Patent ID: 8470292

Claim:
A hydrogen production method from water by thermochemical cycles, comprising: a) thermochemically reducing GeO 2 to generate gas phase GeO(g) and oxygen according to Reaction Formula 1; b) cooling the gas phase GeO(g) to recover solid phase GeO(s), Ge(s), and GeO 2 (s), or a mixture thereof; and c) allowing recovery materials recovered in the step b) to react with water to generate GeO 2 and hydrogen according to Reaction Formula 2, Reaction Formula 4, or Reaction Formula 2 and Reaction Formula 4, GeO 2 →GeO+½O 2 (Reaction Formula 1) GeO+H 2 O(g)→GeO 2 +H 2 (Reaction Formula 2) ½Ge+½GeO 2 +H 2 O(g)→GeO 2 +H 2 (Reaction Formula 4) wherein GeO 2 generated in the step c) is again input to the step a), and the steps a) to c) are repeatedly performed.