| 摘要 |
Lubricating oils or components therefor are produced from petroleum waxes by a process comprising the following steps: (a) isomerizing a petroleum wax in the presence of hydrogen in a first zone over a catalyst containing a hydrogenation/dehydrogenation component and a solid acid-acting refractory support; (b) isomerizing at least the portion boiling in the lubricating oil boiling range of the effluent from the first zone in the presence of hydrogen over a catalyst containing a hydrogenation/dehydrogenation component and a solid acid-acting refractory support in a second zone; (c) separating the portion boiling in the lubricating oil boiling range from the effluent from the second zone; and (d) dewaxing this portion. The wax starting material may be one obtained from a residual oil or a distillate oil, preferably the former, and may be soft wax obtained by de-oiling crude wax. Both isomerization zones may operate under the following conditions: temp. 316-492 DEG C., pressure 35-140 atmospheres absolute, space velocity 0.1-5 litres of wax/hour/litre of catalyst, and hydrogen/wax mole ratio 5-50. The catalyst in each zone may be at least one metal and/or oxide and/or sulphide thereof of Group II, V, VI or VIII of the Periodic Table. Preferably, the catalyst in the first zone is sulphur-resistant, e.g. tungsten and nickel oxides and/or sulphides, and that in the second zone is sulphur-sensitive, e.g. platinum. The support for the catalysts may be silica/alumina/BF3, silica/magnesia, silica/alumina/zirconia, alumina/fluorine, acid-treated clay, montmorillonite clay, a zeolite clay, or a molecular sieve. The effluent from the first zone is preferably fractionated or flashed to remove hydrocarbons boiling below the lube oil range, and the wax from the dewaxing stage (d) may be recycled to the second isomerization zone. The dewaxing stage is conventional, preferably by solvents, e.g. liquid propane, benzene, toluene, methyl ethyl ketone, or toluene/methyl ethyl ketone mixtures. The process gives higher lube oil yields than known single stage processes. |
