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Projects on coal characterization
01 Solid fuels (sources, winning, properties) 02lOOO50 Negative influence of enterprises of the LvivVolyn Basin engaged in coal production Ivan&iv, O.E. ef al. Geol. Geokhim. Goryuch. Kopalin, 1999, 2, 2&28. (In Ukrainian) A description of negative influence of enterprises of the Lviv-Volyn Basin engaged in coal production, coal enrichment, and burning. There are proposals for the complete utilization of waste of coal output and enrichment as well actions directed to the improvement of ecological situation of the western region, taking social and economic reality into consideration. Ecological problems of the Lviv-Volyn Basin can be solved only at the state level for the development of fuel and power complex of Ukraine. 02/00051 Non-covalent interactions in coals Larsen, J.W. Prepr. Symp. - Am. Chem. Sm., Div. Fuel Chem., 2000, 45, (1), 181-184. The interactions between bituminous coals and organic molecules can be quantitatively described using only two terms: interactions dependent on polarizability and acid/base interactions, especially hydrogen bonding. Except for groups having an unpaired electron (the coal radical sites), the same two forces so dominate coal-coal interactions that it is not necessary to invoke any others. Except for radical sites, HOMO-LUMO gaps are so large that X-K and charge transfer interactions (aromatic ‘stacking’ interactions) are improbable. 02lOOO52 Petrochemistry of Pathakhera coals, Pathakhera coalfield, M.P., (India) Shukla, R.R., Siddharth, S. Ulrra Sci. PhJ.7. Sci., 2000, 12, (I), 58-61. A detailed macro and micro-petrological investigation of five coal seam profiles of Permo-Carboniferous age from the Pathakhera coal field, Satpura basin, M. P. was undertaken in order to characterize them petrochemically and to focus on their rank. These coals are vitrinite rich (46.36-51.27) inertinite (41.83-46.43) and exinite (5.81-7.72). Proximate analysis suggest that these coals are medium to high volatile bituminous in rank. Their vitrinite reflectance are ranging between 0.66 and 0.72. 02/00053 Point dilution method of a radioactive tracer,. applied for the assessment of the fractured zone in Vahas coal mine, Bulgaria Eftimi, R., Ahmataj, S. Geol. Miner. Resur., 1999, 6, (2), 8-12. (In Bulgarian) For the protection of Valias coal mines from the groundwater of over lined gravely aquifer is necessary for the determination of the thickness of the intensive fractured zone caused by the exploitation. In Valias coal mine this problem was resolved in an original way. By the method of Point Dilution of a Radioactive Tracer was measured the groundwater flow velocity, at different time in four wells located inside and outside rock massive movement zones. By the comparison of the behaviour of groundwater flow velocity between the wells inside and outside the rock massive deformations zones, and at different depths of the wells, the thickness of intensive fractured zones was estimated. 02100054 Projects on coal characterization Bjorkman, A. Fuel, 2001, 80, (2), 155-166. Danish power stations use coals, imported from various countries around the world. Since the coals may differ considerably in burning properties, the purchasers have a marked interest in characterization of the coals prior to use. In a Danish project existing methods were compared, using ten selected coal samples and equipment and techniques for particulate coal in the USA and Sweden were also used. TGA measurements and chemical and petrographic characterizations were made in Denmark. A multivariate analysis of six selected characterizations, using the Sandia equipment (CA, USA) results as target parameters, was made to create a statistical model which would allow characterization of an ‘unknown’ coal with a minimum of analytical effort and cost. In a separate investigation, involving a flatflame burner, an entrained-flow reactor (both in USA) and a TGA, oxidative coal pyrolysis was studied. A distributed activation energy concept was applied to produce kinetic parameters for a large-scale combustor model to evaluate the conditions in a flame. A parallel project (named IKI) presents an innovation with pyrolysis by a controlled laser beam of a very thin sample plate in a specific chamber, followed by isothermic gasification. The characterizations obtained with the IKI method on coal samples of the DP agree well with the Sandia results. Compared with the concept of coal ranks, for which two coals of same rank may behave differently, coal characterization methods have taken big steps forward, but we are still far from seeing the new tools employed in practice. 02/00055 Review on determination methods for trace element fluorine in coal Qi, Q. et (11.Meitan Zhumhuu, 2000, 23, (2), 7-l 1. (In Chinese)
A review, with 29 references, on methods for the determination of the trace element fluorine in coal. Indirect methods include alkali-fusion/ ion chromatography or the fluoride ion-selective electrode (ISE) method; the high-frequency induction furnace/ISE method; the oxygen bomb combustion/ISE method and the pyrohydrolysis/ISE method. Direct methods include spectroscopic methods, e.g. the proton-induced gamma-ray emission (PIGME) method; the mass spectroscopic method, e.g. the spark source mass spectrometry (SSMS) method. The applicability and existent problems were in particular were compared, analysed, and discussed in order to help analysts to be more critical about the method they use. In addition further investigations on the methods for determination of fluorine in coal were suggested.
