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Volume 64, Issue 1
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[in Japanese]1985 Volume 64 Issue 1 Pages 1
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (280K) -
Susurnu YOKOYAMA1985 Volume 64 Issue 1 Pages 2-18
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSHitherto, the chemical structure of coal derived oil was represented to oversimplification as the hypothetical mean structure. In this review, a more detailed assessment was made by the presentation of the actual profile with the distribution of chemical structure. This procedure consists of a separation by GPC/ DS (distillation) and HPLC for coal oils into specific chemical constitution having a homologus ring cluster and a narrow molecular weight distribution. Subsequently the structural analysis was conducted by a low voltage MS method to these fractions.
Fundamental information for the separation behavior of amine column as packing material on HPLC, GPC and the distillation fractionation was presented in the coal oil fractions separated by preparative LC/GPC/DS as reference materials because these fractions are chracterized previously in the chemical structure by MS analyses. Struc tural analyses of DS-HPLC fractions by LV-MS spectra are described for the assign ment of compound types by Z numbers and for quantitative estimation of these contents.
Presentation of structural results are subjected to a three dimensional diagram for aromatic ring numbers (Ra), naphthenic ring numbers (Rn) and alkyl carbon numbers attached to these rings (Cal). Coal oil derived from hydrogenolysis of Akabira coal (C%: 83.0) was estimated for the structural distribution of compound type and assessed by Ra-Rn-Cal diagram to characterize the chemical structure.View full abstractDownload PDF (2555K) -
Kazuo IINUMA1985 Volume 64 Issue 1 Pages 19-25
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCurrent status and outlook concerning modeling in combustion systems are described. Because of complexity of the phenomena, combustion has hardly been understood in terms of the intrinsic fundamental processes. Thus modeling techniques are indispensable from academic interest as well as practical point of view. Although recent advances in numerical computation made it possible in principle to solve the governing conservation equations for various combustion systems, there are still many difficult problems. In order to overcome these difficulties, considerable simplications and assumptions must be made introducing uncertain phenom enological submodels. In the main part of this review, present state of the art of combustion modeling in practical systems are summarized by dividing into two parts, continuous (furnace and combustor) and intermittent (spark and compression ignition engines) combustion. It should be emphasized that more detailed measurements or diagnostics are necessary to obtain reliable models which can predict practical combustion behaviors. Finally it is concluded that cooperation of investigators in the field of computation and measurement will be advisable for further development.View full abstractDownload PDF (1487K) -
Coal Liquefaction with the Recycled Hydrogen Donor SolventRyohei MINAMI, Tamio SHIRAFUJI, Mikio KATO, Yoshihiko SUNAMI1985 Volume 64 Issue 1 Pages 26-35
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSRepeated cycles experiments of coal liquefaction-distillation-solvent hydrogenation were conducted batchwise using Australian Wandoan coal to determine the product distributions including component identifications in order to establish the basis of the process.
The following results were obtained.
1) The hydrogen consumption was 2.0wt% dry coal basis for the solvent hydrogen-ation stage and 1.9wt% dry coal basis for the liquefaction stage, totalling 3.9wt%.
2) The total oil yield was 37wt% dry coal basis, and main oil product is naphtha (20wt%). The H/C atomic ratio of the naphtha was as high as 1.7 and “fa” value was as low as 0.26 close to petroleum naphtha.
3) There was a tendency that liquid yield at the liquefaction stage increases with the hydrogen consumption at the solvent hydrogenation stage.
4) Main component of the recycle solvents were binuclear aromatics. The H/C atomic ratio of the solvent increased to 1.20.View full abstractDownload PDF (1585K) -
Atsushi INABA, Keiji MIKI, Kazuteru OSAFUNE, Ikuo SAITO, Yoshiki SATO, ...1985 Volume 64 Issue 1 Pages 36-41
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA Taiheiyo-coal derived liquid, which had liquefied at 450°C, was hydrotreated on Co-Mo/Al2O3 catalyst at 375-450°C under 15. 3MPa of hydrogen pressure using fixed bed reactor at 100N1/h hydrogen flow rate and LHSV 1.0h-1. From the analysis of distilled oil with gas chromatograph and that of SRC with 1H-NMR, it was indicated that the reaction at 375°C was mainly the transformation of aromatic rings to naphthenic ring as well as removal of hetero atoms. It was also found that the hydrocracking of SRC occured at higher temperatures.
The conversion of SRC included in Taiheiyocoal derived liquid was higher than SRC in Miikecoal derived liquid, which had been prepared at the same conditions of the first stage as Taiheiyo coal. From the analysis of coal liquid, it was indicated that SRC of Taiheiyocoal was smaller in molecular weight and was higher in content of hetero atoms than SRC of Miikecoal. It appeared that these character-istics affected the conversion of SRC.View full abstractDownload PDF (932K) -
Mamoru KAIHO, Tsutomu KATO, Mitsunori MAKINO, Mitsuo KOBAYASHI, Yasuma ...1985 Volume 64 Issue 1 Pages 42-49
Published: January 20, 1985
Released on J-STAGE: October 21, 2011
JOURNAL FREE ACCESSIn order to estimate the thermal efficiency of the production of high calorie gas from coal, calculation formulas were derived assuming a process that consists of two steps, i. e. hydrogasification and hydrogen manufacture, and the value of the efficiency was calculated on the basis of the material balance of hydrogasification obtained under various experimental conditions. Relationships were determined between the feeding ratio of hydrogen to coal and the coal conversion or the heat value of the product gas and between the coal conversion and the heat value of the product gas or of the residual char so that the thermal efficiency can be estimated accurately.
