Patent GB-792806-A (GB)
Title: Improvements in or relating to hydroforming processes employing alumina catalysts
IPC: C10G35/06
Filed: 1954-11-22
Abstract: The hydroforming of Coastal, virgin, naphtha of 50 octane number boiling at 200 DEG  to 330 DEG  F. is effected in the presence of a platinum catalyst supported on a base of eta alumina (see Group III). The hydroforming is effected at 900 DEG  F. under a pressure of 200 p.s.i.g. and with a 6/1 hydrogen/hydrocarbon ratio. Specifications 667,145 and 754,552, [both in Group III], are referred to.ALSO:Alumina, especially suitable as a catalyst support and consisting mainly of eta alumina, is prepared by hydrolysing an aluminium alcoholate with aqueous ammonia, at 35 DEG  to 100 DEG  F., the concentration of NH3 being from 1.8 to 3.4 weight per cent and the volume of aqueous ammonia being within the range of 1 to 10 volumes per volume of alcoholate, and thereafter aging the resulting hydrous alumina slurry for a 1/2 to 15 hours preferably at 35 DEG  to 80 DEG  F., separating the aged alumina and finally heating it to 400 DEG  to 1250 DEG  F. to dehydrate it.  Water immiscible alcohols, i.e. C5 and higher, are preferred for the formation of the alcoholate and these may be mixed with a hydrocarbon for example petroleum distillate boiling within 200 DEG  to 500 DEG  F., the hydrocarbon serving to control the reaction, to act as a solvent for the alcoholate and to aid the separation of the alcohol from the slurry after hydrolysis.  The alumina in the slurry is in the form of the beta trihydrate and may be dried at 200 DEG  to 400 DEG  F. before conversion to crystalline eta alumina by dehydration, preferably in the presence of air.  Catalytic components may be incorporated in the alumina before or after the drying step and before or after conversion to eta form. Molybdenum, vanadium, tungsten or chromium oxide or metallic salts of molybdic acid such as the calcium or cobalt salts may be employed as catalysts; thus molybdenum oxide may be slurried with the hydrous alumina or the latter can be dried and the molybdenum oxide sublimed thereon.  The molybdenum oxide content may be from 5 to 20 per cent and the chromia content may be up to 40 per cent. The alumina is particularly suitable for platinum or palladium containing catalysts, 0.001 to 2.0 per cent of platinum, or 0.5 to 5 per cent of palladium normally being employed.  The platinum may be applied to the hydrous, dried or calcined alumina as aqueous solutions or dispersions, e.g. of chloro-platinic acid, potassium platinum chloride, platinum disulphide, tetramino platino chloride, potassium platino-nitrite, dichloro diamino platinum, ammonium platino-nitrite or dinitrito-diaminoplatinum; the solutions are preferably employed in amounts to impregnate the alumina with the desired amount of platinum whilst just wetting the total alumina. After drying and, if desired, calcining, the catalysts may be reduced with hydrogen at 200 DEG  to 1000 DEG  F. at pressures up to 1000 p.s.i.g.  The alumina may be treated before, after or during impregnation with the active catalytic components, with an aqueous dilute solution containing an oxidizing acid such as nitric, perchloric or hypochlorous acids together with a hydrogen halide, and preferably a mixture of nitric and hydrochloric acids.  The catalysts may also be treated with a gaseous halogen, e.g. chlorine, to absorb an amount of 0.1 to 10 per cent by weight thereof.  Examples compare the effect of different temperatures of hydrolysis, concentration of ammonia, and duration of ageing.  According to Example (4), aluminium amylate was hydrolysed with water containing 2.4 per cent NH3 and the resulting alumina was dried at 250 DEG  F. and contacted with a solution of hydrochloric and nitric acids at 150 DEG  F. for one hour, after which the product was calcined for four hours at 1100 DEG F.  The calcined material was washed, dried at 250 DEG  F., calcined for one hour at 1150 DEG  F. and impregnated with chloroplatinic acid solution after which it was dried at room temperature for 24 hours, then at 250 DEG  F. for four hours, and finally calcined for one hour at 1150 DEG  F. to yield a finished catalyst containing 0.6 per cent platinum.  The catalysts are employed for the hydroforming of petroleum hydrocarbons in the presence of hydrogen, (see Group IV (b)).  Specifications 667,145 and 754,552 are referred to.