This paper shows a case of Rio Tinto dealing with Clean Coal Technologies, as a global resource corporation. The company supplies coals, other fuel and raw materials with various customers located in Asia and Pacific region significantly. As such a fuel and raw material provider, Rio Tinto deals with various projects of CCT and its own initiatives, challenging the global warming issue.

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Related to recent price rise of fossil fuel and progress of global warming, the following outlines are introduced: (1) current situation and future outlook of demand for energy supply, (2) latest technological development trends of environmental clean coal technology (CCT) and carbon dioxide capture and storage (CCS)

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Coal fired power engineering is a major power generation technology. For the security of fuel supply and the control of global warming, it is very important to develop the new technology of fuel diversification and the control of CO_2 emission. In this paper, some new technologies for these purposes on pulverized coal combustion boiler are discussed.

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Coal is the main production and consumption energy in China. Recently, with the shortage in oil and the increasing oil price, more attentions are paid in coal to liquid technology. This report is to introduce current energy status, especially coal reserve and properties, and the research and development in coal to liquid technologies and projects in China.

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Chemical structure analysis of brown coals is very difficult because of mixture components. But multi nuclear solid state NMR has great possiblity to analyze chemical structure since multi apporoach can apply using individual nuclei. Total multi nuclear solid state NMR is very powerful and useful in order to clarify the chemical structure of brown coals.

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Pulse ^1H-NMR spectroscopy was used with the aim to study the phase state of methane absorbed in coal. Spin-spin relaxation time, T2, was employed to evaluate the condition of methane. The signal of methane introduced into coal sample consist of at least three components, that is, relatively slowly decaying component, L1, intermediate component, L2, and rapidly decaying component, L3. The T2 for L1 component shows almost the same value for gaseous methane. This imply that the L1 component arise from the gaseous methane existing in a gap of coal particles. The T2 value for L2 and L3 component is shorter than that for L1 components suggesting the effects of spin-spin interaction, while the relaxation mechanism of gaseous methane mainly affected with spin-rotation interactions. The results indicate that the methane in L2 and L3 component exists in a dense or restrained condition result not only from the adsorption of methane on the surface of coal but also from solid solution in coal.

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Effect of organic solvents and additives on coal swelling, i.e., correlation of some solvent properties such as basicity, solubility parameter, and steric bulkiness to swelling rates and degrees, and effectiveness of mixed solvents and some strong hydrogen bond breaking additives for coal swelling are reviewed.

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Several fractions contained in two kinds of bitumens mined by open-cut and SAGD methods were analyzed in detail, using ^1H-NMR, ^<13>C-NMR, and GPC, to examine the effect of mining method on the molecular structure of asphaltene, which is the heaviest fraction in bitumen. Also, the results were compared with that for vacuum residue obtained from a conventional petroleum oil. The asphaltene of SAGD mining contained a smaller amount of inorganic matter and had smaller condensed rings than that of open-cut mining. The asphaltene in bitumens had higher average molecular weight, lower aromaticity, greater number of unit structure, and higher polarity than that in the petroleum oil.

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Since not only the polar characteristics, but also the mobility of macromolecular network structure of coal is used to be reflected on the dielectric property, the measurement of the temperature dependency of the dielectric property can be a powerful tool to evaluate the thermal plastic nature of the macromolecular association in coal. This paper is describing a new methodology to determine the Initial Softening Temperature (ST), and Maximum Fluidity Temperature (MFT) of coal, based on the dielectric property.

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The adsorption of mercury from aqueous solution on sulfur-impregnated coal, which was prepared using K_2S, has been studied. With increasing temperature of sulfur-impregnation, specific surface area of the obtained coal increases, while sulfur content of the coal is almost constant. The sulfur-impregnated coal obtained at 900℃ shows the highest and fastest adsorption of mercury from aqueous solution at 25℃. The desorption extents of adsorbed mercury are negligible in distilled water, and 10% in 0.1M HCl solution. These results indicated that sulfur-impregnated coal could be used as an effective adsorbent for mercury.

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To develop an efficient cleaning process of hydrocarbon resources, metal loaded carbon was used for removal of organic sulfur from coal extract liquid. The coal extract liquid was prepared from Illinois No. 6 with tetralin under pressurized conditions. The desulfurization extent of organic sulfur in coal extract increased with increasing of heating temperature and holding time by using Ni loaded carbon. Organic sulfur of 90-96% could be removed from the coal extract liquid heated at 350℃ for 4-6h due to adsorption by the nickel loaded carbon.

