CONTROL OF NITROGEN OXIDE REACTIONS IN OFF-GASES FROM THE DIAZOTIZATION/COUPLING OF AROMATIC AMINES

摘要

ABSTRACT OF THE DISCLOSUREThe deposition of an aromatic diazonium nitrate onthe walls of a pipeline through which is conducted a residualgas produced in the diazotization of a primary aromatic mono-amine is prevented by heating the walls of the pipeline,limiting the residence time of the gas in the pipeline, orproviding for the absence of nitrogen dioxide in the gas.Nitrogen dioxide can form in the pipeline when nitric oxideand molecular oxygen are present, but the deposition of thediazonium nitrate, formed from the nitrogen dioxide via areaction with the monoamine, is prevented by the hot pipelinewalls and/or short residence time.