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Volume 63, Issue 3
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[in Japanese]1984 Volume 63 Issue 3 Pages 155
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (229K) -
Tadatoshi CHIBA1984 Volume 63 Issue 3 Pages 156-166
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSProper lumping of reaction paths as well as reactants and products is needed to describe the reaction mechanisms of coal liquefaction as there are too many species and elementary paths to be identified chemically . This paper reviews existing reaction models which aimed to explain kinetic data consistently and typical experimental findings of coal liquefaction reaction characteristics which contributed to develop such models.
In most of the models the reactants and products are characterised by components which are obtained by means of solvent extractions. More reaction paths have been introduced to older models without assessing experimentally. To use these for simple design of reactor and evaluation of coal reactivity it is recommended to simplify them to a reasonable extent. Models which are based on the lumping of components by solvent extraction are rather inconvenient for designs of distillation operation and recycle solvents. It seems therefore necessary to develop other useful methods of product lumping such as those based on boiling range, etc.
Also, although there have been some experiments to quantify the contributions of coking reactions and hydrogen transfer processes during liquefaction, more systematic work on them is expected in future.View full abstractDownload PDF (1339K) -
Takahiro SUZUKI, Masaru ISHIDA1984 Volume 63 Issue 3 Pages 167-173
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA computer-aided method to automatically calculate the standard enthalpy of formation ΔHfº and the standard absolute entropy Sº for organic compounds in the ideal gas state is proposed. For inputting the structure of the molecules, a new structured linear notation is developed. It can be applied to a large variety of organic molecules such as polycyclic aromatic compounds. As an example of its application, an algorithm to automatically calculate ΔHfº and Sº for the heavy liquids based on the Benson method is presented. This system is immediately extended to the estimation of other physical properties by group-contribution methods.View full abstractDownload PDF (666K) -
Toshimitsu SUZUKI, Masaru MISHIMA, Junji KITAGUCHI, Yoshihisa WATANABE1984 Volume 63 Issue 3 Pages 174-184
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCatalytic steam gasification of four different coals, Miike, Takashima, Taiheiyo, and New Lithgow ones, using sodium hydridotetracarbonylferrate was carried out in a semi flow type fixed bed reactor at 650-800°C to investigate the coexist effect of iron and sodium. Miike and Takashima coals impregnated with sodium hydridotetracarbonylferrate (Fe; 5wt%, Na; 2.05wt%) as a catalyst were completely burnt out at 700°C within 15 min. On the other hand, the same coals impregnated with sodium carbonate (Na; 2.17wt%) were completely reacted during 15 min with increasing temperature to 800°C. When the amount of sodium ferrate was reduced to one-third (Fe; 1.67wt%, Na; 0.68wt%), the ferrate exihibited moderate catalytic activity toward the gasification of Miike and Takashima coals. The gas production rate per unit residual carbon of Miike coal impregnated with sodium ferrate (Fe; 1. 67wt%, Na; 0.68 wt%) gradually increased with increasing reaction time, and at any stage of the gasification reaction, the rate was remarkably higher than that for the raw coal. Addition of the ferrate to Taiheiyo and New Lithgow coals accelerated gasification considerably, but gasification of those coals was not promoted as in the case of Miike or Takashima one. It is assumed that this excellent catalytic activity of sodium hydridotetracarbonylferrate comes from the binary effect of iron and sodium.View full abstractDownload PDF (1284K) -
Syoaki IDE, Taichi OGAWA, Takeshi KUROKI, Tadashi IKEMURA1984 Volume 63 Issue 3 Pages 185-194
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn order to reduce energy cost through the recovery of certain products and fuel oils from plastic wastes, the catalytic decomposition of polystyrene was studied. In this particular work, attention was directed primarily toward specification of the decomposition products and how to control the reactions leading to their formation. It was found that the type of reaction products formed was determined mainly by reaction temperature and acidity of the catalyst used . Over a catalyst of low acidity, benzene was the main reaction product and the decrease in molecular weight was not important. But when using a catalyst of high acidity, a large amount of benzene, cumene and methyl-substituted indans were formed . Indan skeltons may possibly be formed at the chain ends of the catalytically decomposed polystyrene. The molecular weight of the catalytically decomposed polystyrene could be controlled to remain within the range of 1000 to 10000 by the selection of reaction temperature.View full abstractDownload PDF (1155K) -
Koji CHIBA, Hideyuki TAGAYA, Shimio SATO, Takashi WATANABE1984 Volume 63 Issue 3 Pages 195-202
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSSolvent for coal liquefaction are very important. They determine the liquefaction efficiency. In this study, three anthracene oils were obtained by the different hydrogenation conditions: Weakly hydrogenated anthracene oil (WA), medium (MA), Strongly (SA) were obtained. They were separated to 5 or 6 portions by fractional distillation.
