Journal of the Fuel Society of Japan
Online ISSN : 2185-226X
Print ISSN : 0369-3775
ISSN-L : 0369-3775
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Volume 66, Issue 5
Displaying 1-8 of 8 articles from this issue
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  • [title in Japanese]
    [in Japanese]
    1987 Volume 66 Issue 5 Pages 321
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.321
    JOURNAL FREE ACCESS
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  • Analysis of Circulating Fluidized Bed Combustion Technology
    Quantitative Evaluation of Development Subjects and the Analysis of Factors Influencing Efficiency and Emission Control
    Takehiko FURUSAWA, Tadaaki SHIMIZU, [in Japanese]
    1987 Volume 66 Issue 5 Pages 322-337
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.322
    JOURNAL FREE ACCESS
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    The technology of circulating fluidized bed coal combustion has drawn keen attention as an alternative to the conventional processes and is considered to offer potential break-throughs of various problems which the conventional dense phase fluidized bed combusiton technology could not have solved.
    However, the details of the technology have not been reported so far. Quantitative and detailed analyses of this technology conducted by use of officially available information is reported in this paper. The analyses include the circulating rate and loading of solids, heat recovery and heat transfer rate as a function of loading of solids, the design of the cyclones related to high concentration of solids within the combustor, s
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  • Flow Properties in Liquefier and Preheater of Direct Coal Liquefaction Process
    Shigeharu MOROOKA, Tokihiro KAGO, Katsuki KUSAKABE, Yasuo KATO
    1987 Volume 66 Issue 5 Pages 338-347
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.338
    JOURNAL FREE ACCESS
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    This is a quantitative review of gas-liquid-solid flow in direct coal liquefaction processes. The gas holdup in liquefiers is much larger than that in bubble columns for usual air-water systems, while the axial liquid mixing is much smaller in reverse. This indicates that the homogeneous bubble flow prevails in the reactors. By introducing a small amount of coalesced bubbles, the axial liquid mixing is increased to the level of the fully heterogeneous flow regime. Gas holdup, axial liquid mixing and mean settling velocity of solid particles in liquefiers are correlated by experimental equations and figures as functions of reactor diameter and operational conditions.
    The accumulation of ash particles growing in liquefier is simulated with a population balance equatign based on the sedimentation-dispersion model. The parameters used in the model can be obtained from the experimental results in cold model reactors except for the particle growth rate, which is dependent on coal species and reaction conditions and must be determined in each case.
    The radial and axial mixing of liquid in horizontal preheaters is affected by liquid or slurry viscosity. If the viscosity is substantially increased in the preheater, the intermixing between the liquid plug and bottom flow becomes insufficient. The heat transfer coefficient between the wall and the three-phase flow is well correlated by an experimental equation including the data at the Wilsonville pilot plant.
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  • Hydrocracking of Wandoan Coal Liquids (III)
    Upgrading of Middle Distillate of Wandoan Coal Liquids
    Toshiaki KABE, Hideo OHNUMA, Osamu NITOH, Shinichi WATANABE, Yosimasa ...
    1987 Volume 66 Issue 5 Pages 348-357
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.348
    JOURNAL FREE ACCESS
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    In order to develop an effective use of coal liquids, the middle distillate of Wandoan coal liquid obtained by a coal liquefaction plant of 1t/d (Sumitomo Metal Co., Ltd) was hydrocracked under initial hydrogen pressure of 5.9 MPa at 400°C, in the presence or absence of Ni-Mo-Al2O3 catalyst. The raw coal liquid contained mainly condensed aromatic compounds and n-paraffins, and the content of 2 rings aromatics such as naphthalene was major, namely 30.1%. To clarify the behavior of gaseous hydrogen in the process of hydrocracking, 3H labeled gaseous hydrogen was used as tracer. When coal liquid was hydrocracked in 3H atomosphere, 3H atoms were transfered to coal liquid even without catalyst. The catalyst promoted the 3H transfer, and then a small amount of sulfur more accelerated the catalytic activity. The behavior of 2 and 3 rings aromatics in the products indicated that the hydrocracking was proceeded by the hydrogen donation from some donor compounds in coal liquid without catalyst. Furthermore, the hydrocracked products of acridine and carbazole in the products were traced to examine the hydrodenitrogenation process. The most important result obtained was that the hydrodenitrogenation of their compounds were not proceeded in the absence of catalyst but they were hydrotreated rapidly on the catalyst and then hydrodenitrogenated.
