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Tanso 196 - Abstracts
PERGAMON
Carbon 39 (2001) 1117–1118
Tanso 196 – Abstracts Preparation of activated carbon pellets without binder and their methane adsorption properties by Kazuhiro Kanazawa, Kiyoto Inomata, Yasuhiko Urabe, Hideyuki Hosono and Toshinari Araki Frontier Technology Laboratory, Tokyo Gas Co., Ltd.: 1 -7 -7 Suehiro, Tsurumi, Yokohama 230 -0045, Japan Activated carbon pellets were prepared from cellulose microcrystals without a binder. The column form of activated carbon pellets was maintained after heat treatment by use of compressed cellulose microcrystals. The bulk density of the activated carbon pellets increased with increasing compression pressure of the raw materials. On the other hand the total pore volume decreased. The bulk density of the activated carbon pellets is 2.5 times greater than that of activated carbon powder under the same sintering conditions. The amount of methane adsorption at 308C is 82 mg / g at 0.86 MPa. The total methane storage efficiency of adsorbed gas is 280 cm 3 in 1 cm 3 volume of the activated carbon pellet prepared in this work, being 1.7 times higher than that of the methane compressed at 13.0 MPa. [Tanso 2001 (No.196) 2–8]
Applications of carbon nanotubes and nanofilaments as electrodes of electrochemical supercapacitors: effect of chemical oxidation by Laurent Duclaux*, Yasushi Soneda** and Mitsunori Makino** ` Divisee ´ , CNRS* Centre de Recherche sur la Matiere ´ ´ , 45071 Orleans Cedex University: 1 B rue de la Ferollerie 2, France
** National Institute for Resources and Environment: 16 -3 Onogawa, Tsukuba, Ibaraki 305 -8569, Japan Carbon nanofilaments obtained by the catalytic decomposition of CO and a carbon deposit containing a large amount of SWNTs (Single-Walled Carbon Nanotubes) obtained by electric-arc discharge were used as electrodes of electro-
chemical capacitors with 6M KOH electrolyte. The specific capacitance was estimated by cyclic voltammetry measurements and impedance spectroscopy. Acidic oxidizing treatment of nanofilaments with concentrated HNO 3 , mixture of H 2 SO 4 / HNO 3 , and fuming HNO 3 allow one to increase the specific capacitance ten times to a value of 80 F / g. This result is attributed to both textural and structural modifications by acid treatment and the development of oxygenated surface functional group enhancing the pseudocapacitance. The capacitive property of the electric-arc discharge carbon deposit (18 F / g) is attributed mainly to SWNTs bundles. Acid treatments enable one to slightly enhance their specific capacitances (30 F / g). [Tanso 2001 (No.196) 9–13]
Effect of VGCF addition into the carbon electrode for electric double layer capacitor (EDLC) by Toshikazu Takeda*, Risa Takahata**, Yong Jung Kim***, Kenji Koshiba***, Kiyohiro Ishii***, Toshiyuki Kasai*** and Morinobu Endo***
* CCR. Corporation: 8, Tsuchidana, Kanagawa 252 -8501, Japan
Fujisawa-shi,
** Nippon Chemi-Con Corporation: 1 -167 -1, HigashiOme, Ome-shi, Tokyo 198 -8501, Japan *** Faculty of Engineering, Shinshu-University: 4 -17 -1, Wakasato, Nagano-shi, Nagano 380 -8553, Japan The most interesting factor in commercial EDLC has been considered the resistance of the entire cell unit, especially for use at higher out-put current density. In order to reduce the resistance of the EDLC cell, the sheet type electrode has been prepared by adding the vapor-grown carbon fibers (VGCFs) as a conductive additive. The cell performances were evaluated by comparing with one including carbon black (CB). Equivalent series resistance, ESR, of electrode and internal resistance for VGCFs-added sheet samples were greatly reduced, in the range of 20% and 50% less, as compared with those of carbon black. The tests for the
0008-6223 / 01 / $ – see front matter 2001 Elsevier Science Ltd. All rights reserved. PII: S0008-6223( 01 )00056-2
1118
Tanso 196 – Abstracts / Carbon 39 (2001) 1117 – 1118
