From the perspective of the matter cycle, a method to use biomass combustion ash as a fertilizer in the production of seedlings and silviculture is suggested. Ash from silica-rich biomass has high solubility due to its silicate microstructure, which makes it very effective as a fertilizer. However, the solubility is lost, along with the porous microstructure, when combustion ash is crystallized in a high temperature oxidative atmosphere. In addition, because the furnace is commonly made of stainless steel that contains chromic element and a high percentage of water is included in biomass, unlike fossil fuel, harmful hexavalent chromium may be found in the combustion ash. In this report, the progress of a study for the reduction of ash crystallization is described.

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The influence of the iron-exchanged zeolite catalysts on the product distribution and gas evolution behavior in the catalytic reforming of bio-oil model compound between 350 and 450 ℃ was examined in this study. The bio-oil model compound was prepared by dissolving 9 species of oxygen-containing reagents into deionized water. Four zeolites, Na-Y, NH_4-Y, Fe-Y1 (prepared from Na-Y), and Fe-Y3 (prepared from NH_4-Y), were used as catalysts in this study. By using zeolite catalysts, the product distribution changed slightly in the reforming of bio-oil model compound at 400 ℃. In the case of reforming by using Fe-Y1 catalysts, the liquid yields decreased with increasing reforming temperature.

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Enokitake (Flammulina velutipes) is one of the most popular cultivated mushrooms in Japan. A huge amount of waste culture is disposed thus its utilization as biomass fuel is needed. Due to high moisture content of waste mushroom culture, drying is necessary prior to use. As an approach for drying, compositing is proposed. A laboratory scale composter is operated. Change in temperature, CO_2 formation, and water evaporation with time was measured during composting. A mathematical model is also proposed to predict the change in temperature and moisture evaporation.

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Japanese cedar bark was pyrolyzed at 350℃ or 500℃ in N_2 with or without H_2O. Solid residues and tars obtained were respectively analyzed using FT-IR and GC-MS for investigating the effect of H_2O. The effect of adding H_2O was remarkable at 500℃: yields of the solid residue decreased largely. FT-IR analyses of the solid residues showed strong peaks derived from benzene and phenolic ethers in all cases. Tars obtained were almost the primary/secondary tars, which were roughly classified in low molecular oxygenates, guiacol/phenol derivatives and phenanthrene hydro type derivatives. The proportions of both low molecular oxygenates and phenanthrene hydro derivatives among tars obtained in the presence of H_2O were higher compared to those obtained in N_2 alone, which suggested H_2O accelerated the decomposition of the primary tars.

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Ni-loaded brown coal catalyst with 20 wt% of Ni content was synthesized, and their reforming property for biomass tar was evaluated at low temperature. The catalyst was prepared with impregnation method followed by heat treatment at various temperatures. Tar reforming testing was performed with a two-stage fixed bed reactor at 400, 500 and 600 ℃. Although tar reforming was promoted by increasing catalyst bed temperature, the performance high enough was obtained at 500 ℃ using the catalyst pretreated at 500 ℃. In addition, drastic performance enhancement was achieved at 400 ℃ by reducing the pretreatment temperature from 650 ℃ to 400 ℃. Transmission electron microscopy reveals that the drastic performance enhancement is attributed to the suppressed growth of Ni on the carbon support.

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This paper reports on the supported-K on gasification rate. Especially, the gasification kinetic rates of herbaceous and woody biomass-derived char have been revealed bymeasuring the rate of weight loss during its reaction with CO_2 as a function of temperature. The experimental results show that the high gasification rate of biomass char is appeared i.e., 2-14 times higher than that of raw-biomass char by directly supported-K.

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A sewage sludge carbonized fuel sample was blended into pulverized bituminous coal and the co-gasification reactivity was discussed in this study. First, the mixed sample was pyrolyzed and the char sample was gasified with steam in a TGA at 800℃. The coal char reactivity was accelerated by the blending sewage sludge carbonized fuel. Alkali metal species should have an influence on the reactivity. Second, the mixed sample was gasified with CO_2 in a PDTF under the high-temperature and elevated-pressure condition which is similar to the conditions in an entrained flow gasifier. The distinguish synergy between coal and sewage sludge carbonized fuel was found in the carbon conversion during co-gasification, although the synergy was not found in the co-gasification of coal and woody biomass.

