GB709616A - Supported platinum catalyst and process for producing and applying the same - Google Patents

Abstract

Gasoline fractions are hydroformed using a catalyst containing 0.01-2 per cent platinum, prepared by impregnating a porous carrier with a solution of a platinum compound in the presence of a basic nitrogen compound soluble in the impregnating solution, and heating to above 260 DEG C. (see Group III). The gasoline fraction treated may have a boiling range of 10-220 DEG C. or may be a naphtha fraction boiling at 65-220 DEG C. In addition to straight-run gasolines containing naphthenic hydrocarbons, the treatment may also be applied to thermally cracked gasolines, either alone or mixed with straight-run gasolines. Hydroforming is carried out at a temperature of 315-595 DEG C., a pressure of 3.5-70 atmospheres, a space velocity of 0.1-20 parts by weight of gasoline per hour per part of catalyst, and in the presence of 0.1-10 mols. of hydrogen per mol. of hydrocarbon.ALSO:In preparing a catalyst containing 0.01-2 per cent. of platinum by impregnating a porous carrier with a solution of a platinum compound and heating to above 260 DEG C., the impregnation is carried out in the presence of a basic nitrogen compound soluble in the impregnating solution, in order to obtain an even distribution of the platinum through the carrier. The catalyst may also contain 0.1-8 per cent. combined halogen based on the weight of the carrier. Alumina is the preferred carrier material, but silica, magnesia, thoria, zirconia, zinc oxide, or mixtures of these oxides, may also be used. The oxides are prepared by dehydration of hydroxides of aluminium, zirconium, thorium, and zinc, or hydrated oxides of silicon and magnesium; alumina prepared from alumina hydrogel and spherical gel particles of silica are also referred to. The carrier may be dried, pelleted with the aid of stearic acid, rosin, hydrogenated coconut oil, or graphite as a lubricant, and calcined at 425 DEG - 700 DEG C. Halogen is incorporated before drying the carrier, or before or after calcination. Suitable halogen substances are hydrogen halides, ammonium fluoride or cholride, and solutions of free halogens; chlorine and fluorine may be used together. Preferred proportions are 0.1-3 per cent. fluorine and 0.5-5 per cent. chlorine. When ammonium chloride is used in the preparation of the carrier, washing may be controlled to leave some chlorine in the product. Platinum compounds mentioned are chloroplatinic acid, ammonium platinum chloride, trimethylbenzyl ammonium platinum chloride, tetramino platino chloride, ammonium platino nitrate, and dinitro amino platinum; aqueous or other solutions of these compounds may be used. Suitable basic nitrogen compounds are ammonium hydroxide, ethylene diamine, propylene triamine, butylene tetramine, methylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, butylamine, aniline, ethanolamine, propanolamine, butanolamine, diethanolamine, triethanolamine, hexamethylene tetramine, hexamethylene diamine, ammonium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium citrate, ammonium propionate and ammonium butyrate; ammonium nitrate, acetate, and chloride may be employed in conjunction with a basic compound. For impregnation, the solutions of the platinum compound and the nitrogen compound may be mixed, or they may be applied separately, in either order; the mixed solutions may have a pH of 5-10 (preferably 8-10). The impregnated carrier is dried at 95 DEG -260 DEG C., and then heated in air at 260 DEG -595 DEG C.; before heating in air. it may be reduced in hydrogen at 260 DEG -595 DEG C. Regeneration of the catalyst may be effected by heating in air at 315 DEG -430 DEG C. In examples carriers of alumina, silica spheres, silica-alumina, and silica-magnesia are impregnated with aqueous solutions of chloroplatinic acid and ammonio platino nitrate in the presence of ammonium hydroxide, ammonium carbamate, ethylene diamine, diethylene triamine, and propylene triamine, hydrogen fluoride and hydrogen chloride are also added. The catalysts are especially suitable for reforming gasoline fractions in the presence of hydrogen (see Group IV(b)) and may also be used for the hydrogenation of monoolefins, diolefins, unsaturated cyclic hydrocarbons, and unsaturated ketones, alcohols, and acids, cracking hydrocarbons, dehydrogenation of organic compounds, and oxidation of olefins (to olefin oxides), alcohols, and ketones. Fixed bed, fluidized, compact moving bed, or slurry processes may be employed.