GB943737A - Improvements in or relating to the production of carbon disulphide and hydrogen sulphide - Google Patents

Abstract

Carbon disulphide and by-product hydrogen sulphide are produced by reacting a preheated, vaporized, hydrocarbon feed consisting predominantly of hydrocarbons having at least 5 carbon atoms/molecule and which is liquid at ambient temperature and is substantially completely vaporized at below 200 DEG C., with sulphur vapour in the presence of a catalyst, without premixing of these reactants prior to entry into a reaction zone containing the catalyst and which is maintained at 700-1300 DEG C. The hydrocarbon feed may be aliphatic, alicyclic or aromatic preferably consisting predominantly of hydrocarbons having at least 6 carbon atoms/molecule. The reaction may be effected under atmospheric pressure and at 800-900 DEG C. under isothermal or adiabatic conditions. To avoid cracking of the hydrocarbon feed by preheating at high temperature, the sulphur vapour may be superheated and the hydrocarbon feed preheated to a correspondingly lower temperature. The reaction may also be effected in the presence of hydrogen, preferably introduced with the hydrocarbon feed, to produce exothermic reaction with the sulphur to avoid corrosion of the apparatus by sulphur vapour preheated to too high a temperature. Under adiabatic conditions in practice with a well lagged reactor the reactants are preheated to 700 DEG C. to promote exothermic reaction. Catalysts referred to are: molybdenum oxide/g -alumina, nickel/a -alumina or silica gel, chromium with molybdenum oxide/g -alumina or vanadium oxide/silica gel or corundum, and preferably potassium vanadate/silica gel or corundum. The catalyst may be employed as a static, moving, or fluidised bed. Gases leaving the reaction zone are cooled to condense sulphur which is recycled, further cooled, or washed with light oil to isolate carbon disulphide, and washed with aliphatic amine to isolate hydrogen sulphide. Hydrogen sulphide after recovery from the amine may be converted to sulphur by the Claus process, such sulphur being recycled, or may be employed as such, for example, in the manufacture of sodium sulphide. Dilution of the hydrocarbon feed with an inert gas, e.g. nitrogen, is also referred to. Specifications 644,030 and 798,947 are referred to.