著者

荒牧 憲隆 村上 拓馬

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.138, no.4, pp.33-43, 2022-04-29 (Released:2022-04-28)

参考文献数

18

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We proposed a new gasification method to convert unused organic matter in sedimentary rocks to bio methane gas using microorganisms, known as Subsurface Cultivation and Gasification (SCG). Our approach uses hydrogen peroxide (H2O2) to decompose organic matter rapidly into usable substrates for methanogens. We previously reported that H2O2 would be useful for effective SCG at lignite, and conversion of organic matter from lignite into biogenic methane with the help of microorganisms is expected to be highly profitable. However, physical properties of the sedimentary rock are thought to change with the decomposition of sedimentary rock in the SCG method.A series of one-dimensional compression tests were performed for artificial coal seams prepared using the lignite sampled from Tempoku coalfield in the northern Hokkaido to investigate the stability of coal seam during an industrial production of substrates for methanogens in the subsurface environment. H2O2 was used in the one-dimensional compression tests to produce lower-molecular-weight organic components as a substrate of methanogen. Moreover, H2O2 solution was repeatedly injected into the artificial coal seam under compressive pressure. Oxidative decomposition of the artificial coal seam produced a high yield of low-molecular-weight organic acids. However, settlement of the artificial coal seam subjected constant loading was dependent on concentration and injection amount of H2O2.The biomethane deposits might become mechanically unstable during promoting decomposition of organic matter of coal seams, even if lignite has the greater resource potential for biomethane.

著者

荒牧 憲隆 山本 健太郎 平 瑞樹 林 泰弘 根上 武仁

出版者

公益社団法人 地盤工学会

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.9, no.3, pp.309-322, 2014 (Released:2014-09-30)

参考文献数

28

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宮崎県と鹿児島県の県境,霧島山中央部に位置する新燃岳において,2011年1月19日から始まった52年ぶりの噴火は,新燃岳火口から南東方向に大量の火山灰を降らせた。発生した火山灰の量は,4,000万~8,000万tと推定されており,宮崎県南部周辺の広範囲で降灰が確認されている。この突発的な火山災害により,斜面等に降り積もった火山灰堆積地盤での降雨や火山性地震による安定問題や処分された火山灰のリサイクル方法が重要な課題となってくる。本研究は,上記のことを鑑み,新燃岳より噴出した火山灰を用いて,新燃岳火山灰質土の物理・力学性質を実験的に検討し明らかにすることを目的としている。その結果として,噴火直後の火山灰質土の物理・力学特性は,砂質土と概ね類似した傾向を示し,リサイクル材として有用な材料であることが示された。しかし,火山灰質土特有の性質も包含しており,凍結融解の繰返しにより火山灰質土が細粒化していくことが認められ,物理的な風化の影響により材料特性が経時的に変化していくことが予想される結果となった。

著者

荒牧 憲隆 清松 潤一 岡林 巧 藤井 治雄

出版者

公益社団法人 地盤工学会

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.9, no.3, pp.359-373, 2014 (Released:2014-09-30)

参考文献数

31

被引用文献数

1 3

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我が国には,火山灰質粗粒土が広く分布し,特殊土として取り扱われ利用されることが多い。これらの土粒子には,粒子内空隙を有することが知られており,現在の地盤材料の試験方法では対応が困難となることも見受けられる。そのため,物理的諸性質の測定値には,ばらつきが多くなることが予想される。本研究では,粒子内空隙を有する種々の火山灰質粗粒土を対象に,土粒子の密度試験ならびに粒度試験を行い,測定値のばらつきに及ぼす試料の準備や実験方法での影響因子について検討することを目的としている。その結果,火山灰質粗粒土の物理的性質の評価においては,人的,機械的なばらつきに加え,材料そのものの特性により,著しく影響を受けることが認められた。このような材料での計測,品質評価においては,試料の均質性や準備状況に充分配慮を行う必要があることが示唆された。

著者

荒牧 憲隆 村上 拓馬

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.137, no.5, pp.51-55, 2021-05-31 (Released:2021-05-27)

