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Volume 64, Issue 9
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[in Japanese]1985 Volume 64 Issue 9 Pages 715
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (253K) -
Quuantitative Evaluation of Development Subjects and the Analysis of Factors Influencing Cold Gas EfflciencyTakehiko FURUSAWA, Toshinori KOJIMA, Seiji TOKAWA, Shuichi TANAKA, Tak ...1985 Volume 64 Issue 9 Pages 716-733
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSPerfomance data obtained from coal gasifiers, which have been so far or which are still being developed, were collected. The obtained data which were revised to meet the consistent material and heat balances were filed in the data base of coal gasiflers. Values of various key factors (heat loss, carbon utilization efficiency, unreacted steam etc.) which control the performance of the gasiflers, were calculated by use of the data base constructed above.
Heat loss from gasifiers was increased with the increased feed rate of coal and the significant effect of scale up on the heat loss was not observed. The cold gas efficiency was increased with the increased operating temperature and pressure. The amount of required oxygen remained constant for each type of oxygen blown gas-solid contactors. However, the amount increased according to the order of fixed beds, fluidized beds and entrained beds. The chemical energy required for the production of oxygen accounted for approximately ten per centof the gross caloric value of coal.
The cold gas efficiency of most fluidized bed gasifiers was increased by improved carbon utilization efficiency until the carbon utilization efficiency remained less than 93%. The cold gas efficiency of entrained bed gasiflers was further increased by the improved carbon efficiency which ranged up to 98%. Since the further increase of carbon utilization efficiency will increase the amount of gas produced, consequently the enthalpy loss of the produced gas, the cold gas efficiency is increased by reduction of heat loss. The reduction of the unreacted steam and the recovery of the enthalpy of the produced gas will result in increase in cold gas efficiency.View full abstractDownload PDF (2946K) -
An Evaluation Method of a Hydrogen Donor Capacity of Solvents Used in Coal LiquefactionsSatoshi OHSHIMA, Kikuko HAYAMIZU, Motoo YUMURA, Yasunori KURIKI, Morio ...1985 Volume 64 Issue 9 Pages 735-740
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe characterization chart proposed by authors is shown to be very useful to analyze a reaction pathway of hydrogenation reactions of coal-derived oils and to evaluate a hydrogen donor capacity of the solvents.
The amount of the hydrogen donor capacity, ΔH2, increased for the hydrogenation reaction can be estimated by the following equation.
ΔH2=37× (Δfa) ΔH2: (mol-H2/kg-solvent)
where (Δfa) is a difference of the aromaticities of the solvent between before and afterthe hydrogenation reaction. This equation holds in the following conditions the reaction pathway for the hydrogenation is only the partial hydrogenation of aromatic ring and not the aromatic ring opening reaction. Furthermore the products do not contain the partially hydrogenated compounds like decaline type and perhydro-compounds, since they do not have donor capacity. The generation of these type hydrogenated compounds lead to the increase Δfa, but the decrease of the hydrogen donor capacity.
To prove the above relation, a coal-liquefaction reaction was carried out using an anthracene and hydrogenated anthracene oils with different hydrogenation reaction depths. As the result of a kinetically analysis, the reaction rate constant kb clearly showed the maximum peak in the plot of kb versus (1-fa). This suggests that this evaluation method for the hydrogen donor capacity is reasonable. There are optimum conditions in the hydrogenation reaction of the solvent. A excessive hydrogenation of the solvent causes to not only a decrement of kb, but also uneconomy because of the increasing in hydrogen consumption.View full abstractDownload PDF (914K) -
The Relation between Hydrocracking and HydrodenitrogenationToshiaki KABE, Masuhiro IIZUKA, Osamu NITOH, Hideo OHNUMA, Yoshimasa I ...1985 Volume 64 Issue 9 Pages 741-747
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn order to determine the mechanism of hydrocracking of coal liquids, heavy fractions of Wandoan coal liquids were hydrocracked in tetralin solvent containing a small amount of 14C-labeled naphthalene.
Wandoan coal liduids were separated into hexane-solubles (HS), toluene-solublehexane-insolubles (HIS-TS) and toluene insolubles (TIS). Hydrocracking of these fractionswas performed with a fixed bed flow microreactor on Ni-Mo-Al2O3 catalyst.Reaction conditions were as follows the temperature was 400°C, pressure 9.8 MPa, H2flow 25 1/h, and WHSV 0 .68/h. The distributions of reaction products and nitrogenconcentrations were determined. The amount of the rehydrogenation of naphthalenesolvent during the hydrocracking was examined by 14C tracer method.
The results are summarized as follows;
1) When HS was hydrocracked, it was hydrodenitrogenated and hydrocracked to light oil. Furthermore, the rehydrogenation of naphthalene solvent proceeded considerably.
2) In the case of hydrocracking of HIS, HS was produced by hydrogenation and denitrogenation of HIS. But the nitrogen content of HIS did not decrease and the solvent was not rehydrogenated.
