摘要:
The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a purified silicon oxide using one or more pure carbon sources, the purified silicon oxide, which was purified as silicon oxide dissolved in an aqueous phase, having a content of other polyvalent metals or metal oxides, in relation to the silicon oxide, of less than or equal to 300 ppm, preferably less than 100 ppm, especially preferably less than 50 ppm and according to the invention less than 10 ppm of the other metals and being obtained advantageously by gel formation in alkaline conditions. The invention also relates to a formulation containing an activator and to the use of purified silicon oxide together with an activator for producing silicon.
摘要:
The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a silicon oxide, purified by acidic precipitation from an aqueous solution of a silicon oxide dissolved in an aqueous phase, using one or more pure carbon sources, the purified silicon oxide being obtained, in particular, by the precipitation of a silicon oxide dissolved in an aqueous phase in an acidifier. The invention also relates to a formulation containing an activator and to a device for producing silicon, a reactor and electrodes.
摘要:
The present invention relates to methods for the technical pyrolysis of a carbohydrate or carbohydrate mixture at an elevated temperature while adding silicon oxide, to a pyrolysis product obtainable in this way, and to the use thereof as a reducing agent for the production of solar silicon from silicic acid and carbon at a high temperature.
摘要:
The invention relates to the use of a ceramic heat exchanger as an integral part of a process for catalytic dehalogenation of silicon tetrachloride to trichlorosilane in the presence of hydrogen, wherein the product gas and the reactant gases are conducted as pressurized streams through the heat exchanger, and the heat exchanger comprises heat exchanger elements made from ceramic material.
摘要:
The present invention relates to a multistage process for preparing trichlorosilane and silicon tetrachloride from metallurgical silicon, in which trichlorosilane and silicon tetrachloride are prepared from metallurgical silicon in a first step, and the silicon tetrachloride is processed further to the trichlorosilane end product in a second step. The present invention further relates to a plant in which such processes can be performed in an integrated manner.
摘要:
The invention relates to a process for producing a product gas mixture containing hydrogen-containing chlorosilanes within an integrated process by hydrogenating integrated process by-product silicon tetrachloride and organochlorosilane, more particularly methyltrichlorosilane, with hydrogen in a pressurized hydrogenation reactor comprising one or more reaction spaces each consisting of a reactor tube of gastight ceramic material, wherein the product gas mixture is worked up and at least a portion of at least one product of the product gas mixture is used as starting material for the hydrogenation or as starting material for some other process within the integrated process. The invention further relates to an integrated system useful for practising the integrated process.
摘要:
The invention relates to the use of a ceramic tube composed of silicon carbide variants in processes for converting chlorosilanes, wherein the tube has a flange or a flare at one end and is closed at the other end.
摘要:
The invention relates to a process for the preparation of acrylic acid and a process for the preparation of polyacrylic acid comprising the process steps: (a1) preparation of 3-hydroxypropionic acid from a biological material to give a fluid, in particular aqueous, phase containing 3-hydroxypropionic acid; (a2) dehydration of the 3-hydroxypropionic acid to give a fluid, in particular aqueous, solution containing acrylic acid; (a3) purification of the solution containing acrylic acid by a suspension crystallization or a layer crystallization to give a purified phase; and corresponding devices for carrying out these processes, and acrylic acid and polyacrylates. The invention is distinguished in that acrylic acid and polyacrylates can thereby be prepared efficiently, inexpensively, and sustainably with simple means and with a high purity on the basis of regenerable raw materials.
摘要:
The present invention relates to a process for purifying low molecular weight hydridosilane solutions, in which a solution to be purified comprising a) at least one low molecular weight hydridosilane, b) at least one solvent and c) at least one impurity selected from the group of the compounds having at least 20 silicon atoms and/or the group of the homogeneous catalyst systems is subjected to a crossflow membrane process with at least one membrane separation step using a permeation membrane.
摘要:
The present invention relates to a process for production of acrylic acid, comprising at least the following steps: a. dehydration of glycerine to an acrolein-comprising dehydration product; b. gas phase oxidation of the dehydration product to obtain an acrylic acid-comprising monomer gas; c. bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; d. work-up of the quench phase to obtain an acrylic acid-comprising monomer phase; whereby, during the dehydration a liquid phase a1 and a gas phase a2 is present, whereby in the liquid phase a1 a plurality of gas bubbles is generated, as well as a process for production of polymers by polymerization of acrylic acid, preferably for production of water-absorbing polymers, the water-absorbing polymers obtainable by this process, a composite, a process for production of a composite, the composite obtainable by this process, and further chemical products.