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Volume 63, Issue 5
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[in Japanese]1984 Volume 63 Issue 5 Pages 297
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (222K) -
Tetsuro YOKONO, Shoichi IYAMA, Yuzo SANADA1984 Volume 63 Issue 5 Pages 298-304
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe dehydrogenation reaction from coal-metal chloride catalysts systems under atmospheric pressure has been studied by gas chromatography in order to establish a simple and rapid method for evaluating coal liquefaction catalysts.
The results of the dehydrogenation experiments were compared with those obtained from high-temperature, high-pressure batch autoclave experiments.
It was found that there is a linear relationship between hydrogen evolution from coal-catalyst systems at atmospheric pressure and total-conversion of coal liquefaction at high temperature, high pressure experiment. The distributions of products correlate also directly with hydrogen evolution.
The highly active metal chloride catalysts for the liquefaction of Akabira coal, Taiheiyo coal and Big Brown Lignite were ZnCl2 and SnCl2.View full abstractDownload PDF (762K) -
A Study on Rate EquationsSatoshi OHSHIMA, Morio SUZUKI, Kazuo SHIMADA, Motoo YUMURA, Toshiichi ...1984 Volume 63 Issue 5 Pages 305-313
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSKinetics of coal liquefaction have been studied for years by many investigators and a variety of reaction models based on the experimental results from batch reaction systems has been proposed.
Besides these, a model commonly applicable to these data was proposed by Chiba et al., which was derived by assuming the coal to be composed of two kinds of fractions different in reactivity.
Recently, a rate equation available for the experimental results from a plug flow reactor and from complete mixing reactor was presented by assuming the existence of an unconvertible component [or an equilibrium conversion] in coal to pyridine or benzene solubles for the results in continuous flow reactors.
In the present study, the rate equations derived by applying the concept of the existence of an unconvertible component were found to be well applicable to the reactions of coal to n-hexane solubles as well as coal to pyridine or benzene solubles concerning to our results obtained by using a c. s. t. reactor and also to the reported data from the batch system.
A simple graphic method was presented in this paper to determine a rate costant and a fractional ratio of the unconvertible component for the rate equation applicable to the reaction in a complete mixing type reactor.View full abstractDownload PDF (941K) -
Correlation between Extraction Yield and Extraction Condition (Temperature and Pressure)Tsuyoshi SAKAKI, Seiji ARITA, Hitoo KAKIYAMA1984 Volume 63 Issue 5 Pages 314-319
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSSupercritical fluid extraction of the coal liquids was carried out using single solvent such as benzene, toluene or p-xylene and an equimolecular mixed solvent of benzene and toluene. The correlations between the extraction yield and extraction conditions, e. g. temperature and pressure, were investigated.
The increase in the extraction temperature resulted in an increase in the extraction yield, and so did the increase in the density of the solvent. The extraction pressure was an indirect factor which influenced the extraction yield through changing the density of the solvent. The following empirical equation concerning the extraction yield (x) was obtained as functions of reduced temperature (T/TC) and reduced density (d/dc) for each single solvent.
x=A (d/dc) +B (T/TC) +C...(1) where, A, B and C are empirical constants for each solvent. The extraction yields calculated from this equation were in good agreement with the experimental values.
The extraction yield of the coal liquids using mixed solvent could be calculated from the equation which was composed of the equations (1) for each single solvent.View full abstractDownload PDF (794K) -
Tetsuo YAMADA, Seikichi SHIMO, Tsutomu SUZUKI, Tsuneyuki HOMMA1984 Volume 63 Issue 5 Pages 320-325
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCatalytic effects of SnO2 and PbO on gasification of carbon under high pressures of CO2 were investigated by means of thermogravimetry (TG), temperature-programmed X-ray diffraction (TPXRD), and scanning electron microscopy (SEM).
Carbon material used was char from phenol-formaldehyde resin. It was mixed each metal oxide of 0.5 atomic % in a mortar grinder for 1 hour.
Nonisothermal TG measurements indicated that these oxides had high catalytic activities but SnO2 was suprrior to PbO in the activity. It was found from TPXRD at the gasification regions that both oxides in the char could coexist together with their metals more easily with increasing of CO2 pressure. According to the observation of SEM, SnO2 was inclined to disperse highly with increase of pressure while it was not seen for PbO.
Such results support the opinion that although either SnO2 or PbO will show the catalytic effect owing to the oxidation-reduction cyclic mechanism, their different activities will depend on the differences in the dispersion on the char.View full abstractDownload PDF (755K) -
Tomoo SUGIYAMA, Akihiro NAKA1984 Volume 63 Issue 5 Pages 326-335
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe mixture of coal and fuel oil (COM) can be handled in a similar manner to that for liquid fuels and can save oil by about 1/2. So, COM is valuable as a substitute fuel for oil.
In this report, many COM samples were prepared by the wet process that coal and fuel oil (class C) were simultaneously pulverized in a ball mill in order to examine the effects of the additives on stabilization.
None of COM samples with no additives were stable in reference to all kinds of coal (bituminous, subbituminous coal or lignite): During the still-storing at 70°C for a week, coal was settling and aggregating to reduce their flowability.
The alcohol base multi-branched high molecular nonionic surface active agents, which had been newly synthesized by the authors, were able to stabilize COM samples regardless of kind of coal (bituminous, subbituminous coal or lignite).
By contrast, anionic surface active agents were inferior in effect on stabilization. In some cases, they were effective, but these effects depended upon the kind of coal. Consequently, this type of surfactant was not suitable for the practical application.View full abstractDownload PDF (957K) -
Koji CHIBA, Hideyuki TAGAYA, Shimio SATO, Masato SAGAWA1984 Volume 63 Issue 5 Pages 336-340
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSHydrogen shuttler reaction from one coal to another was carried out by the liquefaction of two coals which was mixed in apparently non donor condition. Coals had different donor ability which were confirmed by the reaction with benzophenone. The amount of transferred hydrogen from coal to benzophenone was calculated by the amount of diphenylmethane. The order of the hydrogen donor ability of coals were
Miike coal>Taiheiyo coal>Yallourn coal
By mixing Miike and Yallourn coal, positive effect of mixing on conversion was observed at nominal reaction time 0 min. Additivity was observed at nominal reaction time 60 min. By mixing Taiheiyo and Yallourn coal, inhibition effect on conversion was observed. These facts indicated the presence of hydrogen shuttler reaction between coals. The required amounts of hydrogen for coals in coal liquefaction were different. They might determine the effect of coal mixing on conversion.View full abstractDownload PDF (532K) -
Mitsunori MAKINO, Mamoru KAIHO, Mitsuo KOBAYASHI, Tsutomu KATO, Yasuma ...1984 Volume 63 Issue 5 Pages 341-343
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA series of fixed-bed continuous hydrogasification was conducted at 1023 K and 0.1-5 MPa using Taiheiyo coal as feed-stock.
It was found that hydrogen content of residual char was affected at least by two factors i. e. conversion of coal and hydrogen partial pressure in the gasifier. In the range of experimental conditions, hydrogen content of residual char increases lenearly with hydrogen partial pressure, whereas it decreases lenearly with coal conversion.View full abstractDownload PDF (279K) -
Yoshiaki MIURA1984 Volume 63 Issue 5 Pages 344-352
Published: May 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe fundamentals of metallurgical coke making are reviewed in four instalments. This paper, Part I, describes (1) petrographic components and properties of coal as organic sediments, (2) chemical and physical structures of coal as high molecular weight organic compounds consisting of C, H, and O, and behavior during heating, and (3) classification and characterization of coal.View full abstractDownload PDF (1652K)
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