Fuel cells have been highly considered as an alternative power source in the near future. The low temperature-operated polymer electrolyte fuel cells (PEFC) have gain interest for use in automotive and stationary applications. For Pt-metal electrocatalysts, the problems have their high cost and poor availability. For this reason, the major challenges in the fuel cell research are to reduce the cost of the electrocatalyst either by decreasing the Pt loading or by developing a non-noble catalyst. As a strategy, we select coals as new Pt alternative catalysts. In this study, the catalysts are prepared with various conditions using coals and investigated their activity for the oxygen reduction reactivity as a cathode catalyst for PEFC using a rotating disk electrode technique.

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In the air blown IGCC demonstration plant, a small scale air separation unit (ASU) is set up. Nitrogen from ASU is used for the transportation of coal and the char etc., and oxygen is mixed with air as a gasifying agent. From the viewpoint of a highly effective and stable operation of the gasifier, and improvement of plant efficiency in a commercial plant, in order to optimize the oxygen concentration of the gasifying agent, it is necessary to clarify the influence of the oxygen concentration in the gasifying agent on the gasification performance quantitatively. In this study, the influence of the oxygen concentration in the gasifying agent on the gasifier per pass performance was clarified by using a 3t/d bench scale coal gasifier. In addition, the gasification performance in the state of char-balance was estimated from the heat and mass balance of the gasifier. As a result, the influence of the oxygen concentration in the gasifying agent on the gasification performance (cold gas efficiency, char product rate, gas temperature in combustor, etc.) was able to be evaluated quantitatively.

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Lignite and sub-bituminous coal make up about 1/2 of coal resources, but their use is confined. It is important to develop the use technology of these low grade coals as a future energy source while a supply of good-quality bituminous coal becomes tight. Advanced IGCC was proposed with fluidized bed coal gasifier to overcome this issue and to achieve high efficiency. Several types of IGCC systems are compared. Advanced IGCC has can achieve highest efficiency.

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A circulating fluidized bed coal gasifier cold model, which consists of an acrylic riser (0.05m-i.d.×6m-high), a downer (0.1m-i.d.×1.3m-high), a bubbling fluidized bed (0.37m×0.08m×1.5m), was set up. Solid mass flux (G_S) of silica sand particles (density=2600kg/m^3 and average particle size=83μm) and solid separation efficiency of a separator installed at the bottom of the downer were measured. The maximum obtained G_S was 238kg/(m^2・s) when the riser gas velocity (U_<gr>) was 8m/s and solid inventory (I_s) was 50.9kg. It is found that the solid mass flux was obviously affected by the solid inventory and the riser gas velocity. The solid separation efficiency was 98.2-99.6% when the downer gas velocity was 1-3m/s.

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Oil prices will continue to rise though there will be some fluctuation. On the other hand, the price of coal is expected to continue to be low and alternative oil made from coal is expected to add to fuel price stability in the market. But reduction of CO_2 emissions from coal usage is needed to mitigate global warming. We applied the EAGLE gasifier to an alternative oil production process to improve thermal efficiency. The shift reaction is needed to adjust H_2/CO ratio and the steam used for the shift reaction is one of the big reasons for efficiency loss. We developed a method to reduce steam usage by supplying water to the outlet of the gasifier. Water is changed into steam and the shift reaction proceeds without a catalyst because of the high temperature downstream from gasifier. We estimated the steam reduction effect of this method was about 17〜20%.

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We attempted to convert paper sludge ash into functional materials via acid leaching. The extraction behaviors of main elements (Si, Al, Ca, Mg, and Fe) from the ash into 1M HCl and 0.5M H_2SO_4 solutions are almost same, except Ca, due to the formation of gypsum. The ash leached with 1M HCl and H_2SO_4 are converted into zeolite-P and tobermorite, respectively, while original ash is converted into hydroxysodalite. The cation exchange capacities of the products from the ash leached with HCl and H_2SO_4 are 130 and 75cmol/kg, respectively, which are higher than that of the product from original ash. These results indicated that paper sludge ash could be converted into functional materials via acid leaching.

