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Gamma-ray transmission technique for quality control of coal seams
0 1 Solid fuels (sources, winnmg, properties)
01
SOLID Sources,
FUELS winning,
properties
03/01003 A plication of near infrared spectroscopy to rapid analys Ps of coals Kaihara, M. et al. Spectroxopy Letters, 2002, 35, (3), 369-316. Although near IR (NIR) spectra generally have less characteristic absorbance bands than IR spectra, some major properties of coals could be conveniently and rapidly estimated using NIR and partial least squares regression (PLS) model. For example, multiple correlation coefficients for the measured vs. predicted values from obtained spectra, R2, of moisture, volatile matter, oxygen content, maximum fluidity temperature, and solidification temperature were 0.9736, 0.9774 0.8996, 0.8849 and 0.9282, respectively, although the precision of obtained results was not superior to those by the standards of the American Society for Testing and Materials (ASTM).
Binding of atrazine to humic substances from soil. oeat. and coal related to their structure
03/01004
K&&a, N. A. and Perminova, I. V. En~~irowmwtcd Sciem~crrrd Tuchnology, 2002, 36, (17), 3720-3724. Partition coefficients for the binding affinities of atrazine to 16 different humic materials were detected using the ultrafiltration HPLC technique. Sources included humic acids (HA), fulvic acids (FA), and combined humic and fulvic fractions (HF) from soil, peat, and coal humic acid. Each humic material was characterized by elemental composition, molecular weight, and composition of main structural fragments detected by 13C solution-state NMR. The magnitude of Koc values was 87-575 L/kg C, demonstrating relatively low binding affinity of humic substances (HS) for atrazine. Based on measured Koc values, these humic materials were arranged in the following order: coal HA equivalent grey wooded soil HA > chernozemic soil HA and HF > sod-podzolic soil HA equivalent peat HF > sod-podzolic soil FA 3 peat dissolved organic matter. The magnitude of Koc values correlated strongly with the percentage of aromatic C in HS samples (r = 0.91) Hydrophobic binding was hypothesized as the key interaction underlying atrazine binding to HS.
Calculation of the heat capacity of coals OS/O1005 accordin to their elemental composition and the degree of aromatic Bty of the organic matter Gagarin, S. G. and Gyul’maliev, A. M. Khimiya Tverdogo Topliva IMosco~v. Russian Federation), 2002, (3), 3-l I. (In Russian) The molar heat capacity of organic matter of brown, bituminous, and anthracite coals is detected according to the input for the C, H, 0, N, and S atoms, with separating of the C atoms into aromatic, C,, and aliphatic, C,,. These values were obtained by using the data for individual compounds, modelling the structure of the organic matter of mined coals. The specific (mass) heat capacity of a coal (on dry-free basis) is calculated using the values of molecular weight of the fragment containing 100 C atoms. The calculated values satisfactorily agreed with the experimental data.
Combustion and NO, emission behavior of Chinese coals
03/01006
Chen, H. and Xie, K. Chinrse Journal of Chrmical Engineering, 2002, IO. (3), 215-234. Seven Chinese coals ranking from anthracite to sub-bituminous from the Shanxi province were selected for study to forecast the combustion and NO, emission behaviour. Three UK, one Indonesia and one South Africa coals were included in the study for reference. A flat flameturbulent jet apparatus was employed to assess flame stability, ignition performance and NO, emission behaviour for the initial stage of devolatilization and combustion. This apparatus can simulate particle heating rates, maximum temperatures and the influence of the turbulent fluid interactions on the fate of volatiles. To simulate processes occurring over longer residence time, additional devolatilization experiments were performed in a drop tube furnace. Char reactivity was studied through thermogravimetric analysis. Finally, fouling propensity was studied with the aid of a purpose-built laboratory combustor that enabled the characteristics of the ash deposit to be assessed empirically. The results show that Chinese coals do not appear to possess unusual features in respect of NO, formation, flame stability and ignition, char burnout and ash slagging. The range of coals available in China appears sufficiently broad that suits all requirements. In particular, Shenfu coal, with its initial fast devolatilization and nitrogen release rates and its low initial nitrogen content and high char reactivity, will perform well when fired in industrial boilers as far as NO, emission, flame stability and combustion
204
Fuel and Enetxw Abstracts July 2003
efficiency are concerned. Pingshuo coal exhibits high char reactivity and an attractive slagging performance suggesting that this fuel represents a good compromise between NO, emission and overall plant efficiency.
