Patent GB-1354764-A (GB)
Title: Method of activating a catalyst composite
IPC: B01J23/656
Filed: 1971-04-19
Abstract: 1354764 Reforming naphtha ENGELHARD MINERALS & CHEMICALS CORP 19 April 1971 [20 March 1970] 24778/71 Heading C5E [Also in Division B1] Light, normally liquid, hydrocarbon stock is reformed to provide gasoline of enhanced octane value, benzene and other aromatic hydrocarbons, for example toluene and xylenes, by a process wherein the hydrocarbon stock is contacted under reforming conditions (including for example a temperature of from 700 to 1200‹ F., a total pressure of from 50 to 1,000 psig and a hydrogen partial pressure such as to provide from 3 to 20 moles of hydrogen per mole of hydrocarbon stock) with catalyst which has been prepared from a virgin catalyst composite comprising a rhenium component, a platinum component and support material comprising alumina by a method wherein the composite is heated at a temperature of from 800 to 1100‹ F. in a reducing atmosphere containing from 1 to 99À9 mole per cent of hydrogen and from 0À1 to 50 mole per cent of hydrogen sulphide, the balance, if any, of the reducing atmosphere being inert gas, for example nitrogen, for a time sufficient to provide that the resulting activated catalyst has a sulphur: (rhenium plus platinum) atomic ratio of at least 1 : 1. The catalyst may contain from 0À1 to 2 weight per cent of rhenium and from 0À1 to 1 weight per cent of platinum; it is preferred that the catalyst contains rhenium and platinum in a molar ratio of between 1 : 5 and 5 : 1. The catalyst also may comprise acidic support material, for example selected from silicaalumina and crystalline aluminosilicate, in an amount constituting preferably from 5 to 60 weight per cent of the catalyst, and/or halogen, for example fluorine or chlorine, which may be derived by the use in the preparation of the catalyst composite of gaseous hydrogen chloride or of an aqueous solution of hydrogen chloride, and/or sulphur which has been incorporated in the catalyst composite during preparation thereof. Prior to heating in the reducing atmosphere, the catalyst composite may have been subjected to oxidative calcining, for example at a temperature of from 800 to 1200‹ F. in an atmosphere containing molecular oxygen, and/or to sulphiding. The catalyst, which may be used in the form of a fixed bed or a moving bed, may be in the form of macrosize particles obtained, for example, by pelleting, tableting or extruding. As exemplified, desulphurized straight-run naphtha having a distillation range of 200-400‹ F. is reformed, under reaction conditions including a temperature of 925‹ F., a pressure of 200 psig, a weight hourly space velocity of about 3 and a recycle gas to naphtha feed molar ratio of about 10, in the presence of a fixed bed of catalyst which contains about 0À6 weight per cent of rhenium and about 0À6 weight per cent of platinum and which has been prepared by a procedure wherein a catalyst composite, in the form of dried extrudates containing a rhenium component, a platinum component, sulphur derived from a saturated aqueous solution of hydrogen sulphide and alumina having a dry solids content of 38 weight per cent bayerite, 18 weight per cent gibbsite, 29 weight per cent nordstrandite, 13 weight per cent boehmite and 2 weight per cent amorphous hydrous alumina, is heated (optionally after calcination in air at 900‹ F.) at 950‹ F. in a flowing stream of anhydrous annealing gas (93 mole per cent nitrogen; 7 mole per cent hydrogen) containing 2 mole per cent (based on the annealing gas) of hydrogen sulphide.