This paper describes the current trend concerning energy and environmental problems in Japan and the world. The focus will be put on fossil, nuclear and renewable energies as well as the global warming problem. Several proposals will be made based on the analysis of these trends.

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The objective of this study was to formulate a new methodology for the preparation of input files for pyrolysis models that is based on an Artificial Neural Network (ANN) approach. Data obtained on a set of 46 diverse samples indicate that Artificial Neural Network models can be successfully used to generate pyrolysis-model input parameters for samples with an unknown pyrolysis behavior. The results look promising and further study of this approach is needed.

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Pitch coke, pitch and carbon black are carbon products of coal tar origin. These materials were developed in old days and have been treated as old-fashioned. Recently, on behalf of the development of industrial technologies and customers requests, these materials have been improved. As a keynote lecture, the technical trend of carbon products of coal tar origin is discussed.

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At present, coke ovens in Japan have 34 years in average working life. Thus, the lives of most coke oven batteries should come to an end soon. It is thus anticipated that if the coke oven batteries are not replaced, the amount of coke would become short. Coke oven operation has various disadvantages, such as the restriction on the coal brands that a strongly-coking coal has to be used as a raw coal for coke-making, low productivity, the inherent tendency for much energy to be consumed, environmental pollution and so on. In this paper, Research & Development of new cokemaking process were discussed.

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To develop an efficient cleaning process of hydrocarbon resources, an ionic liquid 1,3-dimethyl imidazolium methyl sulfate was used for removal of organic sulfur from coal extract. The coal extract was prepared from Illinois No.6 with tetralin under pressurized conditions. The desulfurization extent of organic sulfur increased linearly with increasing of mass ratio of ionic liquid to coal extract. Organic sulfur of 40 % could be removed from the coal extract at the ratio of ionic liquid to coal extract of 5.0.

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Two lignites and two sub-bituminous coals were treated by hot water extraction (HWE) and hydrothermal treatment (HTT), and the simulated effluents were obtained. The ecotoxicological impacts of these effluents were evaluated by use of acute and chronic toxicity test against some freshwater organisms and Ames mutagenicity test. The effluents from the HWE and HTT did not show any notable mutagenicity. However, an appreciable degree of mutagenicity after chlorination was observed for these effluents. The effluents from HTT indicated a considerable acute and chronic toxicity for freshwater organisms. From the FTIR and GPC analysis of the organic matters eluted in the HWE and HTT effluent, it is found that the toxicity of HWE effluents is caused by the presence of high molecular weight aromatic compounds with hydrophilic substituents.

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We attempt to prepare heavy metal adsorbent from coal with a simple-two step process using rapid pyrolysis and sulfur impregnation. Porous carbon material with high specific surface area can be obtained by rapid pyrolysis using free-fall reactor, and can added sulfur into rapid pyrolysis char using H_2S gas. The sulfur impregnated char was more effective for Pb, Cd and Zn adsorption than raw coal and rapid pyrolysis char, and its adsorption capacity was favorable to commercial charcoal.

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Hyper-coal (HPC) is produced by coal extraction and solid-liquid separation treatment. Ash content of HPC is almost negligible and it has high heat value and excellent thermal plasticity. Because of the excellent characteristics, various applications of HPC are proposed. The 0.1t/d (dry and ash free feed coal basis) Bench Scale Unit (BSU) has been operated for demonstration and optimization of HPC process, and samples for application studies have been produced. The insoluble residiue-coal (RC) was separated by the double settling system and the operation conditions (coal concentration, overflow/underflow ratio of settling, etc.) were improved for high HPC yield. As a result, 96.5% of produced HPC was recovered, and then 60.5wt% of HPC yield (feed coal daf basis) was obtained.

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We have recently presented a new coal fractionation method that can separate a bituminous coal into several fractions having different molecular masses without decomposing the coal. The method extracts coal with a non-polar solvent such as tetralin or 1-methylnaphthalene by increasing the extraction temperature stepwise up to 350℃. In this study the fractionation method was applied to characterize two kinds of Hypercoals (HPC's) obtained under different heating profiles from the same coal. It was clarified that the HPC which gave a coke of higher strength contained a larger amount of the fractions which melts at around 400℃ than the other one. The changes occurred in preparing these HPC's were also discussed by comparing the results of fractionation of the raw coal with those of HPC's.

