TANSO
Online ISSN : 1884-5495
Print ISSN : 0371-5345
ISSN-L : 0371-5345
Volume 1984, Issue 119
Displaying 1-9 of 9 articles from this issue
  • Ikuo Abe, Katsumi Hayashi, Mutsuo Kitagawa, Tsuneaki Hirashima
    1984 Volume 1984 Issue 119 Pages 181-184
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    A method is presented for evaluating the adsorption property of porous carbon materials in gas and liquid phases.Adsorption isotherms of benzene are determined on 19 kinds of activated carbons and the adsorption constants, W°and B, in Dubinin-Radushkevich equation are calculated.An adsorption equation is presented for predicting the adsorption isotherms of various organic compounds from aqueous solution.The equation, which is based on the multiple linear regression analysis, comprises four parameters: molecular refraction (Mr), number of hydrophilic group (Nf), micropore volume (W°), and function of pore volume distribution (B).Mr of adsorbate offers a basis for expressing quantitatively the adsorbentadsorbate interactions associated.with the dispersion forces.Nf in an adsorbate molecule is assumed to represent the strength of the adsorbate-water interactions.W°and B represent the adsorption capacity and the strength of adsorbent-adsorbate interaction, respectively. Another equation, in which the amounts of benzene adsorbed at P/P0= 0.01 and 0.1 are used instead of W° and B, is presented and the method using the equation is very simple and useful for evaluating the adsorption property in gas and liquid phases.
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  • Katsumi Hayashi, Ikuo Abe, Shigekazu Nakano, Mutsuo Kitagawa, Tsuneaki ...
    1984 Volume 1984 Issue 119 Pages 185-189
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Granular activated carbons were prepared from wood pellet which were formed with an extruder from wood scrap by adding pitch and tar as a binder.
    The wood pellet was carbonized at 550°C and activated with steam in butch type rotaly kiln.The experimental conditions were as follows; 850°C of activation temperature, 0.55g. H2O/g.char.hr.of steam rate and 1.5-3.0 hours of activation time.A linear relationship was found between the activation yield and the activation time.
    The surface area and the adsorption capacities for methylene blue, iodine and benzene of the activated carbon at about 45% yield were 900m2/g, 200ml/g, 1300mg/g and 34%, respectively.
    On addition of the binder, the hardness of the activated carbon became higher than that of the activated carbon prepared only from wood scrap and was more than 95% by JIS method at about 45% yield.
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  • Asao Oya, Yoshiaki Uno, Sugio Otani
    1984 Volume 1984 Issue 119 Pages 190-196
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    It was attempted to prepare a carbon product directly from pitch material through dehydrogenation by sulfur. A petroleum asphalt was distilled to result in raw pitch with softening point of 320°C. This raw pitch powder was mixed with sulfur of 5% or less, followed by hot-pressing to mould the specimens (3.1 and 1.5 mm in thickness and 40 mm in diameter) under 5 MPa at 320°C. The obtained specimens were further heated under various conditions.
    Just specimens (1.5 mm in thickness) added 3-5% sulfur were heat-treated with little damage at a slow heating rate of 0.1°C/min up to 500°C. This specimen, after heating to above 1200°C, exhibited about 1.5 g/ml in bulk density, 20% in apparent porosity, 40-50 MPa in bending strength and 90 in Shore hardness. X-ray parameters d002 and Lc of the 2000°C specimen were 3.42Å and 160Å, respectively. The potentialities of the present method are discussed on the basis of the results.
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  • Akira Kojima, Sugio Otani, Isao Tomizuka
    1984 Volume 1984 Issue 119 Pages 197-206
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Structure of low temperature pyrolytic carbons (LTPC) prepared from cis-1, 2-dichloroethylene at 700°C and900°C was investigated by several analytical techniques and high temperature treatment.The LTPC as deposited exhibited Moh's hardness of 8.5, and its structure was found to be quite amorphous by X-ray diffraction, laser Raman spectra, and transmission electron microscopy (TEM).
    However a scanning electron microscopic observation on the cross section of LTPC treated by electrolytic etching and an optical microscopic observation under dossed nicoles clearly indicated the anisotropic structure in which basal planes were roughly parallel to the deposition surface.The heat treatment of LTPC at a temperature higher than 2250°C induced rapid graphitization, which caused the expansion and exfoliation in LTPC layer.
    The rapid growth of graphite layer in this process is also observed by TEM and electron diffraction analysis. The LTPC heat-treated at 2500°Cexhibits 2.25g/cm3 in density and the X-ray parameters are 3.355 Å in d002 and above 1000 Å in Lc (002) .The TEM image of this sample was characterized by the large layer structure having moire pattern.From these results, it may be concluded that the LTPC deposited in the precursor of graphitizing carbon composed with very fine units.
