Thermochemical cyclic system for decomposing H.sub.2 O and/or CO.sub.2 by means of cerium-titanium-sodium-oxygen compounds

A cyclic process for the production of hydrogen from water comprising the steps of:

• (a) reacting ceric oxide, titanium dioxide and sodium titanate at a temperature above 900.degree. C. to cause formation of sodium cerous titanate and oxygen;
• (b) reacting thus-produced sodium cerous titanate with steam and one of sodium carbonate and sodium bicarbonate at a temperature above 500.degree. C. to produce ceric oxide, sodium titanate, carbon dioxide and hydrogen, which is removed from the reaction environment;
• (c) reacting sodium titanate produced in step (b) with water and carbon dioxide to produce titanium dioxide and sodium bicarbonate and removing the thus-produced sodium bicarbonate;
• and
• (d) recycling ceric oxide produced in step (b), titanium dioxide produced in step (c) and sodium titanate remaining from step (c) to step (a).

A cyclic process for the production of hydrogen from water comprising the steps of:

• (a) reacting cerium oxide, titanium dioxide and sodium titanate at a temperature above 900.degree. C. to cause formation of sodium cerous titanate and oxygen;
• (b) reacting the thus-produced sodium cerium titanate with molten alkali-metal hydroxide to form ceric oxide, an alkali metal titanate, water, and hydrogen, which is removed from the reaction environment;
• (c) reacting incompletely sodium titanate produced in step (b) with boiling water to produce sodium hydroxide and titanium dioxide, and removing the thus-produced sodium hydroxide;
• and
• (d) recycling ceric oxide produced in step (b), titanium dioxide produced in step (c) and sodium titanate remaining from step (c) to step (a).