02lOOO56 Structural characterization of carbonaceous solids by high-field NMR spectroscopy Adachi, Y. Nippon Enerugi Gakknishi, 2000, 79, (3), 222-230. In high-field NMR experiments on carbonaceous solids such as coal and pitch, the high-speed magic-angle spinning (MAS) method is a powerful technique for reducing the intensity of the spinning sidebands that disturbs the precise interpretation of the spectrum. However, highspeed MAS produces two unfavourable problems. One is the decline in the rate of polarization transfer from tH to 13C during the crosspolarization (CP), and another is the NMR signal intensity fluctuation in the dipolar-dephasing (DD) experiments. Therefore, the availability of high-speed MAS, variable amplitude (VA)-CP pulse sequence, and DD experiments with the delay times synchronized with sample spinning were examined in the high-field NMR of a carbonaceous sample. It was confirmed that high-field NMR spectroscopy is a useful technique for the structural characterization of carbonaceous solids, as well as low-field NMR.
02/00057 Structural determinations of Pennsylvania anthracites Pappano, P.J. er al. Prepr. Symp. - Am. Chemical Sm., Div. Fuel chemical, 1999, 44, (3), 567-570. Four Pennsylvania anthracites were selected for analysis, based on their availability from currently active mines and presumed geological differences. A battery of experiments was performed on these samples to determine their physical and chemical properties. The data collected from these experiments was used as input for modelling the structure. Visualization of anthracite structure is useful in visualizing the reactions necessary to produce advanced carbon materials, such as graphite, from anthracite.
02/00058 Structural parameters of coals from 002 lattice fringe images using HRTEM Sharma, A. et al. Prepr. Symp. - Am. chemical Sm., Div. Fuel chemical, 1999, 44, (3), 586-590. The structures of three different coals (Pocahontas No. 3, Illinois No. 6, Beulah-Zap) as observed by HRTEM are presented. The stack distribution, using the image analysis technique developed by the authors, was also dealt with.
02/00059 Structural variations in lignite coal: a small angle X-ray scattering investigation Sastry, P.U. et al. Solid Stare Commun., 2000, 114, (6), 329-333. The structural morphology of raw and processed lignite coal specimens from Neyveli (Tamil Nadu, India) is characterized over a length scale of 5-100 nm by small angle X-ray scattering (SAXS). The scattering profile from the unprocessed lignite specimen exhibits two distinct power laws indicating different fractal morphologies over different length states: a pore fractal (dimension D = 2 7) for the pore-coal interface below 17 nm and a surface fractal P.dtmenston D, I 2.3) above ‘. 17 nm. As a result of industrial processing at different temperature, pressure and carbonization, significant changes in the structure are noticed as indicated by the scattering profiles. The fractal roughness of the pore-coal interface becomes smooth (average D, = 2) for a large window of the length scale; whereas a part of the pore fractal transforms to a surface (DI = 2.8). The specimen treated at relatively higher temperature exhibits further variation from the fractal geometry with a tendency to form a new non-fractal micropore structure for the length scale 18 nm.
