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Thermogravimetry-photoionization mass spectrometry of different rank coals
01 Solid fuels {preparation) dichloromethane and the average molecular weight of the extracts were detected. The degree of conversion of the coals studied to the products solubility in dichloromethane was found to be surprisingly high regarding the low-rank coals. This paper puts forward an hypothesis that the high content of sulfur in low rank coals gives them certain properties, typical of coking coals.
00100022 The pore structure of the Argonne coals as interpreted from contrast matching small angle neutron scattering Hall, P. J. er al. Fuel, 2000, 79, (11). 1327-1332. Contrast matching small angle neutron scattering has been performed on a series of Argonne coals using HzO/DzO mixtures using short contact times between the coal and liquid. Calculations of the neutron scattering densities of the coals based on their ‘formulae’ and helium densities are discussed. The results of the CM-SANS are eiven and it is shown that the scattering from the non-contrast-matchgd samples is unreliable. It is also demonstrated that porosity in coals is effectively determined by the presence of water and that porosity levels decrease with increasing rank.
Thermocatalytic processes in the manufacture of chemical products from natural organic polymers - coals and wood biomass 00100023
Kuznetsov, B. N. Khim. Tverd. Topl. (Moscow), 1999, 2, 3-13. (In Russian) Thermocatalytic processes for the conversion of coals and wood biomass are reviewed. Topics include gasification, catalytic hydrogenolysis (hydroliquefaction), Fischer-Tropsch synthesis and carbonization/coking.
Thermogravimetry-photoionization spectrometry of different rank coals
00100024
mass
Zoller, D. L. er al. Energy Fuels, 1999, 13, (5). 1097-l 104. Thermoeravimetrv-ohoto ionization mass soectrometrv ITG-PI-MS) was usedto study;he volatile matter that evolved during’pyrolysis of 26 coals of different rank. The composition of the TGA effluent revealed several significant trends with coal rank. First, the relative intensities of peaks owing to compounds containing oxygen such as C,Ha,O (n = 2, 3, or 4), phenols and dihydroxybenzenes decreased with increasing coal rank. Also, the relative intensities of peaks owing to aromatic compounds such as phenanthrenes, naphthalenes and pyrenes increased with-increasing coal rank. Mass signals due to sulfur compounds evolved from coal showed quality correlations between CSz (%TIC) and pyritic sulfur content and between CHsSH (%TIC) and aliphatic sulfur content. Several of the coals were extracted with a solvent to remove the soluble portion of the coal. TG-PI-MS analysis of the raw coal, extracted material and coal residue remaining after solvent extraction produced very similar mass spectra. These results suggest that the majority of the compounds observed by TG-PI-MS are products of thermal cleavage of bonds within the coal structure. This conclusion is further supported by 337 run laser desorption mass spectrometry of the solvent extracts. In conclusion, the experimental results indicate that volatile matter, such as coal, consists of compounds with a variety of molecular weights, similar to one another in molecular structure.
Trace element analysis of gasification plant samples by i.c.p.-m.s.: validation by comparison of results from two laboratories 00100025
Richaud, R. ef al. Fuel, 2000, 79, (9), 1077-1087. In the absence of either standard methods for trace element analysis of coal-derived chars and ash or standard reference materials for coal gasification samples, a comparative exercise has been undertaken to validate analyses of chars and fines recovered from a coal gasification pilot plant. Several sample digestion methods, used for converting solid samples to aqueous solutions for trace element analysis by i.c.p.-m.s. and i.c.p.-a.e.s., have been compared: peroxide fusion (sodium peroxide + sodium carbonate) and microwave digestion by AEA Technology and wet-ashing (open acid digestion) and microwave digestion by Imperial College (IC). The aim was to analyse samples from a pilot plant scale coal gasification rig. Digestions were carried out using a range of sample sizes, at times as small as 10 mg and analyses of small quantities of these samples were compared with results on the same samples from a specialist contract laboratory (AEA Technology). Elements studied were As, B, Ba, Be, Cd, Co, Cr, Cu, Ga, Hg, Mn, MO, Ni, Pb, Sb, Se, Sn, V and Zn. For the majority of the elements studied, elemental concentrations (l-150 wppm range) were generally in agreement between the two laboratories within 50%. Limitations of the various digestion methods are discussed. All the digestion techniques appeared to lose mercury and therefore a Leco atomic absorption spectrophotometer based method was used to determine Hg. Output solid stream distributions of trace elements from the gasifier indicate that all of the Hg in the fuels was released to 4
Fuel and Energy Abstracts
January 2001
the fuel gas. The primary cyclone fines stream contained the major part of the trace elements from the fuels. The causes of apparent losses of As, MO, Pb, Sn, Zn and Se are discussed.
