Abstract: In a cyclic anthraquinone process for producing hydrogen peroxide, which comprises a distillation unit with vapor compression for concentrating hydrogen peroxide, aqueous condensate from the distillation unit is passed over a bed of a cation exchange resin in its protonated from to provide a purified condensate, and the purified condensate is used as extractant for extracting hydrogen peroxide in the anthraquinone process, as column reflux for the distillation unit or as a diluent for diluting an aqueous hydrogen peroxide solution.

Abstract: Provided are a method and system for efficiently producing a purified aqueous hydrogen peroxide solution having a high purity. This method for producing a purified aqueous hydrogen peroxide solution comprises: step A for vaporizing a raw material containing a crude aqueous hydrogen peroxide solution; step B for condensing at least a portion of the gas and liquid obtained in step A, and separating the gas and liquid into a gas phase and a liquid phase; and step C for returning, into the raw material, at least a portion of a separation liquid which is the separated liquid phase, wherein step C further includes step D for adjusting the concentration of hydrogen peroxide in the separation liquid.

Abstract: A process and apparatus for removing hydrogen sulphide from a gas is disclosed. The process comprises the steps of: providing a gas comprising hydrogen sulphide; supplying oxygen for the process if the gas does not comprise oxygen, or does not comprise sufficient oxygen for converting hydrogen sulphide to elementary sulphur; leading the mixture of gas and, if supplied, oxygen to a tank comprising i) a foam forming liquid, such as a scrubber liquid and ii) a foam layer made from said foam forming liquid on the top of the foam forming liquid where the hydrogen sulphide in the gas is oxidized to elementary sulphur to form a cleaned gas removed from hydrogen sulphide.

Abstract: A metal-free catalytic oxidation system, an oxygenation method and a method for producing benzoic acid derivatives. The system includes a feed device; a tubular reactor; a plurality of venturi nozzles mounted on the tubular reactor at intervals; a tubular filter; a discharge device for a solid phase product; and an intermediate tank for reaction mixture. A low-pressure zone is formed at an output end of each of the plurality of venturi nozzles, and an oxygen inlet corresponds to the low-pressure zone; the tubular filter comprises an inner tube and an outer tube connected to each other, where the inner tube is provided with small holes for solid-liquid separation; the discharge device for the solid phase product is located at an end of the inner tube; and the intermediate tank for reaction mixture is connected to the outer tube of the tubular filter through a pipeline.

Abstract: A low-corrosivity composition suitable for dissolving scale on metals. The scale includes iron sulfide scale. The composition includes an aqueous hydrogen peroxide solution comprising hydrogen peroxide; and an acidic solution comprising at least one acid, where the hydrogen peroxide and acid are present at concentrations such that the hydrogen peroxide does not break down to form visible bubbles at about room temperature, where the hydrogen peroxide and acid are present at concentrations such that iron sulfide scale is removed from a metal with iron sulfide scale, after the composition contacts the metal and iron sulfide scale at an elevated temperature greater than room temperature, and where the hydrogen peroxide and acid are present at concentrations such that pitting is not caused on the metal, the metal comprising carbon steel.

Abstract: A process for manufacturing hydrogen peroxide by an anthraquinone autoxidation process (AO-process) comprising two alternate (essential) steps of: (a) hydrogenation of a working solution in a hydrogenation unit in the presence of a catalyst, wherein such working solution contains at least one alkylanthraquinone dissolved in at least one organic solvent, to obtain at least one corresponding alkylanthrahydroquinone compound; and (b) oxidation of the at least one alkylanthrahydroquinone compound to obtain hydrogen peroxide in an oxidation unit; and further comprising the step of: (c) extracting the hydrogen peroxide formed in the oxidation step in an extraction unit, wherein the units of step (a) to (c), optionally together with further ancillary units as appropriate, constitute a hydrogen peroxide production site, wherein one or more of said units are equipped with one or more sensors for monitoring one or more AO-process parameters at the hydrogen peroxide production site, said sensors being interconnected wit

Abstract: A continuous process for producing hydrogen peroxide by an anthraquinone process, comprising the steps of: (i) hydrogenating an organic working solution containing one or more anthraquinone derivatives in the presence of a heterogeneous catalyst to form a hydrogenated working solution; (ii) oxidizing the hydrogenated working solution by introducing an oxygen-containing oxidizing gas at an overpressure into an oxidation reactor, and contacting the oxidizing gas with the hydrogenated working solution to form an oxidized working solution, whereby hydrogen peroxide is formed; (iii) withdrawing an oxidation off gas from the oxidation reactor; (iv) recovering the formed hydrogen peroxide from the oxidized working solution; (v) subjecting the oxidation off gas withdrawn from said oxidation reactor, which has an excess pressure over atmospheric pressure, to a demisting treatment to obtain a demisted oxidation off gas; and (vi) feeding the demisted oxidation off gas as propellant gas into a gas ejector to produce a va

