著者

山崎 仲道 中塚 勝人 小田 幸人 後藤 芳彦 橋田 俊之 土屋 範芳

出版者

東北大学

雑誌

基盤研究(B)

巻号頁・発行日

2001

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水および二酸化炭素を金属鉄あるいはニッケルとともに水熱条件にさらすと水と二酸化炭素の両者から酸素が金属に引き抜かれ、結果として水から活性に富んだ水素が発生すると同時に二酸化炭素も活性化する。この両者が反応して有機化合物が生成する。この原理を確認し、平成14年度では反応条件と生成物の解析から中性条件では、一酸化炭素を経由するフィッシャートロプシュ反応を主反応とし、メタンからヘキサンまでのアルカン類の生成を確認した。また酸性条件では酢酸を中心としたカルボン酸の生成を、また金属のかわりにマグネタイトを還元剤として使えば、エタノールの生成をそれぞれ確認した。工業化を考えた場合、メタンおよびカルボン酸を高収量で得られることを見出した。工業化では焼却炉あるいは発電所からの廃ガスを直接利用することになる。14年度では反応のプロセスを探求すると同時に工業化のための大量処理を仮定した流通系の連続処理プロセスの小型テストプラントを作成し、非平衡下での反応を調べた。バッチ式オートクレーブを使った平衡系の反応、いいかえれば理想系での実験に比べて流通型オートクレーブは、自然界での現実の反応に近く、また大量処理のための工業化プロセスの主体をなすものであるが、科学的には未踏領域ともいわれる複雑反応系である。ここでは加熱パイプの内部に旋盤による屑状態の鉄を置き、これに塩酸と二酸化炭素を200℃加熱下で流通させ、生成有機物の気体・液体を相互に分離し、それぞれを分析する方法をとった。マイルドな水熱条件下で水起源の活性水素をつくり、二酸化炭素を同時に活性化せしめ、炭化水素を合成、反応条件による反応選択性の可能性を見出し、ついで収量・収率から流通式の非平衡反応で工業化の可能性を提示するという一連の計画を遂行し、流通式非平衡装置の設計・製作および装置の特性試験を行い、それを使って流通系による工業化の可能性を得ることができた。

著者

平野 伸夫 竹之下 愛 土屋 範芳

出版者

一般社団法人 日本鉱物科学会

雑誌

岩石鉱物科学 (ISSN:1345630X)

巻号頁・発行日

vol.38, no.5, pp.198-207, 2009 (Released:2009-11-26)

参考文献数

28

被引用文献数

2 2

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Carbonate hot spring is a natural chemical reaction field for understanding CO2 geological sequestration as a natural analogue. Natural analogue studies are particularly important to understand the kinetics of mineral precipitation which has potential difficulties in experimental investigations. Carbonate sinter is frequently formed in and around carbonate hot spring, which can be suitable to elucidate mechanisms of carbonate precipitation associated with flushing CO2.   Oku-Okuhachikuro hot spring, located in Kosaka town, Akita Prefecture, NE Japan, is an artificial hot spring after drilling of exploration for the Kuroko-deposits, and it is still active where carbonate sinter has still been forming continuously for more than thirty years after drilling. The temperature of spring water is 44 °C and water pH is 6.2, with discharge rate of 0.08 m3/min. The average chemical compositions of sinter correspond about 80 wt% CaCO3, and 4 wt% Fe2O3, associated with minor (<1 wt% each) SiO2, MnO, MgO, Na2O and K2O. Carbonate sinter is mainly composed of aragonite with a small amount of calcite; an intimate occurrence of these two forms of CaCO3 is the most characteristic feature of this locality. However, mineral assemblage, texture and structure of carbonate sinter are different in relation to the distance from the blowout point. Near the blowout point, the sinter is well solidified and shows laminar structure having both of calcite and aragonite. Thickness of Ca-rich laminar ranges from 20 to 150 μm and Fe-rich one is from 10 to 80 μm. Calcite and aragonite assemblage is mainly observed in Ca-rich layer. The Fe-rich layer, however, is composed only of aragonite. The sinter along downstream becomes porous and is monomineralic having aragonite as CaCO3. The observed relations on the special distribution of aragonite/calcite and the possible stability relations of these phases through EPMA and TG-DTA analyses suggest an importance of minor elements (Fe, etc.) in the precipitation of metastable carbonates: this possible effect of the precipitation of metastable phases should be taken into account in the consideration of geochemical processes of CO2 mineral trapping.

