Coal science conference of the Japanese Institute of Energy originated from a small study member for coal petrography in the Coal Technology Laboratory conducted by Dr. Asai who introduced modern coal petrographical knowledge from Germany just after the world war 2nd when domestic coal minimng became active. The author have participated in the member since 1960 when the coal minimg activity was declining and imported coking coal became subsutitutive. The lapse of 30 years have changed the domestic coal industrial and scientific background, and the author's labo. of Coal Geology has been reformed to Organic Geoscience in the Department of Earth & Planetary Sciences. The present main topics of our section are concentrated on available informations obtained from sedimemtary organic matters including coal and petroleum which can be correlated to traditional inorganic geological phenomena and can detect more minute and delicate signs than those in minerals or rocks. The new informations obtained from life-origin organic matters are opening up new fields of geosciences which are partly based on coal science.

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The present work is a study of the solubilization of coal in a TFMS -pentane system via an ionic reaction. The reaction was carried out at low temperature (150℃) without hydrogen gas in order to evaluate TFMS as an acid catalyst for coal solubilization with aliphatic compounds (isopentane and n-pentane).

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Depolymerization of selected coal model compounds using super acid (trifluoromethane sulfonic acid) with isopentane was carried out at 30-150℃ without hydrogen gas. Diphenylmethane and benzylphenylether gave quantitative conversion at 30℃.

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To study the reaction mechanism and to research preferable reaction condition, thermolysis and hydroconversion of aryalkanes as coal-related model compounds were carried out in the absence of catalyst and the presence of metallic iron (Fe) and pyrite (FeS_2). Thermolysis of diarylalkanes was proceeded by radical chain reaction, and was retarded by addition of hydrogen-donor solvents and was slightly accelerated in the presence of hydrogen molecule. Fe catalyst accelerated the hydrogenation of aromatic-ring, and pyrite (FeS_2) promoted the methylene linkage C-C bond cleavage of diarylalkanes. The cleavage related the hydrogen-accepting ability, the C-C bond dissociation eneregy and the resonace energy of species after the C-C bond scission.

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The selectivity for ring-opening of methylnaphthalenes was studied with existence of a NiO-MoO_3/Al_2O_3 at temperatures ranging from 390 to 450℃. Ring-opening proceeded by α-scission of tetrahydro-ring and produced (1-methylbutyl) benzene, pentylbenzene via 1-methyltetralin, 1-butyl-2-methylbenzene, 1-butyl-3-methylbenzene via 5-methyl-tetralin, (2-methylbutyl) benzene, (3-methylbutyl) benzene via 2-methyltetralin and 1-butyl-3-methylbenzene, 1-butyl-4-methylbenzene via 6-methyltetralin. 1-butyl-3-methylbenzene from 1-methylnaphthalene was obtained in highest yield among these products.

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In the hydrogenolysis of trans-stilbene under nitrogen at 380℃, coal liquefaction residues (CLR) act as duplex hydrogen transfer agents donating their inherent hydrogens and shuttling ones from hydrogen donor solvents.

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In order to develope efficient coal liquifaction processes, the effect of the pre- treatment of coal (coal-gel) swollen by various hydrogen-donors on the primary liquifaction has been examined. The liquifaction using a binary system (in situ coal-gel formation), such as tetralin-NMP (10%), achieved an almost complete solubilization to a pyridine extraction. Also, the coal-gel which was prepared by previously swelling a coal with a reduced coal-tar pitch/THF solution followed by removing THF, gave 85-92% of pyridine soluble to sub-bitumious and bituminous coals. One of the characteristic featuers of the later liquifaction process is that the high conversion was obtained without the use of an autoclave (under atmospheric pressure) and stirring.

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Activities of iron-sulfur as catalyst precusors in the liquefaction of various coal using syngas-water were investigated. Both synthetic pyrite and Fe(CO)_5/S were extremely effective. Especially, synthetic pyrite was the most excellent catalyst precusor for Wandoan coal to achieve the high oil yield (oil yield 48.7%, conversion 92.0%) in the two-step liquefaction (375℃, 60min+425℃, 60min).

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The non-covalent bonding in coal have been acknowledge as being of fundamental importance to overall physical properties of coal. To make sure that effect of non-covalent bonding on coal liquefaction, two kinds of alkylated coals were reacted, one is O-alkylation and the other is reductive alkylation. For coal liquefaction, liquid yield of alkylated coal decreased compaired with raw coal. However, TGA measuerments of THF insoluble fraction suggested that depolymerization reaction of reductive alkylated coal proceeded rather than that of raw coal.

