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01872 Study and simulation of coal pyrolysis in a rotary kiln
A arametrlc evaluation of aretIe-phaeo dynam9WOl%l 80 Ice In an Indue Prlal pulverlzed-ooal-tlred Benin, M. P. and Queimx, M. Fuel, Jan. 1996.75, (2). 195.206.
A parametric study on the variation of particle size and number density with boiler operating conditions has been corn leted in a full-scale, tan cntially fund, 85 MW pulvezixed-coal-fued bol*Per, using a laser-based Ia nostic probe. variablesin the test included boiler load (60 or 85 MW “f coal type. and excess air (2.5 or 4.5%). Two bituminous coals were used: HV and LV, with 7 and 10 wt% ash respectively. Measurements were made in ule radiant section, at the entrance to both the convective pass and economizer, and downstream of the economizer. Variations in particle velocity profiles were correlated with changes in boiler load. Port-to-port velocity variations were associated with changes in the gas flow field imposed by boiler geometry and with gas temperature reductions at downstream locations. se/o1862 Phyelcal In@ combuetlon
structure
changes
of Canadlan
coal8
dur-
Preeeurlzad lacer hf. S. and Egsgaard, H.
T$rn=n,
pyrolyele of coal J. Anal. App. Pyrolysis,
1995,34, (2),
Laser-induced pressurized p rolysis of coal using the visible blue-green emission from an argon ion r aser was described, in which buffer gas pressums of up to 10 bars were possible. Gaseous products formed in He and reactive atmospheres of H, and D, were identified by online gas chromatography/mass spectromety (e.g. to examine in-situ deuteration). 99/019&l behavlor
Pyrolyele of coal model compounds. of benzyl-eubetltuted polyaromatlc compound8 S. e.1al., Energy FueLF, 1995, 9, (5), 849-854.
Thermal
Murata, Describes the pyrolysis behaviour of benxyl-substituted naphthalenes, phenanthrenes, anthracenes, and fIuorenes as coal model compounds at 430” in a sealed tube in the presence or absence of 9$l-dihydroanthracenc as a H donor, alpha-substituted type substrates l$d&nxylnaphthalcne, 9benxylphenanthrene, and 9-benxylanthracene selectivley gave toluene as the cleavage product along with the corresponding polyaromatic fragments accompanied by formation of oligomeric products. %I01
065
Reportlng
of clean
coal
technologlee
Courtney. R. S. Energy World, Dec. 1995. (234), 21-22. A letter in answer to John Hunter who argues for development of his idea for a rotary coal gasificer (RCG) system for clean, coal-fired electricity generation (Energy World, October 1995). %I01868 etudlee
Research method of coal pyrolyele
and
analyele
of result8
the
pyrolyele
The role of low-molecular-welght of pltchee et al, Fuel Dec. 1995, 74. (12).
component8
In
Bermcio. J. 1792-1799. Two &hes of different iolatile conien& bb&ed from the same coal tar by di*Rerent procedures, were characterized by elemental analysis, solubilit,y, ‘H n.m.r., donor-acceptor ability, FT-i.r. extrography and sixe-exclusion chromatogra hy. Their pyrolysis behaviour was followed by hot-stage microscopy and tK ermogravunctric analysis. The pitches were carboniz.ed in a horizontal furnace and the resulting cokea were characterized by optical microscopy. Three partly devolatilixed pitches were prepared by thcrmal treatment of the two pitches and their pyrolysis behaviour was comnarcd in terms of mesonhase develooment and o&al texture of coke. The*results indicate a sign&ant influedce of low-niolecular-weight components of pitch on the development of mesophase but no effect on the subsequent optical texture of the coke. 96101868 hydrocarbon8
Some on
effect8
l ootlng
of molecular tendency
etructure
of
and
carbon
(bumem, drpoeltlon
combustion
systems)
mechanleme
In eth-
al., Fuel, Dec. 1995, 74, (12), 1753-1761. Deposition of soot particles during any combustion process is very uadesirable and can cause both mechanical and environmental problems. An investigation has been carried out of the deposition of soot on to both cooled and uncooled metal robes in rich ethene/air flames using a flatflame, water-cooled burner. #II e processesby which soot particles move to the surface of deposition probes, and the way in which they adhere to the surface, have been explored. The results have shown that the temperature of the probe can have a significant effect on the deposition rated and the chemical nature of the deposits. 99/01870 Stablllty of hy ereonlc reactlng l tagnatlon flow a.detonatablr gae mixture l yeteme analyele % y dynamlcal yl;y2> 0. and Rom, J. Co&&on & F&me, Dec. 1995, 103,
of
(4). . The stability characteristics of the reacting hypersonic flow of the fuel/oxidizer mixture in the stagnation region of a blunt body are studied. The conditions for oscillations of the co&bustion front are &umed to be determined mainly by the flow conditions at the stagnation region. The density at the stagnation region is assumed to be constant at hypersonic flow conditions. By assuming a simplified flow model, the time dependent flow equations, including the heat addition due lo the chemical reactions, are reduced to a second-order nonlinear differential quation for the instantaneous temperature. 99101 a71 Stretched lamlnar flamslet modrllng of turbulent chloromethane-alr nonpremlxed jet flame8 ~.$nirii~D. and Puri, I. K. Combustion & F&me, Dec. 1995, 103,
--- ---.
