Process for the manufacture of carbon disulphide

摘要

Carbon disulphide is produced by interacting, in the gaseous state and in the presence of a catalyst, sulphur and an olefinic hydrocarbon, and/or a saturated hydrocarbon containing at least 3 carbon atoms in the molecule, or a mixture of one or more of such hydrocarbons and methane and/or ethane, the catalyst being periodically regenerated. The catalyst may be activated alumina, silica gel, fuller's earth, bauxite, or silica-alumina gel containing 2-10 per cent of silica. Catalyst promoters, e.g. oxides or sulphides of iron, chromium, manganese, molybdenum and vanadium, may be present. The mixture of reactants may be heated to 850-1300 DEG F., preferably 1100-1175 DEG F., prior to reaction. The pressure may be subatmospheric or superatmospheric, e.g. up to 500 p.s.i., preferably 100 p.s.i. An excess, e.g. 10-30 per cent, of sulphur is preferably employed. Inert gases, e.g. nitrogen or flue gas, may be included in the reaction mixture. The reaction may be operated isothermally or adiabatically. Reactivation may be effected by purging at atmospheric or superatmospheric pressure with oxygen-containing gas, e.g. air at 800-1200 DEG F., liquid or vaporous sulphur at 500-1200 DEG F., preferably 1100 DEG F., or steam at 1000-1200 DEG F., in particular at or above reaction temperature with sulphur mixed with methane, or methane and ethane, in considerable stoichiometric deficiency. One or more static beds of catalyst may be on stream while a similar number are being regenerated. Using a moving or fluidized bed, catalyst may be continuously removed, regenerated and returned to the process. Using sulphur vapour a temperature of 500-1200 DEG F., preferably 1100 DEG F., may be employed. Passage of sulphur vapour is continued until liquid sulphur withdrawn from the reactor is free from discoloration. A single reactor with continuous production of carbon disulphide may be employed if during regeneration methane or ethane is admixed with the sulphur and a temperature of 1000-1200 DEG F. is employed. The product gases are cooled, e.g. by passing through a waste heat boiler, an air-cooled multi-finned radiator, or conventional water cooler, and scrubbed with liquid sulphur in a tower provided with bubble plates, or Rasching rings. The sulphur is recycled to the process. The point at which regeneration is required is determined by inspection of the recycled sulphur. The remaining sulphur is removed by scrubbing in a similar tower with lubricating or light gas oil. The carbon disulphide may be recovered by absorption in petroleum naphtha of b.p. 250-400 DEG F., benzene, or O-dichlorobenzene, followed by stripping and fractionation. Scrubber oil containing sulphur is cooled to 100 DEG F. or lower, sulphur crystallized therefrom, and removed by sedimentation, filtration or centrifugation. Specification 644,030 is referred to.