Research object - electrolytic decomposition of water in molten and solid electrolytes. Hydrogen production. Purpose of the work – working out of scientific fundamentals and development of equipment for the electrochemical extraction of hydrogen from waste steam of thermal and nuclear power stations by using as electrolyte alkali metals hydroxide melts and solid electrolytes based on stabilized zirconium dioxide.
Research methods - voltammetry, electrolysis, spectrophotometry, differential thermal and chemical analysis, gravimetry.
The state of the problem of utilization of waste steam of thermal and nuclear power stations has been analyzed. Investigations have been carried out to assess the ability of alkali metal hydroxide melts to retain steam. It has been found that among the hydroxides of lithium, sodium, potassium hydroxides, potassium hydroxide has the highest absorptiveity in the temperature range 350-450 0C. A voltammetric method for monitoring of the water content of alkaline melts has been developed.
To titrate water in melt, sodium peroxide was used, which is quantitatively decomposed by water into oxygen and sodium hydroxide. Calibration curves have been plotted. Water decomposition in molten potassium hydroxide has been assessed. It has been found that after the saturation of the melt with steam at 350 0C, electrolysis at an interelecrode voltage of 1,5-1,8 B (i = 0,3 - 1,0 А/sm2) ensures hydrogen evolution at the nickel cathode with a current yield of 95-97%. Alkali metal does not deposit on the cathode.
A basic circuit of the electrochemical reactor for electrolytic water decomposition in molten electrolytes is proposed.
Keywords: Electrolytic production of hydrogen, steam, molten and solid electrolytes