著者

土屋 範芳 鈴木 舜一 小田 幸人 飯島 章夫

出版者

Japan Association of Mineralogical Sciences

雑誌

岩鉱 (ISSN:09149783)

巻号頁・発行日

vol.84, no.3, pp.89-96, 1989-03-05 (Released:2008-03-18)

参考文献数

44

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Carbonaceous material in pelitic rocks and limestones of the Ayukawa and the Daioin Formations in the Hitachi metamorphic rocks was investigated by means of X-ray powder diffraction technique. Carbonaceous material in these metasediments was graphitized under the conditions of greenschist facies. rystallite thickness Lc (002) ranges from 29 to 170 Å in the Ayukawa Formation and that from 120 to 300 Å in the Daioin Formation. Lc (002) of carbonaceous material in pelitic rocks containing biotite is more than 60 Å and increases with increasing metamorphic grade. Lc (002) value at a boundary between greenschist and epidote-amphibolite facies may be estimated 260-300 Å from the data of Lc (002) of the lower part of the Daioin Formation. Lc (002) of the Ayukawa Formation surrounding the sheared granite is above 200 Å. As compared with the general value of the Daioin Formation, Lc (002) of the Daioin Formation around the sheared granite is not so high. Thermal effect of the sheared granite was not marked, which suggests that the sheared granite intruded under low temperature condition.

著者

岡本 敦 平野 伸夫 土屋 範芳

出版者

一般社団法人日本鉱物科学会

雑誌

日本鉱物科学会年会講演要旨集

巻号頁・発行日

vol.2008, pp.13, 2008

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石英脈の組織発達の支配要因を明らかにするために、流通式水熱反応実験を行った。シリカの析出条件は温度が400-430度、圧力が31MPaである。Siに過飽和な溶液は350-370度で石英、アモルファスシリカ、または花崗岩を溶解させて作成し、その溶液を花崗岩を敷き詰めた反応管に流して析出様式を観察した。析出物の種類(石英、クリストバライト、アモルファスシリカ)、またその析出の仕方は溶液の濃度と反応場所(石英表面、長石表面、流体中)によって異なることが明らかとなった。特に、低濃度(C/Ceq < 1.5)では花崗岩上の石英表面にのみ石英は析出し、ほかの表面では析出は起こらない。このことは、石英脈の組織は脈形成時の溶液濃度(Si)に対して制約を与えることを示唆している。

著者

本庄 鉄弥 土屋 範芳 中塚 勝人

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.111, no.4, pp.205-211, 1995-04-25 (Released:2011-01-27)

参考文献数

37

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Self-Organizing Neural Network (SONN) was constructed for the purpose of mineral identification. This system consists of two different kinds of networks, Kohonen's Self-Organizing Map and three layer feedforward neural network based on the back-propagation learning algorithm. The former step, Self-Organizing Map, could divide minerals into some categories by the similarities on the selected characteristics of minerals. This rough division of whole input patterns on feature maps was closely analogous to the first step of classification by human brains. The later step, each category had the three layer feedforward neural network independently, and then the minerals belonging to the same category could be identified.In this study, 82 minerals were identified by 5 characteristics of cleavage, metallic luster, Mohs hardness, streak, and color. Some minerals have plural input patterns on the 5 characteristics mentioned above. Therefore, total number of input patterns was 119 for 82 minerals.After constructing the feature maps and the back-propagation learning, this system could suggest the suitable mineral name for unlearning input patterns. The advantage of the proposed method is that scaling up of the system is possible with relatively small increase in learning times. Further, it should be stressed that this technique can be used in other problems where recognition and identification are necessary.

著者

平野 伸夫 竹之下 愛 土屋 範芳

出版者

一般社団法人 日本鉱物科学会

雑誌

岩石鉱物科学 (ISSN:1345630X)

