved therein, said process also comprising (a) distilling/stripping nitric acid from said process stream, (b) recovering nitric acid from the top of the distillation/stripping vessel and recycling same to said nitration reaction and (c) washing the process stream comprising said at least one dinitro aromatic compound, but having said nitric acid removed therefrom.
Dependencies are inferred from the claim text.