    (Study on the low temperature pyrolytic carbon.VII.)
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  • Shangyu Gao, Kiyoshi Yamabe, Hiroshi Takahashi, Yasukazu Saito
    1984 Volume 1984 Issue 119 Pages 207-214
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Three kinds of commercial activated carbons (S, D and P), made from different starting materials and activation methods, were surface-modified after the evacuation at 1000°C by the following procedures: deash-H2 reduction, H2O2 oxidation and air oxidation.Pore structures and surface areas were determined by N2 gas adsorption, whereas surface species were analyzed by thermogravimetry and mass spectrometry during the heat/evacuation treatment.
    The deash-H2 reduction procedure eliminated almost all of the surface oxygenated species which decomposed to CO, CO2 and H2O during the heat/evacuation treatment.In contrast, oxidation procedures were effective to generate oxygenated species.The most effective was the air oxidation procedure.In the oxidized samples, it was to be noted that the fraction of the oxygenated sites on the surface was found for the sample S (ZnC12-activation) larger than for the samples D and P (gas-activation).
    Judging from the composition of desorbed gases, oxygenated surface species such as hydroxylic and carboxylic groups (large CO2 and H2O) were deduced to form mainly by the H2O2 oxidation.On the other hand, carbonyl, quinoic and carboxylic anhydride groups (large CO and little H2O) seemed to be produced dominantly by the air oxidation procedure.
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  • Kenji Miyazaki, Hisayoshi Yoshida, Kazuo Kobayashi
    1984 Volume 1984 Issue 119 Pages 215-221
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The graphitization of glass-like carbon by boron carbide was investigated.The pieces of the glass-like carbon were buried in boron carbide powder and hot-pressed under the pressure of 19.6 MPa at 2200°C.Boron distribution, texture change and graphitization of hot-pressed glass-like carbon were measured.
    The hot-pressed glass-like carbons could be generally classified into three zones from the distribution and the concentration of boron.These zones were named as phase 1, 2 and 3 in order from the region contacted with boron carbide toward the center of glass-like carbon matrix.Characteristics of each phase are as follows.
    Phase 1 shows granular texture consisted of carbon grains and boron carbide ones. Boron also existed in carbon as a solid solution.The carbon have three dimensional ordered structure.
    In phase 2, boron existed only in carbon as a solid solution.The region located at the side contacted with phase 1 showed optical anisotropic texture.The major part of the region located at the side contacted with phase 3 showed a homogeneous and optical isotropic texture.
    In phase 3, boron could not be almost detected and the major part showed the same optical isotropic texture as that of original glass-like carbon.
    In phase 1 boron content was generally scattered from 2 to 10 wt% and in which boron solid-soluted in carbon was about 1-2 wt%.In phase 2 boron content showed the maximum value of 1-2 wt% at the boundary region with phase 1, and it decreased with approaching toward phase 3.
    It was considered that graphitization of glass-like carbon hot-pressed in boron carbide powder at 2200°C was proceeded by the diffusion of boron forming boron carbide and three zones above mentioned were formed in consequence of the content of boron which diffused into glass-like carbon at 2200°C.
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  • Katsumi Hayashi, Ikuo Abe, Shigekazu Nakano, Tsuneaki Hirashima, Mutsu ...
    1984 Volume 1984 Issue 119 Pages 222-228
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The activated carbon was prepared by the following procedure;saw dust from pine was impregnated with the concentrated aqueous solution of zinc chloride, phosphoric acid and calcium chloride respectively and then heated at temperature from 400-700°C for 75 minutes.
    In the case of the activated carbon with zinc chloride at 500-600°C, its pores were widely distributed in the range of radii from 1 to 5 nm.The meso-pore volume was over 70% of the total volume, about 1.4 ml/g.The specific surface area was 1500-1600 m2/g. As to the product activated with phosphoric acid at 600°C, its pore size distribution had a maximum at radii of about 1-2 nm.The volume of pores with radii of 2-5 nm was less than that of the carbon activated with zinc chloride.The total pore volume was about 1.0 ml/g and the surface area was 1270 m2/g. For the activated carbon prepared by activation with calcium chloride, its surface area and pore volume were quite small as compared with those of other specimens, 400 m2/g and 0.35 ml/g.
    The pore volume obtained by mercury porosimetry was larger than that by nitrogen adsorption method, in all specimens.This result would suggest that the volume of mercury filling into the voids between the particles are regarded as the pore volume.
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  • Michio Horie
    1984 Volume 1984 Issue 119 Pages 229-236
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
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  • T. Tsuzuku
    1984 Volume 1984 Issue 119 Pages 237-246
    Published: October 25, 1984
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
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