Kontinuierliches Verfahren zur Rückgewinnung brauchbarer Bestandteile der Gase, welche bei der katalytischen Herstellung von Chlorcyan aus Blausäure und Chlor bzw. bei der anschliessenden Trimerisierung des Chlorcyans zu Cyanurchlorid in der Dampfphase anfallen

1,268,673. Separating chlorine and cyanogen chloride from mixtures with hydrogen chloride. AGRIPAT S.A. 9 July, 1969 [10 July, 1968], No. 34482/69. Heading B1L. [Also in Divisions Cl and C2] Hydrogen chloride is separated from chlorine and cyanogen chloride by passing the mixture (which has originated from the catalytic production of cyanogen chloride from hydrocyanic acid and chlorine, or from the trimerization of cyanogen chloride to cyanuric chloride) by line 9 to jacketed absorber 1 where pentachloroethane is agitated in contact with the gas stream. The pentachloroethane preferably contains a small proportion of iodine to prevent undue chlorination by the chlorine in the gas stream. The bulk of the hydrogen chloride, which is not absorbed, rises through condenser 2 and leaves by line 10. Solvent containing cyanogen chloride and chlorine passes by line 3 to evaporator 4, and thence in gaseous form up through distillation column 5 to condenser 6. Solvent condensate therefrom is returned by line 13 to absorber 1, while cyanogen chloride and chlorine pass to reactor 7 which is irradiated with u.v. light. This causes any entrained solvent to be converted to hexachloroethane, which is condensed in liquid air trap 8. Residual gases pass by line 11 back to a cyanogen chloride or cyanuric chloride reactor.