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This study aimed to clarify the behavior of closed pores in coal chars during gasification process. Closed pore volume was calculated in terms of helium density and ash fraction. Closed pore surface area was calculated based on Small-Angle X-ray Scattering (SAXS). Close pore volume and closed pore surface area are rapidly decreased at an initial stage of char gasification. On the other hand, open pore immediately increased. These results would be indicated that closed pore was opened at an initial reaction. When gasification temperature was changed, the variation of closed pore surface area indicates different behavior. Then, we examined how closed pore contributed to the development of pore structure in each stage of gasification.

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Catalytic cracking of oil sand bitumen with zirconia-alumina-iron oxide catalyst in a steam atmosphere was examined to produce light oil. The experiment was carried out using a fixed-bed reactor, and bitumen diluted with toluene was fed to the reactor. Heavy oil fraction was oxidatively cracked with the active oxygen species generated from steam over the catalyst. Hence, large amounts of light oil, such as gasoline, kerosene, and gas oil, were produced. However, some coke formed after the reaction of bitumen, while coke did not form in case of atmospheric-residual oil (AR). It was supposed that coke formed because the amount of Conradson carbon residue of bitumen is larger than that of AR. To enhance the reaction of heavy oil fraction with the active oxygen species over the catalyst, 1-mthylnaphthalene was used as solvent instead of toluene. As a result, coke was not formed.

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Nippon Oil is working on the catalyst development to meet the Japanese specification of diesel, which is distilled from the oil sands-derived synthetic crude oil. The cetane number of the product oil, which is obtained by hydrotreating over the NiW catalyst supported on the amorphous silica-titania, was higher than that of the feed oil. The main factor of the cetane number-increase is the naphthenic ring opening activity of the developed catalyst.

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Oil sand bitumen produced by SAGD mining method was treated at 450℃ and about 30MPa for less than 120min, using water, nitrogen, or toluene as a reaction medium, to clarify an effect of water on its pyrolysis reaction. Through detail analyses of middle distillate obtained using water and nitrogen, their component distributions were not different. However, at longer treatment times, the reaction with water gave a higher yield of middle distillate and a lower yield of coke than that with nitrogen. Water may not have worked as a reactant like toluene but an effective reaction media due to its dispersion effect.

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Now that the depletion of fossil fuels such as conventional oil is a matter of world concern, it is essential to investigate an efficient utilization method of unconventional heavy oil. To upgrade the heavy oil such as oil sand bitumen efficiently, it is important to suppress excessive polymerization and decomposition of light oil produced by the cracking of heavy oil. In this work we focused on the nature of supercritical water that it can dissolve hydrocarbons such as light oil, and utilized it to carry away light oil produced by the cracking of heavy oil instantly from the reaction system to avoid its further decomposition. Pyrolysis behavior of an oil sand bitumen in a flowing stream of nitrogen instead of supercritical water was first examined in detail to verify the concept. It was shown that the pyrolysis method increased the yield of light oil significantly by minimizing the formation of light hydrocarbon gas and coke. Then the pyrolysis behavior of the bitumen in a flowing stream of supercritical water was investigated.

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Brown coals were extracted in tetralin at the temperatures of 400〜440℃. The yields of the heavy extracts (toluene-soluble, >250℃) were 32〜39wt%, and the oxygen contents were 6〜9wt%. Hydrocracking of the heavy extract was carried out at 450℃ for 4hr, and the properties of the product oil was compared with those of petroleum atomospheric residues.

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The influence of the nickel catalyst on the hydrogen evolution behavior in the steam gasification up to 900℃ of the rice straw was examined in this study. Hydrogen began to evolve from about 700℃, and the maximum rate of hydrogen evolution was reached at 900℃ for 10min for the rice straw without catalyst. On the other hand, a new peak appeared at around 700℃ for the rice straw with the nickel catalyst. This low temperature peak has grown as the nickel loading increases. Moreover, the amount of hydrogen evolution increased from 30mmol/g for the rice straw without nickel catalyst to 45mmol/g for the rice straw with nickel catalyst more than 5wt%. When the hydrothermal-treated rice straw residue rich in cellulose component was gasified with steam, the hydrogen evolution at low temperature (700℃) was promoted and the amount of hydrogen evolution increased to about 60mmol/g by the addition of nickel catalyst more than 2wt%.

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Transesterification of sunflower oil (SFO) and waste cooking oil (WCO) with methanol was performed by using CaO catalyst at 80-120℃ under reflux condition. The FAME yield of SFO was higher than that of WCO under the same condition due to the presence of free fatty acid in WCO. At the reaction temperature of 80℃ for 120min with 3wt% CaO catalyst, the FAME yield of SFO and WCO reached more than 92% and 84%, respectively. The fuel properties of the BDF produced from SFO at 120℃ with 5wt% CaO catalyst satisfied the values required in the EU standard for biodiesel fuel (EN-14214).