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Chemical structure analysis of coals is very difficult because of mixture components. But recent solid state NMR has great possibility to analyze chemical structure because of progress of pulse techniques. We have studied quantitative analysis using new pulse sequence and clarified the strength of cokes from the view points of Chemical structural analysis for Coals using solid state NMR These recent solid state NMR techniques are very powerful and useful in order to clarify both the chemical structure and functions of coals.

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HyperCoal is produced from various ranks of coals, and the extraction yield is determined by the coal rank used and its extraction condition such as the type of solvent and extraction temperature. Some application technologies are being investigated; for example additives for cokemaking and fuel for low-temperature catalytic gasification. Properties of HyperCoals produced from various extraction conditions are discussed.

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Solvent-free hydrogenation of HPC, which is ashless coal made by solvent extraction without hydrogen, was investigated. It was found that hydrogenation of HPC proceeded quickly in the initial stage of hydrogenation, then slowed down along with decrease in hydrogen pressure. Sufficient hydrogen supply made the conversion rate enhanced up to 89%.

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Hyper-coal (HPC), which is produced by solvent extraction of coal, has advantages of extremely low ash content and high fluidity upon melting, but exhibits relatively poor carbonization yield and vigorous foaming during carbonization. In this study, HPCs prepared from bituminous coals were further treated by solvent fractionation, and the carbonization properties of the fractions were elucidated. It was demonstrated that eliminating 20-50wt% soluble components from HPC was appropriate to obtain dense carbon material from HPC.

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We have previously proposed a coal fractionation which utilizes sequential thermal extraction below at 350℃. In this study we applied the fractionation method to an Australian brown coal, Loy Yang (LY), to examine the validity of the method for fractionating brown coal. By the fractionation method using 1-MN, tetralin, and water as the extraction solvent, LY coal was fractionated into 5 fractions: one solvent soluble fraction at room temperature, 3 extract fractions recovered as solids, and the residue. The total extraction yields using 1-MN, tetralin, and water were 47, 57, and 56%, respectively. All the solid extracts recovered, interestingly, softened and melted below 230℃. The solid extracts obtained using tetralin and water were further separated into 4 constituents, through a sequential solvent extraction, which have different softening and melting behaviours.

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Seven brown coals were extracted by water at less than 350℃ and its extracts are subsequently gasified at near extraction temperature using a novel Ni/Carbon catalyst. Extraction yields of 7 brown coals used ranged from 40 to 70 wt% at 350℃. The reactivity with the oxygen of the treated coal was less than that of the parent coal. The extraction-gasification experiment was actually performed by connecting the catalytic reactor in series just after the extractor. The LY coal was actually converted to the treated coal and the product gas, the mixture of CH_4, H_2, and CO_2, indicating that the proposed process can be realized.

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We have previously presented a new coal extraction method which brings coal into contact with a flowing stream of non-polar solvent such as tetralin or 1-methylnaphthalene under 10 MPa at 350℃. Furthermore, we presented a new coal fractionation method based on the extraction method and showed that bituminous coals could be separated into several fractions having different molecular mass. In this study the fractionation method was applied to fractionate four kinds of coals including lower grade coals in order to develop an effective utilization method of them. Tetralin and 1-methylnaphthalene were used as the solvent, and the effect of the solvent type was discussed. It was found that tetralin extraction made a very slight change on coal structure by hydrogenation and gave a higher extraction yield, especially for lower grade coals. Since the slight change contributed to the enhancement of fusibility of coal fractions, the extraction using tetralin at lower than 350℃ can be an efficient mild conversion process of low grade coals.

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We have shown phase diagram in nanopores by molecular simulations, and thermodynamically predicted the results with no adjustable parameter. With this success whole LJ phase diagrams can be predictable. These results implied the modified Kelvin diameter and the Gibbs-Thomson diameter are not able to apply for micropores and nanopores of coal.

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Solvent swelling of coals has been studied for decades to understand coal crosslinking and pore structures, and coal-solvent interaction, and also to develop new coal conversion processes including preswelling. Here, several topics of coal swelling, i.e., swelling mechanism, anisotropy in swelling, and swelling of solvent-soluble component are reviewed.

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In order to characterize cross-linked macromolecular network structure of coal a series of solvent swelling experiment using not only coal but also synthetic model polymers has been conducted by using specially designed handmade apparatus which has a capability to determine the swelling rate (V) besides the equilibrium swelling ratio(Q), with reasonable accuracy, it was found that the rate of swelling has been reflected more sensitively on the such macromolecular network structure of coal as covalent cross-linking, non-bonding interaction based on oxygen-atom functionality. Several useful swelling index have been introduced for the practical use.