Abstract: A process for manufacturing hydrogen peroxide by an anthraquinone autoxidation process (AO-process) comprising two alternate essential steps of: (a) hydrogenation of a working solution in a hydrogenation unit in the presence of a catalyst, wherein the working solution contains at least one alkylanthraquinone dissolved in at least one organic solvent, to obtain at least one corresponding alkylanthrahydroquinone compound; and (b) oxidation of the at least one alkylanthrahydroquinone compound to obtain hydrogen peroxide in an oxidation unit; and further comprising step (c): extracting the hydrogen peroxide formed in the oxidation step in an extraction unit, wherein the hydrogenation, oxidation and extraction steps are performed in an reactor system which is designed as a compact modular system of a hydrogenation, an oxidation and an extraction unit, and wherein the reactor system is configured to operate without a reversion (regeneration) unit for continuous reversion of the working solution as a small to medium

Abstract: Process and device for separating liquid from a multiphase mixture contained in a vessel and comprising solid particles and at least one liquid phase forming together at least one suspension, and a gas phase in which at least part of the mixture is circulated through at least one cross-flow filter located outside the vessel, therefore separating said part of the mixture into a filtered liquid and a concentrate.

Abstract: A continuous process for the production of propylene oxide comprising reacting propene with hydrogen peroxide in methanolic solution in the presence of a titanium silicalite-1 catalyst to obtain propylene oxide, wherein a reaction feed comprising propene, methanol and hydrogen peroxide is introduced into a reactor, said reaction feed containing potassium cations and phosphorus in the form of anions of at least one phosphorus oxyacid.

Abstract: The present invention relates to a method for the preparation of hydrogen peroxide through a continuous process, extracting hydrogen peroxide produced from reduction and oxidation of a working solution and recycling the oxidized working solution back to the reduction process, wherein the composition of the working solution, i.e. the composition of 2-alkylanthraquinone and 2-tetrahydroalkylanthraquinone, is optimized to increase the solubility of the quinones and to improve the reaction rate. The working solution comprises 2-alkylanthraquinone, 2-tetrahydroalkylanthraquinone and an organic solvent, wherein 65-95 mol % of the alkyl group of 2-alkylanthraquinone and 2-tetrahydroalkylanthraquinone is amyl and the remaining 5-35 mol % of the alkyl group is ethyl, and the molar ratio of 2-alkylanthraquinone to 2-tetrahydroalkylanthraquinone is from 4:6 to 1:9.

Abstract: Process and device for separating liquid from a multiphase mixture contained in a vessel and comprising solid particles and at least one liquid phase forming together at least one suspension, and a gas phase in which at least part of the mixture is circulated through at least one cross-flow filter located outside the vessel, therefore separating said part of the mixture into a filtered liquid and a concentrate.

Abstract: A process for production of hydrogen peroxide which comprises the following steps: (a) hydrogenation of a working solution comprising at least one non-ionic quinone compound selected from the group consisting of anthraquinone and its derivatives, phenanthrenequinone and its derivatives, naphthoquinone and its derivatives, and benzoquinone and its derivatives, wherein the total molecular weight of optional groups attached to the quinone skeleton is lower than 500, to obtain at least one corresponding hydroquinone compound; (b) oxidation of the at least one hydroquinone compound to obtain hydrogen peroxide; and (c) separation of the hydrogen peroxide, during and/or subsequently to the oxidation step b); wherein the working solution of either step a) and/or b) comprises less than 30% by weight of organic solvent.

Abstract: An aqueous hydrogen peroxide solution containing i) less than 50 wppm alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; ii) less than 50 wppm of amines having a pkB of less than 4.5 or the corresponding protonated compounds in total; and iii) at least 100 wppm anions or compounds that can dissociate to form anions in total, where the wppm are based on the weight of hydrogen peroxide and the concentration of hydrogen peroxide is more than 50% by weight based on the total weight of the hydrogen peroxide solution. A process for preparation of said hydrogen peroxide solution and the use of said solution in a process for epoxidation of olefins is also disclosed.

