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

藤井 孝志 菅井 裕一 佐々木 久郎 橋田 俊之 當舎 利行 中尾 信典

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.129, no.12, pp.701-706, 2013-12-01 (Released:2014-12-01)

参考文献数

17

被引用文献数

1 1

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Understanding of interfacial interactions among supercritical CO2 (scCO2), water, and mineral phase is necessary for a precisely prediction of CO2 migration into aquifers. The purpose of this study is to assess the impact of scCO2 on flow property of Kimachi sandstone and Iidate granite in a CO2 rich dense phase i.e., the condition of which scCO2 is expected to displace formation water in the course of CO2 injection. In this experiment, the permeability test for CO2 gas was conducted before and after a CO2 saturation procedure that is filled with scCO2 in pores of rocks. To investigate a mechanical property of rock specimen in the presence of scCO2, the axial strain was also measured using a laser displacement sensor during scCO2 saturation processes. Our results showed that both Kimachi sandstone and Iidate granite samples tested have a more or less decreasing trend of gas permeability with increasing exposure time to scCO2. It was further shown that the axial strain of Kimachi sandstone and Iidate granite increased as scCO2-exposure time increased. Additionally, increases in masses and dimensions of test samples before and after scCO2 saturation processes were clearly observed under atmospheric pressure conditions. It can, therefore be said that Kimachi sandstone and Iidate granite could be capable of swelling and permeability change accompanied by CO2 sorption into their internal structures in the presence of scCO2. Furthermore, the observed significant reduction in permeability cannot fully be explained by two model predictions based on Kozeney-Carman equation and Hagen-Poiseuille law, considering CO2 sorption onto mineral phases. The present results pointed out that CO2 sorption on rocks under geological CO2 storage conditions could have a significantly impact on flow property of rocks during CO2 injection and storage processes.

著者

佐藤 一永 橋田 俊之

出版者

一般社団法人日本機械学会

雑誌

年次大会 : Mechanical Engineering Congress, Japan

巻号頁・発行日

vol.2013, pp."J061023-1"-"J061023-2", 2013-09-08

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The influence of uniaxial compressive stress on the oxygen ion and mixed conductivity of Zr_<0.82>Y_<0.18>O_<1.91>, Ce_<0.9>Gd_<0.1>O_<1.95-δ>,Yba_2Cu_3O_<7-δ>,and La_2NiO_<4+δ> were investigated by using AC 4 probe method under controlled oxygen partial pressure condition. The applied compressive stress was ranged from 0 Mpa to 350 MPa for these specimens in air at 600℃. In order to clarify the reason for the phenomenon of conductivity change, the mixed conductivity of Ce_<0.9>Gd_<0.1>O_<1.95-δ> for the application of stresses were measured under reducing conditions. The experimental result revealed that as the application compressive stress increases, the carrier concentration remain steady, whereas the mobility decreases. The conductivity was decreased with increasing compressive strain, this trend agreed with that of the simulation results. Therefore, the decrease of mobility was considered to be the reason for the decline conductivity under compressive strain/stress conditions.

著者

佐藤 一志 粟山 仁 橋田 俊之 高橋 秀明

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.56, no.526, pp.1400-1405, 1990-06-25

被引用文献数

2 2

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The J-integral-based technique for measuring strain-softening curves is applied to determine the fracture toughness of granite. The measuring method has been recently proposed by Li for concrete. This method provides information on the fracture process zone formation and can be used for fracture toughness determination in strain-softening materials. CT specimens of three different sizes, 1.5inch, 2.5inch and 6inch CT were tested to examine the specimen size effect of measured strain-softening curves. Strain-softening curves measured on 2.5inch CT specimens are shown to be in good agreement with that determined from 6 inch CT specimens, indicating the possibility of determining the valid fracture toughness value by means of the J-integral-based technique. The test results for 1.5inch CT specimens, however, yield a lower fracture toughness value than that obtained on the other specimen sizes, suggesting the need of detailed investigations on specimen size requirements for the reliable use of subsized specimens. Finally, the strain-softening curves obtained by the J-based technique are compared with existing data determined by uniaxial tensile tests on several types of granite.