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00925 Sorption properties of carbonaceous materials
01 residence times can be varied between ~0.02 and -10 s depending upon operating conditions and positions of injection and sampling probes. Observation ports are available for sample collections and for optical investigation of the reactions or temperature measurements. Although the gas temperature profile in the furnace is affected by the water-cooled injection probe, the furnace is able to achieve isothermal operation in a developing laminar flow regime. The suitability of the furnace for coal research experiments was demonstrated by results from a series of brown coal devolatilization tests.
Radial distribution (X-ray) study of Boragolai coal 99100915 Boruah, R. K. et al. Indian J. Pure Appl. Phys., 1997, 35, (12), 771-772. From an X-ray diffraction pattern the coal reveals that it is amorphous in nature. Radial distribution analysis of its XRD pattern indicates that this coal is lignitic in type and there is no evidence of its graphite-like structure. Reactions of Pittsburgh No. 8 coal with maleic 99100916 anhydride evidence for the existence of reactive diene structures in goal Larsen, .I. W. et al. Energy Fuels, 1998, 12, (5). 856-863. NMR was deployed to research the reaction between ‘sC-labelled maleic anhydride and Pittsburgh No. 8 coal. The occurrence of the following reactions has been ruled out: ene reaction, maleic anhydride polymerization, ester formation, radical addition, electron transfer and physical entrapment. Model systems demonstrated Michael addition to -SH, but does not occur with -OH groups and cannot explain the observed 10-20 wt% incorporation of maleic anhydride. All data were consistent with Diels-Alder reactions. There are not enough reactive dienes in any coal structure model to yield the large maleic anhydride incorporations observed. It is concluded that current coal structures are either seriously incorrect or the coal is exhibiting strongly enhanced reactivity whose origin is not understood.
99100917
Reactive inerlinite in coals of South Africa
Kruszewska, K. Karbo-Energochem. Ekol., 1998,43, (3), 93-98. (In Polish) During the coking process, reactive inertinite with colour and reflectivity approximated to vitrinite has the capacity to pass through a mesophase and together with vitrinite forms a coke of mosaic structure. An incompletely transformed semi-reactive inertinite with slightly brighter colour and higher reflectivity is visible in coking mass in the plastic form. The most oxidized pieces of inertinite do not undergo any transformations and form separated bodies in coking mass. This paper then discusses how reactive inertinites in coals of South Africa have been differentiated depending on a deposit pattern.
The reactivity of chars from coal, peat and wood 99108978 towards NO, with and without CO
Zevenhoven, R. and Hupa, M. Fuel, 1998, 77, (11) 1169-1176. In this paper the reduction of NO by chemical reaction with chars prepared from bituminous coal, peat and wood was studied, with and without CO present in the gas. Chars were prepared in pure nitrogen at the same temperatures (750, 850 and 950°C) as for the NO reduction. Tests were conducted in a quartz fixed bed reactor with gas analysis for NO, CO and the product gas COz. Since no oxygen was present, the bulk gas was nitrogen. Eleven different solid fuel qualities were studied. Chars from peat and lignite appeared more reactive with respect to NO than chars from bituminous coal or wood. This trend was different from char gasification reactivities of these fuels, which increased with increasing fuel volatility. Activation energies were in the range 28-131 kJ/mol for the NO reduction with CO catalysed by the char against 29-95 kJ/mol for the NO reduction by char. The reduction of NO for peat was found to be faster without CO than with CO present in the gas. Correlations between NO reduction capacity and char composition were made, which showed the catalytic effect of calcium, magnesium and potassium.
Reactivity of granular coal injected in rotary kiln at 99100919 discharge end and its effect on ore reduction Zhao, Q. et al. Gangtie, 1997, 32, (7) 10-13, 9. (In Chinese) Studied was the reactivity of granular coal injected into rotary kiln at the discharge end and its effect on ore reduction. The pulverized coal injected at the discharge end of the kiln was heated at high speed, the structure of the coal was changed and the reactivity of the coal with CO2 was increased. The relationship between coal gasification rate constant (Km) and heating speed (v,) is Km = Av,~ and the relationship between pellet reduction rate and Km is approximately linear. By pulverized coal injection the mechanism of the increase in reduction was revealed.
Reactor and process for upgrading solid materials, such as coal, having low thermal conductivity
Solid fuels (sources, winning, properties)
fluid and the solid materials in the region of the plate. Thus, substantially all of the solids are heated or cooled to a desired temperature range by heat exchange between the heat-transfer fluid and the solids via the plates.
99100921 Review of research of low molecular weight compounds of coal Wang, N. el al. Meitan Zhuanhua, 1997, 20, (3). 19-24. (In Chinese) Research of low-molecular-weight compounds in coal is reviewed. Areas covered are; the history and present situation of research on low molecular weight compounds in coal; methods and problems of research on the low molecular weight compounds of coal; and the role of the low molecular weight compounds of coal in the conversion of coal.
