Effective synthesis of methanol using high-CO2 and PT conditions at deep-sea hydrothermal systems

• Project/Area Number: 15K13603
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Geochemistry/Cosmochemistry
• Research Institution: University of the Ryukyus
• Principal Investigator: TOKI Tomohiro 琉球大学, 理学部, 准教授 (50396925)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2016: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2015: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 二酸化炭素 / 還元反応 / 金属触媒 / 流体定常条件 / 水素還元状態 / 表面活性 / 海底熱水系 / メタノール合成 / 高温・高圧

Outline of Final Research Achievements

The degree of activation was compared by changing the kind of alloy and the metal added to the alloy as to how efficiently the surface of the alloy used as the catalyst was activated. As a result, it was revealed that under all conditions, the most important condition was to have the alloy fully suck hydrogen in the first place. When the oxidation reduction state of the element was confirmed using the X-ray on the metal surface, it was in a reduced state in a state where hydrogen was sufficiently absorbed, and when the reduction reaction of carbon dioxide occurred, the surface was oxidized. Under steady flow conditions of fluids closer to the conditions of the site, the alloy of lanthanum and nickel showed remarkably high reducing power.

Research Products

• [Journal Article] Formation of gas discharging from Taketomi submarine hot spring off Ishigaki Island in the southern Ryukyu Islands, Japan (2017)
  • Author(s): Tomohiro Toki, Daigo Iwata, Urumu Tsunogai, Daisuke D. Komatsu, Yuji Sano, Naoto Takahata, Hiroshi Hamasaki, Jun-ichiro Ishibashi
  • Journal Title: Journal of Volcanology and Geothermal Research Volume: 330 Pages: 24-35
  • DOI: 10.1016/j.jvolgeores.2016.11.018
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Effect of CO2 on hydrogen absorption in Ti-Zr-Mn-Cr based AB2 type alloys (2017)
  • Author(s): Nobuko Hanada, Hirotaka Asada, Tessui Nakagawa, Hiroki Higa, Masayoshi Ishida, Daichi Heshiki, Tomohiro Toki, Itoko Saita, Kohta Asano, Yumiko Nakamura, Akitoshi Fujisawa, and Shinichi Miura
  • Journal Title: Journal of Alloys and Compounds Volume: 705 Pages: 507-516
  • DOI: 10.1016/j.jallcom.2017.02.067
  • Peer Reviewed
• [Presentation] AB2型水素吸蔵合金のCO2被毒耐性と炭化水素生成反応の相関とメカニズム (2017)
  • Author(s): 平敷 大地，土岐 知弘，花田 信子，荒西 研吾，石田 政義，中川 鉄水
  • Organizer: 第12回水素若手研究会
• [Presentation] AB2型水素吸蔵合金のCO2被毒耐性と炭化水素生成反応の相関とメカニズム (2017)
  • Author(s): 平敷 大地，土岐 知弘，花田 信子，荒西 研吾，石田 政義，中川 鉄水
  • Organizer: 日本金属学会2017年秋期大会