Abstract: Substituted or unsubstituted cyclohexylamine and substituted or unsubstituted dicyclohexylamine can be produced by catalytic hydrogenation of substituted or unsubstituted aniline by using a ruthenium catalyst which in addition to ruthenium also contains palladium, platinum or palladium and platinum on a support from the group consisting of Al.sub.2 O.sub.3 and aluminum spinel treated with chromium and manganese and containing the noble metals in a total amount of 0.05-5% by weight and a weight ratio of Ru:Pd, Ru:Pt, or Ru:Pd/Pt of 1:9-9:1. All percentages are based on the total weight of the catalyst.

Abstract: In a process for the preparation of aqueous formaldehyde solutions consisting of the following steps:(a) reaction of a methanol/water/air mixture in vapor form at elevated temperature over a catalyst,(b) absorption of the reaction mixture in one or more successive absorption stages with the formation of a methanol-containing aqueous formaldehyde solution and(c) removal by fractional distillation of a fraction esentially containing methanol and water,the methanol/water/air mixture which is required for the reaction is evaporated by means of heat which is withdrawn by indirect heat exchange from the formaldehyde solution being formed in the absorber and/or at least some of the vapors obtained by fractional distillation are condensed by means of liquid water. This condensate is fed together with fresh methanol and with air into the evaporator which is upstream from the catalyst stage.

Abstract: Optionally substituted cyclohexylamine and optionally substituted dicyclohexylamine can be obtained by the catalytic hydrogenation of optionally substituted aniline, a ruthenium catalyst which is supported in Al.sub.2 O.sub.3 treated with compounds of rare earth metals and of manganese and which has a ruthenium content of 0.05-5% by weight, relative to the total weight of the catalyst, being employed.

Abstract: A demountable wheel optionally mountable on a hub equipped with cyclindrical studs and on a hub equipped with tapered studs. For this purpose the wheel is provided with a first ring of bores accommodating hubs having cylindrical studs and with a second ring of tapered bores accommodating hubs having tapered studs.

Abstract: A process has been developed for the oxidation of organic substances, dissolved or dispersed in an aqueous system, with a gas containing molecular oxygen at elevated temperature and under elevated pressure chiefly to carbon dioxide and water, with subsequent phase separation of the reaction mixture into a gaseous phase substantially containing inert gas, carbon dioxide, steam and organic constituents and a liquid phase substantially containing water, characterized in that the pressure is adjusted, at the given temperature, so that by evaporation of water from the aqueous system, more steam than the exothermicity of the oxidation reaction gives rise to, goes into the gaseous phase, which is fed to a heat exchanger in which the amount of heat required to maintain the oxidation temperature is completely or partially transferred to a mixture of water and a gas containing molecular oxygen, which mixture flows in on the other side of the heat exchanger and is subsequently fed to the reactor.

Abstract: A process for regenerating a deactivated oxidation catalyst, especially one containing vanadium oxide, wherein the deactivated catalyst is treated with an aqueous solution of ammonia and/or an amine at an elevated temperature so as to dissolve at least a portion of the catalyst and the resultant solution or suspension is treated in a known manner to obtain the reactivated catalyst.

Abstract: Hydrocarbons containing 4 to 20 carbon atoms are oxidized by a process which includes the following steps:A. Reacting the hydrocarbons with a gas containing molecular oxygen in the presence of a boron compound;B. hydrolyzing the resulting reaction mixture which contains at least one boric acid ester with an aqueous medium containing boric acid;C. separating the hydrolyzate into a substantially organic component from which the oxidation product is recovered and a substantially aqueous component containing boric acid and water-soluble organic secondary products;D. recovering boric acid from the aqueous component;E. oxidizing the residual boric acid mother liquor from (d), or a part thereof in the liquid phase with a gas containing molecular oxygen; andF. returning the resulting solution from (e) to hydrolysis step (b).

Abstract: Hydrocarbons containing from 4 to 20 carbon atoms are oxidized with a gas containing molecular oxygen in the presence of a catalyst and/or auxiliary agents. The resulting reaction mixture is saponified with an aqueous alkaline solution and the resulting alkaline solution containing organic impurities is subjected to liquid phase oxidation with a gas containing molecular oxygen in at least a stoichiometric quantity sufficient for completely burning the organic ingredients, the oxidation taking place in a reaction zone heated to at least 200.degree.C under a pressure sufficient to keep at least some of the water in the liquid phase. The alkali carbonate/bicarbonate solution formed is recycled to the hydrolysis stage.