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Volume 67, Issue 5
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[in Japanese]1988 Volume 67 Issue 5 Pages 279
Published: May 20, 1988
Released on J-STAGE: June 28, 2010
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Yasuji SAITO1988 Volume 67 Issue 5 Pages 280-292
Published: May 20, 1988
Released on J-STAGE: June 28, 2010
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Keizo FUJII1988 Volume 67 Issue 5 Pages 293-305
Published: May 20, 1988
Released on J-STAGE: February 23, 2011
JOURNAL FREE ACCESSPeat has long been recognized as a precursor of coal. Peat may accumulate in a wide range of depositional area, including river flood-plains, deltas, swamps, tectonically ac-tive backarc basins associated with mountain building process, and strike-slip basins in conti-nent.
The formation of peat is very sensitive with following basic requirements:
(a) substantial growth of plants with at least some woody or fibrous components;
(b) sufficient standing water around accumulated plant material to exclude oxidation or bacterial destruction of the organic components;
(c) the absence of inorganic sediment during peat accumulation.
Coal is composed of three kinds of maceral groups. The study of the decomposition of plant components associated with each depositional area has enabled prediction of the occur-rence and distribution of the precursors of coal macerals.
The development from peat through anthracite is termed coalification according to in-crease of burial depth. Chemical and physical changes in the coalification process are dependent on initial depositional environments of plant materials.View full abstractDownload PDF (1700K) -
Tsukasa CHIKATA, Keiichi HAYAKAWA1988 Volume 67 Issue 5 Pages 306-313
Published: May 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA coal liquefaction process with bituminous coal has been developed as a part of a national project “SUNSHINE”, supervised by NEDO. In this process, Australian Wandoan coal has been considered as a promising raw material so that various studies have been done.
For a better understanding of the liquefaction reaction behavior of Wandoan coal in continuous flow unit, effects of reaction time and the duplicate reactors on products yield were studied. Furthermore, the change of coal particle size distributions with reaction time were also investigated.
As one of the investigations of reaction time, a series of experiments of ultra-short con-tact time reaction (about 15 seconds) were carried out. From these experiments, it was clarified that the decomposition of coal particles were remarkably proceeded even under ultra-short contact conditions so that a coal particle with the size of 100μm was immediately smashed into over 20 fragments with around 30% of that converted to distillable oil products and that there was no effect of catalyst in this stage.
It was also confirmed that resid yield was decreased but oil yield was increased according to the number of reactors from single to duplicate.View full abstractDownload PDF (885K) -
Kiyoshi IDOGAWA, Koji IKEDA, Takashi FUKUDA, Hideo NARITA, Yosuke MAEK ...1988 Volume 67 Issue 5 Pages 314-321
Published: May 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA semi-cylindrical bubble column of 50cm in diameter equipped with a simultaneous injection nozzle of gas and liquid was used as a cold model for s liquefier of the direct coal liquefaction.
The gas holdup and the jet length in the column were affected significantly by the liquid flow. After the temperature of the feed fluids was suddenly changed, thermal image pictures were taken at regular time intervals, and the presence of the stagnant zone in the periphery was revealed.
Unsteady-state thermal behavior in the bottom part of a liquefier was simulated on the basis of a heat balance model with lumped parameters such as heat exchange rate, heat capacity of the reactor wall, and heat evolution by the liquefaction reaction. The possibility of heat ac-cumulation in the stagnant zone was elucidated in cases where the heat capacity of the reactor wall was larger than that of the stagnant liquid and where the heat exchange rate between the jet and stagnant zone was small.View full abstractDownload PDF (1154K) -
Isao MOCHIDA, Xing Zhe ZHAO, Kinya SAKANISHI1988 Volume 67 Issue 5 Pages 322-329
Published: May 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe structural change of the asphaltene in a brown coal liquid was com-paratively studied before and after the single-and two-stage hydrotreatments, using the same commercial Ni-Mo/Al2O3 catalyst in the batch autoclave. The less catalyst deactivation as well as higher performances in the denitrogenation (>80%) and up-grading of the asphaltene were obtained in the two-stage hydrotreatment of 390°C-2h and 430°C-2h. The two-stage hydrotreat-ment extensively hydrogenated the polar aromatics in the first stage at a lower temperature to improve their solubility and cracking reactivity, followed by effective hydrocracking and denitrogenation in the second stage at a higher temperature, while the single-stage reaction at a higher temperature allowed lower performances except for the apparent cracking extent because of insufficient hydrogenation.
The structure of the heavy polar fraction in the asphaltene was analyzed in detail to characterize the remaining nitrogen compounds and clarify the reasons of their lower reactivity for the denitrogenation and their influences on the catalyst deactivation.Key WordsView full abstractDownload PDF (828K) -
Mitsuho HIRATO, Yoshihiko NINOMIYA, Masahiko ASAMI1988 Volume 67 Issue 5 Pages 330-336
Published: May 20, 1988
Released on J-STAGE: October 21, 2011
JOURNAL FREE ACCESSHigh temperature fusion behavior of mixtures of ash exhibiting a wide range of melting temperature and additive has been investigated under reducing (CO/CO2) at mospheres. Six additives were used: limestone, two iron ores, red mud, CaO obtained by calcin-ing CaCO3 reagent, and Fe2O3 reagent. Characteristic ash fusion temperatures were measured in an electric furnace in conformity to the JIS M8801 method. A microscope equipped with a high temperature heating stage was also used to perform in-situ observation of the reaction and fu-sion behavior between the ash and the additive. The mixtures, treated in several temperature ranges from 900 V to the fluid temperature, were quenched rapidly and identified by the X-ray diffraction.
(1) It was found that fusion behavior of ash-iron are mixtures and ash-imestone mix-tures approximately coincided with that of the ash-reagent mixtures. The minimum value of hemispherical temperature was 100°C to 500&D lower than that of original ash. The fluxing deg;C f-fect of red mud was lower than that of Fe2O3 reagent.
(2) Partially fused phases were observed at temperatures 100°C to 200°C below the softening temperature. From X-ray analysis FeO was found to be the principal fluxing element that controls partial ash melting
(3) At softening temperature a shift from the local solid-solid reaction mode to the liquid-solid slurry reaction mode was observed. Above the hemispherical temperature volatiles and CO2 gas were released in the form of bubbles and the shape of molten ash was changed into a sphere in a graphite crucible. This melting behavior was observed in all ashes irrespective of the presence of additives.View full abstractDownload PDF (1187K) -
Masaaki TANINO, Yoshiaki SHOJI, Takao OKADA, Jun FUKAI, Takatoshi MIUR ...1988 Volume 67 Issue 5 Pages 337-341
Published: May 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe covering material of an electric cord was pyrolyzed in an atmosphere of nitrogen. The solidified tar yield was got up to 63wt% and the others were produced as gases at the pyrolysis completion under the heating condition of 1°C/min.
The partially combustion method and the high pressure pyrolysis method were conducted to reduce the solidified tar yield. The principal components of hydrocarbons, in the partially combustion were C1, C2 and C4. The hydrocarbons above C5 were not detected. The tar was reduced with increases of oxygen concentration and final temperature, while CO and CO2 in-crease with oxygen concentration. On the other hand, the solidified tar in the high pressure pyrolysis method was not producted on the range above 5kg/cm2, and the liquefied oil was done at 75wt% of yield.View full abstractDownload PDF (520K) -
[in Japanese]1988 Volume 67 Issue 5 Pages 342-352
Published: May 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1265K)
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