(4),
An ex rimental and numerical investigation of a nonpremixed turbulent flame gcumin~ chloromethane (CH,Cl) 1s uresented. Fmite-rate chemistrv pla s an imp&ant role in haldgen&l fla&es due lo the inhibitory eff& of ii alogcns on hydrocarbon combustion. The objective of Ihe study is to assess the a plicability of the stretched laminar flamelet model that accounts for Fmite-rate chemistry and differential diffusion effects.
E!872 Lebas. E. et al.,
Study
end
elmulatlon
ot coal
IChemE Res. 1st Event-Eur. Eng., Rugby, UK, 1995. 1,
pyrolysle Conf
In a rotary
Young
Res. Gem.
372-374. Tbe D~OW.SS of coal particles pyrolysis in a rotary kiln has been simulated with-a one dimensio&l steady&& mathematicai model. The model has to take into account the pyrolysis of coal as well as problems related to the technology of rotary kdns: granular solid movement, gasescombustion and heat transfer phenomena. The results are compared with operational data.
Eng.,
Inst.
99lOl973 heatlng
of klnetlc
Ulanovskii, M. L. Ko&s Khim., 1995, (3). 2-6. (In Russian) Reviews the methods of the study of coal pyrolysis kinetics. 96101867
Combustion
-
Gentxis, T. and Chambers, A. Energy Sources, 1995, 17. (1). 131-149. The paper discusses the than es in the physical structure that occur during pulverized coal combustion. %article size and porosity effects are discussed Eaihars of a subbituminous and both high- and low- volatile bituminous se/o1992
Soot %I01 869 me/air flames Smedley, J. M. et
OG
Chem
Thermal
analyele
of coal
under
condltlone
of raDld
rc;vo24n,H. B. and Vastola, F. J. Fuel Process. TechnoL, 1995, 44, (l), - . Describes a quantitative calorimetric study on five coals of different ranks. Coal samples were rapidly pyrolyzed to 875 K with a 200 K/s heating rate and the enthalpy changes were measured. Overall heat effects of pyrolysis in the temperature range from 298 to 875 K were found to be endothermic in nature. 99101974 Thermophoretlc tlcles durlng devolatlllzatlon Ma, J. ef al, Energy Fuels,
eampllng
of coal-derived
soot
par-
1995. 9, (5). 802-808. Thcrmophoretic sampling of soot particles formed during high-temperature coal devolatilixation is performed in order to examine soot particle sixes and shapes.
96/01875
Trajectorlee of burnlng coal ewlrllno reactlvo flow8 Gorres, 5. et 01, Int. J. Heat & Fluid Flow, Oct.
partIcIer
In
hlghly
1995,16, (5): 440450. Finite-element computations and measurements of a strongly swuling flow with pulverized coal combustion are presented.
elngle
Ladommatos. N. cl al., Fuel, Jan. 1996, 75, (2), 114-124. The tendency of various single-component hydrocarbons to release soot from a laminar diffusion flame was investigated using experimental results obtained by the authors and other investigators. The hydrocarbon cornpounds considered include alkanes, alkenes, alkynes, aromatics and polyaromatics. It was found that the structure of hydrocarbon molecules is one of the principal factors governing their sooting tendency in laminar diffusion flames. The ring is by far the most important molecular or submolecular structure and fused cyclic molecules are the most prolific sooter. In the case of non-aromatic hydrocarbons, secondary structural influences that tend to increase the sooting tendency arc the length of the main chain or ring circumference (in terms of carbon atoms) and the number. position and length of side-chains.
%I01 976 Underetandlng NO, flamee: Experlmente and modelllng Turns, S. R. Prog. Energy Cornbust.,
formatlon
In
nonpremlxed
1995, 21, (5), 361-385. Experimental studies and models of NOr formation in simple nonpremixed flames at atmospheric pressure are reviewed. Laminar flames are briefly discussed, while the bulk of the review focuses on axisymmetric, turbulent, jet flames. The issue of the scaling of NO, emission indices with nozzle exit diameter, initial ‘et velocity, and fuel type is a major theme of the article. The failure ot a simple leading-order scaling is investigated and interpreted in terms of the various in&related ameters affe&ng NO formation: the relative importance of various N.F -forming chemical pathways, departures of O-atom concentrations and temperatures from their equilibrium values. flame strain, and flame radiation.
