Verfahren zur Herstellung von Sulfurylfluorid

Sulphuryl fluoride, SO2F2 is produced by reacting sulphur dioxide with nitrosyl fluoride or a complex of formula NOF.3HF, or a mixture thereof, in the gas phase in the presence of activated carbon as catalyst at at least 125 DEG C. The nitrosyl fluoride may be made by passing NOCl over AgF or from NO and F2. The NOF.3HF complex may be made from hydrogen fluoride and nitrosyl chloride as described in Specification 941,537. In the process, metered mixtures of SO2 and NOF or NOF.3HF are passed through a tubular nickel reactor containing activated carbon whose average mesh size is between 1/25th and 1/4th of the reactor diameter, heated electrically. The temperature range of 325-475 DEG C. is preferred. Sub- or super-atmospheric pressures may be employed. A mol. ratio of SO2 : NOF or complex of 1 : 2 to 1 : 2.5 is preferred. Contact times from 5 seconds to 5 minutes are used. The products leaving the reactor may be fed through a water scaub tower and 10% NaOH solution and then dried by CaCl2 and condensed. The condensate is fractionally distilled to recover SO2F2.