cycle life and lifetime properties showed that it is also effective for the improvement of cyclic performance, life time as compared with that of CB based samples. The present results will be effective to design the electrode of a practical EDLC cell for especially high power use. [Tanso 2001 (No.196) 14-18]
Synthesis of ternary cesium-acrylonitrile-graphite intercalation compound by Takayuki Yoshioka**, Rika Matsumoto*, Yoichi Takahashi* and Noboru Akuzawa***
* Department of Applied Chemistry, Chuo University: 1 13 -27, Kasuga, Bunkyo-ku, Tokyo 112 -8551, Japan ** Graduate School of Science and Technology, Niigata University: 8050, 2 -nocho, Ikarashi, Niigata 950 -2181, Japan *** Department of Chemical Science and Engineering, Tokyo National College of Technology: 1220 -2, Kunugida, Hachioji, Tokyo 193 -8610, Japan The sorption isotherm and the desorption behavior of acrylonitrile (AN) into CsC 24 at 300K were investigated. The maximum amounts of acrylonitrile sorbed, AN / Cs, was 1.2|1.4, and the sorption-desorption process was irreversible. The stage structure of the resulting ternary compound, after exposure to air, was determined by X-ray diffraction and Raman shift measurements and was confirmed to be mainly ternary stage-2 structure with Ic 51.00 nm. The change of XRD patterns of the compound with time was not very significant, while the electrical conductivity decreased rapidly. The heat-treatment of the sample gave little effect for the stabilization of the ternary compound. [Tanso 2001 (No.196) 19–21]
Synthesis of all-carbon chains and nanoparticles by chemical transformation of halogenated hydrocarbons at low temperatures by Ladislav Kavan J. Heyrovsky Institute of Physical Chemistry: Dolejskova 3, CZ-182 23 Prague 8, Czech Republic The paper reviews synthetic procedures towards carbonaceous materials via chemical dehalogenation or dehy-
drohalogenation of halogenated hydrocarbons, which take place at mild temperatures and pressures. Special attention is being paid to a preparation of unusual carbon structures, viz. sp-bonded all-carbon chains(carbyne-like materials), fullerenes, and carbon nanotubes. This article upgrades previous reviews on this subject, published in 1997. Among the most interesting recent outputs, we may quote the preparation of fullerene C 60 and multiwalled carbon nanotubes by simple chemical reactions occurring at ambient conditions. [Tanso 2001 (No.196) 22–38]
Acceptance test of graphite components in a nuclear reactor by Masahiro Ishihara*, Satoshi Hanawa**, Tatsuo Iyoku** and Shusaku Shiozawa*
* Department of Advanced Nuclear Heat Technology, Japan Atomic Energy Research Institute: 3607, Narita, Oarai-machi, Higashiibaraki-gun, Ibaraki-ken, 311 -1394, Japan ** Department of HTTR Project, Japan Atomic Energy Research Institute: 3607, Narita, Oarai-machi, Higashiibaraki-gun, Ibaraki-ken, 311 -1394, Japan The HTTR is the first high temperature gas-cooled reactor in Japan. It is a test reactor with a thermal power of 30 MW and a maximum coolant outlet temperature of 9508C. To achieve high temperature coolant core the internals were made of graphite and carbon materials due to their excellent thermal resistivity. After the fabrication of the graphite and carbon components they were installed in the HTTR, which is now in the power-up testing stage. Concerning the inspection standard of the graphite and carbon components, no domestic standard exists as the main components in the nuclear reactor. It is necessary, therefore, to prescribe inspection standards for the HTTR graphite components. Much research and development in relation to the inspection standard, e.g. in the research field of nondestructive examination of the graphite material, had been performed, and JAERI then established the inspection standard. The acceptance test of the graphite and carbon components was carried out based on this inspection standard. This paper prescribes the outline of the established inspection standard. [Tanso 2001 (No.196) 39–48]
