Patent GB-791094-A (GB)
Title: Improvements in or relating to the manufacture and use of supported molybdenum-containing catalysts
IPC: F02B3/06
Filed: 1955-11-22
Abstract: Gasoline fractions are reformed in the presence of a supported catalyst comprising a molybdenum compound and an iron group metal compound prepared by compositing a molybdenum compound with solid support particles of definite size and shape which have been calcined at 620-870 DEG  C., calcining the intermediate composite at a temperature not higher than 565 DEG  C., compositing with an iron group compound, and calcining the final composite at 565-760 DEG  C. (see Group III).  In Example VI a catalyst comprising alumina, silica, molybdenum oxide and cobalt oxide is used for reforming a straight run naphtha at 516 DEG  C. and 47.5 atmospheres in the presence of hydrogen.  Specification 657,400, [Group III], is referred to.ALSO:Catalyst comprising a solid support, a molybdenum compound and an iron group metal compound is prepared by compositing a molybdenum compound with solid support particles of definite size and shape which have been calcined at 620-870 DEG  C., calcining the intermediate composite at a temperature not higher than 565 DEG  C., compositing with an iron group compound and calcining the final composite at 565-760 DEG  C.  The support is preferably a gamma or other adsorptive alumina which has been prepared by precipitation from an aluminium salt or an aluminate or by treatment of naturally occurring alumina with acid, and formed into pellets or spheroidal particles.  Other suitable materials for the support are silica, zirconia, thoria, magnesia, titania, and zinc oxide, used alone or in combination with one another or with alumina. Before calcining, the carrier or the intermediate or final composite may be dried at 93-205 DEG  C. for 1-10 hours or more; calcination takes place in an oxidizing atmosphere, e.g. air, in a reducing atmosphere, or in nitrogen or methane for 0.5-10 hours or more.  Molybdenum is introduced as an aqueous or ammoniacal solution of molybdic acid or ammonium paramolybdate.  In order to introduce the iron group metal compound, use may be made of solutions of cobalt nitrate, bromate, bromide, chlorate, chloride, fluosilicate, or iodide, cobalt potassium sulphate, cobalt ammonium nitrate, chloride, or sulphate, nickel bromide, chloride, fluosilicate, iodide nitrate, or sulphate, nickel ammonium nitrate or sulphate, iron ammonium sulphate, or ferrous or ferric bromide, chloride, or nitrate.  The final catalyst preferably contains 1-12 per cent by weight of molybdenum and 0.5-10 per cent by weight of cobalt or other iron group metal.  Fluorine and/or chlorine may be introduced in amounts of 0.1-10 per cent by weight or more by treating the support before calcination with an aqueous solution of hydrogen fluoride and/or hydrogen chloride. Before use the catalyst may be sulphided by treatment with hydrogen sulphide or other sulphur compound.  The catalyst may be regenerated by means of an oxygen-containing gas, preceded if desired by a reducing gas.  The catalyst is suitable for the treatment of gasline, aromatic solvents, kerosene, stove oil, diesel fuel, gas oil, or fuel oil to remove impurities containing sulphur, nitrogen, oxygen, and arsenic.  Treatment of the oils in the presence of hydrogen may be carried out at temperatures of 260-427 DEG  C. and pressures of 3.4 to 340 atmospheres.  Other processes for which the catalysts may be used are reforming gasoline, hydrocarbon dehydrogenation, isomerization, destructive hydrogenation, hydrogen transfer, alkyl transfer, or polymerization.  Fixed bed, moving bed, fluidized or slurry type processes may be employed.  In Examples I-IV catalysts comprising 6 per cent molybdenum and 3 per cent cobalt supported on alumina pellets are prepared using different calcination temperatures for the alumina and for the intermediate and final composites.  When these catalysts are used for the removal of thiophene and quinoline from naphtha, the catalyst prepared according to the invention provides the best removal of the basic nitrogen compound.  Example V describes the use of the catalyst in the treatment of cracked naphtha with hydrogen to reduce the sulphur and nitrogen contents and the unsaturation.  In Example VI alumina-silica pellets are impregnated with molybdenum and cobalt and used for reforming straight run naphtha in the presence of hydrogen.  Specification 657,400 is referred to.