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198 results on '"Nomura, Mikihiro"'

20. Sorption of Polar Sorbates NH 3 , H 2 O, SO 2 and CO 2 on Selected Inorganic Materials.

Author

Zarębska, Katarzyna, Nomura, Mikihiro, Wolczko, Marta, Szczurowski, Jakub, Pawlak, Bartłomiej, and Baran, Paweł

Subjects
*CARBON dioxide, *MOLECULAR sieves, *WATER vapor, *ZEOLITE Y, *HYDROGEN bonding, *COORDINATION polymers
Abstract

In this paper, the sorption of NH3, H2O, SO2 and CO2 was tested for several selected inorganic materials. The tests were performed on samples belonging to two topologies of materials, faujasite (FAU) and framework-type MFI, the structures of which differ in pore size and connectivity. All sorbates are important in terms of reducing their emissions to the environment. They have different chemical nature: basic, alkaline, and acidic. They are all polar in structure and composition and two of them (ammonia and water vapor) can form hydrogen bonds. These differences result in different interactions with the surface of the adsorbents. This paper presents experimental data and proposes a mathematical description of the sorption process. The best fit of the experimental data was obtained for the Toth and GAB models. The studies showed that among the selected samples, faujasite has the best sorption capacity for ammonia and water vapor, while the best sorbent for sulfur dioxide is the MFI framework type. These materials behave like molecular sieves and can be used for quite selective adsorption of relevant gases. In addition, modification of the faujasite with organic silane resulted in a drastic reduction in the surface area of the sorbent, resulting in significantly lower sorption capacities for gases. [ABSTRACT FROM AUTHOR]

Published
2023
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25. Overvoltage reduction in membrane Bunsen reaction for hydrogen production by using a radiation-grafted cation exchange membrane and porous Au anode

Author

Sawada, Shinichi, Tanaka, Nobuyuki, Kubo, Shinji, Shin-ichiro, Imabayashi, Nomura, Mikihiro, and Yamaki, Tetsuya

Abstract

An electrochemical membrane Bunsen reaction using a cation exchange membrane (CEM) is a key to achieving iodine-sulfur (IS) thermochemical water splitting for the mass-production of hydrogen. In this study, we prepared a radiation-grafted CEM with a high ion exchange capacity (IEC) and a highly-porous Au-electroplated anode, and then used them for the membrane Bunsen reaction to reduce cell overvoltage. The high ionic content of our CEM led to low resistivity for proton transport, while the high porosity of the electrode led to a large effective surface area for anodic SO2 oxidation. The cell overvoltage for the membrane Bunsen reaction was significantly reduced to 0.21 V at 200 mA/cm2, one-third of that achieved using a commercial CEM and non-porous anode. From the analysis of the current-voltage characteristics, the grafted CEM was demonstrated to play a dominant role in the overvoltage reduction compared to the porous Au anode.

Published
2020

30. Development of Cation Exchange Membranes for Electrodialysis by Ion Beam Technology

Author

Miyashita, Taishi, Nomura, Mikihiro, Sawada, Shinichi, Koshikawa, Hiroshi, Yamaki, Tetsuya, Taishi, Miyashita, Shinichi, Sawada, Hiroshi, Koshikawa, and Tetsuya, Yamaki

Abstract

We prepared cation exchange membranes (CEMs) by an ion-track grafting technique, which involves irradiation of a polymer substrate with MeV heavy ions to form the nano-sized cylindrical ion tracks and subsequent graft polymerization to create the ion channels. The prepared CEMs exhibited the resistance lower than that of the commercially-available Nafion212 membrane and conventional γ-ray-grafted CEMs even at the low water uptake. This result indicates efficient proton transport in the cylindrical ion channels, and so our ion-track-grafted CEMs are the promising materials for electrodialysis applications., 第30回日本MRS年次大会

Published
2020

32. ICOM 2020

Author

Yoshioka, Tomohisa, primary, Akamatsu, Kazuki, additional, Nakagawa, Keizou, additional, Takaba, Hiromitsu, additional, Araki, Sadao, additional, Kamio, Eiji, additional, Matsuoka, Atsushi, additional, Kai, Teruhiko, additional, Kawakatsu, Takahiro, additional, Ohshiba, Yuhei, additional, Higa, Mitsuru, additional, Ishii, Katsunori, additional, Nomura,, Mikihiro, additional, Saeki, Daisuke, additional, Tsuru, Toshinori, additional, Moriyama, Norihiro, additional, and Sakai, Motomu, additional