Miike coal-1 and 2 were liquefied under the pressure of nitrogen. 1-Methylnaphthalene and WA were used as the solvent. Miike coal-1 contained 23. 6% of ash, and Miike coal-2 contained 8. 5% of ash. Conversions of Miike coal-1 were higher than those of Miike coal-2. Both conversion of Miike coal-1 and that of Miike coal-2 were decreased with an increase in the boiling point of anthracene oil.
Conversions for Miike coal-2 were decreased with an increase in boiling point of WA and SA, and increased with an increase in boiling point of MA. Conversion did not depend upon the degree of hydrogenation for used anthracene oil. Optimum hydrogenation conditions for anthracene oil must be present. Hydrogen shuttler reaction was expected for the anthracene oil which had higher boiling point. However the degree of hydrogen consumption was larger in the case of anthracene oil than that in the case of tetralin.View full abstractDownload PDF (1033K) -
Keiji MIKI, Toshio YAMAKAWA1984 Volume 63 Issue 3 Pages 203-210
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAn Australian brown coal (Yallourn coal, C; 64.2%, H; 4.9%, N; 0.7%, S; 0.3%, Odiff·; 29.9%, ash; 1.1%) was treated with potassium t-butoxide-H2O in dioxane at 150°C for 24hr. As the result of carbonyl cleavage, the degradation product dissolves in THE/H2O (8: 2 v/v), which corresponds to 40% of a starting material (THF/H2O extraction residue, Fig.1). Due to the mild reaction, it is considered that the product remains its original structural nature except carbonyl and carboxyl groups.
Structural analysis was attempted by using nmr measurements; 1H-nmr and 13C-nmr (gated decoupling and INEPT as a solution, CP/MAS and CP/MAS/DD as a solid). The result indicates that the degradation (DP-TH) and extraction (SE-TH) products may have 3-4 substituted benzene nucleus with 1 naphthene or heterocyclic ring (Table 2). The INEPT spectra provide considerably detailed information of alkyl side chains in the coal (Fig.3); the presence of paraffinic, methyl, ethyl, isopropyl and butyl groups is suggested. It is noticiable that the tertiary carbon compared with bicyclo [2.2.2] octane type compound appeared at shielded field in the spectrum.
The structural parameters and the distribution of various carbon fractions estimated from the CP/MAS and CP/MAS/DD nmr show good agreement with those from the 1H-nmr and gated decoupling nmr (Table 3 and 4), despite of an appropriate amount of oxygen containing groups. Thus the structures of insoluble fraction (DP-R) and original coal are also reffered on the basis of the solid nmr data.View full abstractDownload PDF (843K) -
Basic Study of Solvent HydrogenationRyohei MINAMI, Motofumi KAMINAKA, Keiichi HAYAKAWA, Yoshihiko SUNAMI1984 Volume 63 Issue 3 Pages 211-218
Published: March 20, 1984
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA basic study of the solvent hydrogenation for coal liquefaction was carried out using a batch autoclave.
Tetralin and methyltetralins were selected as typical hydrogen donor solvents and the effects of kinds of catalysts, temperature, pressure and solvent species on the kinetics of hydrogenation were investigated.
The following results were obtained.
1) Among some catalysts (Mo-Co, Mo-Ni, Cu-Cr, Ni, Red Mud) the catalysts containing Mo were suitable for the production of tetralin and methyltetralins.
2) The rate of hydrogenation changed with the solvent spiecies according to the following order.
naphthalene>1-methylnaphtha lene>2-methy lnaphthalene>dimethylnaphthalenes
3) Based on the experimental results, the hydrogenation reactions of naphthalene and methylnaphthalene were of first order with respect to hydrogen partial pressure and the concentration of each substrate as shown by the next equation.
-d/dt CN=ka KN/1+ΣKi·CioPH2·CN
CN: Concentration of naphthalene (mol%)
Cio: initial concentration of component i (mol%)
KN: adsorption equilibrium constant of naphthalene
Ki: adsorption equilibrium constant of component i
ka: rate constant at the rate determining step
PH2: hydrogen partial pressure (kg f/cm2)View full abstractDownload PDF (988K)
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