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Solvent extraction is a promising technology for removing ash from coal. The resultant coal extract (Hypercoal) usually has ash content around 0.1wt% or less. Among the eluted metals, Fe is the most prevalent, having a mass percentage &ge; 50%. Coal rank and solvent polarity affect little. This highlights the importance for studying the structures of Fe, especially organic-Fe complexes in coal extract and the raw coal as well. In this paper, a novel technique, electron spin resonance (ESR) spectroscopy was employed for direct measurement of Fe. The results indicate that, a few amount of metals in a coal are even insoluble in HNO_3 (2 M) or HF (48%), among which, Fe is the most prevalent. It has two major configurations as detected by ESR at liquid-nitrogen temperature (77K): high-spin Fe3* oxidation state in which Fe is coordinated by an octahedron of oxygen in a rhombic asymmetry, and high/low-spin Fe^<3+> porphyrin in which Fe is coordinated by tetrapyrrolic nitrogen. Due to their highly organic affinity, these species are inevitably eluted during coal extraction, which are also detected in coal extract.

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Brown coal has many oxygen-containing functional groups such as carboxyl groups and it is ion-exchangeable with metal. We prepared Ni ion-exchanged brown coal with mixture of swine wastewater and waste liquid from electroless nickel plating, and examined the activity for tar decomposition.

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In this study, the influence of experimental conditions (reaction time, solution pH, initial concentration of metallic ion) on ion-exchange properties of Pb^<2+> and Cd^<2+> by an Australian brown coal was investigated. In order to change the cation-exchange properties, brown coal was heated up to 300℃ and the behavior of the cation exchange was also examined. In all samples, the adsorbed amount of metallic ions increased with contact time, after 60 min the amount of M^<2+> adsorbed reached an equilibrium. Moreover, the amount of M^<2+> adsorbed increased with increasing solution pH and initial concentration of M^<2+>. The maximum adsorbed amount of Pb^<2+> and Cd^<2+> from the aqueous solutions at pH 6 was 1.5 and 0.7 mmol/g, respectively. The amount of carboxyl groups in the brown coal decreased by heat-treatment. In the cation-exchange experiment from the solution containing Pb^<2+>, Cd^<2+> and so on, the heat-treated brown coal adsorbed Pb^<2+> preferentially.

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It is important to obtain not only organic but also inorganic matter (minerals) in raw coal for effective coal utilization and examination of geological processes. Nuclear Magnetic Resonance (NMR), a very useful technique for evaluating short- and medium-range structure of each nuclide, has been applied to structural analysis of inorganic matter in this study. We successfully identify Al-containing minerals (kaolin, montmorillonite, muscovite and alumina) by high-magnetic field (16.4 T)^<27> Al MQMAS NMR, which enables to obtain high-resolution spectra for half-integer quadrupolar nuclides, and categorize coal samples into five groups based on total Si and Al contents in raw coal. In addition, the relationship between mineral types and chemical composition of organic matter has been discussed.

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In order to characterize gas generation behavior of plastics, a monitoring system using Fourier transform-infrared spectrometer (FT-IR) has been applied. This system can monitor continuously and simply the several kinds of gases, such as hydrocarbons, CO and CO_2. Using this system, the influences of pyrolysis conditions on gasification of plastics were investigated. In the case of pyrolysis in hydrogen atmosphere, the amounts of gas from polyethylene were increased to about 95%.

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The Upgraded Brown Coal (UBC) process is a new technology to convert low rank coal into transportable solid fuel with higher calorific value without trouble of spontaneous combustion. A pilot plant with a capacity of 3 ton/day had been constructed on Java Island in Indonesia and operated to acquire data for feasibility study. Stable continuous operation of the plant had been demonstrated using Indonesian low rank coal. The spontaneous combustion of the UBC product is suppressed compared with bituminous coal. Based on the results of the operation, a demonstration plant with a capacity of 600 ton/day is currently being constructed on Kalimantan Island in Indonesia. The operation of the demonstration plant will begin in 2008.