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We have previously presented a new coal solvent extraction method and have shown that the method is effective in separation and structural analysis of coals. In this study we applied this method as an upgrading method of low rank coals. The method treats low rank coals in 1-methylnaphthalene at lower than 350℃ for a certain period and subsequently separates an extract from the residual coal by filtration at that temperature. The extract dissolved in the solvent at room temperature was composed of the compounds whose molecular weights were less than 500. The elemental composition of the low-molecular substances was surprisingly almost the same as those of bituminous coals. Furthermore, the extraction yield was much larger than that obtained through a heat treatment in a nitrogen atmosphere under the same heating condition followed by extraction at 350℃. Thus, it was clarified that the method not only can extract a large amount of low-molecular substances from the low rank coal but also can upgrade those molecules significantly.

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We have recently proposed a new upgrading method of low rank coals, which consists of treatment of the coals in 1-methylnaphalene at lower than 350℃ for a certain period and subsequent separation of extracts from the coals through filtration. This method was found to be effective in recovering a large amount of low-moleculer substances which were significantly upgraded in terms of elemental composition. In this study we examined the effects of temperature, time, and pressure on the upgrading behaviors of a brown coal. The treatment for a longer time resulted in larger extraction yields and more decomposition of oxygen functional groups, as was expected. When the holding time at 350℃ exceeded 1h, however, the extraction yield did not increase any more and the extract slightly became heavier. It was also found that pressure did not largely affect the upgrading behavior.

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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. When the organic matters contained in the simulated effluents were removed by coagulation, the optimum conditions, such as coagulant dose and pH, were investigated. TOC and molecular weight of organic matters dissolved in the simulated effluents were analyzed by TOC analyzer and size exclusion chromatography (SEC). Also, the environment impacts of these effluents were evaluated by the Ames mutagenicity test. The mutagenicity of chlorinated effluents was reduced after coagulation process by use of PAC treatment.

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We have recently proposed a new coal fractionation method utilizing solvent extraction at lower than 350℃, and have succeeded in separation of bituminous coals into fractions with different molecular weight without decomposition of the coal by the proposed method. For brown coals, not only such separation but also upgrading is essential to recover useful fractions. And it is important to combine upgrading and separation efficiently. In this research the proposed method was applied to a brown coal using either tetralin or 1-methylnaphthalene as an extraction solvent, and the effect of solvent type on properties of the product was examined. Mild hydrogenation as a means of upgrading brown coals was expected by using the tetralin. It was found that the fractionation method using tetralin could separate the brown coal into fractions having different elemental compositions and significantly hydrogenate the fractions at the same time. The fraction extracted using tetralin, was more abundant in hydrogen and aliphatics than that using 1-methylnaphthalene.

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The proposed technology is a new concept and scientific area with the aim of energy-saving drying for frozen coal by using liquefied DME (dimethyl ether) gas. In this method, liquefied dimethyl ether (DME) is contacted with iced solid fuels. Thus ice is extracted by the DME, and is formed mixture. Because of the low normal boiling point (-25℃) of DME, liquid state is stable for DME and DME is easily used as extractant. We removed efficiently ice from iced solid fuels by using DME below freezing point. DME gas is perfectly recycled and DME does not remain in those materials. We invented a drying method for iced solid fuels below freezing point in cold district.

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As a part of basic study on in-situ de-sulfurization and ash modification to convert fly ash into cementitious material in pulverized coal fired boiler, we carried out trial firing in a bench-scale test furnace. Fine particles of the calcium compound that can be collected in cement manufacturing process were injected under firing conditions. As a result the condition that de-sulfurization rate 40% or more was able to be achieved, and a fly ash which is mainly composed of cement minerals and non-crystal substances and contains only about 10-15% of free CaO were confirmed.

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Brown coal has many oxygen-containing functional groups such as carboxyl groups and it is ion-exchangeable with metal species. We have carried out a nickel recovery from nickel electroless plating wastewater using brown coal. However, it was recognized that ion exchange was obstructed by the influence such as the phosphoric acid ions in wastewater. In this study, it aims at the improvement of the nickel recovery by removing the phosphoric acid ion.