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Tar decomposition techniques are desired to prevent blockage troubles in biomass gasification processes. In this study, various catalysts were examined to improve the performance of tar decomposition at low oxygen atmosphere. It found that BaZrO_3-based Co or Mn with Ni catalysts were the strongest activity in tar decomposition and syngas generation.

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The coal pyrolysis is the important reaction that has much influence on initial situations in coal combustion and gasification processes. The CPD model is one of the most useful primary pyrolysis models considering coal chemical structures and has been modified to be high accuracy. However, it just described tar as abstract "tar". We extended the CPD model to describe primary tar compositions as actual chemical species. Aromatic nucleus clusters in coal were described as 1 to 3 aromatic rings. Therefore the model can describe the tar as the typical chemical species (benzene, naphthalene, and phenanthrene). As a result, it became possible to calculate the gas phase decomposition behavior by using the gas phase reaction mechanism in existence. CO_2, H_2O and O_2 gasification experiments were simulated by combining the extended CPD model, the gas phase reaction mechanism and char gasification models.

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From the viewpoint of effective utilization of carbon resources in waste materials, carbonizing technology process system has been implemented. In this study, we investigated carbonization of waste woody biomass and its char used as solid fuel. The waste woody biomass was loading to alkali metal as NaOH, using the thermogravimetry with a differential thermal analyzer (TG-DTA), while combustion experiment was carried out on char by the model combustor. On the other hand, combustion exhaust gases of char also evaluated. As a result, the Na loading has improved the combustion properties of char. However, we need to examine for incomplete combustion due to the ash increment.

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In coal-fired power plant, hydrogen sulphide (H_2S) concentration in boiler has a tendency to become higher owing to low-NO_x combustion, sulfide corrosion of boiler tube hence becomes a severe problem. In this study, numerical model, which is to evaluate H_2S behavior in pulverized coal combustion, was developed. Sulfur behavior was experimentally investigated by using the drop tube furnace (DTF). Results show that sulfur is mainly released as H_2S irrespective of coal property and pyrolysis temperature, and devolatilization rate of sulfur depends on the rate of the form of sulfur in coal, namely, organic sulfur, pyritic sulfur and sulfate sulfur. Therefore, H_2S devolatilization model was developed using the form of sulfur as input parameters. Gaseous reaction model and gas-solid reaction models were also developed and these models were introduced into the numerical simulation code. Furthermore, numerical simulation was performed for the coal combustion test furnace. Results show that the calculated profile of H_2S is qualitatively in good agreement with the experimental result, and the difference of H_2S behavior caused by the difference of coal property can be numerically predicted.

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Chlorine release from two coal chars during CO_2 gasification at 1000・C has been examined with a fixed-bed quartz reactor. The Cl present in char is evolved as water-soluble and water-insoluble Cl-species, regardless of the type of char, and about 15-60 % of the former Cl-species exists in HCl form. Most of the water-soluble groups can be released before char conversion reaches 50 wt%, whereas the evolution of the water-insoluble groups proceeds more remarkably at the latter stage of the gasification. Chlorine conversion increases with increasing char conversion, and there is an almost 1:1 linear relationship between the two under the conditions applied.

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The purpose of this study is to analyze introduction scenarios of low-grade coal and an optimal fuel mix in the power generation sector in Japan considering the uncertainty of the fossil costs in the future. For that purpose, the authors develop an optimal power mixture model with technical data of low-grade coal. Authors obtained the following result. In order to introduce the low-grade coal in 2020, it is necessary to be dried before shipping to Japan, and to lighten shipping fee. Efficiency and initial cost of each dry method are not dominant factors for introduction of low-grade coal.