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Concept of the present study is to apply the oil agglomeration technique to pretreat coal for coprocessing with vacuum bottom of Athabasca bitumen. Coals used were Illinois, Montana and Wyoming. Pulverized coals were agglomerated with the bitumen. The parent coals and neat and deoiled agglomerates were liquefied in the presence of the bitumen as a solvent and FeS_2 as a catalyst under H_2 at 10MPa. Findings were as follows; the bitumen for agglomeration was effective for ash removal and recovery of coals were good over 95wt%, but not for the swelling.

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Explosive pretreatment of Illinois No.6 coal for direct coal liquefaction was carrried out using binary water-organic system, such as water-methanol, water-benzene, water-cyclohexanol, water-formaldehyde, etc. This technique was extremely effective for the conversion of coal. The mechanism of this process is discussed on the basis of the liquefaction profile combined with electron microscopic observation.

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The surface oxygen complexes produced from carbon gasification with oxygen were characterized by combining DRIFT (Diffuse Reflectance Infrared Fourier Transform) and TPD (Temperature Programmed Desorption) techniques. It is found that cyclic acid anhydride and/or lactone, carbonyl and ether complexes are formed during the gasification and that the decomposition of cyclic acid anhydride and/or lactone is responsible for CO_2 evolution at around 900K in TPD. Some of cyclic acid anhydride/lactone could be hydrated to carboxylic acid at room temperature when the gasified sample is exposed to water vapor. In addition, thermal stability of these carbon oxygen complexes was discussed.

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A modeling method is proposed to simulate carbon gasification. This method simulates carbon gasification by removing carbon atoms from carbon crystallite model according to reaction index determined by molecular orbital calculation. Free valence for each carbon atom was employed.

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The influence of thermal treatment on the amount of oxygen for theoretical combustion, volume of carbon dioxied formed by perfect combustion, oxygen ratio and amount of steam fed into a gasifire were investigated on 17 coals of various rank. These factors were influenced by coal rank and the temperature of pyrolisis.

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The diffusion-reaction systems of high temperature gasification in coal char particles were investicated experimentally. Results were analysed taking in to account the effectiveness factors to obtain the gasification rate constant free from mass transfer resistance.

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The gasification reactivity of the chars prepared from an Australian brown coal, Morwell, by several methods was measured, and was correlated with several char properties. Although the chars were prepared at the same temperature of 750℃ under the same heating rate, the char yield, the pore surface area and the ultimate analysis varied significantly depending on the coal pre-treatment method and/or the atmosphere during the pyrolysis. An excellent correlation whose correlation coefficient was 0.99 was obtained between the gasification rate and the oxygen content of the char. This is because the oxygen content measured in this work well corresponds to the amount of active site of the char.

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The amount of oxygen uptake on carbons during the gasification was estimated by continuously measuring the weight change and the gaseous products. A sensitive thermobalance and a efficient mass spectrometer were used for this purpose. Step response experiments for ^<18>O_2 injections were also performed to examine the transient behavior of the gasification reaction. The role of adsorbed oxygen in the gasification mechanism was examined in detail based on these experiments.

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CO_2 gasification of iron loaded Yallourn coal, caron black and active carbon was carried out using a thermobalance. The sample was heated to 800℃ under Ar and then gasified with CO_2. When the sample was treated at 780℃〜800℃ with CO for 120s, rapid weight decrease was observed for selected samples. Such rapid gasification is considered to be due to the highly dispersed state of iron on carbon species.

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The application of extra-heavy oil, such as Orimulsion^[○!R] fuel, to Integrated Gasification Combined Cycle Power Plant attracts attention recently. This report presents the investigation results of adaptability of multi-fuel gasification using coal and orimulsion in fuel in an air-blown two stage entrained flow gasifier. It was cleared that the method of multi-fuel gasification, orimulsion fuel to the combustor and coal to the reductor, was the most excellent judging from the evaluation of operational performance and plant thermal efficiency.