02lOOO60 Study on alkylation reactions of coal Niu, R. et al. Meitnn Zhuanhua, 2000, 23, (2), 12-16. (In Chinese) A study of alkylation reaction of coal was reviewed with 18 references along with the mechanism of 0-alkylation, and 0-alkylation in acid and base catalysts. The effect of elements and application of the reactions were discussed. The alkylation of coal is a promising technology in coal comprehensive application. Fuel and Energy Abstracts
January 2002
7
A review, with 29 references, on methods for the determination of the trace element fluorine in coal. Indirect methods include alkali-fusion/ ion chromatography or the fluoride ion-selective electrode (ISE) method; the high-frequency induction furnace/ISE method; the oxygen bomb combustion/ISE method and the pyrohydrolysis/ISE method. Direct methods include spectroscopic methods, e.g. the proton-induced gamma-ray emission (PIGME) method; the mass spectroscopic method, e.g. the spark source mass spectrometry (SSMS) method. The applicability and existent problems were in particular were compared, analysed, and discussed in order to help analysts to be more critical about the method they use. In addition further investigations on the methods for determination of fluorine in coal were suggested.
02lOOO56 Structural characterization of carbonaceous solids by high-field NMR spectroscopy Adachi, Y. Nippon Enerugi Gakknishi, 2000, 79, (3), 222-230. In high-field NMR experiments on carbonaceous solids such as coal and pitch, the high-speed magic-angle spinning (MAS) method is a powerful technique for reducing the intensity of the spinning sidebands that disturbs the precise interpretation of the spectrum. However, highspeed MAS produces two unfavourable problems. One is the decline in the rate of polarization transfer from tH to 13C during the crosspolarization (CP), and another is the NMR signal intensity fluctuation in the dipolar-dephasing (DD) experiments. Therefore, the availability of high-speed MAS, variable amplitude (VA)-CP pulse sequence, and DD experiments with the delay times synchronized with sample spinning were examined in the high-field NMR of a carbonaceous sample. It was confirmed that high-field NMR spectroscopy is a useful technique for the structural characterization of carbonaceous solids, as well as low-field NMR.
02/00057 Structural determinations of Pennsylvania anthracites Pappano, P.J. er al. Prepr. Symp. - Am. Chemical Sm., Div. Fuel chemical, 1999, 44, (3), 567-570. Four Pennsylvania anthracites were selected for analysis, based on their availability from currently active mines and presumed geological differences. A battery of experiments was performed on these samples to determine their physical and chemical properties. The data collected from these experiments was used as input for modelling the structure. Visualization of anthracite structure is useful in visualizing the reactions necessary to produce advanced carbon materials, such as graphite, from anthracite.
02/00058 Structural parameters of coals from 002 lattice fringe images using HRTEM Sharma, A. et al. Prepr. Symp. - Am. chemical Sm., Div. Fuel chemical, 1999, 44, (3), 586-590. The structures of three different coals (Pocahontas No. 3, Illinois No. 6, Beulah-Zap) as observed by HRTEM are presented. The stack distribution, using the image analysis technique developed by the authors, was also dealt with.
02/00059 Structural variations in lignite coal: a small angle X-ray scattering investigation Sastry, P.U. et al. Solid Stare Commun., 2000, 114, (6), 329-333. The structural morphology of raw and processed lignite coal specimens from Neyveli (Tamil Nadu, India) is characterized over a length scale of 5-100 nm by small angle X-ray scattering (SAXS). The scattering profile from the unprocessed lignite specimen exhibits two distinct power laws indicating different fractal morphologies over different length states: a pore fractal (dimension D = 2 7) for the pore-coal interface below 17 nm and a surface fractal P.dtmenston D, I 2.3) above ‘. 17 nm. As a result of industrial processing at different temperature, pressure and carbonization, significant changes in the structure are noticed as indicated by the scattering profiles. The fractal roughness of the pore-coal interface becomes smooth (average D, = 2) for a large window of the length scale; whereas a part of the pore fractal transforms to a surface (DI = 2.8). The specimen treated at relatively higher temperature exhibits further variation from the fractal geometry with a tendency to form a new non-fractal micropore structure for the length scale 18 nm.
02lOOO60 Study on alkylation reactions of coal Niu, R. et al. Meitnn Zhuanhua, 2000, 23, (2), 12-16. (In Chinese) A study of alkylation reaction of coal was reviewed with 18 references along with the mechanism of 0-alkylation, and 0-alkylation in acid and base catalysts. The effect of elements and application of the reactions were discussed. The alkylation of coal is a promising technology in coal comprehensive application. Fuel and Energy Abstracts
January 2002
7