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The coal flow depends on the railways and coastal shipping because the energy producing and consuming regions are geographically distinct in China. The aim of this study is to quantify the interregional coal flows and to estimate the amount of the CO_2 emissions from coal transportation regionally including a case-study with introducing the advanced coal-fired power generation technology. We have designed the distribution map of the coal power plants and coal field area, and the coal transportation network using Geographic Information System (GIS). The transport cost optimization explains that coal flows from North area to South area, and the CO_2 emissions from coal transportation in coastal area is more than three times that in coal-mining area.

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The oil industry has been grappling with this issue to solve the problem on a heavy oil surplus. Gasification is one of the promising technologies for this issue. Gasification products can be used for electric power generation and chemical production. The purpose of this study is the evaluation of the energy production in the process of the heavy oil gasification system for hydrogen and power production. The analysis of thermal efficiency shows 45-58% at hydrogen production and 37-49% at power production. Vacuum residue is most superior at thermal efficiency in the heavy oils.

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We proposed a new type of fossil fired power generation plant which combines oxy-fuel combustion IGCC with a biomass combustion boiler. To analyze the thermal efficiency of the hybrid plant we used a new method which allocates turbine power output by exergy. The net efficiency of the hybrid plant was 35.7 % which is higher than 32.3% of the conventional IGCC with carbon capture (CC). According to the exergy analysis, corresponding efficiency contributed by biomass was estimated 43.3 %. The study also analyzed the generating costs of both plants, generating cost of the hybrid plant was estimated 13.46 \/kWh while conventional IGCC with CC was 14.1 \/kWh.

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Coal contains various hazardous trace elements. For these hazardous elements, especially volatile elements, such as Hg is in great concern, because those elements are likely to be released into air when coal is burned. In this study, we examined the determination of trace elements in coal by use of microwave-acid digestion (MW-AD) followed by inductively coupled plasma mass spectrometry (ICP-MS) or inductively coupled plasma atomic emission spectrometry (ICP-AES), and the effect of MW-AD condition upon the recovery of trace elements was investigated. In addition, the concentration of Hg in coal was measured by use of heat-vapor atomic absorption spectrometry (HVAAS).

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To regenerate the flue gas desulfurization ( FGD ) gypsum produced from coal fired power plant, change in chemical form of calcium and release behavior of mercury were investigated with the addition of carbon. The release behavior of mercury from FGD gypsum generated from a commercial plant was compared to that from model compounds prepared from chemical reagents. It was observed that FGD gypsum contained 0.7 ppmw of mercury and its release behavior was similar to that of HgO. When gypsum was converted to CaO by carbon reduction, release of mercury was accelerated at temperature range from 250 to 300 oC. HgO in FGD gypsum was reduced by carbon and converted to high volatile elemental mercury. It can be concluded that mercury compounds are easily removed in the regeneration process of FGD gypsum by carbon reduction.

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In recent years, protections of environmental pollution and global warming are most important issues to discuss the world energy use. Efficient and clean use of fossil energy resources in the world has been increasing in importance. Coal is produced all over the world also, and it amount of reserves is larger than any other fossil fuels (oil, natural gas, etc.). Consequently, IGFC (Integrated gasification fuel cell combined cycle) has been attracting attention as one of efficient coal utilization. However, trace elements in coal are emitted to coal syn-gas in vapor phase, and affect fuel cell electrodes to deteriorate their performances. In this study, we assess the effect of trace element in syn-gas on SOFC power generation. We have tested a button cell in 900℃ for about 20 hours with simulated gas doped vapor As and Se.

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In order to provide practical knowledge in operating soot-blowers without ash related problems, a series of slagging tests has been conducted at 1.5 MWth pilot plant having a test probe simulating the water-wall. The heat flux through the test probe drops dramatically at the initial stage of ash deposition. In our study, initial heat flux (qo), this heat flux decreasing rate, and the heat flux at which decreasing behavior switches to a gradual decrease (qt) are parameters used to predict the soot-blowing timing. A simple equation is obtained for predicting the soot blowing timing and discussion is made on the derivation of the equation.