Abstract: An electroactivated film that includes: a first electrode that is spaced apart from a second electrode, a water insoluble electrically conductive medium which is permeable to moisture and oxygen and which contacts both electrodes, an electrocatalyst which can be reversibly oxidized and reduced and which facilitates the production of a peroxide when an electrical potential is imposed across the electrodes, and optionally a peroxide-activating catalyst which converts the peroxide to an activated peroxide, wherein one or both electrodes have electrocatalyst immobilized thereupon.

Abstract: A method for producing hydrogen peroxide by an anthraquinone process includes the steps of: reducing with hydrogen a working solution containing an organic solvent and anthraquinone in the presence of a hydrogenation catalyst; and activating the hydrogenation catalyst when a hydrogenation selectivity has decreased due to repeated use, wherein the catalyst activation step includes a step of treating the hydrogenation catalyst with a first alkaline aqueous solution of pH 10 or above containing an alkali metal, and then washing the treated hydrogenation catalyst with water or a second alkaline aqueous solution that is more weakly alkaline than the first alkaline aqueous solution so as to set a catalyst soak solution comprising 5 parts by weight of pure water in admixture with 1 part by weight of the activated hydrogenation catalyst to a pH of 8.0 or above.

Abstract: The present invention relates to a method for the preparation of hydrogen peroxide through a continuous process, extracting hydrogen peroxide produced from reduction and oxidation of a working solution and recycling the oxidized working solution back to the reduction process, wherein the composition of the working solution, i.e. the composition of 2-alkylanthraquinone and 2-tetrahydroalkylanthraquinone, is optimized to increase the solubility of the quinones and to improve the reaction rate. The working solution comprises 2-alkylanthraquinone, 2-tetrahydroalkylanthraquinone and an organic solvent, wherein 65-95 mol % of the alkyl group of 2-alkylanthraquinone and 2-tetrahydroalkylanthraquinone is amyl and the remaining 5-35 mol % of the alkyl group is ethyl, and the molar ratio of 2-alkylanthraquinone to 2-tetrahydroalkylanthraquinone is from 4:6 to 1:9.

Abstract: An aqueous hydrogen peroxide solution containing i) less than 50 wppm alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; ii) less than 50 wppm of amines having a pkB of less than 4.5 or the corresponding protonated compounds in total; and iii) at least 100 wppm anions or compounds that can dissociate to form anions in total, where the wppm are based on the weight of hydrogen peroxide and the concentration of hydrogen peroxide is more than 50% by weight based on the total weight of the hydrogen peroxide solution. A process for preparation of said hydrogen peroxide solution and the use of said solution in a process for epoxidation of olefins is also disclosed.

Abstract: A method for causing chemical reactions between fluids, comprising the steps of arranging a plurality of metal sheets for providing first fluid flow channels adjacent to and in heat transfer contact with second fluid flow channels between adjacent ones of the metal sheets, placing catalyst material within at least some of the flow channels, passing a first fluid mixture through the first fluid flow channels and a second fluid mixture through the second fluid flow channels, wherein the first fluid mixture is different from the second fluid mixture, each fluid mixture undergoing separate reactions, one of the reactions being endothermic while the other reaction is exothermic, and causing heat to transfer between the adjacent fluid flow channels.

Abstract: A composition including at least one peroxide-generating electrocatalyst, at least one peroxide-activation catalyst, and carbon.

Abstract: The invention relates to a process for the production of hydrogen peroxide comprising a liquid-liquid extraction step, said extraction step comprising contacting an organic feed solution containing hydrogen peroxide with an extraction solvent comprising less than about 30 wt % of water to achieve extraction of hydrogen peroxide to said extraction solvent and obtaining an extract containing hydrogen peroxide.

Abstract: The present invention provides a method for producing hydrogen peroxide, comprising the steps of: alternately reducing and oxidizing a working solution containing anthraquinone compounds as a reaction medium, wherein a mixture of alkyl-substituted anthraquinones and alkyl-substituted tetrahydroanthraquinones in a molar ratio of from 2:1 to 8:1 is used as the anthraquinone compounds in the working solution, in the reduction step all of the tetrahydroanthraquinones and some or all of the anthraquinones in the working solution are reduced; and keeping the content of alkyl-substituted anthrahydroquinones in the working solution after the reduction step and before the oxidation step higher than the content of alkyl-substituted tetrahydroanthrahydroquinones, wherein ethylanthraquinone and ethyltetrahydroanthraquinone are used as anthraquinone compounds in the working solution in a total proportion of both of from 10 to 45 mol % of all of the anthraquinone compounds in the working solution.