Carbon 39 (2001) 1117–1118
Tanso 196 – Abstracts Preparation of activated carbon pellets without binder and their methane adsorption properties by Kazuhiro Kanazawa, Kiyoto Inomata, Yasuhiko Urabe, Hideyuki Hosono and Toshinari Araki Frontier Technology Laboratory, Tokyo Gas Co., Ltd.: 1 -7 -7 Suehiro, Tsurumi, Yokohama 230 -0045, Japan Activated carbon pellets were prepared from cellulose microcrystals without a binder. The column form of activated carbon pellets was maintained after heat treatment by use of compressed cellulose microcrystals. The bulk density of the activated carbon pellets increased with increasing compression pressure of the raw materials. On the other hand the total pore volume decreased. The bulk density of the activated carbon pellets is 2.5 times greater than that of activated carbon powder under the same sintering conditions. The amount of methane adsorption at 308C is 82 mg / g at 0.86 MPa. The total methane storage efficiency of adsorbed gas is 280 cm 3 in 1 cm 3 volume of the activated carbon pellet prepared in this work, being 1.7 times higher than that of the methane compressed at 13.0 MPa. [Tanso 2001 (No.196) 2–8]
Applications of carbon nanotubes and nanofilaments as electrodes of electrochemical supercapacitors: effect of chemical oxidation by Laurent Duclaux*, Yasushi Soneda** and Mitsunori Makino** ` Divisee ´ , CNRS* Centre de Recherche sur la Matiere ´ ´ , 45071 Orleans Cedex University: 1 B rue de la Ferollerie 2, France
** National Institute for Resources and Environment: 16 -3 Onogawa, Tsukuba, Ibaraki 305 -8569, Japan Carbon nanofilaments obtained by the catalytic decomposition of CO and a carbon deposit containing a large amount of SWNTs (Single-Walled Carbon Nanotubes) obtained by electric-arc discharge were used as electrodes of electro-
chemical capacitors with 6M KOH electrolyte. The specific capacitance was estimated by cyclic voltammetry measurements and impedance spectroscopy. Acidic oxidizing treatment of nanofilaments with concentrated HNO 3 , mixture of H 2 SO 4 / HNO 3 , and fuming HNO 3 allow one to increase the specific capacitance ten times to a value of 80 F / g. This result is attributed to both textural and structural modifications by acid treatment and the development of oxygenated surface functional group enhancing the pseudocapacitance. The capacitive property of the electric-arc discharge carbon deposit (18 F / g) is attributed mainly to SWNTs bundles. Acid treatments enable one to slightly enhance their specific capacitances (30 F / g). [Tanso 2001 (No.196) 9–13]
Effect of VGCF addition into the carbon electrode for electric double layer capacitor (EDLC) by Toshikazu Takeda*, Risa Takahata**, Yong Jung Kim***, Kenji Koshiba***, Kiyohiro Ishii***, Toshiyuki Kasai*** and Morinobu Endo***
* CCR. Corporation: 8, Tsuchidana, Kanagawa 252 -8501, Japan
Fujisawa-shi,
** Nippon Chemi-Con Corporation: 1 -167 -1, HigashiOme, Ome-shi, Tokyo 198 -8501, Japan *** Faculty of Engineering, Shinshu-University: 4 -17 -1, Wakasato, Nagano-shi, Nagano 380 -8553, Japan The most interesting factor in commercial EDLC has been considered the resistance of the entire cell unit, especially for use at higher out-put current density. In order to reduce the resistance of the EDLC cell, the sheet type electrode has been prepared by adding the vapor-grown carbon fibers (VGCFs) as a conductive additive. The cell performances were evaluated by comparing with one including carbon black (CB). Equivalent series resistance, ESR, of electrode and internal resistance for VGCFs-added sheet samples were greatly reduced, in the range of 20% and 50% less, as compared with those of carbon black. The tests for the
0008-6223 / 01 / $ – see front matter 2001 Elsevier Science Ltd. All rights reserved. PII: S0008-6223( 01 )00056-2
1118
Tanso 196 – Abstracts / Carbon 39 (2001) 1117 – 1118
