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Volume 64, Issue 10
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[in Japanese]1985 Volume 64 Issue 10 Pages 795
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (234K) -
Isao MOCHIDA, Yozo KORAI1985 Volume 64 Issue 10 Pages 796-808
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSRecent interest in carbon fibers produced from mesophase pitch has strong incentive for the development of some novel aspects in the carbonization chemistry. The properties, structure and preparation of carbonaceous mesophase pitch and derivative carbons are summarized in this paper with emphases on the phase transition, chemical structure of the components, their interaction to exhibit characteristic properties, and the preparative kinetics.
First of all, thermotropic behaviors of mesophase pitch are described according to three categories of phase diagrams, single fraction, diluted and co-operating liquid crystals, which are characterized by properties of respective components and their interaction.
Secondly, the size, shape, aromaticity and substitutional groups, including naphthenic or short alkyl groups, of the component molecules in the mesophase pitch are characterized to be correlated to its fusibility, solubility, molecular orientation and reactivity. Thus, the anisotropy and fusibility for spinning or moulding are revealed to be controlled by the blending and structural modification.
Finally, the preparative design of mesophase pitch for carbon fiber and its application for better preparation of anisotropic spheres, needle coke and blast furnace coke are reviewed based on the structural and property understanding. The usefullness and the physical and chemical mechanism of carbonization are introduced.View full abstractDownload PDF (2597K) -
Effect of Presulfurization of Ni-Mo-Al2O3 on Hydrocracking of Coal LiquidsToshiaki KABE, Masuhiro IIZUKA, Osamu NITOH, Hideo OHNUMA, Yoshimasa I ...1985 Volume 64 Issue 10 Pages 809-815
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn order to determine the effect of presulfurization of Ni-Mo-Al2O3 on hydrocracking of coal liquids, Wandoan coal SRC was hydrocracked in tetralin solvent containing a small amount of 14C labeled naphthalene.
Wandoan coal SRC was separated into hexane-soluble (HS) and toluene-solublehexane-insoluble (HIS-TS). SRC and these fractions were hydrocracked at 400°C under9.8 MPa using a fixed bed flow reactor with WHSV of 0.68. Ni-Mo-Al2O3 catalyst was used under a reduced or a presulfided conditions. The distributions of reaction products and nitrogen contents were determined. The amount of the rehydrogenation of naphthalene during the hydrocracking was examined by 14C tracer method.
The results can be summarized as follows;
1) Presulfulization of Ni-Mo-Al2O3 has a higher effect on the hydrogenating activity, and it accelerated the conversion of the heavy fraction to the light fraction and the rehydrogenation of naphthalene. However, it has little effect on denitrogenating activity, therefore SRC was not denitrogenated so much.
2) The comparison of activities between reduced and presulfided catalysts suggested that HS was hydrocracked to light oil and HIS was hydrogenated to HS.
3) From 14C tracer studies, the rehydrogenation of the solvent was found to be relatively small in the presence of the heavier fraction in the reactants.View full abstractDownload PDF (960K) -
Conversions and Hydrogen Consumption EfficiencyMasao NAKADA, Seiji ARITA1985 Volume 64 Issue 10 Pages 816-821
Published: October 20, 1985
Released on J-STAGE: February 23, 2011
JOURNAL FREE ACCESSThe utility of iron sulfide catalyst on coal liquefaction is widely recognized recently, because of its low corrosive activity and cost. But generally, iron sulfied catalyst has little surface area and this makes the catalysis activity relatively lower. So it is very important to increase the surface area of iron sulfide for catalyst preparation. Recently, this kind of works using red mud as iron sulfide source, crushed coal and iron sulfide at the same time, or penetrating FeSO4 into coal using ion-exchange function of coals are often reported. In this report, Wandoan coal was added to aqueous solution of FeCl3 and (NH3) 2S was added slowly to sulfrize Fe (III) ion (deposited iron sulfide catalyst). Successive electron-microscopic observation revealed that coal was wrapped in iron sulfied. Direct hydrogenation of the coal was conducted at 400°C for 60 min.(initial hydrogen pressure 8.7 MPa). The conversion and hydrogen consumption by deposited iron sulfide catalyst were compared with other three usual catalysts (iron sulfide powder, Ni-Mo/Al2O3 and ZnCl2) under the same conditions. The conversions (2% catalyst to Wandoan coal) decreased in the order, Ni-Mo/Al2O3>deposited catalyst>ZnCl2>iron sulfide powder. Hydrogen consumption efficiency on Wandoan coal liquefaction decreased in the order, iron sulfide powder ≅ deposited iron sulfide>Ni-MO/Al2O3>ZnCl2. The deposited catalyst showed an excellent activity for Wandoan coal conversions next to Ni-Mo/Al2O3 and a high hydrogen consumption efficiency.View full abstractDownload PDF (1452K) -
Kenji HASHIMOTO, Kouichi MIURA, Ji-Jun XU, Tetsuo SHIODE, Akira WATANA ...1985 Volume 64 Issue 10 Pages 822-829
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe purpose of this work is to examine if the metals involved in coals catalyze the gasification of carbonaceous materials. Minerals were isolated from three kinds of coal by seven different methods, and were supported on a pure carbon (carbon black). Samples thus prepared were gasified in an atmospheric pressure of steam at 818°C. The mineral extracted with HNO3 or HCl was very effective to accelerate the CO2 formation reaction as well as the gasification reaction. On the other hand, the mineral isolated by an oil agglomeration method, the residue after the completion of the gasificationa, nd the so-called ash were not effective at all, but they showed a little activity when they were supported on the carbon after the treatment with HNO3. The rate of CO formation was practically constant for all the samples. This means that the active metals in coals catalyze only the CO2 formation reaction. Of the metals in the minerals, Na, K and Ca which are bound to carbon were supposed to catalyze the gasification reaction from the measurements of the amounts of metals involved and the X-ray diffraction patterns of the isolated minerals. The amount of oxygen trapped by the chars were also measured by use of a Curie-point pyrolyzer, and the gasification rate was found to be intimately related to the amount of oxygen trapped by the minerals on the chars.View full abstractDownload PDF (1169K) -
Hidero UNUMA, Shouhei TAKEDA, Takashi TSURUE, Saburo ITO, Sogo SAYAMA1985 Volume 64 Issue 10 Pages 830-839
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe requirement for the studies on the basic properties or thermal behavior of coal ash increases in the fields of coal gasification, liquidization, combustion or coal ash utilization. In this study, 24 coal ash samples were tested through chemical analysis, X-ray diffraction, TG-DTA and JIS melting test. In addition, ash model samples were prepared and tested to discuss the fusibility and the fusing behavior in the view of mineral composition of coal ash.