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Fly ashes E and G those discharged from a same pulverized coal combustion boiler were classified into two components, such as smaller fly ash particle under 38μm and larger fly ash particle above 125μm. The carbon contained in both components were separated from fly ash by using the Ultrasonic Oil Agglomeration method. Properties of separated carbons were investigated by applying the X-ray diffraction, SEM (Scanning Electron Microscope) and TGA (Thermogravimetric Analysis). Following results are obtained. (1) The carbon remains in the larger fly ash as the unburned char, and that contained in smaller fly ash are carbon black and rock carbon. (2) Significant differences of the carbon contents and their properties between the fly ashes E and G are found. The carbon content in smaller components of fly ash G is fairly greater than that in smaller components of fly ash E, although the coal G shows a good combustibility. These observations of the properties of carbon containing in fly ash present significant Informations on the for rational operation and control in the process of pulverized coal combustion process.

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To clarify the effect of pressure load on the behavior of coal, product gases and the properties of the coal during carbonization were examined. By increasing the pressure load (〜40MPa) during the carbonization, H_2 and CO formations were significantly suppressed; the amount of pyridine extractable from the solid residue (coke) significantly increased at the carbonization temperature of 350 to 400℃; and the yield of coke increased. These effects were found to be brought about through the suppression of cross-linking reactions during the initial stage of carbonization under the pressure load. This fording partly clarified the mechanism by which the metallurgical coke having good properties could be produced from weakly coking coals by the hot-briquetting method.

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For the development of functional carbon materials from or with brown coals, the effect of iron exchange on carbonization was examined by means of electrical conductivity measurement, IR spectroscopic method, etc. The exchanged iron promoted carbonization by assisting the elimination of carboxyl groups. The addition of iron exchanged brown coals to poly (vinylidene chloride) also showed the promotive effects on the carbonization of these mixtures.

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X-ray photoelectron spectro scopy (XPS) was applied to the direct determination and quantification of organic sulfur forms in coals. Some model compounds were measured to interpret sulfur 2p signals from coal. The influence of inorganic sulfur species, such as pyrite, were discussed.

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Sorption phenomena of methanol on coal was investigated using Taiheiyo coal. Taiheiyo coal oxidized by air at 120℃ was also used. The amount of methanol sorbed in coal was considerably increased by repeated sorption and desorption. Isotherm profile of oxidized coal appeared to be much different from that of unoxidized coal. Rate of methanol sorption on oxidized coal was low compared to unoxidized coal in the first run. Repeated sorption and desorption gave similar isotherm profile observed for unoxidized coal.

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The demineralized and acetylated coals were extracted with pyrizine or chloroform. The effect of acetylation on non-covalent interaction of coals was investigated from the extractabilities and the changes in yeild for each molecular weight distribution.

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Carbon disulfide (CS_2)-N-methyl-2-pyrrolidinone (NMP) mixed solvent (1:1 by volume) give high extraction yields for many bituminous coals at room temperature. Heavy extract fraction, e.g. pyridine insoluble (PI) fraction obtained from the extract of coal was found to become insoluble in the extracting solvent at room temperature. Solubility of PI fraction in the mixed solvent was found to increase greatly by the addition of tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). In this study, effects of the addition of various electron acceptors on the extraction yields of coals and solubility of PI fraction are investigated and interactions between coal molecule and electron acceptor are discussed.

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The change in noncovalent interaction in coal with electron acceptor has been investigate by means of EPR and ^1<HNMR> spectroscopy. The iodine doped in high rank coal interacts with polyaromatics in coal and enhance the mobility of coal molecules. The interaction of TCNQ with functional groups in low rank coal may results the enhancement of macro molecular phase in coal. Electron acceptor doping technique has been found to be useful in investigating the type and number of noncovalent interactions in coal.

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In order to obtain an insight into the chemical structure of Zao Zhuang coal, two chemical reactions of the coal, cleavage reaction of ether bonds in the coal with SiCl_4-NaI and oxidation with RuO_4, were carried out. On the basis of the analytical data for the original coal and the reaction products, a structural model for Zao Zhuang coal was proposed and it was also evaluated by using computer simulation technique.

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Pulverizing behavior of coals in organic solvents has been studied by use of a homogenizer. The pulverized particles exhibited a particle size distribution consisting of coarse and fine particle fractions devided at around 70μm. Coal was pulverized easily in solvents such as toluene and hexane which hardly swelled the coal. The coal kept in air for a long time was hard to pulverize compared to the coal preserved in water. The fine particle fraction gave a higher conversion to solvent solubles by liquefaction with tetralin than the coarse particle fraction.