Use of infrared thermography for the evaluation of heat losses during coal storage 00/00026
Fierro, V. et al. Fuel Process. Technol., 1999, 60, (3). 213-229. During coal storage, exothermic processes occur, which reduces the coal’s calorific value and in turn results in financial losses. Methods for evaluating the effectiveness of control of spontaneous heating of coal and for oredictine hot soots in coal oiles were studied. In the investigat;on, the type of coal used was ‘Mezcla’. Three experimental coal piles were built: a high porosity pile, a periodically compacted oile and a pile with a low angle slope in the-prevailing wind- direction. ASINEL develooed a mathematical model that allowed the calculation of the heat fluxes due to spontaneous heating. The self-heating behaviour of the pile was also followed by an infra-red thermogravimetric camera that permitted the detection of heat fluxes.
Water-related issues in permafrost mining, with special emphasis on the coal mining of Spitsbergen (Norway) 00100027
Wandinger, M. Mine Water Environ., 1999, 18, (1), 67-74. Permafrost mining is described, with special emphasis given to water issues. Most of the mines discussed are Spitsbergen coal mines (Norway). In general, when mining within the permafrost zone, problems include supplying water for the operational processes, the explosivity of the very dry coal dust and hoar-frost formation due to humidity introduced by ventilation. In the non-frozen rocks below the permafrost, the technical problems are largely the same as encountered while mining elsewhere in the world. However, special care must be taken in-the transition zone between the permafrost and the nonfrozen rocks. It is possible for methane to accumulate below the impermeable permafrost and for groundwater intrusions to occur.
XAFS study on the thermal behavior of nickel species dispersed in brown coals Shirai, M. et al. Jpn. J. Appl. Phys., Part 1, 1999, 38, 77-80.
00/00026
The behaviour of ion-exchanged nickel species in pyrolysed Loy Yang brown coal was analysed. Chlorine gas evolution was affected by the amount of nickel species loaded. XAFS analysis showed that the exchanged nickel ions aggregated to metal particles during pyrolysis and that the agglomeration temperature depended on the nickel loading. Nickel species catalytic behaviour for the pyrolysis of coal can be explained by their aggregative behaviour.
Preparation 00100029 A new physical process for desulfurization of low-rank coals Celik, M. S. and Yildirim, I. Fuel, 2000, 79, (13), 1665-1669. A processing route involving low temperature carbonization followed by dry magnetic separation is put forward for the desulfurization and deashing of typical low-rank lignitic coals. The -3 mm lignite samples were subjected to low temperature carbonization at 600°C for 15 min and then upgraded by magnetic separation. Under optimum conditions, a remarkable decrease in both ash and more importantly in total and particularly organic sulfur was achieved. A systematic study of the mechanism of the sulfur removal together with the literature findings reveals the formation of an iron-sulfur coordination compound in coal. A study of a multistage column for fine coal beneficiation Gu, X. et al. Coal Prep. (Cordon & Breach), 1999, 20, (I-2). 107-117.
00100030
For fine coal beneficiation a novel multistage column was successfully developed. In order to enhance the separation process, this new column uses vortex-inducing contactors. This paper presents an exoerimental studv of the beneficiation characteristics of such a miltistage column’in terms of recovery rate, heating value recovery and impurity rejection. The paper also describes the effects of dosage on the column performance. Comparisons are made between these test results and those obtained from the conventional column (minus the vortex-inducing contactors).
