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Aihua Zhang, Mamoru Kaiho, Osamu Yamada, Hajime Yasuda, Mokhtar Zabat, ...
Article type: Article
Pages
357-360
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Hydrogasification of Taiheiyo coal were carried out with a Batch type reactor. The influence of hydrogen pressure was discussed by comparing the results obtained at 7.1MP and 3.6MP hydrogen pressure. It was found that Hydrogasification is fundamentally dominated by H_2/coal ratio, but H_2 pressure affects product distribution. At lower H_2 pressure, some gas phase reactions such as methanation of CO, hydrogenation-decomposition of C_2H_4, C_6H_6 and C_<10>H_8 were suppressed, resulting in the less formation of CH_4.
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Hiroaki Inoue, Katsuyasu Sugawara, Takuo Sugawara, Yukio Enda
Article type: Article
Pages
361-364
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Alkaline metal content was determined by a dissolution method for five kinds of coal and their chars with the use of sulfuric acid, hydrofluoric acid and ammonium acetate solutions. Behavior of potassium and sodium was followed in pyrolysis and gasification of the samples using fixed bed and free-fall reactors.
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W.-C. XU, M. KUMAGAI
Article type: Article
Pages
365-368
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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The evolution behaviors of nitrogen in coal during flash hydropyrolysis were investigated by using a continuous free-fall type reactor. The effects of temperature, hydrogen pressure, coal type and atmosphere were studied. The results showed that NH_3 was the main gaseous product, together with a little amount of HCN. The increases of temperature and hydrogen pressure promoted the evolution of coal-N. The dependencies of N-distribution on reaction conditions were the same for coals used. The evolution of coal-N to volatiles increased proportional to the increase of coal conversion.
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Takashi HORIE, Motoki KOBAYASHI, Kaoru ONOE, Tatsuaki YAMAGUCHI
Article type: Article
Pages
369-372
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Using helium or carbon dioxide as plasma sources, Yalloum coal decomposition by microwave plasma technique was performed. Changes with the content of C, H, O from untreated coal into oily products, gaseous products and residue were observed. This report described the roles of carbon dioxide during plasma reactions with regard to higher reactivity of coal and selective synthesis of chemical feed-stock gases or fuel oils.
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Hiromi ASO, Hirokazu ODA, Kazuaki SHIBUYA
Article type: Article
Pages
373-376
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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This study was done about the effect of mineral component and pyrolysis condition of coals exerted on the pore-structure and reactivity of chars about 43 kind of standard coal samples. The coal sample was stirred in 1mol/l-HCl for 24 hours, and minerals were removed. Three kinds of chars were prepared under different heating conditions. Though almost the specific surface area of parent coals increased, the true density did not change by demineralization. Yield of chars increased by demineralization. As for reactivity of chars, the difference by the coal kind became small by demineralization. The reactivity of chars were as high as heating rate was fast. There was hardly difference by heating rate though the inter-crystalline and combination stracture of oxygen were observed by using XRD and XPS.
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Noriko YOSHIZAWA, Katsuhisa MARUYAMA, Yoshio YAMADA, Hiroyuki FUJIMOTO ...
Article type: Article
Pages
377-380
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Influences of stacking structure of aromatic layers and structure out of layers upon an XRD pattern were studied in order to establish the characterization method of size of aromatic layers in carbonaceous materials. According to the results with Warren-Bodenstein calculation, presence of stacking structure decreases the width of 11 band in XRD pattern, which could cause overestimation of layer size by our method derived from the Diamond method. It was also found that consideration of methylene group and biphenyl-like structure in chars was effective to raise the preciseness of our characterization method.
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Jie Wang, Risa Ishida, Seiko Akashi, Takayuki Takarada
Article type: Article
Pages
381-384
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Zhiheng WU, Yoshikazu SUGIMOTO, Hiroyuki KAWASHIMA
Article type: Article
Pages
385-388
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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In order to study the change and release of different nitrogen structures during coal pyrolysis, two model coals containing pyrrolic or pyridinic nitrogen with or without catalyst addition have been pyrolyzed in a fixed-bed reactor at 10℃/min up to 1000℃. Pyrolysis results show that iron and calcium catalysts catalyze char nitrogen release at different temperatures. XPS analysis indicates that the catalysts mainly catalyze the release of pyridinic and quaternary nitrogen.
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Takahiro YOSHIDA, Kinya SAKANISHI, Ikuo SAITO, Toshimasa TAKANOHASHI, ...
Article type: Article
Pages
389-392
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Ash in coal is a major problem in utilizing of coals. In order to make ashless coal (Hypercoal, HPC) with high production yield, solvent extraction at 360-380℃ was carried out using various organic solvents. The effects of different coals and solvents on the HPC yield and the ash content were investigated. When various coals was treated with dimethylnaphthalene at 360℃ for 60min in a batch reactor, the extraction yields of 21-39% was obtained regardless of coal rank. We succeeded in obtaining HPC under 0.1% of ash for several coals.
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Kazu-aki Hata
Article type: Article
Pages
393-396
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Supercritical water oxidation process has been developed as a technology decompose refractory organic materials completely. This technology will make it possible to utilize low grade fuels such as low rank coal or vacuum residue of heavy oil which has been difficult to burn. The purpose of this study is to develop the calorimetry in supercritical water in order to measure the quantity of heat in supercritical water oxidation process of coal and coal model compounds.