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Authors had developed the plant cultivation bed with used paper. This time The cultivation bed was made from mixing with used paper and unused wood resources. For the usage expansion, large-scale construction machine such as cylinder of 30cm diameter and 30cm cube are developed.

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New utilization of charcoal is studied. This value added to charcoal is used as recarbarizer for casting. Charcoal is added in the melted iron in the furnace. The carbon is important element for casting. Coke from coal is usually used as recarbarizer. Charcoal can take place of coke.

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From the viewpoint of global warming and recovery resources and energy from organic wastes, the carbonizing process is paid the attention to intermediate processing of the organic solid wastes. This study is focused on carbonization of industrial organic solid waste such as thinned woody waste vary with combustible gases utilized as recovery energy. The proper conditions such as different carbonizing temperature rates were investigated for the possibility of solid fuel. Therefore, pyrolyzing products such as generated gases, tar and char were measured using the thermogravimetry with a differential thermal analyzer (TG-DTA) and a batch-wise fixed-bed reactor with the GC-TCD & GC-FID analyzers.

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Amorphous silica-alumina could be prepared with dicarboxylic acids. The activity for the silica-alumina in dodecane cracking was much lower than that for zeolite. When the silica-alumina was used as a matrix, however, the product distribution changed compared with the single use of zeolite or silica-alumina and the comparable activity to that of zeolite was obtained.

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Authors had developed the plant cultivation bed with used paper. This time The cultivation bed was made from mixing with used paper and unused wood resources. The molding condition with used paper and unused wood resources such as scobs bark and chips is discussed. The characters of these carbon plant bed is also discussed.

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Authors had developed the plant cultivation bed with used paper. This time The cultivation bed was made from mixing with used paper and unused wood resources. These molded product with used paper and unused wood resources are carbonized by a large-scale electric furnace and the new furnace by using the exhausted gases during carbonization. This carbonization process is discussed.

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In pulverized coal fired boilers, molten ash particles generated during combustion have possibility of adhesion on surface of heat exchanger tubes. This causes problems of heat transfer inhibition such as slagging and fouling as well as boiler trouble on operation. In order to solve this problem, surface treatment technology of the heat exchanger tubes is developed in this study. This paper describes dependence of the adhesive force between the deposition layer and the tube surface on the coal types.

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Arsenic content in fly ashes and its leaching characteristics has been investigated for various coal types to control arsenic concentration in waste water from landfill leachates. It was found that arsenic leaching characteristics was strongly affected by pH of the leachate. Relation between ash composition and pH of its leachate was studied to estimate arsenic leaching characteristics. The fly ash samples were corrected from an ESP in a large scale pulverized coal combustion process. Ash composition was strongly changed in coal types. The B/A ratio was employed as an index to evaluate pH of the leachate.

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A relationship between mode of occurrence of inorganic matter and the amount of fine particles formed by vaporization and condensation was investigated. A method of making combustible particle including only one kind of mineral using polycarbonate and mineral particles was developed. The degree of contribution of included minerals and different kinds of minerals to formation of the fine particles at 1673K was confirmed using the particles.

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The fly ashes from coal A and B, generating from a shell coal gasifier in China, were sampled respectively to investigate the physicochemical characteristics of fly ash. The results show that Coal A is rich in Ca, and coal B is rich in Fe. The elements migration is different during gasification, and the influence of the coal type is significant. The number of fly ash particles in diameter at 1μm from coal A is much more than that of fly ash from coal B. There are many fine particles adhere to the big spherical fly ash particles. These small particles are rich in Al-Si and have the appreciable amounts of Ca with low fusion temperature, which may be the reasons for the fine particles sticking to the big spherical particles.

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The compositions of ashes and slags of various coals and their relations to the melting properties were investigated. Viscosities, which should be an important factor on smooth exhaustion of molten slags and adhesion property of ashes in high temperature coal gasification, were estimated in the temperature ranges of 1000〜1700℃.

