Journal of the Japan Institute of Energy
Online ISSN : 1882-6121
Print ISSN : 0916-8753
ISSN-L : 0916-8753
Volume 78, Issue 1
Displaying 1-3 of 3 articles from this issue
  • Seiji NOMURA, Kenji KATO, Ikuo KOMAKI, Yuji FUJIOKA, Koji SAITO, Ikuro ...
    1999 Volume 78 Issue 1 Pages 33-41
    Published: January 20, 1999
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The viscoelastic properties of coals in the thermoplastic phase during carbonization were measured with dynamic mechanical oscillation instrumentation. The temperature dependence and frequency dependence of viscoelastic properties of the coals were similar to those of polymers and thermosetting resins and this method proved promising in studying the coal structural changes during thermoplastic phase from the analogy to polymers.
    As the coals started to soften, the storage modulus (G') and the loss modulus (G'') decreased and the loss tangent (tan δ=G''/G') increased. While for the caking and slightly caking coals tanδ exceeded unity which showed that the bulk structure of the coal was flowing, for the non-caking coal it was lower than unity in the whole temperature range. Near the temperature of maximum fluidity, tanδ showed a peak while G' and G'' minimum (104-105 Pa) and the complex viscosity (η*) also minimum (104-105Pa·s). Further increase in temperature decreased tanδ and the gel point where tanδ=1 was reached near theresolidification temperature. There was a close relationship between the caking characteristic parameters measured with conventional method and the rheological moduli obtained here. The difference in G' near the resolidificationtemperature among the coals suggested that the compressibility of semi-coke layer could be evaluated by this method.
    The frequency dependence of the viscoelastic properties of coal was measured at 450°C. As cure reaction proceeded, the crossover point of G' and G'' shifted toward low frequency side. This shift might be correlated to the molecular weight and molecular weight distribution of the coal in plastic state. Furthermore η*decreased as the frequency increased which suggests that the Gieseler plastometer overestimates the fluidity in high fluidity range due to the high rotation speed.
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  • Catalyst Production System
    Katsumi HIRANO, Nobuo SUZUKI, Yoshiteru MIYAKE, Masato KOUZU, Shigeru ...
    1999 Volume 78 Issue 1 Pages 42-52
    Published: January 20, 1999
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The catalyst production system has been developed for a 150t/d NEDOL process pilot plant (PP). The following results were obtained through the PP operation;
    (1) Catalytic activity of pulverized pyrite in an inert atmosphere of 0.7μm of median diameter compares favorably with that of the synthetic pyrite.
    (2) From a viewpoint of economical and operable efficiency, two stage pyrite pulverization system (wet-type ball mill-wet-type agitated mill) is the optimum catalyst production system.
    (3) Catalyst slurry of pulverized pyrite characterizes high viscous and pseudo-plastic.
    (4) It was confirmed through the PP operation that the catalyst production system designed from above test data operated stably and produced highly active catalyst.
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  • Relation between Vehicle Speed and Cruising Range
    Shozo HARADA, Koji KOREMATSU
    1999 Volume 78 Issue 1 Pages 53-58
    Published: January 20, 1999
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    With increased environment concern electric vehicle programs are more viable now than ever before, but the most critical obstacle to practical EV use is short cruising range. In this paper a mathematical model for estimation of cruising range between charges of electric motorcycle is developed. As the depth of discharge can be expressed as a function of discharge output which depends on operating modes, the cruising range can be estimated preciously.
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