Fuel
and
Energy
Abstracts
March
19%
127
A parametric study on the variation of particle size and number density with boiler operating conditions has been corn leted in a full-scale, tan cntially fund, 85 MW pulvezixed-coal-fued bol*Per, using a laser-based Ia nostic probe. variablesin the test included boiler load (60 or 85 MW “f coal type. and excess air (2.5 or 4.5%). Two bituminous coals were used: HV and LV, with 7 and 10 wt% ash respectively. Measurements were made in ule radiant section, at the entrance to both the convective pass and economizer, and downstream of the economizer. Variations in particle velocity profiles were correlated with changes in boiler load. Port-to-port velocity variations were associated with changes in the gas flow field imposed by boiler geometry and with gas temperature reductions at downstream locations. se/o1862 Phyelcal In@ combuetlon
structure
changes
of Canadlan
coal8
dur-
Preeeurlzad lacer hf. S. and Egsgaard, H.
T$rn=n,
pyrolyele of coal J. Anal. App. Pyrolysis,
1995,34, (2),
Laser-induced pressurized p rolysis of coal using the visible blue-green emission from an argon ion r aser was described, in which buffer gas pressums of up to 10 bars were possible. Gaseous products formed in He and reactive atmospheres of H, and D, were identified by online gas chromatography/mass spectromety (e.g. to examine in-situ deuteration). 99/019&l behavlor
Pyrolyele of coal model compounds. of benzyl-eubetltuted polyaromatlc compound8 S. e.1al., Energy FueLF, 1995, 9, (5), 849-854.
Thermal
Murata, Describes the pyrolysis behaviour of benxyl-substituted naphthalenes, phenanthrenes, anthracenes, and fIuorenes as coal model compounds at 430” in a sealed tube in the presence or absence of 9$l-dihydroanthracenc as a H donor, alpha-substituted type substrates l$d&nxylnaphthalcne, 9benxylphenanthrene, and 9-benxylanthracene selectivley gave toluene as the cleavage product along with the corresponding polyaromatic fragments accompanied by formation of oligomeric products. %I01
065
Reportlng
of clean
coal
technologlee
Courtney. R. S. Energy World, Dec. 1995. (234), 21-22. A letter in answer to John Hunter who argues for development of his idea for a rotary coal gasificer (RCG) system for clean, coal-fired electricity generation (Energy World, October 1995). %I01868 etudlee
Research method of coal pyrolyele
and
analyele
of result8
the
pyrolyele
The role of low-molecular-welght of pltchee et al, Fuel Dec. 1995, 74. (12).
component8
In
Bermcio. J. 1792-1799. Two &hes of different iolatile conien& bb&ed from the same coal tar by di*Rerent procedures, were characterized by elemental analysis, solubilit,y, ‘H n.m.r., donor-acceptor ability, FT-i.r. extrography and sixe-exclusion chromatogra hy. Their pyrolysis behaviour was followed by hot-stage microscopy and tK ermogravunctric analysis. The pitches were carboniz.ed in a horizontal furnace and the resulting cokea were characterized by optical microscopy. Three partly devolatilixed pitches were prepared by thcrmal treatment of the two pitches and their pyrolysis behaviour was comnarcd in terms of mesonhase develooment and o&al texture of coke. The*results indicate a sign&ant influedce of low-niolecular-weight components of pitch on the development of mesophase but no effect on the subsequent optical texture of the coke. 96101868 hydrocarbon8
Some on
effect8
l ootlng
of molecular tendency
etructure
of
and
carbon
(bumem, drpoeltlon
combustion
systems)
mechanleme
In eth-
al., Fuel, Dec. 1995, 74, (12), 1753-1761. Deposition of soot particles during any combustion process is very uadesirable and can cause both mechanical and environmental problems. An investigation has been carried out of the deposition of soot on to both cooled and uncooled metal robes in rich ethene/air flames using a flatflame, water-cooled burner. #II e processesby which soot particles move to the surface of deposition probes, and the way in which they adhere to the surface, have been explored. The results have shown that the temperature of the probe can have a significant effect on the deposition rated and the chemical nature of the deposits. 99/01870 Stablllty of hy ereonlc reactlng l tagnatlon flow a.detonatablr gae mixture l yeteme analyele % y dynamlcal yl;y2> 0. and Rom, J. Co&&on & F&me, Dec. 1995, 103,
of
(4). . The stability characteristics of the reacting hypersonic flow of the fuel/oxidizer mixture in the stagnation region of a blunt body are studied. The conditions for oscillations of the co&bustion front are &umed to be determined mainly by the flow conditions at the stagnation region. The density at the stagnation region is assumed to be constant at hypersonic flow conditions. By assuming a simplified flow model, the time dependent flow equations, including the heat addition due lo the chemical reactions, are reduced to a second-order nonlinear differential quation for the instantaneous temperature. 99101 a71 Stretched lamlnar flamslet modrllng of turbulent chloromethane-alr nonpremlxed jet flame8 ~.$nirii~D. and Puri, I. K. Combustion & F&me, Dec. 1995, 103,
--- ---.
