Patent GB-794809-A (GB)
Title: Improvements in or relating to the hydrogenation of petroleum fractions
IPC: B01J21/04
Filed: 1957-01-10
Abstract: Petroleum fractions containing aromatic compounds boiling in the range 300-650 DEG  F. are upgraded by hydrogenation at 500-675 DEG F., 100-1000 p.s.i.g., in the presence of 5000-8000 S.C.F. of hydrogen per barrel of feed over a platinum on eta alumina catalyst (see Group III).  Specified feeds are kerosene, diesel fuel, gas oil and jet fuel.  The principle reaction is the hydrogenation of aromatics, and the process is of particular value in the treatment of feedstocks containing 10-50 per cent of aromatics and having a naphthene content of less than 30 per cent. The catalyst may contain 0.001-5 per cent of platinum and the support alone or after deposition of the catalyst may be acid treated before or after calcination.  Regeneration of the catalyst may be effected by a hydrogen treatment, e.g. at 900-1100 DEG  F. for 1-8 hours at reaction pressure, or by an oxidative treatment with air diluted with nitrogen at a temperature below 1050 DEG  F. for an initial period followed by undiluted air at 950-1175 DEG  F. for 1-4 hours or more at reaction pressure.  A non-regenerative procedure may also be used wherein the catalyst is stripped with hydrogen at 500-800 DEG  F. and reaction pressures for 5-60 minutes at intervals of 5-180 minutes. High sulphur feed stocks may be hydrodesulphurized over a cobalt molybdate catalyst if desired.  In an example a mixture of xylenes and a kerosene was submitted to a continuous operation using feed rates of 0.8-1.0 vol./vol./hr. and details are given of the aromatic contents of the products at intervals.ALSO:A catalyst comprising platinum on eta alumina is prepared by impregnating the support with a water-soluble inorganic platinumcontaining compound, dried at 100-600 DEG  F. and calcined at 800-1250 DEG  F. for 1 to 24 hours and is used in hydrogenating petroleum fractions boiling in the range of 300-650 DEG  F. (see Group IV (b)).  The eta alumina support is prepared by heating alumina beta trihydrate at 450-1400 DEG  F., the trihydrate itself being prepared by hydrolysing aluminium alcoholate with aqueous ammonium hydroxide containing 1.8 to 3.4 weight per cent ammonia in an amount of 1 to 10 volumes per volume of aluminium alcoholate at 35-100 DEG  F. with agitation.  The resultant slurry is aged for 1 to 15 hours at 35-80 DEG  F. and then dried at 200-400 DEG F to recover dry alumina.  This is dehydrated preferably at 450-1100 DEG  F. in air or inert gases to give eta alumina.  The base may be calcined at 800-1600 DEG  F. for 1-24 hours before impregnating. Chlorplatinic acid and platinum sulphide are suitable compounds for impregnating; colloidal solutions of platinum compounds can also be used.  A preferred solution contains 15 grams of chlorplatinic acid (40 per cent by weight platinum) per litre of solution which gives about 0.6 per cent platinum in the catalyst, but the strength can be varied to give 0.001 to 5 per cent of platinum on the support.  The final catalyst or the alumina base, before or after calcination may be acid treated with an aqueous dilute mixed acid solution containing nitric, perchloric or hypochlorous acid and a hydrogen halide (including HF).  A mixture of nitric acid, in an amount of 0.1-8 per cent by weight based on the catalyst, and hydrogen chloride, 1-30 per cent by weight based on catalyst is preferred in 50-500 weight per cent of water based on catalyst.  The catalyst is mixed with the acid solution and heated on a steam bath at 150-190 DEG  F. for at least one hour, drained and washed with water, dried at about 250 DEG  F. and recalcined at 800-1250 DEG  F. for 1-4 hours.  In hydrogenating petroleum fractions at 500-675 DEG  F. and 100-1000 p.s.i.g. in the presence of 5000-8000 S.C.F. of hydrogen per barrel of feed, the catalyst may be regenerated by a hydrogen treatment at 900-1100 DEG F. for 1-8 hours or by an oxidative treatment with air diluted with nitrogen at a temperature below 1050 DEG  F. for an initial period followed by undiluted air at 950-1175 DEG  F. for 1-4 hours.  In a nonregenerative procedure the catalyst is stripped with hydrogen at 500-800 DEG  F. for 5-60 minutes at intervals of 5-180 minutes.