Abstract: Provided is a provides a method for producing hydrogen peroxide, comprising a step of reducing and then oxidizing a working solution containing an organic solvent, anthraquinone having an alkyl substituent, and tetrahydroanthraquinone having an alkyl substituent to produce hydrogen peroxide; and a working solution regeneration step of removing an inert substance, generated as a sub product by the production of hydrogen peroxide, from the working solution and re-circulating the working solution deprived of the inert substance back into the step of producing hydrogen peroxide; wherein the working solution regeneration step includes i) a first distillation step of recovering the organic solvent by distillation performed at an atmospheric or a lower pressure; and ii) a second distillation step of, following the first distillation step, recovering the anthraquinone and the tetrahydroanthraquinone by distillation performed at a still lower pressure at 200° C. or higher for a residence time of 1 hour or longer.

Abstract: Hydrogen peroxide is prepared by an auto-oxidation method via hydrogenation in a microreactor. A working solution containing a reactive carrier compound is hydrogenated with hydrogen in a microreactor and is subsequently auto-oxidized to produce hydrogen peroxide.

Abstract: A molten salt and process for preparing a molten salt or hydrogen peroxide uses ionic hydroquinones or hydroquinone derivatives as O2 reduction catalysts.

Abstract: The present invention includes methods and apparatuses that utilize microchannel technology and, more specifically in exemplary form, producing hydrogen peroxide using microchannel technology. An exemplary process for producing hydrogen peroxide comprises flowing feed streams into intimate fluid communication with one another within a process microchannel to form a reactant mixture stream comprising a hydrogen source and an oxygen source such as, without limitation, hydrogen gas and oxygen gas. Thereafter, a catalyst is contacted by the reactant mixture and is operative to convert a majority of the reactant mixture to hydrogen peroxide that is withdrawn via an egressing product stream. During the hydrogen peroxide chemical reaction, exothermic energy is generated. This exothermic energy is absorbed by the fluid within the microchannel as well as the microchannel itself.

Abstract: Hydrogen peroxide produced in an auto-oxidation process is recovered from H2O2-containing organic solution via liquid-liquid extraction with an aqueous medium in a device having elongated channels, with a small cross-sectional dimension, that facilitate efficient extraction of aqueous hydrogen peroxide from the organic solution.

Abstract: The invention relates to a process for production of hydrogen peroxide according to the anthraquinone process including altemate hydrogenation and oxidation of one or more quinones selected from anthraquinones and/or tetrahydro anthraquinones in a working solution comprising at least one quinone solvent and at least one hydroquinone solvent, wherein said at least one quinone solvent comprises isodurene in an amount from 15 to 100 wt %. The invention also relates to a composition useful as a working solution at production hydrogen peroxide.

Abstract: The present invention provides a method for producing hydrogen peroxide, comprising the steps of: alternately reducing and oxidizing a working solution containing anthraquinone compounds as a reaction medium, wherein a mixture of alkyl-substituted anthraquinones and alkyl-substituted tetrahydroanthraquinones in a molar ratio of from 2:1 to 8:1 is used as the anthraquinone compounds in the working solution, in the reduction step all of the tetrahydroanthraquinones and some or all of the anthraquinones in the working solution are reduced; and keeping the content of alkyl-substituted anthrahydroquinones in the working solution after the reduction step and before the oxidation step higher than the content of alkyl-substituted tetrahydroanthrahydroquinones, wherein ethylanthraquinone and ethyltetrahydroanthraquinone are used as anthraquinone compounds in the working solution in a total proportion of both of from 10 to 45 mol % of all of the anthraquinone compounds in the working solution.

Abstract: Hydrogen peroxide is prepared by an auto-oxidation method via oxidation in a microreactor. A working solution containing a reactive carrier compound is hydrogenated with hydrogen in a first step and is subsequently oxidized in a microreactor to produce hydrogen peroxide.

Abstract: Hydrogen peroxide is prepared by an auto-oxidation method via hydrogenation in a microreactor. A working solution containing a reactive carrier compound is hydrogenated with hydrogen in a microreactor and is subsequently auto-oxidized to produce hydrogen peroxide.

