Abstract: An apparatus for chlor-alkali electrolysis, comprising a cathode half-cell, an oxygen-consuming electrode arranged therein, a conduit for supply of gaseous oxygen to the cathode half-cell and a conduit for purging the cathode half-cell with inert gas, enables the flexible use of power by a method in which chlorine is produced in the apparatus by chlor-alkali electrolysis, wherein, when power supply is low, the oxygen-consuming electrode is supplied with gaseous oxygen, and oxygen is reduced at the oxygen-consuming electrode at a first cell voltage, and when power supply is high, the oxygen-consuming electrode is not supplied with any oxygen, and hydrogen is generated at the cathode at a second cell voltage which is higher than the first cell voltage.

Abstract: The present invention relates to a process for preparing aqueous colloidal silica sols of high purity from silicate solutions, to aqueous colloidal silica sols with a specific profile of impurities, and to the use thereof. The invention further encompasses high-purity aqueous silica obtained as an intermediate in the course of the purification process, high-purity silicon dioxide obtainable by dewatering, and the use thereof.

Abstract: The invention relates to a method for producing a thermoelectric component or at least a semifinished version thereof, in which at least one thermoelectric active material in dry powder form is introduced into at least some of the holes of a perforated template. It addresses the problem of specifying a method which can be conducted in a particularly economically viable manner. The problem is solved by virtue of the active material remaining in the holes of the template, and the template filled with active material becoming a constituent of the thermoelectric component produced.

Abstract: An apparatus for chlor-alkali electrolysis, comprising a cathode half-cell, an oxygen-consuming electrode arranged therein, a conduit for supply of gaseous oxygen to the cathode half-cell and a conduit for purging the cathode half-cell with inert gas, enables the flexible use of power by a method in which chlorine is produced in the apparatus by chlor-alkali electrolysis, wherein, when power supply is low, the oxygen-consuming electrode is supplied with gaseous oxygen, and oxygen is reduced at the oxygen-consuming electrode at a first cell voltage, and when power supply is high, the oxygen-consuming electrode is not supplied with any oxygen, and hydrogen is generated at the cathode at a second cell voltage which is higher than the first cell voltage.

Abstract: The present invention relates to an integrated plant which comprises a plant for the electrothermic production of hydrogen cyanide and a separating device for separating hydrogen cyanide from the reaction mixture of the electrothermic production of hydrogen cyanide while obtaining at least one stream of gas containing hydrogen and/or hydrocarbons, the integrated plant having a device for introducing a gas into a natural gas network, to which device a stream of gas containing hydrogen and/or hydrocarbons is fed from the separating device via at least one conduit. This integrated plant affords flexible use of electricity by a method in which a stream of gas, containing hydrogen and/or hydrocarbons, is fed into a natural gas network from the separating device and the amount and/or the composition of the stream of gas fed into the natural gas network is changed in dependence on the electricity supply.

Abstract: The present invention relates to an integrated plant which comprises a plant for the electrothermic production of hydrogen cyanide and a plant for electricity generation, the plant for the electrothermic production of hydrogen cyanide being connected to the plant for electricity generation via a conduit and electricity being generated in the plant for electricity generation from a product gas obtained in the plant for the electrothermic production of hydrogen cyanide. This integrated plant affords flexible use of electricity by a method in which, at times of a high electricity supply, the plant for the electrothermic production of hydrogen cyanide is operated and at least some of the hydrogen and/or gaseous hydrocarbons obtained in addition to hydrogen cyanide is stored and, at times of a low electricity supply, stored hydrogen and/or gaseous hydrocarbons are fed to the plant for electricity generation.

Abstract: The present invention relates to an integrated plant which comprises a plant for the electrothermic production of ethyne and a plant for electricity generation, the plant for the electrothermic production of ethyne being connected to the plant for electricity generation via a conduit and electricity being generated in the plant for electricity generation from a product gas obtained in the plant for the electrothermic production of ethyne. This integrated plant affords flexible use of electricity by a method in which, at times of a high electricity supply, the plant for the electrothermic production of ethyne is operated and at least some of the hydrogen and/or gaseous hydrocarbons obtained in addition to ethyne is stored and, at times of a low electricity supply, stored hydrogen and/or gaseous hydrocarbons are fed to the plant for electricity generation.

Abstract: The present invention relates to an integrated plant which comprises a plant for the electrothermic production of ethyne and a separating device for separating ethyne from the reaction mixture of the electrothermic production of ethyne while obtaining at least one stream of gas containing hydrogen and/or hydrocarbons, the integrated plant having a device for introducing a gas into a natural gas network, to which device a stream of gas containing hydrogen and/or hydrocarbons is fed from the separating device via at least one conduit. This integrated plant affords flexible use of electricity by a method in which a stream of gas, containing hydrogen and/or hydrocarbons, is fed into a natural gas network from the separating device and the amount and/or the composition of the stream of gas fed into the natural gas network is changed in dependence on the electricity supply.

