Patent ID: 8894960

Claim:
A process for reprocessing the exhaust gas from a plant for producing hydroxylamine or hydroxylammonium salts by catalytic reduction of nitrogen monoxide with hydrogen for the purpose of utilization of at least a part of the nitrogen monoxide and if appropriate hydrogen present in the exhaust gas from a main reactor for producing hydroxylamine or hydroxylammonium salts, which comprises, in a first separation stage, selectively separating off nitrogen monoxide from the exhaust gas of the plant for producing hydroxylamine or hydroxylammonium salts and wherein a second separation stage is provided in which dinitrogen monoxide is removed from a residual gas of the first separation stage, wherein the selective removal of nitrogen monoxide is carried out in a reactor for producing hydroxylamine or hydroxylammonium salts by catalytic reduction of nitrogen monoxide with hydrogen, which reactor is designed for complete conversion of the nitrogen monoxide, and which reactor is a separate reactor downstream from the main reactor, wherein said separate reactor downstream of the main reactor has a space-time yield, based on hydroxylamine or hydroxylammonium sulfate, of 30 to 60% below the space-time yield of the main reactor.