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This paper aims to evaluate the addition of an Mg-based additive to coal on the emission/reduction of particulate matter (PM) during coal combustion. Four pulverized coals with different mineralogical properties were investigated. Each of them was mixed with Mg-based additive and combusted at 1723K in a lab-scale drop tube furnace (DTF). The results indicate that the Mg-based additive tested here has a pronounced impact on particle size distribution of PM and the morphologies of individual ash particles. For all the coals tested here, addition of the Mg-based additive increased the coarse ash fraction and substantially reduced the amount of ash particles smaller than 2.5μm (PM_<2.5>). This is because the Mg-based additive is able to reduce ash melting point via the formation of low-melting eutectic compounds which promote the coalescence among sub-micron mineral particles. The effect of the Mg-based additive on PM_<2.5> reduction also depends on the properties of the original minerals present in the coal. The comparisons indicate that the model can satisfactorily predict ash formation and properties, taking into account both coalescence of included minerals and fragmentation of excluded minerals.

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Biodesulfurization of coals by use of Thiobacillus ferrooxidans was examined, and the coking property of the biodesulfurized coal was investigated in terms of button index (free swelling index). The % removal of inorganic sulfur was 40-90% when the biodesulfurization was carried out for four high sulfur coals. Also, biodesulfurization favorably worked for the removal of As and Se from coal. The chemical structures and coking property was not changed after biodesulfurization. These results suggest that the possibility of clean coke preparation from biodesulfurized coals.

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The removal of hazardous trace elements, such as Hg, Se, and B, from a flue gas desulfurization wastewater obtained from a pulverized coal combustion system was examined. B and Hg were effectively removed from the wastewater (simulated wastewater) by use of a glucamine type chelate resin or fiver. However, Se was hard to remove from the wastewater by using the adsorption method. The removal of Se from the wastewater by use of TiO_2 photocatalytic reduction was also attempted. Se(VI) in the wastewater was reduced to Se(0) and effectively removed from the wastewater.

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Boron is one of the most toxic and high volatile elements present in coal. As part of a series of studies carried out on coal cleaning to prevent environmental problems and to promote efficient coal utilization processes, the removal of boron by leaching with water and acetic acid has been investigated. The effects of the addition of ash components, that is, SiO_2, Al_2O_3 and CaO in the control of boron release during pyrolysis and gasification were investigated. Here, 20-60% of boron in coal was removed by leaching the coal with water and acetic acid. Boron leached by water and acetic acid was related to volatiles released from coal in pryrolysis below 1173K. The addition of ash components such as SiO_2 and Al_2O_3 was found to be effective in suppressing the release of boron during pyrolysis at temperatures below and above 1173K, respectively. The addition of CaO to coal was effective in suppressing the release of boron during gasification at 1173K.

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Boron contained in coal are partly released to the flue gas during combustion. Boron are captured in flue gas cleaning systems and the emissions of these elements are generally low. However, it is important to understand the behavior of boron to improve the reliability of the gas cleaning systems. Though a lot of researches examined the behavior of boron, the behavior of these elements in coal combustion has not been clarified in detail yet. In this research, the release behavior of boron from coal was investigated using a drop tube furnace (DTF). As a result, it is thought that a part of the boron would be absorbed in molten slag during combustion.

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Ash-free coal process based on the organic solvent extraction of a coal has been developed in order to remove ash. This ash-free coal called Hyper Coal (HPC) is expected to include less hazardous heavy metals, such as mercury, arsenic and selenium, by the organic solvent extraction. Therefore, it is important to understand the distribution behavior of these heavy metals in this process. In particular, emission of mercury to the atmosphere in coal combustion processes has been becoming one of the most major sources of human-induced mercury emission. The distribution behavior of mercury in the HPC production was investigated in this study. By measuring the distribution behavior for the four coals with different locality, mercury distribution behavior from the raw coals to the corresponding HPCs was significantly different although mercury concentration values in the HPCs were very similar. In order to make clear the mercury behavior in detail, the mode of occurrence in these coals was investigated by using reported selective leaching procedure.

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The elution behavior and control of hazardous trace elements from coal ash which was produced from the coal fired power plant were investigated. When the leaching test was carried out for seven coal ashes, the elution of As and Hg was not observed. However, the concentrations of B and Se in the leachate frequently exceeded the environmental quality standards for soil pollution in Japan. Also, the elution control of hazardous trace elements was examined. The elution of B and Se from coal ash was effectively inhibited by an acid washing using 0.1M HCl.

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