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Hyper-coal (HPC) is an ash-free coal produced by the solvent de-ashing technology. Coal is thermally (360-400℃) extracted into the coal-derived solvent (two ring aromatics). The extracted slurry was introduced into the settler. The solid phase (insoluble slurry) was gravitationally concentrated at the settler bottom and withdrawn as the under flow (UF). Though the liquid phase (solution) is clarified and withdrawn as the over flow (OF), and the OF is further filtrated through the stainless mesh filter (0.5 micro-meter pore). Ash concentrations in HPCs after filtration were 400-800ppm as the actual results. On the other hand, the target spec of ash concentration was 200ppm for the direct combustion fuel for gas-turbine. We tried some way to growth cohesion of the sub-micron insoluble particles which passed through the filter. One way was to mix a coal which gave a sticky insoluble to take in the surrounding sub-micron particles. Other way was to set down the filtration temperature to solidify a small amount of the extracted fraction. The precipitate might also affect to take in the sub-micron particles. We finally succeed to make the HPC continuously which had less than 200ppm of ash content.

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Ashless coal (HyperCoal; HPC) was produced by thermal extraction at 360℃ using a mixed solvent of 1-methylnaphthalene (1-MN) and indole (IN). The extraction yield increased with increasing the concentration of IN. The rate of increase in the extraction yields varied with the coal rank, depending on the content of oxygen. Under 13% of oxygen in raw coals, the rate increased with oxygen. This trend may be related to the weight composition of different oxygen functional groups.

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The catalyst for transforming from higher hydrocarbons such as coal tar in hot COG (Coke Oven Gas) in the steel making process to lower hydrocarbons was developed and pilot plant operation was carried out using this catalyst in a national project. Developed catalyst showed very high activity and target value set for the project was cleared even without the following steam reforming of light hydrocarbons. Reformed gas composition indicates that transforming of higher hydrocarbons to lower ones proceed together with steam reforming of light hydrocarbons.

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Fuel cells have been highly considered as an alternative power source for the near future. The low temperature-operated proton exchange membrane fuel cells (PEFC) has gain interest for use in automotive and stationary applications. For Pt-metal alloy electrocatalysts, the cost to produce and commercialize fuel cells is high. Therefore, the major challenges in fuel cell research are to reduce the cost of the electrocatalyst either by lowering the Pt loading or by developing a non-noble catalyst. The exploration for new alternative Pt catalysts from such materials as a graphene-structure, coals has become the challenge in fuel cell research, although coals contained many impurities. The preparation of treated coals and their activity as an cathode catalyst for PEFC were investigated. The electrocatalytic activity for the oxygen reduction reaction over the catalysts was evaluated using a single-stack fuel cell and a rotating disk electrode.

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In coal gasification process, H_2S is produced and have harmful effects for the process. We study method of removal H_2S by activated coke. Purpose of this study is investigation of effect of COS and CO_2 to H_2S adsorption capacity of activated coke. In this study, I compared H_2S & COS simultaneous adsorption amount to H_2S adsorption amount by thermogravimetric analyzer (TGA) and fixed bed reactor.

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A new concept for catalytic coal gasification has been developed. Special attention is paid to the catalyst loading and regeneration using crude vinegars (CV) derived from different lignocellulosic biomass resources. It is found that calcium loaded by impregnation with CV indicates higher catalytic activity than that loaded by impregnation with acetic acid aqueous solution. Furthermore, the primary loaded calcium can be regenerated from the gasification ash by CVs. CVs are found to be capable to revitalize catalytic activity of indigenous mineral matters in coal.

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To preserve fossil fuels all over the world, it is important to develop the efficient use of low rank coals like brown coal and lignite. Upgraded Brown Coal (UBC), which is the coal dewatered and stabilized in heated oil, is the promising way to use low rank coals as sophisticatedly as bituminous coals. In this paper, fundamental combustion characteristics and kinetics of UBCs are examined via thermo-gravimetric analyses. The results obtained are compared with those of some kinds of bituminous coal. The UBC seemed to have higher reactivity during combustion. There is a little difference in the volatile evolution process between the UBC and bituminous coals.

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This paper shows the crude coke oven gas (hot COG) reforming technology without catalysts and its business evaluation. The aims for research and development of this technology is to produce synthesis gas that can be converted to clean liquid fuels, such as methanol or DME (dimethyl ether). By reforming the hot COG with tar generated in coke ovens, it is possible to use of the heat energy of COG. Through the study, in economical evaluation it has been clear that hot COG reforming technology is excellent.