Abstract: The present invention relates to a method for limiting the load of electricity transmission networks, comprising the generation of heat by operating an apparatus for the oxidation of a hydrocarbon-containing gas, in which alternatively a required provision of heat from the oxidation of the hydrocarbon-containing gas is substituted by the provision of heat from electrical energy with an apparatus for providing heat by using electrical power and the hydrocarbon-containing gas that is not oxidized is provided. A facility for carrying out the present method is also described.

Abstract: The present invention relates to a method for obtaining a hydrocarbon-containing gas, comprising the generation of heat by operating an apparatus for the oxidation of a hydrocarbon-containing gas, characterized in that alternatively a required provision of heat from the oxidation of the hydrocarbon-containing gas is substituted by the provision of heat from electrical energy with an apparatus for providing heat by using electrical power and the hydrocarbon-containing gas that is not oxidized is provided. A facility for carrying out the present method is also described.

Abstract: A method for modification of a methane-containing gas stream, comprising the steps of: i) withdrawal of at least one substream from a methane-containing gas stream; ii) treatment of the substream with an electrically generated plasma, generating a modified gas composition which comprises a lower fraction of methane than the methane-containing gas stream used and iii) return of modified gas composition into the methane-containing gas stream. This method makes possible the storage of excess power in a natural gas line grid.

Abstract: The present invention relates to a process for preparing aqueous colloidal silica sols of high purity from silicate solutions, to aqueous colloidal silica sols with a specific profile of impurities, and to the use thereof. The invention further encompasses high-purity aqueous silica obtained as an intermediate in the course of the purification process, high-purity silicon dioxide obtainable by dewatering, and the use thereof.

Abstract: The present invention relates to a process for producing SiO2 mouldings, comprising the preparation of a free-flowing aqueous SiO2 composition, solidification of the aqueous SiO2 composition and drying of the solidified SiO2 composition, wherein the aqueous SiO2 composition is a self-assembly composition. The present invention further relates to a moulding obtainable by the process according to the invention.

Abstract: A method for modification of a methane-containing gas stream, comprising the steps of: i) withdrawal of at least one substream from a methane-containing gas stream; ii) treatment of the substream with an electrically generated plasma, generating a modified gas composition which comprises a lower fraction of methane than the methane-containing gas stream used and iii) return of modified gas composition into the methane-containing gas stream. This method makes possible the storage of excess power in a natural gas line grid.

Abstract: A process for reactions with or to form peroxidic compounds in a wall reactor whose reaction space has a specific material coating is described. Both higher space-time yields and increased selectivities can be achieved by means of the process.

Abstract: A process for the selective catalytic reduction of nitrogen oxides with ammonia in a lean-mix exhaust gas from a combustion process operated with a first, lean-mix air/fuel mixture, wherein the ammonia required for selective reduction is obtained from a second, rich-mix air/fuel mixture which contains nitrogen monoxide by reduction of the nitrogen monoxide in a NH3 synthesis step to give ammonia with the formation of a product gas stream, and where the nitrogen monoxide-containing second air/fuel mixture is supplied to the NH3 synthesis step for reduction of the nitrogen monoxide to ammonia over a three-way converter catalyst and the ammonia formed is separated from the product gas stream and is stored in a storage medium for use as and when required for selective catalytic reduction.

Abstract: Reactions between at least two fluid reactants are performed in a reactor comprising wall elements (1), slot-shaped reaction spaces (3) and cavities (5) for conducting a fluid heat-carrier through. Depending on the process and throughput, a modular structural design is chosen wherein an arbitrary number of wall elements (1) are assembled to a right-parallelepipedal block (24), the reaction spaces (3) are formed between lateral surfaces (2) of right-parallelepipedal wall elements (1), the reactants are introduced into the reaction spaces (3) from edge regions of one side of the block (24) and are conducted through the reaction spaces (3) in parallel flows and the fluid heat-carrier is conducted through the tubular cavities (5) extending in the interior of the wall elements (1).

Abstract: The production of foam which occurs in many chemical and physical materials conversion processes can be avoided by performing the materials conversion process in an ascending jet reactor, including a baffle-free container with a tapering lower section, preferably a conical lower section, and a device for gas injection, and the contents of the reactor are thoroughly mixed by means of ascending jet circulation caused by gas injection.

Abstract: A bubble column can be operated using countercurrent flow including perforated trays. The space-time yield of gas-liquid reactions can be considerably increased if the perforated trays have a substantially uniform distribution of holes, if the cross-sectional area of the individual holes is 0.003 to 3 mm2, particularly 0.01 to 0.5 mm2, and if the open area of the trays is 3 to 20%, particularly 3 to 10%, and if the bubble column comprises passages for liquid between adjacent liquid zones. The bubble column can be used for carrying out gas-liquid reactions, such as oxidation reactions with air, with the gas and liquid preferably being passed in countercurrent flow through the column. Cocurrent flow may also be used.

Abstract: A method for epoxidation of olefins with 2 to 6 C atoms, especially propene, with hydrogen peroxide in the gas phase at a temperature below 250° C. The reaction is carried out by bringing a gas mixture containing the olefin, hydrogen peroxide and water into contact with the catalyst from the series of compounds of an element of the 4th to the 6th subgroup of the periodic table or of arsenic or selenium and molecular sieves in the absence of a liquid phase. Titanium-containing molecular sleeves are preferred catalysts.