Abstract: A method for producing hydrogen peroxide by an anthraquinone process includes the steps of: reducing with hydrogen a working solution containing an organic solvent and anthraquinone in the presence of a hydrogenation catalyst; and activating the hydrogenation catalyst when a hydrogenation selectivity has decreased due to repeated use, wherein the catalyst activation step includes a step of treating the hydrogenation catalyst with a first alkaline aqueous solution of pH 10 or above containing an alkali metal, and then washing the treated hydrogenation catalyst with water or a second alkaline aqueous solution that is more weakly alkaline than the first alkaline aqueous solution so as to set a catalyst soak solution comprising 5 parts by weight of pure water in admixture with 1 part by weight of the activated hydrogenation catalyst to a pH of 8.0 or above.

Abstract: A gas/liquid reaction with a liquid containing at least one chemical compound in solution which can react with a gas in the presence of a solid catalyst maintained in suspension in the liquid, the reaction being carried out with separation (recovery) of said solid catalyst by filtering. Recirculating a fraction of the reacted solution without involving any additional pump or ejector, wherein the recirculated fraction provides for a primary filter for reacted solution being tangentially skimmed over.

Abstract: The invention concerns a process for the preparation of hydrogen peroxide by the anthraquinone cyclic process. The process includes a regeneration stage in which working solution is regenerated by being brought into contact with an aqueous solution containing an alkyl anthrahydroquinone and/or an alkyl tetrahydroanthrahydroquinone in deprotonated form. The working solution regenerated in the regeneration stage is returned to the cyclic process.

Abstract: The invention relates to a process for the production of hydrogen peroxide by the anthraquinone process, comprising a hydrogenation stage, an oxidation stage and an extraction stage. According to the invention, catalytic hydrogenation of anthraquinone derivatives dissolved in a working solution is carried out in the presence of added molecular oxygen. Per mol hydrogen, 0.1 to 10 mmol oxygen is preferably introduced into the hydrogenation stage with the hydrogenating gas, in mixture with an inert gas and/or dissolved and/or dispersed in the working solution. This increases the residence time of the catalyst.

Abstract: The invention is directed to a continuous hydrogenation process in which a hydrogenable compound is dissolved in a working solution with hydrogen and a heterogeneous catalyst. At least part of the hydrogen-containing waste hydrogenation gas generated in the reaction is compressed and then recycled into the hydrogenation reactor. A jet pump is used for the compression of the waste hydrogenation gas and a liquid or gaseous feedstock of the hydrogenation process is used as the motive agent. Preferred motive agents are the hydrogenation gas or a working solution recycled into the process. The process is particularly suitable for performing the hydrogenation step in the anthraquinone process for the production of hydrogen peroxide.

Abstract: The invention relates to a process for production of hydrogen peroxide according to the anthraquinone process including alternate hydrogenation and oxidation of one or more quinones selected from anthraquinones and/or tetrahydro anthraquinones in a working solution comprising at least one quinone solvent and at least one hydroquinone solvent, wherein said at least one quinone solvent comprises isodurene in an amount from 15 to 100 wt %. The invention also relates to a composition useful as a working solution at production of hydrogen peroxide.

Abstract: The anthraquinone process for producing hydrogen peroxide, including a hydrogenation step, an oxidation step and an extraction step. The oxidation waste gas leaving the oxidation reactor at an excess pressure is passed as a propellant jet to one or more gas jets and whereby a vacuum is produced for auxiliary processes, such as drying of the working solution, distillation of the aqueous hydrogen peroxide solution and drawing off of ventilator gases from solvent storage tanks.

Abstract: A continuous catalytic hydrogenation process, in which a reaction mixture containing the substance to be hydrogenated, the hydrogenation product, hydrogen and the hydrogenation catalyst suspended in the reaction mixture is recirculated in a reactor. Part of the hydrogenation product is removed from the reactor and the substance to be hydrogenated and hydrogen are fed into the reaction. In this process the substance to be hydrogenated and the hydrogen are mixed before entering the reactor. A venturi nozzle is particularly suitable as the mixing device.

Abstract: The invention is directed to a continuous hydrogenation process in which a hydrogenable compound is dissolved in a working solution with hydrogen and a heterogeneous catalyst. At least part of the hydrogen-containing waste hydrogenation gas generated in the reaction is compressed and then recycled into the hydrogenation reactor. A jet pump is used for the compression of the waste hydrogenation gas and a liquid or gaseous feedstock of the hydrogenation process is used as the motive agent. Preferred motive agents are the hydrogenation gas or a working solution recycled into the process. The process is particularly suitable for performing the hydrogenation step in the anthraquinone process for the production of hydrogen peroxide.

