Patent GB-1269765-A (GB)
Title: Hydrocarbon reforming catalyst
Inventor: ERICKSON HENRY
IPC: B01J23/656
Filed: 1970-03-20
Abstract: 1,269,765. Hydrocarbon reforming catalysts. ENGELHARD MINERALS & CHEMICALS CORP. 20 March, 1970 [21 March, 1969], No. 13707/70. Heading B1E. [Also in Division C5] A hydrocarbon reforming catalyst comprising rhenium and a Group VIII noble metal, for example platinum, supported on calcined alumina is prepared by a process which comprises (i) forming an aqueous slurry of hydrated alumina, the slurry having dissolved therein a water-soluble compound of rhenium and a water-soluble compound of a Group VIII noble metal, (ii) optionally treating the slurry with a water-soluble ionic sulphiding agent, for example hydrogen sulphide or ammonium sulphide, in order to convert the Group VIII noble metal compound to the corresponding metal sulphide, (iii) drying the slurry at a temperature insufficient to cause substantial release of water of hydration from the hydrated alumina, for example at a temperature not greater than 500‹F, (iv) forming the dried slurry into particles, for example by tabletting or extruding, and (v) calcining the particles, for example at a temperature of from 600 to 1200‹F. The slurry may contain from 5 to 16 weight per cent of hydrated alumina calculated as Al 2 O 3 ; from 50 to 95 weight per cent of the alumina content of the slurry may be alumina trihydrate selected from bayerite, gibbsite and nordstrandite (randomite), the balance of the alumina content being alumina monohydrate (boehmite) and/or amorphous hydrous alumina. The slurry preferably contains the rhenium compound and the Group VIII noble metal compound in amounts to provide that from 0.1 to 2 weight per cent of the catalyst is rhenium, calculated as metal, and from 0.1 to 1 weight per cent of the catalyst is Group VIII noble metal, calculated as metal; it is preferred that the catalyst contains rhenium and Group VIII noble metal in a molar ratio of between 1:5 and 5:1. The slurry may be dried by drum drying, flash drying, spray drying or tunnel drying; the particles may be calcined in an inert atmosphere, for example nitrogen, an oxidizing atmosphere, for example dry air, or a reducing atmosphere, for example an atmosphere containing hydrogen. The catalyst also may comprise acidic support material, for example selected from silica-alumina and crystalline aluminosilicate (the latter having a silica to alumina molar ratio of at least 2.0; containing uniform pores having a size of between 6 and 15 Angstroms and optionally having been cation exchanged with ions selected from hydrogen, ammonium and rare earth metal ions), in an amount constituting up to 85 weight per cent of the catalyst, and/or halogen, for example fluorine and/or chlorine, which may be incorporated by treating the calcined particles with gaseous hydrogen chloride or with an aqueous solution containing hydrogen chloride or ammonium chloride. As exemplified, catalyst is prepared from a slurry comprising perrhenic acid (Example 1) or ammonium perrhenate (Example2), chloroplatinic acid and alumina having a dry solids composition 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, the slurry optionally being sulphided by having added thereto an aqueous solution of hydrogen sulphide. Reference is made to Specification 1,269,764.