03/01007 Determination of the acid distribution and total acidity of low-rank coals and coal-derived materials by an improved barium exchange technique
Allardice, D. J. et al. Furl, 2003, 82, (I), 35-40. The Schafer technique for the determination of acid distribution and total acidity of low-rank coals has been modified and improved to make the determinations quicker and cheaper without loss of accuracy. The acidity determinations have been extended to hydrophobic coal-derived materials by the addition of a trace of methanol (<0.3%, v/v) to the exchange medium.
03/01008 Distribution of sulfur in coal of Hongyang Third Mine in Shenyang, China
Zhou, Z. et al. Donghei Dame Xurhao. Ziran Kcmrhau. 2002. 23. (2). 164-166. (In Chinese) All kinds of sulfur, ash, total sulfur with different density in coal of Hongyang Third Mine in Shenyang were studied. The relations of total sulfur and size, total sulfur and density, total sulfur and ash, density and distribution of sulfur were studied. The mineral sulfur whose content is 77.39% in the total sulfur of the coal is the major modality, and the sulfur of the coal samples is well distributed. It doesn’t change with the particle, the density and the ashes. The pyritic sulfur in coal with small grain is difficult to remove by common methods. Organic sulfur content is 20% in the total sulfur of the coal.
03lO1009 Effects of heatin rate and particle size on pyrolysis kinetics of Gediz Bignite
Guldogan, Y. et al. Energy Sources, 2002, 24, (g), 753.-760. Gediz lignite was pyrolysed in a thermobalance apparatus at atmospheric pressure in this study. Effects of heating rate and particle size on the pyrolysis kinetics were examined. Experiments were conducted at non-isothermal conditions with a heating rate range of 10 to 90 Wmin under an argon atmosphere in the pyrolysis temperature interval of 298 to 1173 K. Two different particle size ranges were tested: 595 > D, > 297 and 53 > D > 44 pm. Average relative volatile matter yields were calculated as 48.6 and 39.0% of the total volatile matter yields from 678 to 777 K for the linear segments of the thermogravimetric (TG) curves of the larger and smaller size particles, respectively TG data were analysed by a reaction rate model assuming first-order kinetics, and lower apparent activation energies were calculated at higher heating rates. Minimum apparent activation energy was obtained as 9.05 kJ/mol at the heating rate value of 90 Ki min with 53 > D, > 44 nm size particles.
03/01010 Fluorine distribution characteristics in coal and behavior of fluorine during coal combustion Qi, Q. et al. Huagong Xuebao (Chinese Edition). 2002. 53. (6). 572-577. (In Chinese) In this paper the concentrations of fluorine in typical Chinese coals are detected by the pyrohydrolysis/FISE method. The distribution characteristics of fluorine in coal are obtained. The correlation between fluorine and ash, the probable mode of occurrence of fluorine in coal are discussed. Fluorine concentration ranges 17-3145 ug g-’ and the mean value is close to 200 ugg-or. Good correlation between fluorine and ash content suggested that fluorine is present in these coals in inorganic mineral species. Fluorine emission characteristics during coal combustion are studied systemically in tube furnaces for the first time. The influence factors on fluorine emission and the relationship of fluorine emission with coal type, combustion temperature, retention period and combustion atmosphere are obtained and the production mechanism of gaseous fluorine during coal combustion are proposed. Experimental results indicate that fluorine emission appears to begin at 573-673 K and emission rates reaches about 96% at above 1473 K. Gaseous fluorine is probably originating from fluorine occurring as organic forms or adsorbed inorganic form in coals at low temperatures, and appears to come mainly from fluorine occurring as inorganic salt forms in coal at high temperatures.
03/01011 Gamma-ray transmission technique for quality control of coal seams Raja, N. et al. Canadian Journal of Physics, 2002, 80. (5), 551-555. The useful heat value (UHV) that is the figure of merit for coal depends on various parameters such as fixed carbon, volatiles, ash, and moisture. The percentage of these materials present in a given sample of coal can be estimated by gamma-ray transmission studies. Using gamma rays of energies 30.85 and 81.0 keV, coal samples were studied and the relationships between attenuation coefficients and known UHV and ash contents were obtained. These relationships can be used to measure UHV/ash values for other samples using this simple, fast. and reliable non-destructive method.
