著者

武山 詳 坂口 清敏 渡邉 則昭 土屋 範芳

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.135, no.3, pp.25-30, 2019-03-31 (Released:2019-03-29)

参考文献数

26

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Gypsum aggregate specimens have been used in the present study, because brittle, semi-brittle and ductile stress-strain behaviors of the specimen can be controlled only with confining stress level at the room temperature. At confining stresses up to 40 MPa, tri-axial compression and fluid flow experiments have been conducted on the intact specimens and single fracture specimens. It has been indicated that stress-strain behavior is independent of existence of fracture. Moreover, permeability of the single fracture specimen is much higher than intact specimen at conditions of brittle, semi-brittle, intermediate state between semi-brittle and ductile and ductile condition. On the other hand, permeability of the single fracture specimen is not so different from that of the intact specimen at conditions of a transitional behavior between semi-brittle and ductile stress-strain behaviors. As for the geothermal reservoir in the semi-brittle and ductile region, it was suggested that the fracture is retained and permeability is maintained when fracturing occurs due to hydraulic crushing or the like.

著者

最首 花恵 小坂 拓也 土屋 範芳 渡邉 則昭

出版者

日本地熱学会

雑誌

日本地熱学会誌 (ISSN:03886735)

巻号頁・発行日

vol.39, no.1, pp.15-24, 2017-01-25 (Released:2017-07-25)

参考文献数

19

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Hydrogen produced by the water-splitting reaction is one of the alternate sources derived from fossil fuels. However, the present systems for the hydrogen production still require the extra energy or processes such as heating, milling and adding the chemical agent. The hot springs in Japan are naturally in high temperature and in wide range of pH. We investigated the combination of hot spring water and waste aluminum that are appropriate for hydrogen production without extra energy. Here, we used waste aluminum for reducer of water-splitting reactor. The hydrogen production system in Onsen (hot spring) area has a potential to promote not only the environmental and energy problems but also the activation of the local community as the system of “local production for local consumption”. In this study, the effects of the characters of hot springs and the conditions of the hydrogen generator system were revealed by the laboratory experiments. The water-splitting reaction was enhanced by using the hot spring water of (1) lower pH (< 2), (2) higher temperature, and (3) higher ratio of HCl/H2SO4. The concentration of cations in the fluid is not related to the reaction rate of hydrogen production. The prototype of the hydrogen generator for the water splitting reaction by using the acidic hot spring water and waste aluminum was developed and used in two type systems: batch and flow-through. The laboratory experiment by using the original generator revealed that hydrogen production was more efficient in the flow-through system because of constant pH value of fluid.