GB663128A - Improvements in or relating to conversion of hydrocarbons and catalysts therefor - Google Patents

Abstract

Aluminium alcoholates of C4 or higher alcohols having a solubility of less than 15 grams per 100 c.c. of water, such as butyl and amyl alcohols, pentanols, hexanols, methyl butanols, heptyl and octyl alcohols, are prepared by adding aluminium chips to the alcohol, preferably with the addition of a hydrocarbon solvent such as petroleum distillate, and in the presence of a catalyst such as mercury or salts thereof especially the chloride, iodine or an aluminium halide. Heat may be necessary to initiate the reaction. Excess alcohol is preferably used, particularly in the absence of a solvent but small amounts of unreacted aluminium may be separated by filtration at a temperature above the melting-point of the alcoholate. Examples relate to aluminium reacted with n-amyl alcohol in the presence of petroleum distillate and mercuric chloride. The alcoholates are hydrolised to alumina for the preparation of catalysts (see Group III) suitable for hydroforming hydrocarbons at temperatures of 850-1100 DEG F., pressures between atmospheric and 400 p.s.i.g., and liquid feed rate of 0.1-2 v./v./hour. An example relates to hydroforming naphtha, employing a molybdenum/alumina catalyst at 200 p.s.i.g. pressure, a feed rate of 0.97 v./v./hour at 929 DEG F. and 1970 cu. feet of hydrogen per barrel, gasoline of octane number 95 being obtained.ALSO:Alumina suitable for a catalyst or carrier, particularly for hydroforming and cracking operations, is prepared by reacting aluminium or a 90 per cent alloy thereof with, for example, copper, in the form of chips or turnings with a substantially water insoluble anhydrous alcohol or mixture of alcohols of C4 or higher, to form an alcoholate with the simultaneous generation of hydrogen which is removed and purified. The alcoholate with unreacted alcohol, if any, is added to an aqueous liquid, the alumina produced by the hydrolysis of the alcoholate forming on settling a slurry with the lower aqueous layer, from which the alcohol may be decanted for refuse. A hydrocarbon such as petroleum distillate is preferably added to the alcohol to assist separation and to act as a solvent for the alcoholate. The alcohols, such as butyl, heptyl, octyl and mixed amyl alcohols, pentanols, hexanols have solubility less than 15 and preferably less than 5\13 grams per 100 c.c. of water. The alcoholate formation may be initiated by heat and catalysed by mercury or a salt thereof, iodine or an aluminium halide. The aqueous liquid may be water acidified with acetic acid and may contain metal salts such as those of Group VI of the Periodic Table for promoting the finished catalyst. Alternatively a silica sol may be used whereby a silica alumina composite catalyst results. The alumina slurry may be concentrated by decanting and/or heating and impregnated with promoter salts, or impregnation may follow drying. Examples of catalysts suitable for reforming and cracking operations relate to alumina gels impregnated with molybdenum oxide with or without calcium oxide, or with the oxides of cerium, chromium, potassium, vanadium, tungsten or boron. Silica-alumina gels wherein the silica sol effecting the hydrolysis is formed for example, by passing sodium silicate solution through an acid regenerated cation exchange resin, may be impregnated with molybdenum, cerium, chromium or potassium oxides. Alternatively a silica sol may be mixed with the alumina slurry. Alumina gel microspheres may be formed by peptilying the alumina slurry by heating to 220 DEG F. emulsifying the sol with naphtha using " rosol" as emulsifying agent, the pH being adjusted to 9 by the addition of morpholine to the oil. The slurry may also be sprayed into an atmosphere containing ammonia, methylamine, sulphur dioxide, hydrogen sulphide or boron trifluoride. A molybdenum impregnated zinc aluminate catalyst may be formed by evaporating the alumina slurry to a 12,5 per cent solids content, mixing with acetic acid and zinc oxide and grinding, after which ammonium molybdenate is added followed by further grinding, heating and activating. In catalytic cracking operations temperatures of 850-1100 DEG F., pressures from atmospheric to 100 p.s.i.g. and feed rates from 0.2 to 4 V/V/H may be employed. An example relates to a boron/alumina catalyst used to crack gas oil of boiling point 485-700 DEG F. at 850 DEG F., 2,0 V/V/H and 30-minute process period. 44 per cent by volume of the product boiled below 400 DEG F. and the gasoline wet comprised 25 per cent aromatics, 35 per cent olefin and 40 per cent paraffins.