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Synthetic fuels derived from coal, natural gas, biomass and so on receive broad attention under the circumstances that oil prices are hovering at a high level. The objectives of this report are to clarify how synthetic liquid fuels derived from the natural resources like coal, natural gas, and biomass will be introduced to Japanese market under several scenarios and what conditions will simulate the introduction of coal-derived liquid fuels. Our evaluation model was used to simulate the trend of the synthetic fuels toward 2050, planning the scenarios on energy prices, world's supply of crude oil, and global environment.

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Effect of alkaline earth metals on the decomposition of 2000 ppm NH_3 in a syngas-rich fiiel gas (50 % CO/25 % H_2/5 % CO_2/3 % H_2O) with an Australian a-FeOOH-rich limonite has been studied with a vertical, cylindrical flow-type quartz reactor under the conditions of 0.1 MPa, 750℃ and 45000 h^<-1>. Mg cations added to the limonite, at a low loading of 3 mass% Mg, suppress the deposition of carbon by the disproportionation of CO in the syngas apparently, and the Mg-added limonite catalyst achieves the almost complete decomposition of NH_3 in this atmosphere to N_2 and maintains the high performance for about 15 h. These observations suggest that the Mg-added limonite is a promising catalyst material for NH_3 decomposition.

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Two coals with different content of calcium were blended and combusted using a drop tube furnace in air at 1450℃. Emission properties of PM_<10> were studied. A random Coalescence-fragmentation Model was developed to simulate the size distributions and chemical compositions of PM generated during the combustion of both single and blended coals. The results show that samples with higher content of calcium and iron release lower amount of PM_<10>. For the case of coal blend of 40/60 with about 22wt% of calcium and iron, about half amount of PM_<10> is reduced. Meanwhile, the simulated results of particle size and chemical forms of PM show good agreement with their experimental data. These results indicate that the high amount of calcium and iron in raw samples improve the viscosity of particles and then promote the coalescence of fine Al-Si(<10 μm ) with Ca or Fe-bearings to form larger Ca-AI-Si or Ca-Fe-Al-Si, and therefore the emissions of PM_<10> is reduced.

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Carbonization and activation behavior was examined to recycle waste wood as carbon resources. The technique to predict specific surface area from carbonization and activation yield of waste phenolic resin, rice husk and waste wood was established. Furthermore, carbonization and activation was performed after having impregnated calcium hydroxide in waste wood. Carbonization and activation material from calcium addition waste wood adsorbed phosphoric acid ion in solution with high performance.

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To develop an efficient recovery process of zinc from various secondary resources, release behavior of zinc from dusts and etfect of coexisting elements on carbon reduction were investigated with the addition of Prima coal as a reducing agent Change in zinc form in the dusts with temperature was clarified by a sequential leaching analysis. Two kinds of zinc dust were used which contained ZnO and ZnFe_2O_4 as major zinc components, respectively. The release extents of zinc for dusts were higher than that for ZnO reagent and achieved to 99% at 1273 K. Formation of iron compounds was observed for dust A from 1073 K. Volatilization of zinc was accelerated by FeO and Fe above 1173 K. The release of zinc from dust B was affected by coexisting chloride, fluoride, and lead in the sample.

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Release behavior of mercury was investigated during pyrolysis of coals in the temperature range from 200 to 900℃. Soluble forms of mercury in coal were classified into two fractions by using distilled water and HNO_3 solution. The H_2O soluble of mercury was released at the temperature lower than 300℃, while the HNO_3 soluble of mercury was released in the temperature range from 300℃ to 900℃.

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A simple and precise method was developed for the determination of mercury (Hg) in coal, coal fly ash (CFA), waste incineration ash (WIA), and soil by use of oxygen flask combustion (OFC) followed by cold vapor atomic fluorescence spectrometry (CVAFS). A KMnO_4 solution was used as an absorbent, and a bag oblate was used as a wrapping material in the OFC method. The Hg-free graphite, which had been prepared by use of a mild pyrolysis procedure at 500℃, was used as the combustion agent, and the determination of Hg in ash and soil was successfully carried out. For twelve certified reference materials (six coals, three CFA samples, and three soil samples), the Hg contents obtained by this method were in good accordance with the certified or reference values. In addition, real samples including nine brands of Japanese standard coals (SS coals), nine CFAs collected from some coal-fired power plants, five WIAs collected from waste incineration plants, and two soils were analyzed by the present method, and the data were compared to those from the authentic microwave-acid digestion (MW-AD) method.