As a result, the following characteristics were made clear;
(1) the coal conversion is not affected by the gasification pressure and it is deter-mined almost wholly by the hydrogen/coal ratio;
(2) the heat value of the gas produced is well related to the hydrogen/coal ratio and attained to the maximum value of about 6, 500 kcal/m3 at a hydrogen/coal ratio of 0.5m3/kg; and
(3) the total heat value of the gas produced or the residual char is in a good linear relation with the coal conversion.
For a process wherein the total amount of hydrogen necessary for the hydrogasification is furnished completely by gasification of the residual char produced in the hydrogasification step, the heat value of the gas calculated is 6, 010-6, 430kcal/m3 and the thermal efficiency of the process about 0.534-0.679. The thermal efficiency was also calculated on a process wherein an adequate amount of coal was supplemented in addition to the residual char in the hydrogen manufacture step, or a process wherein unreacted hydrogen in the product gas was separated and recycled to the hydrogasification step to fill up the defficiency of the hydrogen in the hydrogasification step.View full abstractDownload PDF (1213K) -
Tomoo SUGIYAMA, Akihiro NAKA1985 Volume 64 Issue 1 Pages 50-59
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn the previous papers, the authors reported that the multi-branched high molecular nonionic surface active agents had good effects on stabiliza-tion of COM.
This paper covers discussion of additive mixing methods for assuring stability of COM.
First, a COM sample was prepared by using Bank coal as a typical bituminous coal in order to evaluate a homomixer and a propeller in mixing effect. As a result, it was found that stabilization of COM would require sufficient mixing by homomixer. The same COM, diluted with A heavy oil, was subjected to microscopical examination. It showed that coal particles in an unstable COM would remarkably coagulate but those in a COM sufficiently mixed with an additive would not. This phenomenon was regarded as a COM stabilizing mechanism.
Then, for finding an appropriate mixing rate, the abovementioned sample and COM with Beluga coal as a typical lignite were subjected to a continuous mixing (1 ton/hr) test with a line mixer. This test found that stabilization of COM would be promoted as the peripheral velocity of the agitator was higher, or would need powerful agitation (more than 15 m/sec of peripheral velocity, more than 106kg·m/m3 of mixing energy).
In order to lower the required mixing energy, the authors designed and discussed a new method that an additive was diluted with heavy oil (part of COM materials) before mixing it into COM. This heavy oil dilution method provided much higher mixing efficiency, or yielded far more stable COM than the direct addition method.View full abstractDownload PDF (2216K) -
Minoru MORITA, Shiraio SATO, Takao HASHIIVIOTO, Mitsuo YOKOE, Kouji CH ...1985 Volume 64 Issue 1 Pages 60-67
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSOn the basis of the following guides an efficient direct coalliquefaction-reactor has been developed: They consists of:
(1) using tubular units through the liquefaction beginning at a paste preheating so that the reactor may have higher space-time-yields;
(2) operating it under larger values of paste Re number at which no solid particle sedimentation occurrs and the paste flow pattern is close to plug flow;
(3) suppling hydrogen from several inlets distributing along its axial direction both to compensate hydrogen pressure decrease and to meet effectively hydrogen requirement, with progress of liquefaction;
(4) equipping some gas-liquid separators in such a way that they can adjust gas flow rate in the reactor to suppres gas-void-fraction increases which cause space-time-yield decrease;
(5) being provided with a stirred tank at a step within the paste preheating process where coal swelling brings about a marked rise of paste viscosity to result in plugging if tubular units are used.
To investigate characteristics of the reactor designed on the basis of the guides, a bench scale apparatus was made so as to almost followed them and its properties were studied by experiments and simulation. The experimental results were in accord with the expectations. The simulated results were qualitatively coincide with exper imental ones although reaction progresses in the former were greater than those in the latter.View full abstractDownload PDF (1518K) -
Yuji YOSHIMURA, Minoru KURITA, Toshio SATO, Hiromichi SHIMADA, Yoshino ...1985 Volume 64 Issue 1 Pages 68-72
Published: January 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn order to make clear the behavior of coal mineral remaining in coal liquid on the hydrotreating catalyst, a Wandoan coal derived liquid containing high contents of liquefaction solid was hydroprocessed over the Ni-Mo-γ-Al2O3 catalyst having bimodal pore size distributions.
In these liquefaction residues, kaolin and quartz were not chemically altered and magnetite was undergone chemical transformation to pyrrhotite during hydroprocessing. From the shell like deposits of these metals around the spent cata lysts, these matters might be finely dispersed particles that had equivalent spherical diameter larger than about 1-2μm, which corresponded to maximum size of macropore in used catalysts.
Titanium and calcium metals, which were more concentrated in THF insoluble residue in feed coal liquid, were tend to accumulate in preasphaltene after hydro processing. Furthermore from the more penetrated depth profile of titanium and calcium metals, these metal containing matters might have equivalent spherical diam eter larger than about 0.6μm and 4.4nm micro-pore diameter were too small to be utilized against carbonaceous material deposits. Because active sites might be occupied with sodium metal, which interacted more strongly with those than titanium and calcium metals, titanium and calcium metals migrated more deeper on the catalyst pore walls by surface diffusions.
As a result, silicon and iron metals were tend to plug the catalyst pore mouth and sodium, alkaline earth metals and titanium metals were tend to poison active sites and change micro-pore structure.View full abstractDownload PDF (883K)
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