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LTA, FAU and MFI zeolite membranes were successfully synthesized form coal fly ash by hydrothermal treatment onto 10-cm-long tubular porous α-alumina supports. The membranes were characterized from XRD analysis, SEM observation and the pervaporation performance. Under the optimized conditions, zeolite membranes from coal fly ash showed fairly efficient for the pervaporation separation of organic liquids.

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Our previous studies clarified that the thermal-hydrogenation processing of low rank coal results the elemental composition of reforming coal proceeds to the apparent area corresponding to the bituminous coal through dehydration, decarboxylation and methane removal reactions. Also the H / C and O/C change depending on the reaction conditions of coal reforming was revealed. In this study, along with morphological analysis by optical microscopy and chemical structure analysis by 13C-NMR, reforming coal obtained was evaluated by tests of coking by small test coke oven.

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Thermal-hydrogenation of brown coal was carried out in a hydrogen-donor solvent by using a 50ml batch-type autoclave, and the reformed coal (>500℃) was obtained by vacuum distillation. Coking tests of the reformed coals was performed at 1000℃ for 30min under a N_2 atmosphere, and the products (cokes) were observed by a polarization-microscope. The pictures clearly showed that optically anisotropic textures well developed in the cokes derived from the reformed coals produced at 410℃ for 60 〜 180 min, which indicated that the reformed brown coals could be used as a substitute of coking coal.

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We participate in Japanese national project called COURSE50,in which we aim to apply HPC as a caking additive to make high strength coke for the blast furnace, which maximize the use of hydrogen as a reductant, in order to minimize carbon addition to the furnace. We aim to be able to produce a high-strength coke over 88 of drum index (DI^<150>_<15>) sing the HPC as caking additive and improve bulk density is obtained. In this study,we examined the effect of particle size of coal to the coke strength. Coke strength was strongly increased to nearly 90 of drum index by grain refining of coal, which had enough caking properties. On the other hand, the coke strength decreased by grain refining of coal, which had poor caking properties. It was understood that HPC affected to give suitable caking properties to achive more than 90 of DI even though the base coal blend had poor caking properties.

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Compared with the conventional techniques, high temperature proton NMR relaxation measurement enable to monitor the actual changes in progress of thermal transformation. The quantitative change of specimens can be evaluated by recording the hydrogen content of residual specimens, and qualitative variation of the specimen is able to detect as a change of the relaxation characteristics of signal. In this study, thermoplastic properties of coal, coal blend and coal blend with "High Performance Coking additive, HPC" are investigated by means of proton NMR relaxation measurement from the viewpoints of molecular mobility. The solid echo pulse sequence was employed to generate ^1H-NMR transverse relaxation signals. The echo signals obtained during heat treatment under a flow of nitrogen at a heating rate of 3K/min were deconvoluted into a set of one Gaussian and two Exponential decay components which represent the immobile, intermediate and mobile component, respectively. It is demonstrated that ^1H-NMR relaxation measurement is the appropriate dynamic measurement technique to characterize the thermoplastic properties of coal. Thermoplastic phenomenon of coal is evaluated both qualitatively and quantitatively by the variation of IHm and T2Hm. HPC is effective additive to improve the thermoplasticity of coal blend. The improvement of the thermoplasitic phenomenon of coal blend with HPC is attributed to the quantitative and qualitative change of Hm.

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Steel industries need to increase the use of low-grade coals in coke making due to the recent rapid increase in coking coal price. To do so, it is necessary to effectively use binders, and it is desired to develop a theory on how to mix coals and binders effectively. In this work the coal fractionation method proposed by the authors was applied to characterize coals and binders. Nine different-rank coals and two binders (HPC developed by Kobe Steel and ASP) that were heat-treated at 400℃ in advance were separated into three fractions having different molecular weight by solvent extraction at 350℃. The chemical and physical properties of each fraction were found to be almost independent of the coal and binder types. Based on the results, it was clarified that the thermoplastic behaviors of the mixture of several coals and binders and the strength of their resulting coke can be correlated to the relative abundance of the fractions in the mixture. It is therefore possible to determine an appropriate mixing ratio of coals and binders to obtain high-strength coke. This approach can be expected as a new mixing theory which is applicable even to the low-grade coals that have not been used and newly-developed binders.

