The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform
Hiroshi Nagaishi - One of the best experts on this subject based on the ideXlab platform.
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Addition effects of coal-derived oil and coal on upgrading of oil sand bitumen
Energy & Fuels, 1995Co-Authors: Tadashi Yoshida, Hiroshi Nagaishi, Masahide Sasaki, Takeshi Kotanigawa, Kiyoshi Idogawa, Mitsuyoshi Yamamoto, Akiyoshi Sasaki, Takashi Fukuda, R. Yoshida, Yosuke MaekawaAbstract:The mechanism of synergistic interaction between bitumen and coal in coprocessing was investigated in conjunction with hydrogen transfer between them. Two types of Reaction systems were used in this work: the upgrading of bitumen and coal-derived oil, and the coprocessing of bitumen with either coal-derived oil or coal. Considerable Retrogressive Reaction was observed in the upgrading of bitumen alone at 450 °C but was effectively suppressed by the addition of either coal-derived oil or coal. These results strongly suggest that both coal-derived oil and coal act as good hydrogen donors or shuttlers in the coprocessing. Furthermore, their addition resulted in more production of light oil from bitumen. The conversion of coal into toluene solubles was influenced by the concentration of coal itself in the slurry feed, but the formation of distillable oil from coal seemed to be negligibly small.
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Retrogressive Reaction of coal liquefaction
Journal of The Japan Institute of Energy, 1993Co-Authors: Hiroshi Nagaishi, Masahide Sasaki, Takeshi Kotanigawa, Youseke MaekawaAbstract:The object of this paper is to reduce production of residue discharged from coal liquefaction. Some kinds of residue, for example difference of Reaction temperature, have been examined for their boiling point distribution. From these results, the process of Retrogressive products is estimated.In addition, to make sure the mechanism of Retrogressive Reaction on coal liquefaction, the corresponding raw coal was reacted at various conditions.
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some aspects of solvent effect on Retrogressive Reaction during coal liquefaction
Journal of The Japan Institute of Energy, 1992Co-Authors: Hiroshi Nagaishi, Masahide Sasaki, Kiyoshi Idogawa, Yousuke Maekawa, Yuzo Sanada, Tadatoshi ChibaAbstract:For evaluation of solvent involving coal derived liquids during coal liquefaction, Reaction mechaninsm and rate of coal dissolution and semi-coke formation were examined at 723 K under 10 MPa of nitrogen or hydrogen with tetralin, naphthalene and creosote oil for Taiheiyo and Illinois No.6 coals.Semi-coke was defined on the basis of kinetics as pyridine insolubles obtained by rehydrogenating Reaction residue at 723K and 10 MPa of hydrogen with an excess amount of tetralin and its fromation Reaction was decelerated in the presence of hydrogen donor solvent.The Reaction rate of coal dissolution to pyridine solubles can not represent as a n-th order Reaction with respect to concentration of hydrogen donor solvent under the conditions in which semi-coke formation is observed at the same time with formation of lighter liquid products during coal liquefaction.Pyridine solubles contained inherently in original Illinois No.6 coal seemed to be not concerned with the semi-coke formation even under nitrogen atmosphere. The semi-coke formation, however, occurred with mixed solvent such as creosote oil even under 10 MPa of hydrogen.These results suggested that the semi-coke formation Reaction depended on the concentration of transferable hydrogen in solvent, and mass transfer in the solvent and coal particles was also not ignored to evaluate solvent for coal liquefaction as well as chemical parameters such as the hydrogen donating ability, the amount of transferable hydrogen in solvent.
Masahide Sasaki - One of the best experts on this subject based on the ideXlab platform.