01
SOLID Sources,
FUELS winning,
properties
03/01003 A plication of near infrared spectroscopy to rapid analys Ps of coals Kaihara, M. et al. Spectroxopy Letters, 2002, 35, (3), 369-316. Although near IR (NIR) spectra generally have less characteristic absorbance bands than IR spectra, some major properties of coals could be conveniently and rapidly estimated using NIR and partial least squares regression (PLS) model. For example, multiple correlation coefficients for the measured vs. predicted values from obtained spectra, R2, of moisture, volatile matter, oxygen content, maximum fluidity temperature, and solidification temperature were 0.9736, 0.9774 0.8996, 0.8849 and 0.9282, respectively, although the precision of obtained results was not superior to those by the standards of the American Society for Testing and Materials (ASTM).
Binding of atrazine to humic substances from soil. oeat. and coal related to their structure
03/01004
K&&a, N. A. and Perminova, I. V. En~~irowmwtcd Sciem~crrrd Tuchnology, 2002, 36, (17), 3720-3724. Partition coefficients for the binding affinities of atrazine to 16 different humic materials were detected using the ultrafiltration HPLC technique. Sources included humic acids (HA), fulvic acids (FA), and combined humic and fulvic fractions (HF) from soil, peat, and coal humic acid. Each humic material was characterized by elemental composition, molecular weight, and composition of main structural fragments detected by 13C solution-state NMR. The magnitude of Koc values was 87-575 L/kg C, demonstrating relatively low binding affinity of humic substances (HS) for atrazine. Based on measured Koc values, these humic materials were arranged in the following order: coal HA equivalent grey wooded soil HA > chernozemic soil HA and HF > sod-podzolic soil HA equivalent peat HF > sod-podzolic soil FA 3 peat dissolved organic matter. The magnitude of Koc values correlated strongly with the percentage of aromatic C in HS samples (r = 0.91) Hydrophobic binding was hypothesized as the key interaction underlying atrazine binding to HS.
Calculation of the heat capacity of coals OS/O1005 accordin to their elemental composition and the degree of aromatic Bty of the organic matter Gagarin, S. G. and Gyul’maliev, A. M. Khimiya Tverdogo Topliva IMosco~v. Russian Federation), 2002, (3), 3-l I. (In Russian) The molar heat capacity of organic matter of brown, bituminous, and anthracite coals is detected according to the input for the C, H, 0, N, and S atoms, with separating of the C atoms into aromatic, C,, and aliphatic, C,,. These values were obtained by using the data for individual compounds, modelling the structure of the organic matter of mined coals. The specific (mass) heat capacity of a coal (on dry-free basis) is calculated using the values of molecular weight of the fragment containing 100 C atoms. The calculated values satisfactorily agreed with the experimental data.
Combustion and NO, emission behavior of Chinese coals
03/01006
Chen, H. and Xie, K. Chinrse Journal of Chrmical Engineering, 2002, IO. (3), 215-234. Seven Chinese coals ranking from anthracite to sub-bituminous from the Shanxi province were selected for study to forecast the combustion and NO, emission behaviour. Three UK, one Indonesia and one South Africa coals were included in the study for reference. A flat flameturbulent jet apparatus was employed to assess flame stability, ignition performance and NO, emission behaviour for the initial stage of devolatilization and combustion. This apparatus can simulate particle heating rates, maximum temperatures and the influence of the turbulent fluid interactions on the fate of volatiles. To simulate processes occurring over longer residence time, additional devolatilization experiments were performed in a drop tube furnace. Char reactivity was studied through thermogravimetric analysis. Finally, fouling propensity was studied with the aid of a purpose-built laboratory combustor that enabled the characteristics of the ash deposit to be assessed empirically. The results show that Chinese coals do not appear to possess unusual features in respect of NO, formation, flame stability and ignition, char burnout and ash slagging. The range of coals available in China appears sufficiently broad that suits all requirements. In particular, Shenfu coal, with its initial fast devolatilization and nitrogen release rates and its low initial nitrogen content and high char reactivity, will perform well when fired in industrial boilers as far as NO, emission, flame stability and combustion
204
Fuel and Enetxw Abstracts July 2003
efficiency are concerned. Pingshuo coal exhibits high char reactivity and an attractive slagging performance suggesting that this fuel represents a good compromise between NO, emission and overall plant efficiency.