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Hg^0 vapor is one of the toxic substances derived from gasification and combustion of coal. Previously we have suggested that Hg^0 vapor can be removed as HgS(s) over iron based sorbents in the presence of H_2S and the Effect of HCl depended on the type of iron-based sorbents. In this study, we investigated the decomposition characteristic of mercury reagents grade compounds and mercury species on the sorbents using TPD -Mass method. From the TPD of reagent mercury compounds in He flow, the order of stability of mercury compounds upon heating was obtained as follows: HgSO_4>HgS(red)>HgO>HgS(black)>Hg_2Cl_2&ap;HgCl_2. From the experiments, it seemed that a very similar mercury species is formed over the Fe-based sorbnets both in presence and absence of HCl as HgS. However, the mercury species over the activated carbon (Flue gas deHg sorbent) could not be identified.

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Effect of addition of chlorine containing compounds to coal combustion environment on mercury speciation was investigated by a drop tube furnace. Mercury oxidation rate in 390℃ was found to increase with increasing HCl concentration in gas phase. Because mercury oxidation rate was different for different kind of coal, the heterogeneous reaction on the coal ash and/or unburned carbon particles may be important. At lower temperature (250℃), the amount of mercury adsorbed by the unburned carbon was confirmed to increase as the unburned carbon amount in ash increased

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Mercury speciation over the V_2O_5/TiO_2 based commercial catalyst was investigated. The mercury oxidation rate was found to decrease by increasing NH_3/NO ratio, suggesting that the presence of NH_3 inhibits the Hg oxidation. Behavior of both NO reduction rate and Hg oxidation rate over the catalyst can be explained well by assuming the competitive adsorption of HCl and NH_3 for surface active site. The change of Hg oxidation activity for a long term operation was also examined.

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Partitioning of mercury in fly ashes having particle size distribution and its leaching characteristics were investigated for five different coals to estimate and to control mercury leaching rate in pulverized coal combustion processes. The fly ashes were sieved in seven classifications, and Hg content in the sieved ash was measured a direct determination by GF-AAS. It is found that mercury concentration in the classified is increased with increasing the average particle diameter, hi leaching tests, fly ash particles below 10 μm and above 106 μm were indicated high leaching rate of mercury. To reduce Hg emission, it is effective that large particle size fly ashes containing unburnt carbon and PM10 are decreased by size control of pulverized coal and combustion control.

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Ash-free coal production process has been developed, based on organic solvent extraction of the coal. This ash-free coal, called Hyper-coal (HPC), is expected to be separated from hazardous heavy metals as well as ash contents. Therefore it was important to understand the distribution behavior of heavy metals, such as mercury, arsenic and selenium, in this process. In particular, arsenic and selenium is easier to react with organic matter than mercury and other heavy metals. Then distribution behavior of arsenic in ash-free coal process was investigated in this study. Coal, HPC and various intermediate products sampled from HPC production process were dissolved by fusion method. Arsenic in them were analyzed by HG/ICP/AES (Hydride Generation Inductively Coupled Plasma-Atomic Emission Spectrometry). As the result, arsenic mass balance between input and output was successfully estimated with an accuracy of 10%. Arsenic concentration of HPC drastically decreased as compared with raw coal. From the correlation between distribution of ash and arsenic, it was considered that arsenic was dominantly bonded with the inorganic compound.

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In a series of studies on coal cleaning, the present study was carried out to clarify the release behavior of boron during pyrolysis and gasification and to find an optimum condition for controlled release with some additives. Dependency of boron release on temperature was characterized by two parts, low ( < 1173 K ) and high ( > 1173 K ) temperature range in pyrolysis of coals. Appreciable release of boron was not observed during gasification except for Ebenezer coal. The addition of SiO_2 and CaO was very effective for suppressing the boron release at the pyrolysis below 1173 K and gasification. Al_2O_3 was also effective for the release control of boron in the pyrolysis at 1473 K.

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We attempt to convert incinerated ashes into zeolitic materials using alkali fusion method. Three different types of the ash, coal fly ash (CFA), paper sludge fly ash (PSFA) and industrial waste incinerated fly ash (IWIFA), were used for zeolitic conversion. With increasing the Ca content of the ash, Si concentration decreases in the solution, and the main product phases changed from zeolite (aluminosilicate) to hydrograssular (calcium aluminosilicate), finally to calcite. The Ca content in the ash is important to convert the ash into functional zeolite by alkali fusion.

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