| 摘要 |
1327790 Regeneration of hydrocarbon conversion catalysts UNIVERSAL OIL PRODUCTS CO 17 Nov 1970 [26 Nov 1969] 54542/70 Heading B1E [Also in Division C5] Hydrocarbon conversion catalyst comprising a Group VIII noble metal component, a germanium component and a halogen component supported on porous carrier material, which catalyst has been deactivated by deposition thereon of carbonaceous material during contact with hydrocarbon charge, is regenerated by sequential contact with (a) a sulphur-free first gaseous mixture containing from 0.2 to 3 mole per cent oxygen, water and hydrogen chloride at a temperature of from 375 to 450‹C for a period sufficient to remove the carbonaceous material, for example until the differential temperature across the bed of catalyst is less than 5‹C, (b) a sulphur-free second gaseous mixture containing from 0.2 to 25 mole per cent oxygen, water and hydrogen chloride at a temperature of from 450 to 550‹C for a period of from 0.5 to 10 hours and (c) a sulphur-free third gaseous mixture comprising hydrogen, water and hydrogen chloride at a temperature of from 300 to 600‹C for a period of from 0.5 to 5 hours. After step (b) and prior to step (c), the catalyst is purged from oxygen, for example by contact with a stream of inert gas, for example nitrogen. Step (b) may be effected for an initial period of from 0.5 to 5 hours using a gaseous mixture having a composition corresponding to that of the first gaseous mixture and, after increasing the concentration of oxygen in the gaseous mixture by a factor of from 1.5 to 8 thereby to provide the second gaseous mixture, for a further period of from 0.5 to 5 hours at the temperature used during the initial period; alternatively, the concentration of oxygen in the first gaseous mixture may be increased by a factor of from 1.5 to 8 thereby to provide the second gaseous mixture which is contacted with the catalyst initially at a temperature of from 375 to 450‹C for a period of from 0.5 to 5 hours and thereafter, to constitute step (b), at a temperature of from 450 to 550‹C for a period of from 0.5 to 5 hours. Catalyst which contains labile sulphur may be subjected, prior to step (a), to contact with a sulphur-free gaseous stream containing hydrogen and, preferably, also water and hydrogen chloride at a temperature of from 350 to 600‹C until the effluent gaseous stream.is substantially free from hydrogen sulphide, for example contains less than 1 volume parts per million hydrogen sulphide, the catalyst thereafter being purged from hydrogen, for example by contact with an inert gas, for example nitrogen, preferably with a gaseous stream containing inert gas, water and hydrogen chloride; alternatively, the catalyst may be contacted with a sulphur-free gaseous mixture of hydrogen and hydrocarbon charge under conditions selected both to strip sulphur from the catalyst and to convert the charge. The metal of the Group VIII noble metal component may be selected from ruthenium, rhodium, palladium, osmium, iridium and platinum. The germanium of the germanium component preferably is present in a positive oxidation state, for example the +2 or +4 state. The halogen of the halogen component may be fluorine, chlorine, bromine or iodine. Suitable porous carrier materials (and preferred physical characteristics thereof) are identical to those specified in Specifications 1305133 and 1305134; preferred carrier materials are refractory inorganic oxides, especially gamma-, eta- and theta-aluminas. The catalyst may contain, on a carbon-free elemental basis, from 0.01 to 2 weight per cent Group VIII noble metal, from 0.01 to 5 weight per cent germanium and from 0.5 to 3.5 weight per cent halogen. An example relates to the regeneration of deactivated catalyst comprising platinum, germanium and chlorine supported on gamma-alumina in the form of spheres having a diameter of 1.6 mm. |
