Patent GB-191407866-A (GB)
Title: Process for the Production of Compounds of Nitrogen with Oxygen.
Inventor: CLASSEN ALEXANDER
IPC: C01B21/20
Filed: 1914-03-28
Granted: 1915-06-24
Abstract: 7866. Classen, A. March 28. Catalytic or contact apparatus; catalytic agents, preparation and treatment of.-Nitric pentoxide is prepared synthetically by subjecting air in the presence of finely divided conducting contact substances consisting of metal in a colloidal form, to the simultaneous action of dark and sparking electric discharges at a temperature substantially between 50-90‹ C. The nitric pentoxide is afterwards absorbed in water or alkali lye. The colloidal contact substances are advantageously prepared with the aid of gelatose obtained by lengthy boiling of a solution of gelatine or bone- or fish-glue, although glue, albumen, and salt-like compounds of albumen may be used in the place of gelatose. This method is particularly suitable for the metals of the platinum group, the rare earth metals, gold, silver, tungsten, molybdenum, uranium, titanium, and niobium. The gelatose acts as a protective colloid for the solution of the colloidal metal, and may be added before or after the production of such solution. In the case of gold, the gelatose acts as a reducing-agent in a boiling solution of a salt; while in the case of platinum chloride solution, the reduction is effected in the presence of gelatose by, for example, hydrazine hydrate. The colloidal solution is concentrated, and treated with indifferent carriers, such as asbestos, saw-dust, or kieselguhr, which take up the colloidal metal. The mass is then dried, and may be afterwards calcined. To convert chromium, molybdenum, tungsten, silicon, ferrochromium, ferro-silicon, or chrom-nickel into a finely divided state, they are, after corrosion with acids or bases, treated in a ball-mill with concentrated gelatose solution. The liquid so obtained is used to treat indifferent carriers, such as asbestos. The oxides of uranium, nickel, tungsten, &c. may be used as contact carriers, and they at the same time exercise contact effects. The apparatus used, in one form, comprises concentric tubes a, b, Fig. 1, of dielectric material, the outer tube being immersed in water, which acts as the negative electrode, the positive electrode being a cylinder d of copper-wire net arranged inside the tube b. The contact substance c, for example platinized asbestos, is attached to the outside of the' tube b, for example by an enclosing- web o. Gas is passed through the tube b, which is open at the bottom, and passes away through the reaction space between the tubes a, b. The inner electrode is cooled by the passage of air through a tube g placed inside it. Several of the apparatus may be connected in series so that the gas passes through them in succession. The apparatus may be modified by dispensing with the inner tube band employing a metal tube as the positive electrode, which is surrounded by an asbestos tube coated with the contact substances or which is coated directly with these substances. In another form, the inner electrode consists of a metal tuipe b<1>, Fig. 4, and an insulated wire net d is arranged between this electrode and the outer electrode e. The electrode b<1> and the wire net are spread with the contact masses. The Specification as open to public inspection under Section 91 (3) (a) comprises also the application of the process to the production of ammonia from its elements, the gases being led through a space in which the discharges are taking place, and which is packed with platinized asbestos. It is stated that finely divided metal oxides are formed during the production of the colloidal metals, and that the oxides have a promoting effect on the production of ammonia. The production of ammonia may take place at normal, reduced, or increased pressure. A modification of the apparatus for producing nitrogen oxides is also described, in which a plain metal tube is used as the inner electrode, and contact substances are omitted. In another modification, the inner electrode consists of platinum wire i, Fig. 7 (Cancelled), coiled around a quartz or like tube k, and air is led through a number of pipes surrounding this.- A concentrating-tube is also fitted. This subject-matter does not appear in the Specification as accepted.