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Kobe Steel has developed a coal upgrading process, the UBC (Upgraded Brown Coal) process, for low rank coal. The UBC technology that evaporates moisture of coal in oil can be convert low rank coal into high grade fuel with higher heating value and less propensity of spontaneous combustion. The purpose of this paper is to report on the combustion characteristics of Indonesian UBC. The combustion characteristics of bituminous coal and the UBC on combustion pollutant and the unburnt ratio were quantitatively investigated. Results showed that the UBC has high combustibility and low NOx and SOx generation compared with conventional bituminous coal. Moreover, the ratio of adherent ash on the probe for the UBC combustion was equal to bituminous coal combustion under 1573K.

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In the present study, suppression of carbon deposition onto Ni/Al_2O_3 catalysts were investigated by means of addition of co-catalyst Mg. Particularly, the order of the addition of catalytic constituents, Ni and Mg, were studied.

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How to secure reliability of large capacity coal gasifier is studied and discussed.. It greatly depends on the selection of design criteria and parameters. Recommendable design criteria are shown through analysis of the successful results of gasifier operation at Nakoso 250MW IGCC Demonstration Plant.

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The concept of the exergy recuperative gasification was proposed. The idea is to make use of the waste heat from the gas turbine exhaust and fuel cell as the reaction heat for the gasification instead of the internal combustion. The feasibility of the concept implementation and the system improvement were preliminarily examined and discussed.

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Steam gasification of AD coal was conducted using a circulating dual bubbling fluidized bed (CDBFB) system in this study. The CDBFB consisted of two bubbling fluidized beds, with one serving as a gasifier and the other as a combustor. Two kinds of bed materials (porous γ-alumina particle and non-porous silica sand) were used in the CDBFB system. Carbon yield in product gas in case of alumina was larger than that of silica sand case, because almost all the tar was captured and reformed on the alumina. Furthermore, minimum fraction of carbon combusted to maintain autothermal condition in the CDBFB experiment was predicted by a system simulation considering heat and material flow in the dual bed reactor.

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HyperCoal is a clean coal with ash content <0.05wt%. Oaky Creek [OC] (C=82%), and Pasir [PAS] (C=68%) coals were subjected to solvent extraction method to prepare Oaky Creek HyperCoal [OCHPC], Pasir HyperCoal [PasHPC]. Experiments were carried out to compare the gasification reactivity of HyperCoals and parent raw coals with the 20, 40, 50 and 60% K_2CO_3 as a catalyst at 600, 650, 700 and 775℃ with steam. Gasification rates of both coals and HyperCoals were strongly influenced by the temperature and catalyst loading. Catalytic steam gasification of HyperCoals was found to be chemical re action controlled in the 600〜700℃ temperature range for all catalyst loadings. Gasification rates of HyperCoals were found to be always higher than parent coals at any given temperature for all catalyst loadings. XRD results showed that microstructure of chars prepared from coals and HyperCoals were similar. NMR results show no significant difference between the chemical compositions of the chars. SEM images showed that chars from HyperCoals had coral-reef like structures while dense chars were observed for coals.

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The method to derive reaction formula, CH_mO_n+αO_2+βH_2O→γCO+δH_2+εCO_2+ζH_2O+ηCH_4, from the composition of gas produced has already reported. In order to elucidate the reaction process of gasification, we tried to deform the stoichiometric formula theoretically, CH_mO_n+0.5(1-n)O_2→CO+0.5mH_2, into the actual formula by taking account of the effect of subsequent reactions caused by excess or lack of oxygen, water gas reaction, shift reaction and CH_4 formation. We have presumed the contribution of shift reaction to the performance of HYCOL process.

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It was tried to control the carbon number distribution in the Fischer-Tropsch Synthesis (FTS) over supported cobalt catalyst in a trickle bed reactor. When 1-olefin is added to the system, an effective propagation or degradation of C-C chain occurred based on added 1-olefin. Co-fed 1-olefin could enhance the selectivity of higher hydrocarbons than the added 1-olefin, while suppressing the formation of lighter hydrocarbons especially.

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Effects of NTA on the FTS activity and structure of Co species during the catalyst preparation were investigated to make clear the origin of its promoting effect. The FTS activity of the catalyst prepared from Co nitrate solution modified with NTA strongly depends on the calcination temperature. Higher FTS activities were obtained only when the catalyst was calcined at higher temperature. Diffuse reflectance FT-IR measurements showed that NTA-Co complex formed in the impregnation solution was interacted with Si-OH after impregnation, and preserved during calcinations step (around 523K), which leads to higher dispersion and higher reducibility after calcination.

