| 摘要 |
Hydrocarbon oils are converted to other hydrocarbons, particularly branched and unsaturated hydrocarbons, by irradiation with gamma rays and neutrons in the presence of a hydrocarbon conversion catalyst impregnated with at least 5% by weight of water. Some oxygenated compounds, e.g. carboxyl compounds, are also produced. The catalyst may be suspended in the oil or may be in the form of a fixed or moving bed. The catalyst size is preferably below 1000 microns, with a surface area greater than 50 square meters per gram and a pore volume greater than 0.2 c.c. per gram. Water may be added to the feed material when using a fixed bed to maintain the required proportion of water. The reaction may be carried out in a nuclear reactor, and the feed stream may serve as moderator. After irradiation the product is separated into its constituents, part of which may be recycled. The preparation of three catalysts is described:-alumina catalyst.-An excess of ammonia water was added to an aluminium alcoholate solution. The aqueous slurry was dried at 250 DEG F. and the alumina calcined at 1100 DEG F. for 4 hours, the product having a surface area of 100-200 square metres per gram. Silica-alumina catalyst.-A silica hydrogel was soaked in an aluminium sulphate solution and then treated with ammonia followed by washing free from sulphate. The product after drying and calcining at 1200 DEG F. for 3 hours had a surface area of about 500 square meters per gram. Platinum on alumina.-This was a commercially available catalyst containing 0.6% by weight platinum and 0.6% by weight chlorine in the form of 3/16 X 1/8 inch cylinders having a surface area of 300 square meters per gram and a pore size of 50 to 80 . All three catalysts were impregnated with water, e.g. up to 27% by weight of water. Three oils were subjected to radiation in the Brookhaven nuclear reactor in the presence of the catalysts, and the products were analysed and compared with those obtained using either no catalyst or water-free catalyst. It is stated that the catalyst may contain an additional, e.g. hydrogenating, component affecting the conversion, e.g. the elements, oxides or sulphides of platinum, molybdenum, palladium, nickel, rhodium and euthenium. Silica or salts or oxides of potassium, calcium and magnesium may also be present. A radiochemical accelerator may also be present, e.g. boron 10, lithium 6 and cadmium, as elements or compounds, e.g. tri-n-dodecylborate, which give off alpha or beta rays upon neutron capture. Other catalyst bases referred to are silica, zirconia, titania, magensia, zinc aluminate and activated charcoal. Specifications 802,552, 814,562 and 823,426 are referred to.
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