03/01007 Determination of the acid distribution and total acidity of low-rank coals and coal-derived materials by an improved barium exchange technique
Allardice, D. J. et al. Furl, 2003, 82, (I), 35-40. The Schafer technique for the determination of acid distribution and total acidity of low-rank coals has been modified and improved to make the determinations quicker and cheaper without loss of accuracy. The acidity determinations have been extended to hydrophobic coal-derived materials by the addition of a trace of methanol (<0.3%, v/v) to the exchange medium.
03/01008 Distribution of sulfur in coal of Hongyang Third Mine in Shenyang, China
Zhou, Z. et al. Donghei Dame Xurhao. Ziran Kcmrhau. 2002. 23. (2). 164-166. (In Chinese) All kinds of sulfur, ash, total sulfur with different density in coal of Hongyang Third Mine in Shenyang were studied. The relations of total sulfur and size, total sulfur and density, total sulfur and ash, density and distribution of sulfur were studied. The mineral sulfur whose content is 77.39% in the total sulfur of the coal is the major modality, and the sulfur of the coal samples is well distributed. It doesn’t change with the particle, the density and the ashes. The pyritic sulfur in coal with small grain is difficult to remove by common methods. Organic sulfur content is 20% in the total sulfur of the coal.
03lO1009 Effects of heatin rate and particle size on pyrolysis kinetics of Gediz Bignite
Guldogan, Y. et al. Energy Sources, 2002, 24, (g), 753.-760. Gediz lignite was pyrolysed in a thermobalance apparatus at atmospheric pressure in this study. Effects of heating rate and particle size on the pyrolysis kinetics were examined. Experiments were conducted at non-isothermal conditions with a heating rate range of 10 to 90 Wmin under an argon atmosphere in the pyrolysis temperature interval of 298 to 1173 K. Two different particle size ranges were tested: 595 > D, > 297 and 53 > D > 44 pm. Average relative volatile matter yields were calculated as 48.6 and 39.0% of the total volatile matter yields from 678 to 777 K for the linear segments of the thermogravimetric (TG) curves of the larger and smaller size particles, respectively TG data were analysed by a reaction rate model assuming first-order kinetics, and lower apparent activation energies were calculated at higher heating rates. Minimum apparent activation energy was obtained as 9.05 kJ/mol at the heating rate value of 90 Ki min with 53 > D, > 44 nm size particles.
03/01010 Fluorine distribution characteristics in coal and behavior of fluorine during coal combustion Qi, Q. et al. Huagong Xuebao (Chinese Edition). 2002. 53. (6). 572-577. (In Chinese) In this paper the concentrations of fluorine in typical Chinese coals are detected by the pyrohydrolysis/FISE method. The distribution characteristics of fluorine in coal are obtained. The correlation between fluorine and ash, the probable mode of occurrence of fluorine in coal are discussed. Fluorine concentration ranges 17-3145 ug g-’ and the mean value is close to 200 ugg-or. Good correlation between fluorine and ash content suggested that fluorine is present in these coals in inorganic mineral species. Fluorine emission characteristics during coal combustion are studied systemically in tube furnaces for the first time. The influence factors on fluorine emission and the relationship of fluorine emission with coal type, combustion temperature, retention period and combustion atmosphere are obtained and the production mechanism of gaseous fluorine during coal combustion are proposed. Experimental results indicate that fluorine emission appears to begin at 573-673 K and emission rates reaches about 96% at above 1473 K. Gaseous fluorine is probably originating from fluorine occurring as organic forms or adsorbed inorganic form in coals at low temperatures, and appears to come mainly from fluorine occurring as inorganic salt forms in coal at high temperatures.
03/01011 Gamma-ray transmission technique for quality control of coal seams Raja, N. et al. Canadian Journal of Physics, 2002, 80. (5), 551-555. The useful heat value (UHV) that is the figure of merit for coal depends on various parameters such as fixed carbon, volatiles, ash, and moisture. The percentage of these materials present in a given sample of coal can be estimated by gamma-ray transmission studies. Using gamma rays of energies 30.85 and 81.0 keV, coal samples were studied and the relationships between attenuation coefficients and known UHV and ash contents were obtained. These relationships can be used to measure UHV/ash values for other samples using this simple, fast. and reliable non-destructive method.