Patent GB-582416-A (GB)
Title: Dehydrogenation of hydrocarbons
IPC: C07C5/32
Filed: 1943-04-08
Abstract: Hydrocarbons boiling within the gasoline range are dehydrogenated using a pilled sulph-active metal sulphide catalyst the activity of which is periodically restored by treatment in situ with sulphur dioxide.  Crumbling of the catalyst and the necessity for re-sulphurizing are thereby avoided.  The preferred catalysts consist of a sulphide of a metal of each of Groups 6 and 8, for example tungsten and nickel, if desired with a small quantity of a binder or a minor amount of relatively inert material such as alumina, kieselguhr or clay.  The hydrocarbons, in particular naphthenes and fractions of naphthenic gasolines, are dehydrogenated under known conditions, for example 425-525 DEG C., 10-15atm., a liquid hourly space velocity of 0.5-3, and with 2-10 mols hydrogen per mol.  When necessary, the hydrocarbon feed is stopped, excess hydrocarbons purged with hydrogen or inert gas, and sulphur dioxide which may be diluted with, say, nitrogen passed, generally for 1/2 -4 hrs., and conveniently at the reaction temperature although temperatures from 200 to about 750 DEG C. may be used.  The usual regeneration with oxygen and re-sulphurizing may be interposed after a number of such sulphur dioxide activations.  In an Example, a pilled tungsten sulphide, nickel sulphide, molar ratio 1:2, is used for dehydrogenating a methyl cyclohexane faction of straight run gasoline at 490 DEG C., 30 atm., liquid hourly space velocity 1.5, and with 7 mols. hydrogen per mol. hydrocarbon.  Reactivation is effected periodically, the first time for 5 hrs. at 550 DEG C. and 1 atm., the second for 1/2 hr., the third time with a mixture of 25 per cent. sulphur dioxide, 75 per cent. nitrogen for 5 hrs. at 490 DEG C., and so on up to a total catalyst life of over 1400 hrs.ALSO:Hydrocarbons boiling within the gasoline range are dehydrogenated using a pilled sulphactive metal sulphide catalyst, the activity of which is periodically restored by treatment in situ with sulphur dioxide. Crumbling of the catalyst and the necessity for re-sulphurizing are thereby avoided.  The preferred catalysts consist of a sulphide of a metal of each of Groups 6 and 8, for example tungsten and nickel, if desired with a small quantity of a binder or a minor amount of relatively inert material such as alumina, kieselguhr or clay.  The hydrocarbons, in particular naphthenes and fractions of naphthenic gasolines, are dehydrogenated under known conditions, for example 425-525 DEG  C., 10-50 atm., a liquid hourly space velocity of 0.5-3, and with 2-10 mols. hydrogen per mol.  When necessary, the hydrocarbon feed is stopped, excess hydrocarbons purged with hydrogen or inert gas, and sulphur dioxide which may be diluted with, say, nitrogen, passed, generally for 1/2 -4 hrs., and conveniently at the reaction temperature, although temperatures from 200 DEG  to about 750 DEG  C. may be used.  The usual regeneration with oxygen and re-sulphurizing may be interposed after a number of such sulphur dioxide activations.  In an example, a pilled tungsten sulphide, nickel sulphide, molar ratio 1 : 2, is used for dehydrogenating a methyl cyclohexane fraction of straight-run gasoline at 490 DEG  C., 30 atm., liquid hourly space velocity 1.5, and with 7 mols. hydrogen per mol. hydrocarbon.  Reactivation is effected periodically, the first time for 5 hrs. at 550 DEG  C. and 1 atm., the second for 1/2 hr., the third time with a mixture of 25 per cent sulphur dioxide, 75 per cent nitrogen for 5 hrs. at 490 DEG  C., and so on up to a total catalyst life of over 1400 hrs.