Patent GB-718017-A (GB)
Title: Improvements in and relating to the production of paraffin wax
IPC: C10G73/02
Filed: 1951-01-30
Abstract: Paraffin waxes are produced from a hydrocarbon mixture containing constituents boiling above 320 DEG  C. by distilling to leave a residue boiling above 320 DEG  C., treating the residue with hydrogen at 200-260 DEG  C. and a pressure of at least 5 kg./sq. cm. in the presence of a hydrogenation catalyst comprising a metal and/or metal oxide, and separating paraffin wax fractions from the treated residue by solvent extraction.  Hydrocarbon mixtures specified are those obtained by the conversion of gas mixtures containing carbon monoxide and hydrogen, for example, using an iron or cobalt catalyst supported on kieselguhr, by the low temperature carbonization of lignite, by the distillation of shale or from petroleum fractions.  Catalysts specified are nickel and magnesium oxide precipitated on kieselguhr and iron and cobalt catalysts.  The solvent extraction can be carried out with benzene, carbon tetrachloride or trichlorethylene and isopropanol or normal propanol; part of the solvent is distilled off after each crystallization and filtration stage.ALSO:Paraffin waxes are produced from a hydrocarbon mixture containing constituents boiling above 320 DEG  C. by distilling to leave a residue boiling above 320 DEG  C., treating the residue with hydrogen at 200-260 DEG C. and a pressure of at least 5 kg./sq. cm. in the presence of a hydrogenation catalyst comprising a metal and/or metal oxide, and separating paraffin wax fractions from the treated residue by solvent extraction.  Hydrocarbon mixtures specified are those obtained by the conversion of gas mixtures containing carbon monoxide and hydrogen, for example, using an iron or cobalt catalyst supported on kieselguhr, by the low temperature carbonization of lignite, by the distillation of shale or from petroleum fractions.  Catalysts specified are nickel and magnesium oxide precipitated on kieselguhr and cobalt catalysts. The solvent extraction can be carried out with benzene, carbon tetrachloride or trichlorethylene and isopropanol or normal propanol; part of the solvent is distilled off after each crystallization and filtration stage.  In one example a synthetic product boiling above 340 DEG  C. obtained by passing water gas over a precipitated iron catalyst supported on kieselguhr is mixed with a nickel magnesium oxide catalyst and heated to 250 DEG  C.  Hydrogen and nitrogen is passed into the mixture at a pressure of up to 50 kg./sq. cm. and the reaction mixture then separated from the catalyst and treated with a mixture of benzene and normal propyl alcohol.  The mixture is cooled to 20 DEG  C., wax (M.P. 99.5 DEG  C.) filtered off and after distilling off part of the solvent and again cooling to 20 DEG  C. paraffin wax (M.P. 50/52 DEG  C.) is precipitated and filtered off.  Preparation of catalysts.  The nickel magnesium kieselguhr catalyst is prepared by heating a solution of nickel nitrate and magnesium nitrate, adding the mixture to sodium carbonate solution and then adding kieselguhr.  The resulting precipitate is separated, washed, dried and moulded and then reduced at 380 DEG  C. with a mixture of hydrogen and nitrogen, to produce a catalyst containing 75 per cent. of metallic nickel.  The iron catalyst used for the production of the synthetic product from water gas is prepared by mixing a hot solution of ferric nitrate and copper nitrate with a hot solution of sodium carbonate, to obtain after the precipitation a mixture of pH 7. The precipitated compounds are filtered off and washed, and then mixed with water to form a suspension, to which potassium silicate is added.  This mixture is neutralized with nitric acid and the suspension filtered and moulded. The moulded particles are then reduced with a hydrogen-nitrogen mixture at 280 DEG  C. to produce a catalyst containing 42 per cent. of metallic iron.  The cobalt catalyst used for the production of a synthetic product from water gas is prepared by mixing a hot solution of cobalt, thorium and magnesium nitrates with sodium carbonate solution and then adding roasted kieselguhr.  The suspension is stirred, filtered, and the filtered mass washed, pressed, moulded and dried.  The catalyst particles are reduced in a nitrogen-hydrogen mixture at 400 DEG  C., to produce a catalyst containing 50 per cent. of metallic cobalt.