Abstract: A cyclic process for hydrogen peroxide production comprises a reduction of a quinone compound, followed by an oxidation into hydroperoxide, then finally a water extraction giving an aqueous hydrogen peroxide solution. An aqueous solution containing an organophosphonic acid, such as diethylene triamino pentamethylenephosphonic acid, and optionally associated with nitric acid or a nitrate is introduced during the oxidation and extraction phases to reduce the corrosion during the oxidation and extraction phases and improve the oxidation yield.

Abstract: A process is disclosed for the regeneration, by thermal treatment, of used catalysts for a cyclical process for the production of hydrogen peroxide. According to the process, used aluminosilicate type catalyst is subjected to progressive heating up to a temperature between 700.degree. and 850.degree. C., in the presence of an oxidizing atmosphere circulating co-current to the catalyst being regenerated. The process can be carried out in a rotary furnace inclined to the horizontal by 0.7 to 1% and having radial fins on the lower section of its inner wall, and an adjustable diaphragm at its outlet.

Abstract: Improved methods and apparatus for the purification of industrial flue gases, combustion products and gaseous effluents before their rejection to the atmosphere, said gases and effluents containing as impurities especially sulfur oxide and also oxides of nitrogen, sulphuric fogs, dust and soot, said method comprising essentially the steps of: extracting the dust from the gaseous fluid to be purified; proceeding to a chemical purification phase of the gaseous fluid by establishing intimate contact between said fluid and an aqueous solution of hydrogen peroxide at a temperature lower than 80.degree.C.; and carrying out a concentration phase by effecting a direct contact between the gases and the liquid of the gaseous effluents in the hot state, and said liquid being constituted by sulphuric acid formed during said purification phase. The chemical purification phase is carried out on the gaseous effluents when these latter are saturated with water and is effected at a temperature between 55.degree. and 65.

Abstract: A process for regenerating working solutions used in cyclic processes for the manufacture of hydrogen peroxide using anthraquinones, the process consisting of a first distillation stage in which the solvent is separated under a pressure not greater than atmospheric pressure, and a second distillation stage in which the quinones and "light degraded products" are separated under a lower pressure. All the distillation products are used as a new working solution, the vapors of the second distillation stage being condensed on a liquid film of constantly renewed cold solvent originating from condensable vapors of the first distillation stage.

Abstract: The invention relates to a process for separating mixtures of hydrocarbons, notably conjugated diene hydrocarbons or aromatic hydrocarbons, from mixtures containing the same, by the general technique of permeation or pervaporation through specific membranes.The specific membranes used are formed of a high polymer comprising functional groups chemically combined by covalent bonding within the polymer forming the said membrane, the said groups possessing a physicochemical affinity, notably a capacity to complex, with respect to one of said hydrocarbons and, substantially, the absence of such a capacity with respect to other hydrocarbons of the mixture. For the separation of dienes, such as butadiene and pentadiene, membranes are used containing active nitrile, pyrrolidone, N-substituted groups, such as N-alkyl groups, preferably N-vinyl or N-methyl-pyrrolidone. The membrane can be obtained, for example, by copolymerization of butadiene with acrylonitrile, with the membrane containing about 2.