巻号頁・発行日

vol.38, no.5, pp.198-207, 2009-09-30

参考文献数

28

被引用文献数

1 2

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&nbsp;&nbsp;Carbonate hot spring is a natural chemical reaction field for understanding CO₂ geological sequestration as a natural analogue. Natural analogue studies are particularly important to understand the kinetics of mineral precipitation which has potential difficulties in experimental investigations. Carbonate sinter is frequently formed in and around carbonate hot spring, which can be suitable to elucidate mechanisms of carbonate precipitation associated with flushing CO₂.<br> &nbsp;&nbsp;Oku-Okuhachikuro hot spring, located in Kosaka town, Akita Prefecture, NE Japan, is an artificial hot spring after drilling of exploration for the Kuroko-deposits, and it is still active where carbonate sinter has still been forming continuously for more than thirty years after drilling. The temperature of spring water is 44 &deg;C and water pH is 6.2, with discharge rate of 0.08 m³/min. The average chemical compositions of sinter correspond about 80 wt% CaCO₃, and 4 wt% Fe₂O₃, associated with minor (<1 wt% each) SiO₂, MnO, MgO, Na₂O and K₂O. Carbonate sinter is mainly composed of aragonite with a small amount of calcite; an intimate occurrence of these two forms of CaCO₃ is the most characteristic feature of this locality. However, mineral assemblage, texture and structure of carbonate sinter are different in relation to the distance from the blowout point. Near the blowout point, the sinter is well solidified and shows laminar structure having both of calcite and aragonite. Thickness of Ca-rich laminar ranges from 20 to 150 &mu;m and Fe-rich one is from 10 to 80 &mu;m. Calcite and aragonite assemblage is mainly observed in Ca-rich layer. The Fe-rich layer, however, is composed only of aragonite. The sinter along downstream becomes porous and is monomineralic having aragonite as CaCO₃. The observed relations on the special distribution of aragonite/calcite and the possible stability relations of these phases through EPMA and TG-DTA analyses suggest an importance of minor elements (Fe, <i>etc.</i>) in the precipitation of metastable carbonates: this possible effect of the precipitation of metastable phases should be taken into account in the consideration of geochemical processes of CO₂ mineral trapping.<br>

著者

鈴木 舜一 小田 幸人 土屋 範芳

出版者

日本地質学会

雑誌

地質學雜誌 (ISSN:00167630)

巻号頁・発行日

vol.100, no.4, pp.302-311, 1994-04-15

参考文献数

59

被引用文献数

4 3

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

桑谷 立 岡本 敦 吉田 健太 中村 謙吾 土屋 範芳 駒井 武

出版者

日本地球惑星科学連合

雑誌

日本地球惑星科学連合2018年大会

巻号頁・発行日

2018-03-14

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The high-dimensional and large amounts of data sets in geosciences show very complex behavior and often have large uncertainty. It is important to extract a small number of essential parameters which can explain the phenomenon from high-dimensional data in order to understand the behavior of dynamic solid earth. Under the framework of a big scientific project entitled as “Initiative for high-dimensional data-driven science through deepening sparse modelling” supported by the MEXT in Japan ( http://sparse-modeling.jp/index_e.html ), we try to introduce data-driven approaches into geosciences. In this presentation, we will share some applications in solid-earth science and discuss future prospects.

著者

澤山 兼吾 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.134, no.3, pp.46-52, 2018-03-31 (Released:2018-03-30)

参考文献数

21

被引用文献数

2

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Environmental impact assessment was conducted at the Ohitachi Mine (Cu-Zn-Pb) located in Odate, Akita Prefecture, Japan. Zn concentration in river water exceeded the environmental standard (30 µg/L) even in the downstream of the Mine. Here, treatment facility for acid mine drainage had already constructed, however, the capacity of the facility was not enough to protect the environmental standard of Zn in the downstream. We calculated Zn load (mg/s) and concentration of Zn (µg/L) in individual watershed along the mainstream and branches. Several watersheds which emitted high concentration of Zn were recognized in the mining area. Particularly, discharge of Zn along the mainstream and watershed which includes open adit shows strong effects to concentration and load of Zn in river water. Based on concentration of Zn in river water and flow rate, we calculated mass balance of Zn load between sampling points. In order to protect environmental standard of Zn (30 µg/L) around village in downstream, we have to reduce 4.22 mg/s of Zn load. In that case, we have to reduce discharge of Zn along the mainstream and from open adit in the mining area. Based on the load and concentration of Zn in individual watershed around the mining area, quantitative evaluation is possible to estimate environmental risks of heavy metals in the river water caused by abundant mine.

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.

著者

小山内 康人 高橋 裕平 田結庄 良昭 土屋 範芳 林 保 蛭田 真一

出版者

国立極地研究所

雑誌

南極資料 (ISSN:00857289)

巻号頁・発行日

vol.34, no.3, pp.445-481, 1990-11

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第31次南極地域観測隊(JARE-31)夏隊のセールロンダーネ山地地学・生物調査は, 山地全域においてヘリコプターを用いて実施された。ヘリコプター偵察飛行及び調査慣熟のための陸路調査が1989年12月25日から29日にかけて実施されたのに引き続き, 本調査が1990年1月5日から30日まで行われた。そのほかにあすか観測拠点付近の小山塊における調査・観測が1月1日と1月31日に実施された。調査・観測は38日間におよんだ。今回の行動形態は, 内陸山地でヘリコプターを導入した日本南極地域観測隊としては初めての例であるので, 計画作成から実施経過までを通信, 装備, 食料などの設営面を含めて詳しく報告する。調査結果については現在, 整理・研究中であり, 今後個別に発表されるので, ここでは概要を述べるにとどめる。