Patent GB-755134-A (GB)
Title: Fluid alumina-molybdenum oxide reforming catalyst
IPC: B01J23/28
Filed: 1954-04-13
Abstract: A hydrocarbon oil may be reformed with a catalyst comprising alumina, molybdenum oxide and graphite (see Group III).  In examples naphtha boiling in the range 224-328 DEG  F. was reformed at 925 DEG  and at 955 DEG  F. and 200 p.s.i.g.  Further operating conditions, and properties of the products are given.ALSO:A catalyst for fluid reforming comprises alumina and molybdenum oxide and 0.5-15 preferably 2-5 per cent by weight of powdered graphite.  The latter component is incorporated either during coprecipitation of the alumina and molybdena or during precipitation of alumina, the molybdenum being incorporated subsequently, before or after calcination.  The graphite particles will generally not exceed 50 microns and are preferably of less than 10 microns.  Suitable starting materials are aluminium chloride, sulphate or nitrate (sodium aluminate is preferably not used: the sodium content of the catalyst should preferably be kept below 0.5 per cent of the catalyst); and ammonium mono-, di- or hepta-molybdate or solutions prepared by dissolving molybdic acid or anhydride in aqueous ammonia: 10 to 15 per cent aqueous ammonia is a suitable precipitant, and preferred concentrations of the other reactants are given. Procedures referred to are: bringing together the aluminium and molybdenum solutions and graphite and adding to the mixture (or adding the mixture to) the ammonia; mixing ammonia and the molybdenum solution and adding to this mixture (or adding this mixture to) the aluminium solution-any one or all solutions containing the graphite. The precipitate thus produced is in the form of a gel.  After precipitation the pH should be adjusted to about 8 and the material is preferably allowed to stand and then collected by filtration or decantation with thorough washing.  The precipitate is then dried, preferably by spraying a slurry, to give the catalyst in microspheroidal form.  The catalyst may be calcined in the same operation, or subsequently, e.g. in a rotary calciner for 2 to 6 hours at 900 to 1200 DEG F. in a suitable atmosphere such as air or flue gas.  If desired, the oxygen partial pressure may be reduced to avoid oxidation and loss of graphite.  The molybdenum may be introduced, if not already present, into the slurry for the spray drier or the dried microspheres may be impregnated with the molybdenum solution.  The filter cake may alternatively be dried on trays at 200 to 300 DEG F., followed by grinding.  A high molecular weight water dispersible organic material preferably having molecular weight from 103-107, better an animal protein such as glue, with a molecular weight from 104-106 in quantity from 3-30 per cent, better 5-15 per cent by weight based on the alumina and molybdene may be employed in the precipitation to give a more highly active catalyst, e.g. by pre-dispersing it in one of the reactant solutions or by adding it as separate stream during coprecipitation.  The concentration must be below that at which gel formation takes place. Other materials specified are gelatine, vegetable proteins, cellulosic materials and derivatives thereof, high molecular weight carbohydrates, alcohols and esters, and natural or synthetic emulsions or colloids such as rubber latex, microscopic living organisms, bacteria and moulds.  The organic material may be removed during calcination at e.g. 900 to 1000 DEG F. in air.  In use the catalyst may be regenerated at 900 to 1000 DEG F. with only 1 to 2 per cent of oxygen in the regeneration gas to prevent loss of graphite.  In an example, heating at 1470 DEG F. in nitrogen slightly improves activity.