(4),
An ex rimental and numerical investigation of a nonpremixed turbulent flame gcumin~ chloromethane (CH,Cl) 1s uresented. Fmite-rate chemistrv pla s an imp&ant role in haldgen&l fla&es due lo the inhibitory eff& of ii alogcns on hydrocarbon combustion. The objective of Ihe study is to assess the a plicability of the stretched laminar flamelet model that accounts for Fmite-rate chemistry and differential diffusion effects.
E!872 Lebas. E. et al.,
Study
end
elmulatlon
ot coal
IChemE Res. 1st Event-Eur. Eng., Rugby, UK, 1995. 1,
pyrolysle Conf
In a rotary
Young
Res. Gem.
372-374. Tbe D~OW.SS of coal particles pyrolysis in a rotary kiln has been simulated with-a one dimensio&l steady&& mathematicai model. The model has to take into account the pyrolysis of coal as well as problems related to the technology of rotary kdns: granular solid movement, gasescombustion and heat transfer phenomena. The results are compared with operational data.
Eng.,
Inst.
99lOl973 heatlng
of klnetlc
Ulanovskii, M. L. Ko&s Khim., 1995, (3). 2-6. (In Russian) Reviews the methods of the study of coal pyrolysis kinetics. 96101867
Combustion
-
Gentxis, T. and Chambers, A. Energy Sources, 1995, 17. (1). 131-149. The paper discusses the than es in the physical structure that occur during pulverized coal combustion. %article size and porosity effects are discussed Eaihars of a subbituminous and both high- and low- volatile bituminous se/o1992
Soot %I01 869 me/air flames Smedley, J. M. et
OG
Chem
Thermal
analyele
of coal
under
condltlone
of raDld
rc;vo24n,H. B. and Vastola, F. J. Fuel Process. TechnoL, 1995, 44, (l), - . Describes a quantitative calorimetric study on five coals of different ranks. Coal samples were rapidly pyrolyzed to 875 K with a 200 K/s heating rate and the enthalpy changes were measured. Overall heat effects of pyrolysis in the temperature range from 298 to 875 K were found to be endothermic in nature. 99101974 Thermophoretlc tlcles durlng devolatlllzatlon Ma, J. ef al, Energy Fuels,
eampllng
of coal-derived
soot
par-
1995. 9, (5). 802-808. Thcrmophoretic sampling of soot particles formed during high-temperature coal devolatilixation is performed in order to examine soot particle sixes and shapes.
96/01875
Trajectorlee of burnlng coal ewlrllno reactlvo flow8 Gorres, 5. et 01, Int. J. Heat & Fluid Flow, Oct.
partIcIer
In
hlghly
1995,16, (5): 440450. Finite-element computations and measurements of a strongly swuling flow with pulverized coal combustion are presented.
elngle
Ladommatos. N. cl al., Fuel, Jan. 1996, 75, (2), 114-124. The tendency of various single-component hydrocarbons to release soot from a laminar diffusion flame was investigated using experimental results obtained by the authors and other investigators. The hydrocarbon cornpounds considered include alkanes, alkenes, alkynes, aromatics and polyaromatics. It was found that the structure of hydrocarbon molecules is one of the principal factors governing their sooting tendency in laminar diffusion flames. The ring is by far the most important molecular or submolecular structure and fused cyclic molecules are the most prolific sooter. In the case of non-aromatic hydrocarbons, secondary structural influences that tend to increase the sooting tendency arc the length of the main chain or ring circumference (in terms of carbon atoms) and the number. position and length of side-chains.
%I01 976 Underetandlng NO, flamee: Experlmente and modelllng Turns, S. R. Prog. Energy Cornbust.,
formatlon
In
nonpremlxed
1995, 21, (5), 361-385. Experimental studies and models of NOr formation in simple nonpremixed flames at atmospheric pressure are reviewed. Laminar flames are briefly discussed, while the bulk of the review focuses on axisymmetric, turbulent, jet flames. The issue of the scaling of NO, emission indices with nozzle exit diameter, initial ‘et velocity, and fuel type is a major theme of the article. The failure ot a simple leading-order scaling is investigated and interpreted in terms of the various in&related ameters affe&ng NO formation: the relative importance of various N.F -forming chemical pathways, departures of O-atom concentrations and temperatures from their equilibrium values. flame strain, and flame radiation.
Fuel
and
Energy
Abstracts
March
19%
127