The main mineral composition of coal ash in initial state were determined from low temperature ash samples, which were ashed with oxygen plasma asher, and the result was that they are quartz, kaoline, carbonates and sulfates of alkaline earth metals, iron compounds and feldspars. The transformation, thermal decomposition and interactions between these minerals were investigated by TG-DTA and hightemperature X-ray diffraction.
From the experimental results of model samples, it became clear that the fusibility of coal ash is strongly dependent on the mineral composition of coal ash, and consequently the simulation of thermal behavior of coal ash became possible when mineral composition was taken into account.View full abstractDownload PDF (1277K) -
Yoshinobu KOMATSUBARA, Kazuhiko TSUJI, Ikuo SHIRAISHI, Shiro IDA, Isao ...1985 Volume 64 Issue 10 Pages 840-847
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAbilities for removal of SOx and NOx as well as mechanical strength of some carbon blacks, active cokes, active carbons, PAN-ACF and sponge coke were tested using three kinds of reactors to evaluate them as a moving bed material for the dry simultaneous removal of SOx and NOx in the flue gas. Among the carbons texted, PAN-ACF A and B activated with H2SO4 had the highest catalytic activities for NO-NH3 reaction in a circulating reactor. The three active cokes, BF, Mitsui A and B cokes, were tested using a midget reactor (10m3/h) by repeating the operations of NO reduction with NH3 at 150°C, SOx removal at 150°C, and SO2 recovery at 400°C. An enhancement of catalytic and adsorption activity, maintaning the enough mechanical strength for the moving bed, was observed after several cycles of these operations. The coke gained through the cycles of SO2 adsorption and desorption no sulfur but some oxygens, which appear to be related to the enhanced activity.
A pilot plant of 1000m3/h was successfully operated with BF and Mitsui A cokes, which behaved as expected from the results obtained with a midget reactor. These results may indicate a practical application of a dry process for a simultaneous removal of SOx and NOx with active cokes in the moving bed. A better carbon such as PANACF which can be explored with ease by a circulating reactor can reduce the size and cost of the plant.View full abstractDownload PDF (1218K) -
Mitsushige NAKAYAMA, Takahisa ARAKI1985 Volume 64 Issue 10 Pages 848-856
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIt is very important to know the informations of spray structure on a research and development of combustion systems such as industrial boiler, power plants and internal combustion engine, but it is too difficult to get their characteristics, because an excelent measuring methods have not been developed.
In order to get the information of internal spray structure such as spray concentration, a computed tomography (CT) technique was introduced. CT method is familiar with medical diagnostics.
In this paper, we discussed about following some basic factors;
(1) Algorism of Computed Tomography
(2) Filter function
(3) Minimum number of projection and sampling data
(4) Application to visualization of spray structure
From these discussions, Convolution method was used as reconstruction procedure, modified Shepp and Logan's function was adopted as filter function and a minimum number of oroiection and samplinv was decided as 61 and 30, respectively.
Experimental studies were made by using a visible light as a light source and an Industrial Television Camera as a detector of a transmitted light intensity, and a micro processor was used for a calculation of reconstruction of images.
Appling to a reconstruction of picture of a hollow cone spray atomizer and a fan spray atomizer, reasonable reconstruction data were obtained and this CT method would be useful to study the internal structure of various spray such as vaporizing or combusting process.View full abstractDownload PDF (1540K) -
Shigeki MORIMOTO1985 Volume 64 Issue 10 Pages 857-866
Published: October 20, 1985
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe circumstances of solid fuel burning domestic appliances in England, West Germany and other European countries were surveyed.
The solid fuels consumed for domestic heating are about 10% of the energy in West Germany and about 20% in England.
The solid fuels of those countries are anthracite, bituminous coal and manufactured smokeless fuels. They are less in ash content and are screened at more narrow sizes than Hokkaido house coal.
The standards of the solid fuel burning roomheaters in both countries have been established for the performances and the methods of testing since 20 years . The European stoves have the following performances and constructions.
(1) They are larger and heavier, and have much fuel capacity and higher heating efficiency than Japanese stoves burning solid fuels.
(2) The combustion air is controled by thermostatt working mechanically by boiler water or the other parts of stoves.
(3) They maintain an effective seal of both the door opening and the ash pit opening.
(4) Most of them are covered by ceramic tile, polished soap stone, decorated cast iron, etc., and the visual appearance is most attractive.
In England, some new types of appliances have been developed by colabolation of NCB CRE and appliance makers, which are based on the down draft burning principle and are capable to reduce smoke emissions to the levels 'required by the Clean Air ACT.View full abstractDownload PDF (1451K)
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