参考文献数

9

被引用文献数

1

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We proposed a new gasification method that converts unused organic matter in sedimentary rocks to bio methane gas through the use of microorganisms, known as Subsurface Cultivation and Gasification (SCG). Our approach uses hydrogen peroxide (H2O2) to decompose organic matter rapidly into usable substrates for methanogens. We previously reported that H2O2 would be useful for effective SCG at lignite, and conversion of organic matter from lignite into biogenic methane with the help of microorganisms is expected to be highly profitable. However, changes of physical properties of the sedimentary rock seem to occur due to decomposition of sedimentary rock in the biogenic methane conversion with the SCG method. In this study, immersion tests using a H2O2 solution were performed on two types of lignite to estimate the quantity of low-molecular-weight organic acids and the producing potential for biogenic methane gas. In addition, mass loss rate of lignite with oxidative decomposition of lignite was examined. The mass loss of lignite with the oxidative decomposition increased with increasing the amount of substance in H2O2. Furthermore, it was confirmed that the loss rate depends on the lignite. The biomethane deposits might become mechanically unstable during promoting decomposition of organic matter of lignite seams, if lignite has the greater resource potential for biomethane.

著者

荒牧 憲隆 A.K.M. Badrul Alam 玉村 修司 上野 晃生 村上 拓馬 金子 勝比古

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.133, no.7, pp.173-181, 2017-07-01 (Released:2017-07-28)

参考文献数

33

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Peat from highly organic soil is abundant in Northern Hokkaido, Japan. In the past, peat was used in various applications in Japan, such as an artificial culture of soil, as a fertilizer for gardening, and as an energy resource. However, peat is not used by the modern energy and manufacturing sectors in Japan because it has a high moisture content and low calorific value, which lowers its value as a resource considering its material characteristics and handling difficulties. Furthermore, large amounts of peat are generated at the construction sites in this area, and they are difficult to be reused at their generation sites because peat is a very soft soil and not suitable for construction work. Recently, many Japanese research institutions have been carrying out research and development on renewable energy resources including biomass energy. In Hokkaido, there are many biogas plants for methanizing biomass derived from livestock excrement or food waste. Thus, peat which is high in organic matter could potentially be used as an energy resource. In this study, we investigated the potential of utilizing peat as an energy resource for biogenic methane production in regional cities of Northern Hokkaido, while considering both its material characteristics and resource circulation. Batch tests using a hydrogen peroxide solution were performed on peat and silty soil to estimate the quantity of low-molecular-weight organic acids and the producing potential for biogenic methane gas. The oxidative decomposition of the peat produced a high yield of low-molecular-weight organic acids that were used as substrates for methanogenic microorganisms. In addition, a novel resource circulation method was proposed for peat in order to use it as an energy resource. Moreover, the energy resources problem in Northern Hokkaido was discussed in association with geographical parameters and the construction recycling system in Japan.

著者

荒牧 憲隆 A.K.M. Badrul Alam 玉村 修司 上野 晃生 村上 拓馬 金子 勝比古

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.132, no.12, pp.190-198, 2016-12-01 (Released:2016-12-16)

参考文献数

23

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Recently, the possibility of realizing a subsurface bio-reactor has been realized since microbial methanogenesis has been confirmed in diverse subsurface environments such as coalbeds or petroleum reservoirs. We propose a new gasification method for use in subsurface environments, known as the Subsurface Cultivation and Gasification (SCG). SCG was devised based on the production of biogenic methane gas in subsurface environments. This approach employed hydrogen peroxide to decompose organic matter rapidly. Conversion of organic matter from source rocks into biomethane with the help of microorganisms is expected to be highly profitable. In this study, a series of batch tests using a hydrogen peroxide (H2O2) solution were performed on lignite to estimate the potential of low-molecular-weight organic acid production. The effects of several factors on the production of low-molecular-weight organic acids have been considered, such as, concentration of H2O2, temperature, liquid-solid ratio, and specific subsurface area of lignite. It was found that the quantity of low-molecular-weight organic acids depended on temperature, liquid-solid ratio, and specific subsurface area of lignite; however, there isn't a unique relationship between them and the H2O2 concentration. Moreover, the mass of lignite reduced remarkably when batch tests were performed with a high concentration of H2O2. If H2O2 is to be injected into a target seam with the SCG method, we should estimate the optimum H2O2 concentration to produce low-molecular-weight organic acids with taking into consideration the mechanical stability of the target seam as well as the subsurface environmental chemical reaction with a geological improvement.