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Addition effects of coal-derived oil and coal on upgrading of oil sand bitumen
Energy & Fuels, 1995Co-Authors: Tadashi Yoshida, Hiroshi Nagaishi, Masahide Sasaki, Takeshi Kotanigawa, Kiyoshi Idogawa, Mitsuyoshi Yamamoto, Akiyoshi Sasaki, Takashi Fukuda, R. Yoshida, Yosuke MaekawaAbstract:The mechanism of synergistic interaction between bitumen and coal in coprocessing was investigated in conjunction with hydrogen transfer between them. Two types of Reaction systems were used in this work: the upgrading of bitumen and coal-derived oil, and the coprocessing of bitumen with either coal-derived oil or coal. Considerable Retrogressive Reaction was observed in the upgrading of bitumen alone at 450 °C but was effectively suppressed by the addition of either coal-derived oil or coal. These results strongly suggest that both coal-derived oil and coal act as good hydrogen donors or shuttlers in the coprocessing. Furthermore, their addition resulted in more production of light oil from bitumen. The conversion of coal into toluene solubles was influenced by the concentration of coal itself in the slurry feed, but the formation of distillable oil from coal seemed to be negligibly small.
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Retrogressive Reaction of coal liquefaction
Journal of The Japan Institute of Energy, 1993Co-Authors: Hiroshi Nagaishi, Masahide Sasaki, Takeshi Kotanigawa, Youseke MaekawaAbstract:The object of this paper is to reduce production of residue discharged from coal liquefaction. Some kinds of residue, for example difference of Reaction temperature, have been examined for their boiling point distribution. From these results, the process of Retrogressive products is estimated.In addition, to make sure the mechanism of Retrogressive Reaction on coal liquefaction, the corresponding raw coal was reacted at various conditions.
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some aspects of solvent effect on Retrogressive Reaction during coal liquefaction
Journal of The Japan Institute of Energy, 1992Co-Authors: Hiroshi Nagaishi, Masahide Sasaki, Kiyoshi Idogawa, Yousuke Maekawa, Yuzo Sanada, Tadatoshi ChibaAbstract:For evaluation of solvent involving coal derived liquids during coal liquefaction, Reaction mechaninsm and rate of coal dissolution and semi-coke formation were examined at 723 K under 10 MPa of nitrogen or hydrogen with tetralin, naphthalene and creosote oil for Taiheiyo and Illinois No.6 coals.Semi-coke was defined on the basis of kinetics as pyridine insolubles obtained by rehydrogenating Reaction residue at 723K and 10 MPa of hydrogen with an excess amount of tetralin and its fromation Reaction was decelerated in the presence of hydrogen donor solvent.The Reaction rate of coal dissolution to pyridine solubles can not represent as a n-th order Reaction with respect to concentration of hydrogen donor solvent under the conditions in which semi-coke formation is observed at the same time with formation of lighter liquid products during coal liquefaction.Pyridine solubles contained inherently in original Illinois No.6 coal seemed to be not concerned with the semi-coke formation even under nitrogen atmosphere. The semi-coke formation, however, occurred with mixed solvent such as creosote oil even under 10 MPa of hydrogen.These results suggested that the semi-coke formation Reaction depended on the concentration of transferable hydrogen in solvent, and mass transfer in the solvent and coal particles was also not ignored to evaluate solvent for coal liquefaction as well as chemical parameters such as the hydrogen donating ability, the amount of transferable hydrogen in solvent.
Chunshan Song - One of the best experts on this subject based on the ideXlab platform.
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Observation of Retrogressive Reactions under Liquefaction Conditions Utilizing the Oxidized Coal Completely Dissolved in Solvent at Room Temperature
Energy & Fuels, 1998Co-Authors: Chunshan Song, And Makoto Shimada, Kouichi MiuraAbstract:We have found that the brown coal oxidized by nitric acid at 70 °C can be completely dissolved in tetrahydrofuran at room temperature. Utilizing this oxidized coal, we performed the temperature-programmed Reaction under liquefaction conditions in several types of solvents under nitrogen atmosphere to evaluate the Retrogressive Reactions. More than one-half of the tetrahydrofuran-soluble fraction was converted into the THF-insoluble fractions at 240 °C. The changes in the solid caused by the Retrogressive Reaction were examined from the change in the TG curves of insoluble fractions in toluene or tetrahydrofuran. From this analysis, it was found that two types of Retrogressive Reactions occurred during the liquefaction of the oxidized brown coal: one is the cross-linking Reaction of THF-soluble fraction by the decomposition of oxygen functional groups at low temperatures and the other is the structural change, such as polymerization of the tetrahydrofuran-insoluble fractions, at >350 °C. The Retrogressive...