Additives for smoke abatement, decontamination and energy-saving In burning coal 00/00031
Wang, Q. and Wang, Y. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,165,179 (Cl. ClOL10/02), 19 Nov 1997, Appl. 97,105,071, 31 Jan 1997. 5. (In Chinese)
00100022 The pore structure of the Argonne coals as interpreted from contrast matching small angle neutron scattering Hall, P. J. er al. Fuel, 2000, 79, (11). 1327-1332. Contrast matching small angle neutron scattering has been performed on a series of Argonne coals using HzO/DzO mixtures using short contact times between the coal and liquid. Calculations of the neutron scattering densities of the coals based on their ‘formulae’ and helium densities are discussed. The results of the CM-SANS are eiven and it is shown that the scattering from the non-contrast-matchgd samples is unreliable. It is also demonstrated that porosity in coals is effectively determined by the presence of water and that porosity levels decrease with increasing rank.
Thermocatalytic processes in the manufacture of chemical products from natural organic polymers - coals and wood biomass 00100023
Kuznetsov, B. N. Khim. Tverd. Topl. (Moscow), 1999, 2, 3-13. (In Russian) Thermocatalytic processes for the conversion of coals and wood biomass are reviewed. Topics include gasification, catalytic hydrogenolysis (hydroliquefaction), Fischer-Tropsch synthesis and carbonization/coking.
Thermogravimetry-photoionization spectrometry of different rank coals
00100024
mass
Zoller, D. L. er al. Energy Fuels, 1999, 13, (5). 1097-l 104. Thermoeravimetrv-ohoto ionization mass soectrometrv ITG-PI-MS) was usedto study;he volatile matter that evolved during’pyrolysis of 26 coals of different rank. The composition of the TGA effluent revealed several significant trends with coal rank. First, the relative intensities of peaks owing to compounds containing oxygen such as C,Ha,O (n = 2, 3, or 4), phenols and dihydroxybenzenes decreased with increasing coal rank. Also, the relative intensities of peaks owing to aromatic compounds such as phenanthrenes, naphthalenes and pyrenes increased with-increasing coal rank. Mass signals due to sulfur compounds evolved from coal showed quality correlations between CSz (%TIC) and pyritic sulfur content and between CHsSH (%TIC) and aliphatic sulfur content. Several of the coals were extracted with a solvent to remove the soluble portion of the coal. TG-PI-MS analysis of the raw coal, extracted material and coal residue remaining after solvent extraction produced very similar mass spectra. These results suggest that the majority of the compounds observed by TG-PI-MS are products of thermal cleavage of bonds within the coal structure. This conclusion is further supported by 337 run laser desorption mass spectrometry of the solvent extracts. In conclusion, the experimental results indicate that volatile matter, such as coal, consists of compounds with a variety of molecular weights, similar to one another in molecular structure.
Trace element analysis of gasification plant samples by i.c.p.-m.s.: validation by comparison of results from two laboratories 00100025
Richaud, R. ef al. Fuel, 2000, 79, (9), 1077-1087. In the absence of either standard methods for trace element analysis of coal-derived chars and ash or standard reference materials for coal gasification samples, a comparative exercise has been undertaken to validate analyses of chars and fines recovered from a coal gasification pilot plant. Several sample digestion methods, used for converting solid samples to aqueous solutions for trace element analysis by i.c.p.-m.s. and i.c.p.-a.e.s., have been compared: peroxide fusion (sodium peroxide + sodium carbonate) and microwave digestion by AEA Technology and wet-ashing (open acid digestion) and microwave digestion by Imperial College (IC). The aim was to analyse samples from a pilot plant scale coal gasification rig. Digestions were carried out using a range of sample sizes, at times as small as 10 mg and analyses of small quantities of these samples were compared with results on the same samples from a specialist contract laboratory (AEA Technology). Elements studied were As, B, Ba, Be, Cd, Co, Cr, Cu, Ga, Hg, Mn, MO, Ni, Pb, Sb, Se, Sn, V and Zn. For the majority of the elements studied, elemental concentrations (l-150 wppm range) were generally in agreement between the two laboratories within 50%. Limitations of the various digestion methods are discussed. All the digestion techniques appeared to lose mercury and therefore a Leco atomic absorption spectrophotometer based method was used to determine Hg. Output solid stream distributions of trace elements from the gasifier indicate that all of the Hg in the fuels was released to 4
Fuel and Energy Abstracts
January 2001
the fuel gas. The primary cyclone fines stream contained the major part of the trace elements from the fuels. The causes of apparent losses of As, MO, Pb, Sn, Zn and Se are discussed.