Search for efficient directions in the use of peat in 99100922 the Arkhangelsk region conditions
Sokolov, 0. M. er al. Razved. Okhr. Nedr., 1997, (1 I), 19-20. (In Russian) In peat bogs of this region the ash content is slightly lower than in regions with developed peat industry. In this region especially, calorific value and bulk density of the peat are considered to be prospective as alternative fuel.
Selective maceral enrichment during grinding and effect of particle size on coal devolatilization yields
99100923
Man, C. K. et al. Fuel Process. Technol., 1998, 56, (3) 215-227. Using a wire-mesh apparatus the effect of coal particle size on volatiles yields obtained by rapid heating of a range of particle-size fractions prepared from three different coals were measured. Samples were pyrolysed in helium at heating rates of 1000 K/s to 950” with a 10 s hold time. Particle-size fractions (38-150 ILrn) were prepared by two methods: sieving from a ground coal and regrinding the largest-sieved size fraction. The latter approach was used in an (partially successful) effort to minimize differences in size-cut compositions Total daf (dry ash-free basis) volatile yields increase slightly with decreasing particle size, but for two of the coals, this effect was not monotonic over the size range 38-150 ,Irn and was also dependent on the sample preparation method. In all cases, showing significant differences was the maceral analysis; however, smaller particlesize fractions were generally enriched in liptinite. To examine the effect of particle size without interference from maceral enrichment, a vitrain was used to prepare size fractions of 38-300 /Irn. Volatile yields from these samples were virtuahy identical. Mass transfer effects due to different particle sizes were probably less significant than unavoidable maceral enrichment effects during sample preparation. A comparison of thermogravimetric analysis volatile yield measurements was a reasonable indicator of whether or not the size fraction has a similar composition to the whole coal, for rapid-heating volatile release tests (e.g. drop-tube furnace, wiremesh apparatus) requiring a sized coal sample.
Sorption behaviors of various organic vapors to Argonne premium coal samples
99100924
Shimizu, K. el al. Energy Fuels, 1998, 12, (5) 891-896. In order to clarify the coal-organic interaction, sorption mechanism and micropore and crosslinking structure of coals, sorption of various organic vapours by Argonne Premium coals was investigated. In particular, the sorption at low vapour pressures could be measured under a temperatureand pressure-controlled gravimetric sorption system. Methanol was quickly sorbed by all the coals used. In contrast, pyridine was slowly sorbed by Beulah-Zap lignite coal and a significant portion of pyridine was retained after desorption. The quantity of methanol sorption at saturation vapour pressure (P/P,,) at 30°C showed a good correlation with oxygen % (daf) in the raw coals indicating that methanol is sorbed by the coals through interaction with oxygen functional sites. Both the Langmuir-Henry and Dubinin-Radushkevitch-Henry dual-mode sorption equations could explain the methanol isotherm for high-rank Pocahontas No. 3 and Upper Freeport coals, while for the other coals the Langmuir-Henry equation was better for the approximation. For Illinois No. 6 coal, the sorption could be treated by the Langmuir-Henry equation regardless of the kinds of organic vapours. For Beulah-Zap coal, the sorptions of benzene and cyclohexane were significantly small due to their small interactions with the coal surface, resulting in either dual-mode equation being inadequate. In contrast, benzene or pyridine sorption isotherms could not be determined in highrank coals due to their slow sorption.
Sorption properties of carbonaceous materials 99100925 Zubilin, I. G. et al. Koks Khim., 1998, (4), 14-18. (In Russian) Coke sorption properties were studied and modification of their surfaces was examined. The surfaces were modified by benzamide oxime. Also investigated was the effect of surface modification on sorption of chlorides of copper, cobalt and nickel.
99ioo92o
Conochie, D. S. and Matthews, D. J. PCT Int. Appl. WO 98 30,856 (Cl. F28D9/00), 16 Jul 1998, AU Appl. 97/4,513, 8 Jan 1997, 35 pp. The outer shell of the reactor defines an internal volume for retaining a packed bed of solid materials to be treated and a number of plates of a thermally conductive material which are positioned within the internal volume. Each plate includes one or more passageway or passageways through which a heat-transfer fluid can flow. In use, each plate defines one or more thermally conductive bypass or bypasses between the heat-transfer
Structural changes of organic sulfur compounds occurring in coal from the Janina mine in pyrolysis and hydropyrolysis processes
99100928
Stanczyk, K. Karbo-EnergoChem.-Ekol., 1998.43, (4), 152-154. (In Polish) By using TPR (temperature programmed reduction) the transformation of organic sulfur compounds during pyrolysis and hydropyrolysis of coal was determined. Hydrogen’s role in the transformation of less stable sulfur forms to stable, condensed thiophenic structures is discussed.