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Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Final technical report, Volume 1 - effects of solvents, catalysts and temperature conditions on conversion and structural changes of low-rank coals
1998Co-Authors: Lili Huang, Harold H. Schobert, Chunshan SongAbstract:The main objectives of this project were to study the effects of low-temperature pretreatments on coal structure and their impacts on subsequent liquefaction. The effects of pretreatment temperatures, catalyst type, coal rank, and influence of solvent were examined. Specific objectives were to identify the basic changes in coal structure induced by catalytic and thermal pretreatments, and to determine the reactivity of the catalytically and thermally treated coals for liquefaction. In the original project management plan it was indicated that six coals would be used for the study. These were to include two each of bituminous, subbituminous, and lignite rank. For convenience in executing the experimental work, two parallel efforts were conducted. The first involved the two lignites and one subbituminous coal; and the second, the two bituminous coals and the remaining subbituminous coal. This Volume presents the results of the first portion of the work, studies on two lignites and one subbituminous coal. The remaining work accomplished under this project will be described and discussed in Volume 2 of this report. The objective of this portion of the project was to determine and compare the effects of solvents, catalysts and Reaction conditions on coal liquefaction. Specifically, the improvements of Reaction conversion, product distribution, as well as the structural changes in the coals and coal-derived products were examined. This study targeted at promoting hydrogenation of the coal-derived radicals, generated during thermal cleavage of chemical bonds, by using a good hydrogen donor-solvent and an effective catalyst. Attempts were also made in efforts to match the formation and hydrogenation of the free radicals and thus to prevent Retrogressive Reaction.
Masashi Iino - One of the best experts on this subject based on the ideXlab platform.
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Heat treatment of coals in hydrogen-donating solvents at temperatures as low as 175-300°C
Energy & Fuels, 1994Co-Authors: Jianli Shen, Masashi IinoAbstract:Heat treatment of 7 coals of different rank was carried out in various solvents at 175-300°C under N 2 atmosphere. Retrogressive Reaction of the coal was observed in TET at 175 and 250°C, while, in DM and HHA, which are much strong-er hydrogen donors than TET, the coal underwent dissolution Reactions at 175-300°C. Hydrogen donation to coal radicals from DHA or HHA is suggested for the dissolution Reaction observed in this study.
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Thermal behavior of coals at temperatures as low as 100-350.degree.C: heat treatment of THF-insoluble extract from carbon disulfide-NMP mixed solvent extraction of Zao Zhuang coal
Energy & Fuels, 1992Co-Authors: Jianli Shen, Toshimasa Takanohashi, Masashi IinoAbstract:Heat treatment of THF-insoluble, CS 2 -N-methyl-2-pyrrolidinone (NMP) mixed solvent (1:1 by volume) soluble fraction (TIMS) of the extract, which was obtained from the extraction of Zao Zhuang coal with the same mixed solvent at room temperature, was carried out in several organic solvents at 100-350°C under N 2 atmosphere. Retrogressive Reaction of TIMS, i.e., its conversion to the mixed solvent-insoluble fraction (MI), was observed in tetralin (TET), naphthalene (NAP), and 9,10-dihydrophenanthrene (DHP) at temperatures as low as 100 and 175°C, while MI formation at 175°C was suppressed by adding 9,10-dihydroanthracene (DHA) or 1,4,5,8,9,10-hexahydroanthracene (HHA), which are much stronger hydrogen donors than TET, NAP, or DHP
Youseke Maekawa - One of the best experts on this subject based on the ideXlab platform.
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Retrogressive Reaction of coal liquefaction
Journal of The Japan Institute of Energy, 1993Co-Authors: Hiroshi Nagaishi, Masahide Sasaki, Takeshi Kotanigawa, Youseke MaekawaAbstract:The object of this paper is to reduce production of residue discharged from coal liquefaction. Some kinds of residue, for example difference of Reaction temperature, have been examined for their boiling point distribution. From these results, the process of Retrogressive products is estimated.In addition, to make sure the mechanism of Retrogressive Reaction on coal liquefaction, the corresponding raw coal was reacted at various conditions.