3) In the case of hydrocracking of SRC, HIS was hydrocracked faster than HS, but the hydrocracking of HS and the rehydrogenation of naphthalene solvent did not occur. Therefore, the hydrogenation of each separated fraction is effective to produce light oil.View full abstractDownload PDF (1022K) -
Masatomi AKEZUMA, Hiromi ICHINOHE, Kunio ESUMI, Kenjiro MEGURO, Hidema ...1985 Volume 64 Issue 9 Pages 748-752
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe sedimentation rates of the benzene insoluble matter (BI) obtained from liquefied products by the reaction of 1, 2, 3, 4-tetrahydroquinoline with Taiheiyo and Miike coals were measured by the addition of water/benzene (w/o) emulsions prepared using different emulsifiers.
As a result, the sedimentation rates of both Taiheiyo. BI and Miike BI were accelerated remarkably by the addition of W/O emulsions prepared using sorbitan fatty acid ethers and polyoxyethylene nonyl phenyl ethers. On the other hand, the addition of W/O emulsion prepared using sodium di-2-ethylhexyl sulfosuccinate affected hardly the sedimentation rate of BI. From the sedimentation study of BI, it was found that a separation of BI was enhanced by the addition of W/O emulsions prepared using emulsifiers which exhibited an appropriate emulsion stability and was easily broken by dilution into benzene, resulting supply of water to the BI surface for coagulation of BI particles.View full abstractDownload PDF (595K) -
Shoichi IYAMA, Tetsuro YOKONO, Yuzo SANADA1985 Volume 64 Issue 9 Pages 753-759
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCarbonization of low rank coal under high hydrogen pressure was studied. Our interest is to clarify the effects of hydrogen pressure and soaking time on the resultant cokes. The longer the: soaking time at 748 K under 5 MPa, the more extensive the development of anisotropic texture and the greater the size of optical texture. The effect of hydrogen pressure on the resultant cokes was found to be optimal at 5 MPa. However, no significant change in the anisotropic texture of the resultant cokes was observed when the hydrogen pressure was increased from 5 to 13 MPa.
The effect of partial pressures of hydrogen on the carbonization reaction was also examined. When the partial pressure of hydrogen decreases, the extent of the anisotropic texture is reduced.
The carbonization of Yubarishinko coaking coal was also carried out under high hydrogen pressure. The optical texture of resultant cokes for a hydrogen pressure of 8 MPa shows flow anisotropy.
Moreover, the effect of selenium oxide catalyst on pressure carbonization was also studied. SeO2, which is especially effective in the early stage of carbonization, enhanced the mesophase development for Taiheiyo coal.View full abstractDownload PDF (2093K) -
Kenichi GOMI, Takeo KOMURO, Norio ARASHI, Yukio HISHINUMA, Osamu KANDA ...1985 Volume 64 Issue 9 Pages 760-766
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe effect of NH3 addition on SO2 adsorption properties of steam activated semicoke (activated carbon) has been investigated . When activated carbon was used by repeating SO2 adsorption at 130°C and regeneration in N2 at 450°C, the amounts of surface oxide which were not decomposed at regeneration temperature increased. It was, however, found out that these surface oxides were removed easily by heating the activated carbon in the presence of NH3 at regeneration temperature .With the decrease of amounts of surface oxide, there was an increase in the specific surface area of activated carbon. In addition to the removal of surface oxide with NH3, some surface oxides were found to form basic nitrogen compounds . These compounds are estimated to be active sites for SO2 adsorption.
When NH3 was added in a flue gas, both sulfuric acid and its ammonium saltswere adsorbed on activated carbon. These ammonium salts decomposed to form NH3during regeneration process at 450°C. It is concluded that the NH3 reacts with surface oxide to form H2O and N2 and this effectively decrease the carbon loss during regeneration. With adding NH3 in a flue gas, it is found out that the rate of decrease of SO2 adsorption capacity during repetition of adsorption-regeneration process can be suppressed. However, the strength of a activated carbon was found out to decrease much faster than a activated carbon used without adding NH3 in a flue gas.View full abstractDownload PDF (1074K) -
Yoshiaki MIURA, Masahiro SASAKI1985 Volume 64 Issue 9 Pages 767-778
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSNational Standards (GOST 25543-82) for unified classification of coals were established in USSR on December 20, 1982 as outlined in this report.
First, brown coal, bituminous coal and anthracite are classified by appearance using three kinds of parameters.
Next, classification into four stages-class, category, type and subtype-is made using parameters based on the genetic and industrial properties of coals followed by further division of each stage into several levels, all with systematic numbering. As a result, individual coal is represented by a seven-digit code number.
Then, coals are classified into three groups-mark, group and subgroup-with their general industrial properties as criteria and individual coals are shown by their code numbers in the “industrial classification chart of coal”.
Lastly, a guidance is provided for rational application of each coal and the testing methods are specified for determining the classification parameters.View full abstractDownload PDF (1383K) -
[in Japanese]1985 Volume 64 Issue 9 Pages 779-790
Published: September 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (2003K)
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