Published
2021
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45. Development of low-overvoltage membrane Bunsen reaction technology for thermochemical IS process

Author

Sawada, Shinichi, Kimura, Takehiro, Nishijima, Haruyuki, Tanaka, Nobuyuki, Kubo, Shinji, Shin-ichiro, Imabayashi, Nomura, Mikihiro, and Yamaki, Tetsuya

Abstract

我々は、熱化学水素製造ISプロセスの一工程である膜ブンゼン反応の過電圧低減に向けた研究を進めている。本研究では、放射線グラフト法を用いて高プロトン伝導性の陽イオン交換膜(CEM)を作製して膜ブンゼン反応試験を実施した。CEMは、フッ素樹脂膜に対するスチレンとジビニルベンゼン(DVB)の放射線グラフト重合とスルホン化で作製した(イオン交換容量は2.4 mmol/g)。このCEMは、市販膜Nafionの約2倍のプロトン伝導性を示した。CEMを膜ブンゼン反応器に装着して3時間の連続反応試験を行った後、電流密度とセル電圧の関係から反応過電圧を求めた。Nafionを用いた場合と比較すると、反応過電圧は3分の2程度であった。高プロトン伝導性膜の使用による過電圧低減を実証できた。, World Hydrogen Technologies Convention 2019

Published
2019

48. Annealing treatment for enhancing of H2/C3H8 separation performance on polysulfone membrane.

Author

Caralin, Irmariza S., Widyanto, Alvin R., Widiastuti, Nurul, Wijiyanti, Rika, Gunawan, Triyanda, Karim, Zulhairun A., Nomura, Mikihiro, Yoshida, Yuki, Kusumawati, Yuly, and Purnomo, Adi Setyo

Subjects
POLYMERIC membranes, SEPARATION of gases, FURNACES
Abstract

Recovery of heavier hydrocarbon gas (i.e. C3H8) from permanent gas (i.e. H2) during gas streams process is a great importance economically. Separation of H2/C3H8 gas using polysulfone (PSF) polymeric membrane was studied with the effect of post-treatment process such as annealing to improve the gas separation performance. PSF membrane annealed using a muffle furnace under vacuum conditions at 150°C for an hour. The result showed that annealing process caused a reduction in the mobility of the polymer chain, which was indicated by a shift of 2θ in XRD results. The cross-section morphology of membrane annealed at 150°C was examined by SEM. Annealing process of PSF membrane enhanced the H2/C3H8 selectivity by 619.77%, from 3.08 to 22.19. It was concluded that post-treatment PSF membrane could improve the H2/C3H8 separation performance compared to PSF membrane without annealing treatment. [ABSTRACT FROM AUTHOR]

Published
2020
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49. Improvement N2/SF6 separation performance on P84 derived carbon membrane by incorporating of zeolite-carbon composite.

Author

Widyanto, Alvin R., Caralin, Irmariza S., Widiastuti, Nurul, Gunawan, Triyanda, Wijiyanti, Rika, Salleh, Wan N. W., Ismail, Ahmad F., Nomura, Mikihiro, Suzuki, Kohei, Kusumawati, Yuly, and Purnomo, Adi Setyo

Subjects
CARBON composites, SCANNING electron microscopy, MOLECULAR sieves, CARBON, GLOBAL warming, SURFACE defects
Abstract

SF6 gas is one of the greenhouse gasses which contributed to the global warming effect. Separation of SF6 and N2 was investigated on the P84 and P84/ZCC carbon membrane. Carbon membranes were prepared via pyrolysis process at 700°C under N2 atmosphere. All of the carbon membranes were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD results show a typical peak of carbon membranes at 2θ∼24° and 41-42° which correspond to the amorphous and aromatic graphite structures, respectively. The scanning electron microscopy image observed that the addition of ZCC filler has been successfully incorporated without producing surface defect on the carbon membrane. The introduction of zeolite-carbon composite particles into the co-polyimide matrix enhanced the selectivity of N2/SF6 by 136.85%. The permeability of N2 has improved by 7.65%. Yet the permeability of SF6 has decreased by 54.55%, which indicated the addition of ZCC filler gives a molecular sieving effect. It concluded that the P84/ZCC carbon membrane shows better N2/SF6 separation performance than the pristine P84 carbon membrane. [ABSTRACT FROM AUTHOR]

Published
2020
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