| abstract |
A process for the production of hydrogen is proposed by reacting an aqueous alkaline solution with silicon or a silicon alloy with the elimination of hydrogen and dissolving the silicon in the form of silicon ions. The dissolved silicon ions are precipitated at a temperature of at least 150 ° C. in the form of crystalline, essentially anhydrous silicon dioxide. The temperature during the reaction of the silicon or the silicon alloy with the aqueous alkaline solution is set below the temperature at which the crystalline, anhydrous silicon dioxide is separated out from the aqueous alkaline solution, the reaction temperature preferably being set between 70 ° C. and 150 ° C. , The silicon or the silicon alloy are preferably dissolved in the aqueous alkaline solution at elevated pressure, in particular at a pressure above the saturation vapor pressure. Furthermore, a device for carrying out such a method and its use is proposed. |