| 摘要 |
<p>1404776 Cracking &c UNIVERSAL OIL PRODUCTS CO 29 Sept 1972 [30 Sept 1971] 44978/72 Heading C5E An aromatic concentrate and isobutane are made simultaneously from a hydrocarbon feed by: (a) hydrocracking the feed over a composite catalyst comprising a noble metal of Group VIII or nickel and the product of rection between alumina and a sublimed Friedel-Crafts halide, (b) separating the hydrocrackate to provide an isobutane fraction and a heptane-plus fraction, (c) reforming the heptane-plus fraction to convert naphthenic hydrocarbons to aromatics, (d) separating the reformate to provide an aromatic concentrate and a paraffinic fraction, and (e) recycling at least part of the paraffinic fraction to step (a). As shown, a heavy naphtha enters by line 1, and is cracked at 2 in the presence of hydrogen over a catalyst comprising nickel on alumina, on to which aluminium chloride has been sublimed, and the product is fractionated at 4. Heptanes and higher are reformed at 12 with added hydrogen over a catalyst of platinum, rhenium, and combined chloride on alumina. The entire reformate (as shown) or reformate topped to hexanes is extracted with a solvent, e.g. sulpholane, but others are listed, at 14, and the aromatic fraction sent to the gasoline pool 24. The raffinate is recycled to the cracking zone 2, and the pentane-hexane fraction (if any) to the still 4. Isopentanes and isohexanes from the fractionator go directly to the pool 24. Normal pentanes and normal hexanes are isomerized at 22 over a catalyst of platinum and fluorine on alumina in the presence of hydrogen, and the isomerizate is recycled to the fractionator. Butanes may be dehydrogenated at 17 and alkylated over HF or BF 3 catalyst at 19, or outside olefines may be used for the alkylation. The alkylate goes to the pool 24, unreacted isobutane is recycled. Propane may also be dehydrogenated and used in alkylation, or the propene may be hydrated to isopropanol, which can be used in chemical manufacture or may also go to the gasoline pool. Butane from an outside source may go to the isomerization (22) to provide additional isobutane for the alkylation. The preferred Friedel-Crafts halides are aluminium fluoride and chloride, but aluminium bromide, antimony pentachloride, beryllium chloride, germanium tetrachloride, ferric chloride, ferric bromide, gallium trichloride, stannic bromide, stannic chloride, titanium tetrabromide, titanium tetrachloride, zinc bromide, zinc chloride and zirconium chloride are also referred to. Quench streams may be used to control the temperature in the hydrocracking zone.</p> |