Abstract: A continuous catalytic hydrogenation process, in which a reaction mixture containing the substance to be hydrogenated, the hydrogenation product, hydrogen and the hydrogenation catalyst suspended in the reaction mixture is recirculated in a reactor. Part of the hydrogenation product is removed from the reactor and the substance to be hydrogenated and hydrogen are fed into the reaction. In this process the substance to be hydrogenated and the hydrogen are mixed before entering the reactor. A venturi nozzle is particularly suitable as the mixing device.

Abstract: A continuous catalytic hydrogenation process, in which a reaction mixture containing the substance to be hydrogenated, the hydrogenation product, hydrogen and the hydrogenation catalyst suspended in the reaction mixture is recirculated in a reactor. Part of the hydrogenation product is removed from the reactor and the substance to be hydrogenated and hydrogen are fed into the reaction. In this process the substance to be hydrogenated and the hydrogen are mixed before entering the reactor. A venturi nozzle is particularly suitable as the mixing device.

Abstract: The invention relates to a method for producing catalysts by immersion coating a metallic support with at least one platinum metal. An aqueous medium which comprises at least one platinum metal complex, at least one reduction agent and at least one complexer and which has a pH value of more than 4 is brought into contact with the metallic support in order to deposit the platinum metal, the platinum metal being deposited in the form of discreet, immobilised particles. The invention also relates to the catalysts obtained using this method and to their use for producing hydrogen peroxide and for hydrogenating organic compounds.

Abstract: The invention relates to a method of regenerating hydrogenated and/or oxygenated alkyl anthraquinones and/or alkyl anthrahydroquinones to alkyl anthraquinones and/or alkyl anthrahydroquinones, wherein the reaction is carried out in the presence of a catalyst under electromagnetic irradiation.

Abstract: The anthraquinone process for producing hydrogen peroxide, including a hydrogenation step, an oxidation step and an extraction step. The oxidation waste gas leaving the oxidation reactor at an excess pressure is passed as a propellant jet to one or more gas jets and whereby a vacuum is produced for auxiliary processes, such as drying of the working solution, distillation of the aqueous hydrogen peroxide solution and drawing off of ventilator gases from solvent storage tanks.

Abstract: The invention concerns a catalyst carrier comprising a fibre paper impregnated with a slurry comprising silica sol, micro fibres and a filler, wherein said micro fibres have an equivalent average particle size, measured with sedigraph method, from about 200 nm to about 30000 nm and said filler has an average equivalent particle size, measured with sedigraph method, from about 300 to about 10000 nm. The invention further concerns a method of its preparation, a slurry useful therefore, a catalyst comprising such a catalyst carrier and use of the catalyst.

Abstract: The invention concerns a process for production of hydrogen peroxide according to the anthraquinone process comprising the steps of alternate hydrogenation and oxidation of anthraquinones and tetrahydro anthraquinones in a working solution comprising a mixture of alkyl-substituted anthraquinones and alkyl-substituted tetrahydro anthraquinones dissolved in at least one organic solvent, wherein from 10 to 55 mole % of the anthraquinones and the tetrahydro anthraquinones are substituted with one amyl group, and the molar ratio of alkyl-substituted tetrahydro anthraquinones to alkyl-substituted anthraquinones is at least 1:1. The invention also concerns a composition useful as a working solution in said process.

Abstract: A process for hydrogenating an anthraquinone compound or a mixture of two or more thereof utilizes specific catalysts comprising, as active metal, a metal of transition group VIII of the Periodic Table of the Elements.

Abstract: Process for producing hydrogen peroxide The invention relates to a process for producing hydrogen peroxide by the cyclic anthraquinone process. According to the invention, the rate of oxidation of a hydrogenated working solution containing a tetrahydroanthrahydroquinone derivative is increased if the oxidation is carried out in the presence of a secondary amine. Preferably a slightly water-soluble secondary amine having a boiling point of at least 150° C., in a quantity of 0.001 to 2 mol per mol of tetrahydro compounds, is used.

Abstract: In carrying out the hydrogenation stage of the anthraquinone process for the preparation of hydrogen peroxide in a hydrogenation reactor on a fixed bed catalyst of a particulate catalyst, the service life of the catalyst is increased in that the working solution comprising the reaction carrier and a gas phase comprising hydrogen, are passed through the hydrogenation reactor from the bottom upwards. The empty tube speed of the working solution is 0.05 to 100 m/h, preferably 10 to 50 m/h.