Patent ID: 9302983
Filing Date: 2016-04-05
CPC Classification: C01B,C07C,Y02P

Claim Text:
1. A process for preparing an isocyanate via a gas phase phosgenation of a corresponding amine, the process comprising: reacting carbon monoxide with chlorine with a stoichiometric carbon monoxide excess over chlorine in a gas phase to obtain a phosgene-comprising reaction mixture; dividing the phosgene-comprising reaction mixture into a low-carbon monoxide stream and a carbon monoxide-rich stream by a thermal separating process, wherein: vaporizing the liquid low-carbon monoxide stream with heat generated by reacting the carbon monoxide and chlorine; and introducing the vaporized low-carbon monoxide stream as a phosgene-comprising reactant stream into the gas phase phosgenation of the corresponding amine to obtain the isocyanate and hydrogen chloride as a coproduct.