Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes successively passing a solution to be purified through at least two beds of cation-exchange adsorbents (CEA) and two beds of anion-exchange adsorbents (AEA) according to the sequence: AEA→CEA→AEA→CEA Also provided is a plant for the implementation of the inventive process.

Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes passing a solution to be purified successively through at least one bed of anion-exchange adsorbents (AEA) and at least one bed of cation-exchange adsorbents (CEA). A non-zero proportion of the solution exiting from one of the beds is recycled to a point upstream of the one bed or upstream of a preceding bed or upstream of the first bed of the first of the at least one sequence. Also provided is a plant for the implementation of the inventive process.

Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process includes at least one sequence which includes successively passing a solution to be purified through at least one bed of cation-exchange adsorbents (CEA) and at least one bed of anion-exchange adsorbents (AEA). The beds of adsorbents each exhibit a height to diameter ratio of greater than 3. Also provided is a plant for the implementation of the inventive process.

Abstract: Process for purification of aqueous solutions of hydrogen peroxide comprising the steps of adding one or more macroligands to said solution to form a mixture and forcing the mixture through an ultrafiltration membrane.

Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution to be purified through at least one bed of anion-exchange adsorbents and at least one bed of cation-exchange adsorbents. The at least one bed of anion-exchange adsorbents contains carboxylate ion of formula R--COO.sup.- in which R represents a hydrogen atom, an aryl radical containing from 6 to 10 carbon atoms or an alkyl radical containing from 1 to 4 carbon atoms. The aryl and alkyl radicals are either unsubstituted or substituted by one or more fluorine atoms. A first bed of the at least one bed of anion-exchange adsorbents through which the solution to be purified passes is a bed containing carboxylate ions of formula R--COO.sup.-. Also provided is a plant for the implementation of the inventive process.

Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes successively passing a solution to be purified through at least two beds of cation-exchange adsorbents (CEA) and two beds of anion-exchange adsorbents (AEA) according to the sequence:AEA .fwdarw. CEA .fwdarw. AEA .fwdarw. CEAAlso provided is a plant for the implementation of the inventive process.

Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process includes at least one sequence which includes successively passing a solution to be purified through at least one bed of cation-exchange adsorbents (CEA) and at least one bed of anion-exchange adsorbents (AEA). The beds of adsorbents each exhibit a height to diameter ratio of greater than 3. Also provided is a plant for the implementation of the inventive process.

Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes passing a solution to be purified successively through at least one bed of anion-exchange adsorbents (AEA) and at least one bed of cation-exchange adsorbents (CEA). A non-zero proportion of the solution exiting from one of the beds is recycled to a point upstream of the one bed or upstream of a preceding bed or upstream of the first bed of the first of the at least one sequence. Also provided is a plant for the implementation of the inventive process.

Abstract: A method using auto-oxidation of an anthraquinone derivative in three successive steps, comprising hydrogenating the working solution (at 1), oxidizing the hydrogenated working solution (at 2), and removing hydrogen peroxide using water (at 3). The hydrogenation step is performed in such a way that a hydrogen peroxide equivalent of around 7.9 g/l is achieved at the inlet of the oxidizer (2), and the oxidation step (b) is performed in such a way that the temperature at the top of the oxidizer (2) is below about 50.degree. C., and preferably around 35-40.degree. C. The method is useful for producing hydrogen peroxide in situ in a paper pulp bleaching plant.

Abstract: A plant for producing hydrogen peroxide by autooxidation of an anthraquinone derivative, including a catalytic hydrogenation vessel (1) supplied with hydrogen; an oxidizing vessel (2) supplied with an oxygen-containing fluid, particularly air; an extractor (3) supplied with water; and elements (7,16,19) for successively feeding a working solution containing at least one anthraquinone derivative dissolved in at least one organic solvent through the hydrogenation vessel (1), the oxidizing vessel (2) and the extractor (3), then recirculating it to the hydrogenation vessel (1). Elements (9,26) are provided for diverting at least part of the working solution from the extractor (3) to the oxidizing vessel (2) so that it bypasses the hydrogenation vessel (1). The plant is useful for producing hydrogen peroxide in situ in a paper pulp bleaching plant.

Abstract: Process for purification of aqueous solutions of hydrogen peroxide comprising the steps of adding one or more macroligands to said solution to form a mixture and forcing the mixture through an ultrafiltration membrane.

Abstract: A method using auto-oxidation of an anthraquinone derivative in three successive steps, comprising hydrogenating the working solution (at 1), oxidizing the hydrogenated working solution (at 2), and removing hydrogen peroxide using water (at 3). The hydrogenation step is performed in such a way that a hydrogen peroxide equivalent of around 7.9 g/l is achieved at the inlet of the oxidizer (2), and the oxidation step (b) is performed in such a way that the temperature at the top of the oxidizer (2) is below about 50.degree. C., and preferably around 35.degree.-40.degree. C. The method is useful for producing hydrogen peroxide in situ in a paper pulp bleaching plant.

Abstract: The invention relates to an aqueous composition which is stable with time, containing an organic peroxy acid and at least one thickening agent in a concentration such that the viscosity of the composition is greater than 100 mPa.s, as well as the use of this composition, in particular as a disinfecting and/or cleaning agent.

Abstract: Process for the preparation of a hydroxylated secondary or tertiary amine compound having a hydroxyl function .beta. to the amine function, according to which a primary or secondary amine compound is reacted with a compound containing an epoxy function in the presence of a phase transfer catalyst.

Abstract: A process for preparing any substance capable of forming a clathrate with a gas may start from a mixture in solution or in suspension of this substance with other components. This mixture is contacted with a gas to form a clathrate with the substance, a precipitate is collected, and the substance is recovered. The invention is especially useful for purifying .alpha.-cyclodextrin.

Abstract: The invention concerns derivatives of peroxyacids consisting of inclusion compounds or clathrates, in a hollow molecule which is capable of behaving as a receiving structure which respect to a given peroxyacid, their process of preparation and their uses.

Abstract: Aromatic aldehydes are produced by oxidation with oxygen of a para-cresol derivative in a solvent, in the presence of a base and a catalytic amount of a cobalt compound. The catalyst is a chelated complex of cobalt with a rigid structure that is slightly oxidizable selected from the group consisting of bis-(4-methylpyridine isoindolinato)cobalt(II) acetate, phthalocyaninatocobalt(II), and sulfophthalocyaninanatocobalt(II). The process is particularly suited to the production of p-hydroxy benzaldehydes.

Abstract: A method and apparatus are provided for treating gaseous effluents containing sulfur dioxide. Sulfur dioxide is oxidized by oxygen in a concentrated sulfuric acid medium in the presence of a catalyst comprising electrooxidized salts of Mn+2. The gaseous effluents are converted to directly usable sulfuric acid.