Hydrogen production experiments by the thermochemical and electrolytic hybrid hydrogen production process

Nakagiri, Toshio  ; Horikiri, Morito; Kato, Shoichi ; Kase, Takeshi ; Aoto, Kazumi ; Takamori, Yuji*; Fukasaku, Hiroshi*

Hydrogen production demonstration experiments from water by the thermochemical and electrolytic hybrid hydrogen production process were performed. The feasibility of this hydrogen production process was demonstrated and technical problems to operate longer uration and to develop 1Nl/h-H2 production experimental apparatus were extracted. (1) Continuous and stable hydrogen and oxygen generation by the hybrid process was measured in the four full process experiments and maximum test duration was about five hours. The generation rate of hydrogen and oxygen calculated from measured current in four full process experiments were 4.03ml/h - 5.04ml/h and 2.07ml/h - 2.78ml/h, respectively. The total amounts of generated hydrogen and oxygen in the four experiments were 35.00ml and 20.99ml. (2) Severe material corrosion was not observed for gold plated stainless steel and S03 electrolysis cell (YSZ, Pt paste electrode) which used in sulfuric acid atmosphere at about 550 deg-C, and ionic oxygen conductivity of YSZ did not decrease in the experiments. Nevertheless, corrosion of the gold plated outlet piping of S03 electrolysis cell was observed, and the corrosion by condensed sulfuric acid as suspected. (3) Technical problems to operate the present experimental apparatus for 100 hours and to develop test apparatus to generate 1Nl/h hydrogen, were extracted.