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Inverse liquid chromatography was performed by using some coals as support material. The interaction between aromatic compounds and coals swolen in acetonitrile, methanol or hexane was examined based on the adsorption enthalpy. For Pocahontas and Illinois No.6 coals, the net adsorption enthalpy increased linearly with increasing molecular volume of probe, and little difference was observed for the enthalpy between n-alkylbenzene and PAHs having equivalent molecular volume. This suggests that the adsorption is based on van der Waals interaction between coal and probe molecule. On the other hand, the net adsorption enthalpy of smaller alkylbenzenes and PAHs onto Morwell coal was much lower than that predicted by extrapolating the data for bulky alkylbenzenes. This means that the adsorption of small molecules was accompanied by an endothermic process, which was the disruption of non-covalent bonds caused by the probe molecules introduced.

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A vacuum residue of Illinois No.6 coal (IL-S3) from NEDOL coal liquifaction process was analyzed by ^<13>C-NMR, FT-IR, and pyrolysis GC-MS. The results for these analysis strongly suggest that dealkylation, deoxygenation, and condensation of aromatic hydrocarbons took place during the NEDOL coal liquifaction process.

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Coals of various rank of coals were extracted with CS_2-N-methyl-2-pyrrolidinone mixed solvent (1:1 by volume) at room temperature. The residues were packed in column using chloroform or n-hexane as a mobile phase solvent. Polystyrene standard samples and various polycyclic aromatic hydrocarbons were injected as a probe to investigate cross-linking structure of coal and interaction between probe molecule and coal.

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Coals and related materials were extracted by benzene/ethanol (2/1) at 200℃, and the extractable and nonextractable materials were hydrogenated at 350℃ over Ni-Mo/Al_2O_3. Polycyclic aromatic compounds and long n-alkanes in the extracts and hydrogenated products were investigated.

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Mono-aromatic ring fractions in coal-derived oils were separated into several fractions by high-performance liquid chromatography (HPLC) equipped with carbon packed column (Carbonex, TONEN). Any obtained fractions had a wide molecular weight distribution with same molecular weight compounds each other. This results showed that the carbon packed column separation was due to structural differences of isomers for alkylated aromatic hydrocarbons. Using HPLC equipped with carbon packed column as a separation method of coal-derived oils would be suitable for an analysis of isomeric aromatic components.

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Extraction oil and residues from coal, having low molecular weight component and different degree of polymeric component, are important for elucidation of coalification process because difference of chemical structure among them were expected to occur under the same coalification condition. In this study, chemical structure between extraction oil and hydrogenation oils which were derived by hydrogenation of extraction residues, were compared according to compound type analyses by means of FI and EI MS. A conclusion can be drew that in order of HS, HI, BI and PI component, chemical structure of them were more influenced by coalification reaction and therefore naphthenic rings altered aromatic structure with accompaning the polymerization reaction to macromolecule structure.

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The decomposition rate of non-covalent bondings and the extent of the crosslinking reaction during the pyrolysis of coal were estimated through the methanol vapor swelling of the chars prepared under different conditions. TG, DSC, and TMA were utilized to measure the weight, volume and enthalpy changes during the swelling. Gaseous products during the pyrolysis were also measured. From these measurements the moles of methanol utilized to break the non-covalent bondings (n_<NC,f>) were estimated. It was clarified that n_<NC,f> well represent the extent of crosslinking. Furthermore, the effect of heating rate on the pyrolysis behavior was examined from the viewpoint of the decomposition of non-covalent bondings.

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A new pyrolysis method utilizing oxidation and solvent swelling was presented for increasing the liquid yield. Coal oxidized by several acids at low temperatures to create non-covalent bonding sites, then it was swollen by tetralin or wax. The modified and swollen coal was pyrolyzed using a Curie-point pyrolyzer at 764℃, which realized significant increases in the total volatiles and the tar yield. The increases were found to be realized through the suppression of crosslinking reactions. Thus it was clarified that the coal could be modified to more flexible materials through oxidation and solvent swelling. This presents a possibility to design the coal pyrolysis reaction.

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Loy Yang coal and Blair Athol coal have been pyrolyzed with a Cl-free iron catalyst prepared from ferric chloride. The catalyst enhances the release of coal nitrogen as N_2 gas while it suppresses the formation of NH_3, HCN, and tar-N.