Fuel and Energy Abstracts
March 1999 99
Radial distribution (X-ray) study of Boragolai coal 99100915 Boruah, R. K. et al. Indian J. Pure Appl. Phys., 1997, 35, (12), 771-772. From an X-ray diffraction pattern the coal reveals that it is amorphous in nature. Radial distribution analysis of its XRD pattern indicates that this coal is lignitic in type and there is no evidence of its graphite-like structure. Reactions of Pittsburgh No. 8 coal with maleic 99100916 anhydride evidence for the existence of reactive diene structures in goal Larsen, .I. W. et al. Energy Fuels, 1998, 12, (5). 856-863. NMR was deployed to research the reaction between ‘sC-labelled maleic anhydride and Pittsburgh No. 8 coal. The occurrence of the following reactions has been ruled out: ene reaction, maleic anhydride polymerization, ester formation, radical addition, electron transfer and physical entrapment. Model systems demonstrated Michael addition to -SH, but does not occur with -OH groups and cannot explain the observed 10-20 wt% incorporation of maleic anhydride. All data were consistent with Diels-Alder reactions. There are not enough reactive dienes in any coal structure model to yield the large maleic anhydride incorporations observed. It is concluded that current coal structures are either seriously incorrect or the coal is exhibiting strongly enhanced reactivity whose origin is not understood.
99100917
Reactive inerlinite in coals of South Africa
Kruszewska, K. Karbo-Energochem. Ekol., 1998,43, (3), 93-98. (In Polish) During the coking process, reactive inertinite with colour and reflectivity approximated to vitrinite has the capacity to pass through a mesophase and together with vitrinite forms a coke of mosaic structure. An incompletely transformed semi-reactive inertinite with slightly brighter colour and higher reflectivity is visible in coking mass in the plastic form. The most oxidized pieces of inertinite do not undergo any transformations and form separated bodies in coking mass. This paper then discusses how reactive inertinites in coals of South Africa have been differentiated depending on a deposit pattern.
The reactivity of chars from coal, peat and wood 99108978 towards NO, with and without CO
Zevenhoven, R. and Hupa, M. Fuel, 1998, 77, (11) 1169-1176. In this paper the reduction of NO by chemical reaction with chars prepared from bituminous coal, peat and wood was studied, with and without CO present in the gas. Chars were prepared in pure nitrogen at the same temperatures (750, 850 and 950°C) as for the NO reduction. Tests were conducted in a quartz fixed bed reactor with gas analysis for NO, CO and the product gas COz. Since no oxygen was present, the bulk gas was nitrogen. Eleven different solid fuel qualities were studied. Chars from peat and lignite appeared more reactive with respect to NO than chars from bituminous coal or wood. This trend was different from char gasification reactivities of these fuels, which increased with increasing fuel volatility. Activation energies were in the range 28-131 kJ/mol for the NO reduction with CO catalysed by the char against 29-95 kJ/mol for the NO reduction by char. The reduction of NO for peat was found to be faster without CO than with CO present in the gas. Correlations between NO reduction capacity and char composition were made, which showed the catalytic effect of calcium, magnesium and potassium.
Reactivity of granular coal injected in rotary kiln at 99100919 discharge end and its effect on ore reduction Zhao, Q. et al. Gangtie, 1997, 32, (7) 10-13, 9. (In Chinese) Studied was the reactivity of granular coal injected into rotary kiln at the discharge end and its effect on ore reduction. The pulverized coal injected at the discharge end of the kiln was heated at high speed, the structure of the coal was changed and the reactivity of the coal with CO2 was increased. The relationship between coal gasification rate constant (Km) and heating speed (v,) is Km = Av,~ and the relationship between pellet reduction rate and Km is approximately linear. By pulverized coal injection the mechanism of the increase in reduction was revealed.
Reactor and process for upgrading solid materials, such as coal, having low thermal conductivity
Solid fuels (sources, winning, properties)
fluid and the solid materials in the region of the plate. Thus, substantially all of the solids are heated or cooled to a desired temperature range by heat exchange between the heat-transfer fluid and the solids via the plates.
99100921 Review of research of low molecular weight compounds of coal Wang, N. el al. Meitan Zhuanhua, 1997, 20, (3). 19-24. (In Chinese) Research of low-molecular-weight compounds in coal is reviewed. Areas covered are; the history and present situation of research on low molecular weight compounds in coal; methods and problems of research on the low molecular weight compounds of coal; and the role of the low molecular weight compounds of coal in the conversion of coal.
