GB811371A - Improvements in the production of fuels having high octane values from hydrocarbons - Google Patents

Abstract

Gasolines are reformed by catalytically reforming the initial material at 3-100 atmospheres and 430-570 DEG C. in the presence of 0.3-5 normal cubic metres of hydrogen per kilogram of gasoline at a throughput of 0.5-3 kilograms per litre of catalyst per hour, separating the product into three fractions and catalytically reforming again the middle fraction boiling within the range of 80-170 DEG C. at 450-550 DEG C. in the presence of hydrogen and mixing the product obtained with at least one fraction of the other products from the first reforming. In one modification the initial material is reformed in two or more stages and the middle fraction is recycled and reformed with the initial material in the second and/or later stages; in this case only that part of the resulting middle fraction, which is excess over the initial material treated. In another modification again using two or more stages, the recycled middle fraction is led into the first stage and the initial material into the second and/or later stages. As the catalyst in each stage there may be used platinum or palladium; the oxides, sulphides, selenides, tellurides, borates, sulphates, nitrates, halides, phosphorus compounds, carbonates or silicates of molybdenum, tungsten, chromium, vanadium, rhenium, uranium, titanium cobalt and nickel or mixtures thereof; mixtures or compounds of the compounds of molybdenum, tungsten, chromium, titanium, uranium or vanadium with cobalt, nickel, copper and gold; copper, silver, gold, zinc, magnesium, cadmium, zirconium, tin, manganese, lead, antimony and bismuth, their compounds and mixtures thereof with each other or the above-mentioned metals and compounds. As support may be used silicic acid, silicates of the above-mentioned metals, zinc oxide, magnesia, zirconia, titania, thoria, vanadium oxide and alumines which may contain 0.5-25 per cent by weight of silicic acid or silicates. The carrier can be treated with hydrogen, ammonia, sulphur dioxide, halogen, oxides of carbon, halogensulphonic acids, phosphorus compounds, formic acid, oxalic acid, acetic acid or mineral acids. There may be 0.1 to 20 per cent by weight of the active constituent in the catalyst. The carrier may have a pH value below 8 and is preferably acidic. When using a plurality of reactors for reforming the initial material the pressure may be raised by 5-20 atmospheres between each vessel, temperatures may be gradually raised, e.g. from 430-480 DEG C. to 500-550 DEG C., the amount of hydrogen may be increased and the catalyst volume increased e.g. by 50-400 per cent. The initial material may be reformed in separate fractions which are recombined after reforming. The middle fraction may also be treated in a plurality of vessels and the conditions used are more severe than for the initial material, e.g. the temperature increased by 10-60 DEG C., the throughput lowered by 0.5-1.5 kilograms per litre of catalyst per hour, the amount of hydrogen may be varied by 0.5 cubic metre per kilogram of feed, the pressure reduced by 5-20 atmospheres, the pH of the catalyst carrier may be greater by 0.5-2, the amount of active catalyst on the carrier increased by 30-500 per cent, the diameter of the catalyst pills may be less by 1-10 mm., and the reaction volume may be 10-300 per cent greater. Material in the feed or the product boiling up to 120 DEG C. may be isomerized. The initial material is preferably first refined using the hydrogen produced in the reforming at 150-450 DEG C., 5-120 atmospheres in the presence of catalysts such as the compounds of molybdenum, tungsten, cobalt and nickel or mixtures thereof. The initial material or the product may be subjected to a selective extraction and paraffins again reformed, the aromatic fraction being added to the product.