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Volume 64, Issue 5
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[in Japanese]1985 Volume 64 Issue 5 Pages 303
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (259K) -
Akira AMANO1985 Volume 64 Issue 5 Pages 304-311
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSRole of hydrogen atoms in the pyrolysis of olefinic and aromatic hydrocarbons is discussed with special reference to the hydrogenolysis of propylene and toluene. Hydrogen atoms are shown to serve as chain propagating carrier in the scheme of hydrogenolysis chain, and also to serve as reagent to activate substrate molecules having π-electrons and/or strongly electro-negative atoms. Reaction pathways to form the activated adducts between given substrates and hydrogen atoms, and the fate of the adducts so formed are then presented.Finally, the effect of hydrogen atoms as chemical activator is demonstrated by the hydrogen atom induced coal liquefaction.View full abstractDownload PDF (1410K) -
Masayoshi SADAKATA1985 Volume 64 Issue 5 Pages 312-320
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAreview of the previous combustion works was carried out to find out the most appropriate scaling law for the combustion furnace. First, various characteristics of the combustion furnace were clasified into five categories, namely, Transfer, Pattern, Performance, Emission and Stability . The factors influencing each characteristic were examined and summarized in a diagram . The following seven factors were extracted as the basic factors . These are Geometrical configuration, Reynolds number, Mixing time, Residence time, Reaction time, Air ratio and Preheating temperature. Depending on which factor should be kept constant for scaling, the three different scaling laws were considered . These are the scaling laws of Reynolds number=constant, Residence time=constant and Velocity=constant . The advantages and disadvantages of each scaling were discussed and examples of applying these laws to the practical burner design were illustrated . It was suggested that the scaling law of Residence time=constant can be applied widely compared to other scaling law.
Finally, the research subjects which were required to build the reliable scaling theory were proposed.View full abstractDownload PDF (1392K) -
Repeated Reductive Methylation of Coals in DiglymeTsutomu KATO, Fumihiro KOUNUSHI, Hiroshi OHKAWA, Yoshiharu YONEYAMA, H ...1985 Volume 64 Issue 5 Pages 321-328
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSFive coals of different rank, in Coal/Metal-K/Diglyme system, were reductively methylated one tonine times in 3hr in an omitting extraction to obtain more detailed information about the solubilizationefficiencies of coals and the structural characteristics of solubilized products.
The benzene solubility of each coal increased almost exponentially with increasing of the number of methylation steps, and was as follows after nine methylation steps: Kairan (81%), Akabira (50%), Illinois no. 6 (39%), Daido (31%), Wandoan (16%).
Benzene soluble portion (BS) after each methylation step was separated by gel permeation chromatography (GPC) and structural parameters of these GPC. fractions were calculated. For Kairan coal, the amount of GPC. Fr. 1-3 including high molecular weight components gradually increased from 20% to 50% with the number of methylation steps, and it was clearly observed that part of benzene insoluble portion transfered to BS by step-wise methylation.
In general, reaction in this system is somewhat a less electron transferability which makes possible the formation of a “coal anion”. Consequently, repeated methylation process is more effective to be applied the coal such as Kairan coal that can largely be soluble in benzene in an incipient stage of repetition, since BS which has been dissolved, plays the role of an electron transfer agent. Because of this, it appeared that the effect of repeated methylation on the solubilization of low rank coal such as Wandoan coal can not be expected.
Thus, if it was necessary to dissolve the coal in large quantities in benzene by reductive alkylation, it seemed rather likely that coals were repeatedly alkylated, moreover using a large amount of naphthalene, and by Sternberg's procedure.View full abstractDownload PDF (1177K) -
Analysis of the Recycle Oil Derived from Liquefaction of Taiheiyo CoalKeiichiro ISHIKAWA, Yoshio NIWA, Yazaemon MORITA1985 Volume 64 Issue 5 Pages 329-338
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe chemical structure of product oils and recycle solvents derived from the solvent-recycle liquefaction experiment of Taiheiyo coal was studied by means of “molecular-ion-spectrum method” utilizing FI mass spectrometry. Hydrogenated anthracene oil, used as a starting solvent, is mainly composed of aromatic hydrocarbons of two to four rings. Hydrogen donating compounds contained in the hydrogenated anthracene oil, such as dihydrophenanthrene, tetrahydropyrene, hydrogenated acridines etc., were quickly dehydrogenated in the early stage of recycling. Acidic oil, saturate oil and polar oil were integrated in the recycle solvent by each recycle run, but their compositions did not show a marked change with recycling.View full abstractDownload PDF (1473K) -
Yoshinobu KOMATSUBARA, Kazuhiko TSUJI, Shiro IDA1985 Volume 64 Issue 5 Pages 339-344
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSReactivities of several carbons against a SO2-CO2-H2O mixture gas were studied at the temperature range of 600-1000°C to collect the basic data for the design of reduction process of SO2 to recover elementary sulfur.
The reactivities of carbons against SO2 were generally much higher than those against H2O and CO2 except for Caribbean coke, which contained a significant amount of iron as the catalyst to the gasification by the latter gases. High reactivity of carbon against SO2 may be ascribed to its exothermic reduction. Product distribution were determined by reactivities of gases against carbons (equations (1), (5), (6)) and consecutive reactions among reduced gases (equations (2)-(4), (7)-(10)).
At the lower temperature range, only SO2 was reduced to give elementary sulfur. The higher temperature increased the yield until the reactions of sulfur with hydrogen or carbon monoxide, produced from H2O and CO2, took place, defining the optimum temperature for the highest sulfur yield. Such a temperature varied from a carbon to carbon, depending on its reactivity against the gases.
The reactivities of blast furnace cokes against SO2 were discussed from their optical anisotropy, physical structure and catalytic contaminants, to suggest the second factor most influential under the experimental condition examined in the present study.View full abstractDownload PDF (921K) -
Kunio ESUMI, Atsushi YOKOUCHI, Naoko WATANABE, Kenjiro MEGURO, Hidemas ...1985 Volume 64 Issue 5 Pages 345-349
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe effect of dispersants on dispersion stability of coal-water mixtures was studied by using dispersants. Ionic dispersants rendered most stable coal dispersion than nonionic one and the coals dispersed showed large zeta potential, indicating that surface charge of coals plays an important role in the dispersion stability of coal. Further, coal-water mixtures containing coals with different carbon content showed each different dispersion stability against ionic dispersants.View full abstractDownload PDF (862K) -
Fundamental Study for Simultaneous Control of Nitric Oxide and Sulphur Dioxide Emissions in Fluidized Bed Combustion of CoalTakehiko FURUSAWA, Masaaki KOYAMA, Motoki TSUJIMURA, Yasutsugu WATANAB ...1985 Volume 64 Issue 5 Pages 350-356
Published: May 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe calcined limestone used partly for sulphur retention under a reducing condition was found to provide a strong activity for the nitric oxide reduction by carbon monoxide over the temperature range pertinent to fluidized bed combustion. A thermogravimetric analysis indicated that the enhanced reduction of nitric oxide was attributed to the increase in catalytic activity. The simultaneous removal of sulphur dioxide by calcined limestone and nitric oxide by carbon monoxide was conducted by use of a continuous fluidized bed of quarz sand and calcined limestone. The result indicates that the rate of nitric oxide reduction is enhanced by the simultaneous sulphur retention. This demonstrates that the reduction of nitric oxide formed in fluidized bed combustion of coal is promoted by the simultaneous sulphur capture under a staged air firing.View full abstractDownload PDF (1184K)
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