cycle life and lifetime properties showed that it is also effective for the improvement of cyclic performance, life time as compared with that of CB based samples. The present results will be effective to design the electrode of a practical EDLC cell for especially high power use. [Tanso 2001 (No.196) 14-18]
Synthesis of ternary cesium-acrylonitrile-graphite intercalation compound by Takayuki Yoshioka**, Rika Matsumoto*, Yoichi Takahashi* and Noboru Akuzawa***
* Department of Applied Chemistry, Chuo University: 1 13 -27, Kasuga, Bunkyo-ku, Tokyo 112 -8551, Japan ** Graduate School of Science and Technology, Niigata University: 8050, 2 -nocho, Ikarashi, Niigata 950 -2181, Japan *** Department of Chemical Science and Engineering, Tokyo National College of Technology: 1220 -2, Kunugida, Hachioji, Tokyo 193 -8610, Japan The sorption isotherm and the desorption behavior of acrylonitrile (AN) into CsC 24 at 300K were investigated. The maximum amounts of acrylonitrile sorbed, AN / Cs, was 1.2|1.4, and the sorption-desorption process was irreversible. The stage structure of the resulting ternary compound, after exposure to air, was determined by X-ray diffraction and Raman shift measurements and was confirmed to be mainly ternary stage-2 structure with Ic 51.00 nm. The change of XRD patterns of the compound with time was not very significant, while the electrical conductivity decreased rapidly. The heat-treatment of the sample gave little effect for the stabilization of the ternary compound. [Tanso 2001 (No.196) 19–21]
Synthesis of all-carbon chains and nanoparticles by chemical transformation of halogenated hydrocarbons at low temperatures by Ladislav Kavan J. Heyrovsky Institute of Physical Chemistry: Dolejskova 3, CZ-182 23 Prague 8, Czech Republic The paper reviews synthetic procedures towards carbonaceous materials via chemical dehalogenation or dehy-
drohalogenation of halogenated hydrocarbons, which take place at mild temperatures and pressures. Special attention is being paid to a preparation of unusual carbon structures, viz. sp-bonded all-carbon chains(carbyne-like materials), fullerenes, and carbon nanotubes. This article upgrades previous reviews on this subject, published in 1997. Among the most interesting recent outputs, we may quote the preparation of fullerene C 60 and multiwalled carbon nanotubes by simple chemical reactions occurring at ambient conditions. [Tanso 2001 (No.196) 22–38]
Acceptance test of graphite components in a nuclear reactor by Masahiro Ishihara*, Satoshi Hanawa**, Tatsuo Iyoku** and Shusaku Shiozawa*
* Department of Advanced Nuclear Heat Technology, Japan Atomic Energy Research Institute: 3607, Narita, Oarai-machi, Higashiibaraki-gun, Ibaraki-ken, 311 -1394, Japan ** Department of HTTR Project, Japan Atomic Energy Research Institute: 3607, Narita, Oarai-machi, Higashiibaraki-gun, Ibaraki-ken, 311 -1394, Japan The HTTR is the first high temperature gas-cooled reactor in Japan. It is a test reactor with a thermal power of 30 MW and a maximum coolant outlet temperature of 9508C. To achieve high temperature coolant core the internals were made of graphite and carbon materials due to their excellent thermal resistivity. After the fabrication of the graphite and carbon components they were installed in the HTTR, which is now in the power-up testing stage. Concerning the inspection standard of the graphite and carbon components, no domestic standard exists as the main components in the nuclear reactor. It is necessary, therefore, to prescribe inspection standards for the HTTR graphite components. Much research and development in relation to the inspection standard, e.g. in the research field of nondestructive examination of the graphite material, had been performed, and JAERI then established the inspection standard. The acceptance test of the graphite and carbon components was carried out based on this inspection standard. This paper prescribes the outline of the established inspection standard. [Tanso 2001 (No.196) 39–48]