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Coal solubilization under extremely mild conditions such as a microbiological attack was attempted by using iron complex catalyst which were chemically synthesized as a model of oxygenase. For the solubilization of brown coal, it was required that the reaction site was modified to improve the contact between the coal and active catalytic sites.

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For development of highly active iron catalyst on coal hydroliquefaction, correlation between the activity on the hydrogenation of aromatic hydrocarbons with metallic iron (Fe) and iron sulfides prepared in the various S/Fe ratios and the amount and the strength of adsorbed hydrogen to the surface with TPD method were studied. Aromatic hydrocarbons were strongly adsorbed and hydrogen molecule was weakly adsorbed the moderate amount to the Fe surface. On the other hand, pyrrhotite (Fe_<1-x>S) adsorbed a lot of hydrogen strongly, but did not adsorbed the aromatic hydrocarbons strongly. However, troilite (FeS) and the mixture of Fe and FeS adsorbed a little of hydrogen strongly.

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The hydrogenolysis reaction of model compounds was discussed in the presence of synthetic pyrite as catalyst under 3MPa of initial hydrogen pressure at 325〜500℃ for 15min. At the lower reaction temperature than 400℃ synthetic pyrite catalyst accelerated C-0 bond cleavage and the formation of benzylphenol and the condensed products such as dibenzylphenol and tribenzylphenol. It was difficult to cleave aliphatic bridged C-C bond such as bibenzyl under this reaction condition.

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Catalytic activiy of pulverized pyrite was investigated with a 5L batch-autoclave. The followings are obtained; (1) Pyrite is pulverised smaller than 1μm of average particle size by use of the wet-type or dry-type mill which are applicable to the Pilot Plant. (2) Pulverized pyrite is readily oxidized by atomspheric oxygen and loses the catalytic activity. So it needs treatment under an inert atomsphere and reactivation after oxidation. (3) Catalytic activity of pulverized pyrite increases contrary to the average particle size. In case of the average particle size is smaller than 1μm, pulverized pyrite is nearly comparable to the the synthetic iron sulfide which is the specified catalyst of the Pilot Plant.

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Recoverable catalysts are prepared for the primary coal liquefacton,using carbon black (Kejten-Black). Kejten-Black catalysts are examined in terms of its recovering procedure, the activity for the liquefaction, and the activation by supporting Ni and Mo.

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Cu(OH) is easily decomposed thermally and reduced into copper through cupric oxide below 300℃ in the atmosphere of hydrogen. Supposing that some active catalytic species may be formed in the process of decomposition, the rate of liquefaction is examined by using Cu(OH)_2 and its decomposed compounds, CuO (II), Cu O (I) and Cu, as catalyst.

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For purpose of elucidating the relation between the rate of liquefaction and the distribution of molecular weight of liquefaction products, liquefaction is carried out by using Cu(OH)_2 as catalyst. In order to elucidate the catalyst effect of Cu(OH)_2, the examination is carried out on the relation between of liquefaction ratio and distribution of molecular weight of liquefied products.

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Fe-loaded coal as catalyst was prepared by the reduction of Fe^<2+> with KBH_4 in the presence of coal. Hydroliquefaction of Blind Canyon coal was carried out using Fe-loaded coal as catalyst in 1-methylnaphthalene at 693K under a hydrogen atmosphere. High coal conversion and oil yield were obtained in the reaction with Fe-loaded coal as catalyst. The activity was enhanced when reduction of Fe^<2+> was carried out in the presence of coal, to give highly dispersed Fe species to coal.

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In coal pyrolysis, the yields of chemicals with high economical values, such as BTX, could be increased by varying the reaction conditions. In this study, the effect of catalyst type and metal-loading on the secondary reaction of nascent coal volatiles were studied under high H_2 pressure. The highest BTX yield, 14.0wt%, was obtained by using USY-Zeolite catalyst and the hydrocracking temperature of 600℃.

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We noticed that the CSN of coal decreased by wet milling. It was found that most effective factor of decreasing the CSN is oxidation of coal by oxygen disolved in water during wet milling. The CSN doesn't decrease in water without oxygen. A part of CSN decreasing is attributed the colloidal inorganic matter that separate from corse particle at milling. The CSN decreasing ratio is higher in low rank coal than in high rank coal, because the lower rank coal is more reactive.

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