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We have recently proposed a novel upgrading method of low-rank coals that treats the coal in non-polar solvent such as 1-methylnaphthalene at around 350℃. This treatment successfully produced the upgraded coal which was dewatered and had a large amount of low-molecular-weight compounds whose elemental compositions were comparable to that of bituminous coal. In this study, we examined the possibility of the upgraded coal as a raw material in coke making process. Coal-derived solvents such as carbolic oil, crude methylnaphthalene oil and anthracene oil were used to upgrade a brown coal from the viewpoint of practical application. It was suggested the upgraded brown coals can be substitutes of some slightly-coking coals in coke making process.

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Coke oven diagnosis and repairing system with high speed and high accuracy (DOC) was developed by Nippon Steel Corporation(NSC). And DOC system was already installed to all of the steel works of NSC. Furthermore the rebuilding technology of coke oven has been studied to achieve the environmental enhancement and energy-saving. And new rebuilding technology was applied to Muroran No.5 East coke oven battery as the second case in NSC. In this paper development of coke oven repairing technologies were discussed.

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In coke oven battery, some coke chambers are changed their operation schedule because of repairing. Therefore, it is thought that these coke chambers will affect heat transfer behavior of neighbor combustion flues or coke chambers. In this study, for the purpose of the stable operation of coke oven battery, we developed 1-dimensional mathematical model and numerically investigated the influence of above coke chamber on carbonization behaviour of neighbor coke chambers and combustion flues.

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Utilization of low rank coal for iron making in a blast furnace is very difficult due to the structure of coal. We tried to coke low rank coal using oil-sand bitumen or hyper-coal(HPC) as a binder, and evaluated the obtained coak by several methods including Raman spectroscopy. In this work we evaluated the strength/structure of coak prepared from blended coal with/without a binder. Experimental results revealed that the utilization of HPC as a binder could be an effective way to coak the blended coal to obtain better performance

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In this study, we have investigated the oxidation properties of a brown coal at low temperature under humid atmosphere. Dried brown coal samples of approximately 0.78 g were enclosed in IL of aluminum coated Tedlar bag with water of 0.22 g and pseudo-air consisting of 21 % O_2/He. Then it was heated in a drying oven between 60 and 90 ℃. Gas sampling and analysis by gas chromatography and mass spectroscopy were took place. We have found that the water vapor significantly promote the oxidation of brown coal. The mass spectroscopic investigation with stable isotopes including ^<18>O_2 and H_2^<18>O reveals that the water vapor reacts predominantly with brown coal surfaces. Then the removal of hydrogen (proton) from the complex by oxygen to form water vapor and the evolution of CO_2 from the coal surface occur simultaneously, resulting in promotion of low temperature oxidation. Those findings will help to understand the self-combustion phenomena of brown coal.

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In this study, we developed a low temperature chicken manure ashing and carbonization process. Feature of this process is reforming of tar produced through low temperature ashing and carbonization by Ni based catalyst installed in the furnace. High calorie gas produced by the tar reforming is burned out and then the exhausted hot gas is utilized as heat source of the furnace. We installed a plant with the capacity of 1 ton/day at poultry farmers and demonstrated continuous operation at 600 ℃ for 100h without fatal trouble. Ash and carbonaceous material obtained through the process has suitable properties as a fertilizer.

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We produced an activated carbon with large specific surface area from the lignin mixed with urea or melamine by chemical activation using potassium carbonate. The influences of carbonization temperature on the pore structures such as specific surface area and pore volume were investigated. It was found that the mixing with urea or melamine was effective to enlarge the specific surface area. At the carbonization temperature of 1073 K, the specific surface area of the produced activated carbon became the maximum value. The activated carbon from the lignin mixed with melamine had the larger mesopore volume and the sharper micropore size distribution.

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