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Volume 66, Issue 8
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[in Japanese]1987 Volume 66 Issue 8 Pages 673-674
Published: August 20, 1987
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (323K) -
Tetsuro YOKONO1987 Volume 66 Issue 8 Pages 675-686
Published: August 20, 1987
Released on J-STAGE: October 21, 2011
JOURNAL FREE ACCESSThis paper reviews a substantial number of chemical and physical factors which influence the development of plasticity in coal. Results of our recent studies convincingly show that development of plasticity is essentially a transient hydrogen-donor process (stabilization of the resulting free radicals by hydrogen atoms) in which the solvating and hydrogen donating vehicle is supplied by the coal itself.
The importance of the vehicle of low weight substances of quality and of quantity was stressed.
New methods of characterization of coal and coal tar by means of iodine doping are also discussed.
The understanding of plasticity development is profoundly significant in most process uses of coal and especially to the design of coke furnaces in the future.View full abstractDownload PDF (1462K) -
Tsugio KOJIMA1987 Volume 66 Issue 8 Pages 687-702
Published: August 20, 1987
Released on J-STAGE: February 23, 2011
JOURNAL FREE ACCESSOf the numerous chemical species that are generally present in coal-derived products, the nitrogen-containing polycyclic aromatic compounds have been found to exhibit pronounced carcinogenic and mutagenic effects in biological system. As a result considerable emphasis is currently being placed on the identification and the determination of the nitrogen-containing polycyclic compounds. On the other hand, identification and quantitation of the nitrogen-containing compounds is important to evaluate denitrogenation properties of liquefaction catalysts and to determine the amenability of the liquefaction product to further processing. Nitrogen-containing compounds are present in various chemical forms. This complexity has led to the development of a wide variety of analytical methods aimed at achieving improved separation for characterization of coal liquid.
A multi-step analytical methodology for the separation and identification of nitrogen-con-taining compounds has been developed in our laboratory. The integrated multi-stage separation method employs aqueous extraction of basic nitrogen compounds followed by gel permiation chromatography with subsequent thin layer chromatography. The combination of these techni-ques produces fractions which are chemically much less complex than the starting crude materials. Then this method facilitates the subsequent characterization of coal liquid. In this review, some methods for characterization of azaarenes in these fractions based on information from the retention values obtained in various chromatographic methods and the fluorescence spectra in addition to mass spectra.View full abstractDownload PDF (1734K) -
Tadato YAMAMOTO, Sadao MATUZAWA, Osamu SETOKUCHI, Yukio Simizu, Mituhi ...1987 Volume 66 Issue 8 Pages 703-710
Published: August 20, 1987
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSInduction Period Method, designated by ASTM D525, has been known as one of methods to evaluate the oxidation stability of gasoline. The gasoline in a bomb is oxidized under elevated pressure of oxgen, and in the absorption process of oxgen the time required for the gasoline to reach a finite rate of pressure drop is defined as the induction period.
This method may be utilized to predict the storage stability, that is, the potency to form gum in storage of gasoline.
In this paper, the effect of factors, light irradiation, detergents, and bath temperature, on the induction period, and the limit of the precision of this method have been investigated. The conclusions drawn from these experiments are as follows.
1) The effect of light irradiation: The history of light irradiation by the fluorescent lamp reduces the induction period of the sample. It is expected that the induction period will be reduced by 10% provided the gasoline in a colorless container is kept for 48 hours on a testing bench. Therefore, the sample should be storaged in a colored container or in a cool and dark place.
2) The effect of detergent: The alkaline detergent shows insufficient detergency, and the use of the detergent gradually reduces the induction period as experiments are repeated.
3) The effect of bath temperature: A consideration should be paid on the position of heater to be mounted and the flow rate of water to be supplied in the design of the water bath to heat the bomb.
4) Precision: The limit of the precision of this method, which is easily attainable, is about 0.3% as coefficient of variation (1006/x).View full abstractDownload PDF (779K) -
Katsuki KUSAKABE, Masafumi ORITA, Shgeharu MOROOKA, Yasuo KATO, Koichi ...1987 Volume 66 Issue 8 Pages 711-718
Published: August 20, 1987
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSPulverized Miike coal was treated in molten mixtures of sodium hydroxide and potassium hydroxide at 473-673K. The removal yield of total sulfur, organic sulfur and ash and the change in heating value and volatile matter content were evaluated as functions of coal size, alkali composition, reaction temperature, and reaction time.
No effect of the coal size was observed when the coal was crushed under 300/μm. The rate of demineralization was faster than that of desulfurization. The optimum conditions of temperature and treatment time were 623K and 60min, respectively. The removal yields of sulfur and ash based on the mass of treated coal were not increased under more severe condi-tions because of the decomposition of coal. An increase in the KOH concentration resulted in a higher sulfur removal yield and a lower heating value. The best KOH concentration was about 50wt%.
Under most suitable conditions, the removal yields of total sulfur and ash were 92% (sulfur residue 0.27wt%, db) and 96% (ash residue 0.58wt%, db), respectively. The heating value per dry mass of clean coal was increased by about 7% than the original coal.View full abstractDownload PDF (2208K) -
Yasushi MURANAKA, Ryuuichi KAJI, Norio ARASHI, Hiroshi MIYADERA, Yukio ...1987 Volume 66 Issue 8 Pages 719-725
Published: August 20, 1987
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSHighly loaded coal water mixture (CWM) was prepared using several ball mills. Kinetics on size reduction rate of coals was studied. Breakage rate of coals was found to obey the first order kinetics with respect to weight fraction more than 200 mesh and the relationship between rate constant and hold-up was given.
The critical speed which gives the maximum mill capacity in highly loaded CWM wet grin-ding is smaller than that in dry communition.
Mill capacity can be increased by the optimization of CWM hold-up and the lifted angle of crushing balls. CWM mixing condition in continuous system changes from complete mixing to plug flow as the feed rate of raw materials increases. The ball mill capacity can be increased by keeping plug flow of CWM in a ball mill.View full abstractDownload PDF (750K) -
Masakatsu MIURA, Akira DEGUCHI, Hiromi TAKEUCHI, Hideo HOSODA, Satoru ...1987 Volume 66 Issue 8 Pages 726-733
Published: August 20, 1987
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSTo recover fuel oil from oily sludge, experimental studies were performed using a fluidized sand bed pyrolyzer. The heat energy for the pyrolysis of sludge was supplied from the heat of a partial combustion of sludge. It was revealed that the yield of recovered oil decreased with increasing bed temperature within the range of from 500 to 600°C. The viscosity of recovered oil decreased with the increase of the oxygen concentration in fluidized gas. The properties of the recovered oil ranked with those of the fuel oil. Moreover, the sulfur content in recovered oil was reduced to 70%, as compared with that in sludge. When lime-Stone or natural zeolite were used as the fluidized particles, relatively low viscous oil could be produced, but its yield value was small compared with the use of silica sand. The estimated value of heat con-sumption for pyrolysis was ranged from 390 to 530 kcal/kg.View full abstractDownload PDF (897K) -
[in Japanese]1987 Volume 66 Issue 8 Pages 734-741
Published: August 20, 1987
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1004K)
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