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Jun-ichi OZAKI, Yoshinori UCHIYAMA, Asao OYA
Article type: Article
Pages
397-400
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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Effects of iron catalyst on the carbonization of Loy Yang was studied by targetting fabrication of functional carbon materials from this coal. Peak separation of the carbon (002) region revealed the presence of at least three components, amorphous (A), turbostratic (T) and graphitic (G) components. The manner in the development of crystallite size of the T component was different among the samples with lower iron content (<0.5%Fe) and those with higher content (>5%Fe); i.e. the crystallite of the former group samples continuously growed, on the other hand the latter group showed a levelled growth in the crystallite size. The electrocatalytic activity of the samples with higher iron content had a good correlation with the crystallite size of the T component, however the samples with lower iron content did not. TEM observation confirmed that the presence of a special type of turbostratic structure-TS phase-in the samples with higher iron content.
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V.J. Wargadalam, K. Norinaga, M. Iino
Article type: Article
Pages
401-404
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
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Shape of coal particle/aggregate of Upper-Freeport pyridine soluble (UFPS), Illinois pyridine soluble (ILPS) and asphaltene from coal liquefaction residue (Asp) in dilute solution has been analyzed through viscosity measurements. The measurements were performed in capillary viscometer with the concentration ranged up to 60g/L at 25℃. The critical concentrations(C^*) were observed for UFPS/Pyridine, ILPS/Pyridine and Asp/Toluene, whereas it was not found in Asp/NMP. Applications of Pal & Rhodes equation suggested that coal particles in dilute solution at concentrations below C^* are approximately spherical in shape with some degree of solvation.
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Hidetoshi AOKI, Takahiro SHISHIDO
Article type: Article
Pages
405-408
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
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The chang in the state of coal surface in the carbon dioxide/oxygen combusion process was investigated in compared with the nitrogen/oxygen combustion for the purpose of recycling carbon dioxide in exhaust gas. The luminosity of the coal surface, roughness and form were measured by using the optics microscope, the electron microscope, the laser microscope and so on. Experimental results showed that the combustibility in carbon dioxide/oxygen combustion process was better in the influence of the carbon monoxide which occurs due to the gasification.
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Masahiko MATSUKATA, Momoko HAYASHI, Tomohiro KAWABATA, Eiichi KIKUCHI
Article type: Article
Pages
409-412
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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The release of inorganic matters from coal combustion as volatile matters and aerosols at high temperatures and their deposition on lower temperature surfaces were investigated fundamentally. About 100mg of coal (SS027) smaller than 100μm held in a platinum basket was inserted into an electronic furnace and burned at 1080℃ to release vapor and aerosols of inorganic matters. A packed bed of ZrO_2 beads of 2mm was placed in the downstream of the reactor. The temperature of the bed was controlled at about 100℃ so that inorganic matters would be cauyht on the ZrO_2 beads. The quantities of inorganic matters ccaught on the ZrO_2 beads after 1, 10, 30, 60 and 180min of coal combustion were determined by use of inductively coupled plasma (ICP). It was found that initially, inorganic matters such as alkali, alkaline earth metals and iron release during volatilization followed by the release from char burning process. Inorganic matters further continued to be released from ash.
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Masanori SAKAI, Hideaki MIYASHIGE, Eiji SASAOKA
Article type: Article
Pages
413-416
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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It was reported that the macropourous CaO prepared water vapor swelling method was active for the activity decomposition of N_2O and had good tolerance for sulfation. To elucidate the cause, the change of pore size distribution and the change of surface state by sulfation were investigated. In this result, it was found that moderate development of macroporous pore size, was especially the 100nm〜10μm of CaO, was important. When macroporous pore size moderately developed, sulfation rate was suppressed and the CaO remained a little in the inside of particle played the role of catalyst for N_2O decomposition.
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Chunbao XU, Dapeng KONG, Naoto TSUBOUCHI, Yasuo OHTSUKA
Article type: Article
Pages
417-420
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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The objective of this work is to develop a novel hot gas cleanup method to remove ammonia from coal gasification products with inexpensive raw materials. The catalytic decomposition of 2000ppm NH_3 has been examined with a fixed bed quartz reactor. The Fe-or CaO-containing composites, prepared by carbonizing metal loaded brown coals, catalyze the present reaction and achieve complete decomposition of NH_3 at 750-850℃. Further, the perfect removal of NH_3 at 850℃ by use of a brown coal char with small amounts of inherent Fe and Ca is noteworthy in particular from a practical point of view. The mechanisms of the Fe- and Ca-catalyzed decomposition are discussed in term of formation of nitride intermediates.
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Fuyu NOTOYA, Eiji SASAOKA, Shigeru NOJIMA
Article type: Article
Pages
421-424
Published: September 28, 2000
Released on J-STAGE: March 22, 2017
CONFERENCE PROCEEDINGS
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In order to develop a catalyst for low temperature selective reduction of NO in coal combustion flue gas in presence of ammonia, metallic salt impregnated metal oxides were studied in a continuous quarts fixed-bed reaction system. It was observed that the DeNOx activity of metal chloride impregnated catalyst is higher than the sulfate of the same metal at 100℃. Its activity is influenced by reaction temperature, ammonia gas, and the kind of support. The chloride ion on the metal chloride supported catalyst seems to contribute to its activity.
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