Search for efficient directions in the use of peat in 99100922 the Arkhangelsk region conditions
Sokolov, 0. M. er al. Razved. Okhr. Nedr., 1997, (1 I), 19-20. (In Russian) In peat bogs of this region the ash content is slightly lower than in regions with developed peat industry. In this region especially, calorific value and bulk density of the peat are considered to be prospective as alternative fuel.
Selective maceral enrichment during grinding and effect of particle size on coal devolatilization yields
99100923
Man, C. K. et al. Fuel Process. Technol., 1998, 56, (3) 215-227. Using a wire-mesh apparatus the effect of coal particle size on volatiles yields obtained by rapid heating of a range of particle-size fractions prepared from three different coals were measured. Samples were pyrolysed in helium at heating rates of 1000 K/s to 950” with a 10 s hold time. Particle-size fractions (38-150 ILrn) were prepared by two methods: sieving from a ground coal and regrinding the largest-sieved size fraction. The latter approach was used in an (partially successful) effort to minimize differences in size-cut compositions Total daf (dry ash-free basis) volatile yields increase slightly with decreasing particle size, but for two of the coals, this effect was not monotonic over the size range 38-150 ,Irn and was also dependent on the sample preparation method. In all cases, showing significant differences was the maceral analysis; however, smaller particlesize fractions were generally enriched in liptinite. To examine the effect of particle size without interference from maceral enrichment, a vitrain was used to prepare size fractions of 38-300 /Irn. Volatile yields from these samples were virtuahy identical. Mass transfer effects due to different particle sizes were probably less significant than unavoidable maceral enrichment effects during sample preparation. A comparison of thermogravimetric analysis volatile yield measurements was a reasonable indicator of whether or not the size fraction has a similar composition to the whole coal, for rapid-heating volatile release tests (e.g. drop-tube furnace, wiremesh apparatus) requiring a sized coal sample.
Sorption behaviors of various organic vapors to Argonne premium coal samples
99100924
Shimizu, K. el al. Energy Fuels, 1998, 12, (5) 891-896. In order to clarify the coal-organic interaction, sorption mechanism and micropore and crosslinking structure of coals, sorption of various organic vapours by Argonne Premium coals was investigated. In particular, the sorption at low vapour pressures could be measured under a temperatureand pressure-controlled gravimetric sorption system. Methanol was quickly sorbed by all the coals used. In contrast, pyridine was slowly sorbed by Beulah-Zap lignite coal and a significant portion of pyridine was retained after desorption. The quantity of methanol sorption at saturation vapour pressure (P/P,,) at 30°C showed a good correlation with oxygen % (daf) in the raw coals indicating that methanol is sorbed by the coals through interaction with oxygen functional sites. Both the Langmuir-Henry and Dubinin-Radushkevitch-Henry dual-mode sorption equations could explain the methanol isotherm for high-rank Pocahontas No. 3 and Upper Freeport coals, while for the other coals the Langmuir-Henry equation was better for the approximation. For Illinois No. 6 coal, the sorption could be treated by the Langmuir-Henry equation regardless of the kinds of organic vapours. For Beulah-Zap coal, the sorptions of benzene and cyclohexane were significantly small due to their small interactions with the coal surface, resulting in either dual-mode equation being inadequate. In contrast, benzene or pyridine sorption isotherms could not be determined in highrank coals due to their slow sorption.
Sorption properties of carbonaceous materials 99100925 Zubilin, I. G. et al. Koks Khim., 1998, (4), 14-18. (In Russian) Coke sorption properties were studied and modification of their surfaces was examined. The surfaces were modified by benzamide oxime. Also investigated was the effect of surface modification on sorption of chlorides of copper, cobalt and nickel.
99ioo92o
Conochie, D. S. and Matthews, D. J. PCT Int. Appl. WO 98 30,856 (Cl. F28D9/00), 16 Jul 1998, AU Appl. 97/4,513, 8 Jan 1997, 35 pp. The outer shell of the reactor defines an internal volume for retaining a packed bed of solid materials to be treated and a number of plates of a thermally conductive material which are positioned within the internal volume. Each plate includes one or more passageway or passageways through which a heat-transfer fluid can flow. In use, each plate defines one or more thermally conductive bypass or bypasses between the heat-transfer
Structural changes of organic sulfur compounds occurring in coal from the Janina mine in pyrolysis and hydropyrolysis processes
99100928
Stanczyk, K. Karbo-EnergoChem.-Ekol., 1998.43, (4), 152-154. (In Polish) By using TPR (temperature programmed reduction) the transformation of organic sulfur compounds during pyrolysis and hydropyrolysis of coal was determined. Hydrogen’s role in the transformation of less stable sulfur forms to stable, condensed thiophenic structures is discussed.
Fuel and Energy Abstracts
March 1999 99