All issues
Successor
Volume 67, Issue 4
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
[in Japanese]1988 Volume 67 Issue 4 Pages 209
Published: April 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (226K) -
Akio NISHIJIMA1988 Volume 67 Issue 4 Pages 210-220
Published: April 20, 1988
Released on J-STAGE: February 23, 2011
JOURNAL FREE ACCESSThe deactivation behavior of molybdenum catalysts used for hydrotreating coal-derived liquids is reviewed to obtain information for the design concept for long-life catalysts. Causes for the catalyst deactivation are fundamentally similar to those for catalysts us-ed in petroleum hydroprocessing. However, the deactivation patterns for the catalysts in coal-derived liquid hydroprocessing was different from that found in petroleum hydroprocessing. This is mainly due to differences between coal liquid and petroleum feeds. Characterization of spent catalysts revealed certain differences in features of metal and carbonaceous deposits resulting from the use of coal liquids and petroleum. The changes in physical and chemical pro-perties of used hydroprocessing catalysts are discussed for coal liquids and petroleum, respec-tively. Changes in the local structure of active metals were found to decrease catalyst activity during coal liquid hydrotreating. Based on understanding of the catalyst deactivation, remedies for catalyst deactivation in connection with the development new types longife catalysts are also discussed.View full abstractDownload PDF (1334K) -
Eisuke OGATA, Hitoshi OKADA, Yasukazu YOSHIDA, Yoshio KAMIYA1988 Volume 67 Issue 4 Pages 221-230
Published: April 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe oxidation of different rank coals was carried out at the temperature from 70°C t to 150°C t under oxygen in order to understand the profile of the oxidation of coal. Ox-ygen consumption, weight change of the coals and the amounts of evolved gases such as CO2, CO, CH4 and H2O were measured to monitor the oxidation of coals. Further, the recovered coals were characterized by means of CP/MAS 13C-NMR, IR and elemental analysis.
The oxidation of the coals caused a significant decrease in aliphatic carbons resulting in the evolution of CO2 and H2O, and the lower the coal rank such as Yallourn and Taiheiyo coals is, the greater the tendency. The amount of oxygen incorporated into the coals relatively increas-ed with the carbon content in coal. It was suggested that most of the oxygen incorporated was consumed in the formation of polar groups and the other was consumed in the cross-linking of aromatic structures in coalView full abstractDownload PDF (1034K) -
Structural Analyses of Reduction Products from Peat Humic Acid with Sodium Amalgam by 13C-, 1H-NMR SpectroscopyHiroshi OKA, Minoru FUNAKI, Susumu YOKOYAMA, Yuzo SANADA1988 Volume 67 Issue 4 Pages 231-240
Published: April 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSEthanol-soluble reduction products of peat humic acid have been characteriz-ed by means of 13C-and 1H-NMR spectroscopic technique.
The reduction of peat humic acid with sodium amalgam was carried out in 0.5 N sodium hydroxide aqueous solution at 100°C t for 4hr in a stream of nitrogen. And thus two parts of the ethanol-soluble humic acid and the ethanol-insoluble humic acid were obtained, as a result of a above reaction; the total yield of the ethanol-soluble humic acid namely fulvic acid in four reductive reactions was 43% based on the original peat humic acid. The 13C-NMR spectra of fulvic acid were measured in 26% deuteriodimethylformamide solution with tetramethylsilane as an internal reference.
By using the results of 13C-NMR spectra on a combination with 1H-NMR results, the structural parameters such as fa, Hau/Car and σ were calculated.
It was concluded that the fulvic acid obtained by reduction of peat humic acid, the ratio of aromatic carbon atoms to all carbon in about 50%, and the acids have mainly mono-ring systems with a few of naphthalene units in the aromatic constitution.View full abstractDownload PDF (1028K) -
Yoshitaka YAMAMOTO, Keiji MIKI, Ikuo SAITO, Yoshiki SATO1988 Volume 67 Issue 4 Pages 241-249
Published: April 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSPrefractionation of coal liquids into different types of chemical classes was performed by adsorption column chromatography using a mini pre-packed disposable column (Sep-Pak ALUMINA N Cartridge) instead of acid-base extraction. Model compounds could be separated into 4 fractions such as aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, polycyclic aromatic nitrogen compounds and polycyclic phenolics.
This technique was also applied to the heavy fraction of subbituminous coal liquids. The characterization of the nitrogen containing aromatic compounds was carried out by gas chromatography-mass spectrometry.
Major components of nitrogen compounds are alkylated carbazoles, alkylated benzoquinolines, and alkylated benzocarbazoles. But polycyclic aromatic amines are not detected by our analytical procedure.View full abstractDownload PDF (898K) -
Hayami ITO, Shuhei TATSUMI, Shoichi TAKAO, Harumi HUJIMOTP, Hironori O ...1988 Volume 67 Issue 4 Pages 250-256
Published: April 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn order to develop a preparation system of a highly loaded coal water mixture (CWM) a bench scale test, a pilot scale test and a demonstration test were conducted, where a high concentration wet grinding method was employed.
CWM prepared by the high concentration wet grinding method contains desirable quantity of fine particles which are needed for ensuring lower viscosity at high concentrations and also for good statical stability. One of the major subjects of this grinding method is how to decrease coarse particles over 150μm because the coarse particles tend to become unburned carbon when CWM is burned.
In the grinding tests, it was found that the increases of the length/diameter ratio (L/D) and the number of compartments of mill were both effective to decrease coarse particles. A two-stage grinding method was also effective. Based on these findings, an 1-stage feed and 2-stage grinding system using multi-chambered long tube mills was developed.
In the demonstration test with a capacity of 26t/h, a CWM prepared by this system was found to contain a very little amounts of coarse particle with good rheological properties. The statical stability and the combustibility were also found satisfactory.View full abstractDownload PDF (666K) -
[in Japanese]1988 Volume 67 Issue 4 Pages 257-262
Published: April 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (869K)
- |<
- <
- 1
- >
- >|