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  • Preparation of Fine Coal Fraction for the Production of Highly Concentrated Coal Water Mixture by Wet Ball Milling
    Toshimitsu KOKUBO, Hiroyuki IWATA, Tadao MORO
    1987 Volume 66 Issue 5 Pages 358-364
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.358
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    A fuel of coal water mixture, called CWM, is required to be highly concen-trated with coal for the purpose of combustion without previous dehydration. In the production of CWM it is necessary to prepare a coal fraction with wide size distribution in which the portion of very fine particles is considerable.
    In this study an wet grinding test was carried out to investigate the productivity of fine particle fraction using a small laboratory ball mill depending on mill filling, slurry concentration, ball size and mill speed, from which an optimum condition for the best grinding effect proved to be found with regard to feed slurry concentration and mill filling.
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  • Change of Rheological Behavior in Wandoan Coal-Anthracene Oil Slurry by Heating
    Tsuyoshi SAKAKI, Masao SHIBATA, Seiji ARITA
    1987 Volume 66 Issue 5 Pages 365-372
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.365
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    In order to obtain the foundamental data relating to the slurry preparation of coal liquefaction process, the rheological behavior of Wandoan coal-anthracene oil slurry has been investigated using a coaxial double cylindrical rotation viscometer at temperatures of 30 to 152 t in the range of 30 to 300s-1 of shear rate.
    Wandoan coal slurry had the flow pattern of Ostwald type, and relative viscosity, pseudoplasticity and thixotropy of the slurry increased with an increase in coal concentration at 30°C.
    The rheological behavior of the slurry was reversible against temperature in spite of heat histry up to 77°C. On the other hand, when the coal slurry was heated above 100°C, the apparent viscosity of the slurry At 30°C increased morethan that before heat treatment and the rheological behavior of the slurry became irreversible against temperature. The causes of the change in rheological behavior by heating are the growth of agglomerate structure owing to absorption of anthracene oil by coal particles in the slurry. Because anthracene oil which had been trapped in coal particles and the agglomerate structure is not able to contribute to the fluidity of the slurry, the apparent viscosity of the slurry increased with an increase in temperature above 100°C.
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  • Study on the Conventional Method for the Solvent Extraction of Liquefaction Products
    Yoshiki SATO, Keiji MIKI
    1987 Volume 66 Issue 5 Pages 373-377
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.373
    JOURNAL FREE ACCESS
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    On the method for solvent extraction of liquefaction product, ultrasonic and soxhlet apparatus have been tested to compare the yield, reproducibility and the property of the extract.
    Extractions of n-hexane insolubles, which were produced from the liquefaction of Taiheiyo coal and Yallourn coal at 440°C under initial hydrogen pressure of 85 kg/cm2·G with tetralin/coal weight ratio of 3 and reaction time of 30min, were carried out with benzene and THF. Little difference in total conversion (benzene conversion plus THF conversion) between ultrasonic and soxhlet extractions was observed, but the conversion from benzene extraction revealed lower level in soxhlet method combined with both electric heater and hot water bath than in ultrasonic method.It was considered to be due to the low diffusion efficiency of benzene into sample by the use of soxhlet apparatus. Same conclusion was drawn from the result on the property of extract. Ultrasonic extraction was, therefore, considered to be a new convenient method to evaluate the accurate conversion using small amount of sample.
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  • [title in Japanese]
    [in Japanese]
    1987 Volume 66 Issue 5 Pages 378-389
    Published: May 20, 1987
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.3775/jie.66.378
    JOURNAL FREE ACCESS
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