Use of infrared thermography for the evaluation of heat losses during coal storage 00/00026
Fierro, V. et al. Fuel Process. Technol., 1999, 60, (3). 213-229. During coal storage, exothermic processes occur, which reduces the coal’s calorific value and in turn results in financial losses. Methods for evaluating the effectiveness of control of spontaneous heating of coal and for oredictine hot soots in coal oiles were studied. In the investigat;on, the type of coal used was ‘Mezcla’. Three experimental coal piles were built: a high porosity pile, a periodically compacted oile and a pile with a low angle slope in the-prevailing wind- direction. ASINEL develooed a mathematical model that allowed the calculation of the heat fluxes due to spontaneous heating. The self-heating behaviour of the pile was also followed by an infra-red thermogravimetric camera that permitted the detection of heat fluxes.
Water-related issues in permafrost mining, with special emphasis on the coal mining of Spitsbergen (Norway) 00100027
Wandinger, M. Mine Water Environ., 1999, 18, (1), 67-74. Permafrost mining is described, with special emphasis given to water issues. Most of the mines discussed are Spitsbergen coal mines (Norway). In general, when mining within the permafrost zone, problems include supplying water for the operational processes, the explosivity of the very dry coal dust and hoar-frost formation due to humidity introduced by ventilation. In the non-frozen rocks below the permafrost, the technical problems are largely the same as encountered while mining elsewhere in the world. However, special care must be taken in-the transition zone between the permafrost and the nonfrozen rocks. It is possible for methane to accumulate below the impermeable permafrost and for groundwater intrusions to occur.
XAFS study on the thermal behavior of nickel species dispersed in brown coals Shirai, M. et al. Jpn. J. Appl. Phys., Part 1, 1999, 38, 77-80.
00/00026
The behaviour of ion-exchanged nickel species in pyrolysed Loy Yang brown coal was analysed. Chlorine gas evolution was affected by the amount of nickel species loaded. XAFS analysis showed that the exchanged nickel ions aggregated to metal particles during pyrolysis and that the agglomeration temperature depended on the nickel loading. Nickel species catalytic behaviour for the pyrolysis of coal can be explained by their aggregative behaviour.
Preparation 00100029 A new physical process for desulfurization of low-rank coals Celik, M. S. and Yildirim, I. Fuel, 2000, 79, (13), 1665-1669. A processing route involving low temperature carbonization followed by dry magnetic separation is put forward for the desulfurization and deashing of typical low-rank lignitic coals. The -3 mm lignite samples were subjected to low temperature carbonization at 600°C for 15 min and then upgraded by magnetic separation. Under optimum conditions, a remarkable decrease in both ash and more importantly in total and particularly organic sulfur was achieved. A systematic study of the mechanism of the sulfur removal together with the literature findings reveals the formation of an iron-sulfur coordination compound in coal. A study of a multistage column for fine coal beneficiation Gu, X. et al. Coal Prep. (Cordon & Breach), 1999, 20, (I-2). 107-117.
00100030
For fine coal beneficiation a novel multistage column was successfully developed. In order to enhance the separation process, this new column uses vortex-inducing contactors. This paper presents an exoerimental studv of the beneficiation characteristics of such a miltistage column’in terms of recovery rate, heating value recovery and impurity rejection. The paper also describes the effects of dosage on the column performance. Comparisons are made between these test results and those obtained from the conventional column (minus the vortex-inducing contactors).
Additives for smoke abatement, decontamination and energy-saving In burning coal 00/00031
Wang, Q. and Wang, Y. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,165,179 (Cl. ClOL10/02), 19 Nov 1997, Appl. 97,105,071, 31 Jan 1997. 5. (In Chinese)