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In this research, the CFD simulation of a pulverized coal combustion field formed in a coal combustion test furnace, of which the coal feeding rate is about 100kg-coal/h, is performed using the model employing tabulated devolatilization process (TDP model), which can take into account the effect of the particle heating rate on the amount of volatile and devolatilization rate. To verify the applicability of the TDP model for the combustion field, the measurement of particle velocity using a laser-Doppler velocimetry (LDV) is also performed. The simulation result with the TDP model is compared with the LDV measurement result and the simulation result with the conventional model. As a result, it is found that the result predicted by the TDP model is more accurate than that predicted by the conventional model.

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Fe and Ni catalysts supported on a Canadian peat-derived, H_3PO_4-activated carbon are characterized by several methods, and their performance in NH3 decomposition is investigated with a fixed bed quartz reactor from a viewpoint of hot gas cleanup. The X-ray photoelectron spectroscopy (XPS) analysis of the fresh catalysts after calcination at 500℃ reveals the significant retention of P on their surfaces, whereas the X-ray diffraction (XRD) measurements show the absence of any diffraction lines of Fe species and the appearance of metallic Ni. Both catalysts remarkably promote the decomposition of 2000ppm NH_3 diluted with inert He at 750℃ and show high, stable NH_3 conversions to N_2 of 75-90%. Because Fe and Ni phosphides are detectable by the XRD after the reaction, these species might be catalytically active.

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In the low-temperature biomass gasification, deactivation of the catalyst by carbon deposition is a serious problem due to the cost. In this study, we conducted a study on the carbon deposition onto Ni-supported coal catalyst from several model organic compounds to observe the difference in the carbon deposition behavior from that of a commercial Ni/Al_2O_3 catalyst.

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Merits of thermochemical conversion such as gasification are of short reaction time and compact reactor. In this study, we investigated the effect of dolomite as a catalyst on product gas composition and gasification rate The results show that dolomite can capture and decompose tar and produce more gases asH_2, CO and CH_4 at higher gasification temperature.

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This study aimed to clarify the behavior of closed pores in coal chars during pyrolysis and 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). Closed pore volume of caking model sample chars was larger than that of non-caking model sample chars. The caking probably influences the generation of closed pores at pyrolysis as well as coal chars. Also, closed pore surface area, number of closed pores and closed pore volume are rapidly decreased at an initial stage of char gasification. They might be indicated that closed pore was opened at an initial reaction, and degree of contribution for gasification can be calculated.

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Hot syngas cleaning of biomass gasification using molten carbonate is suggested for high temperature fuel cell (MCFC, SOFC). The molten carbonate is absorbent of desulfurization and dechlorination, and catalyst of tar cracking. Thus, this gas cleaning system consists of a few stages which are molten carbonate reactor and particulate filter. The operating temperature of molten carbonate reactor is 800-1000℃, and is kept by the heat of gasification gas, etc. In this study, the removal of H_2S and the decomposition of benzene using molten carbonate were performed in the bench scale test stand. The performance of gas cleaning was discussed.

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In this work we studied the Hg removal in coal gasification fuel gas by activated carbons (ACs) obtained from coconut shell, phenol resin and ion-exchange resin. ACs showed higher Hg removal performance in the presence of HCl than in the absence of HCl in the fuel gas mixture. After Hg removal experiments, temperature programmed decomposition and desorption (TPDD) method was used to study the stability of mercury species formed on the sorbents. It was found that the treatment of AC with aqua regia as a regeneration method of the spent sorbents affected the mercury removal character of the AC. The HCl remained on the surface of the aqua regia-treated AC resulted in high Hg removal performance of the aqua regia-treated AC. In TPDD experiments it was observed that the mercury evolution peak temperature shifted to higher temperature due to aqua regia treatment of the AC.

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The Hg removal performance of iron sulfide (FeS_2) in coal combustion flue gas was investigated. FeS_2 showed a higher Hg^0 removal performance than activated carbon which is a commonly studied sorbent for Hg removal from coal combustion flue gas. Presence of HCl in the flue gas enhanced the Hg^0 removal performance of FeS_2. Hg^0 was removed by FeS_2 at higher temperature (more than 80℃) when the HCl concentration in the flue gas was high.

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