GB449710A - Improvements in or relating to the conversion of carbon disulphide to sulphur - Google Patents

Abstract

Sulphur is obtained by heating carbon disulphide with sulphur dioxide in the presence of a catalyst comprising a compound of titanium, thorium, uranium, cerium, silicon, tungsten or vanadium, specified in the order of decreasing activity. Mixtures of the above compounds may be used, together with promoters and/or carriers. The catalyst may be used in the form of sulphide; oxide or other compounds readily converted to sulphide, except silicon which remains as the oxide. The carbon disulphide and sulphur dioxide are preferably mixed in equimolecular proportions, the reaction being initiated at temperatures of 180--250 DEG C., and carried out at temperatures up to 450 DEG C., at substantially atmospheric pressure. Sulphur dioxide may be obtained from pyrites or fouled iron oxide used for gas purification, or a portion of the sulphur produced may be burnt to sulphur dioxide. Large concentrations of water vapour should be avoided, owing to the formation of hydrogen sulphide, and the carbon disulphide should be freed from hydrocarbons owing to poisoning of the catalyst. In an example, the catalyst used is titanium sulphide or titanium hydroxide obtained by precipitation with ammonia from the chloride. It may be used in the solid form or on a support, and the reaction is carried out at 250 DEG C. under atmospheric pressure.