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01634 Study of pyrolysis of blends of gas-coking coal and soft brown coal
01 Solid fuels (derived solid fuels) 03/01627 Chemical characteristics of coke on MolHZSM-5 catalysts for methane dehydroaromatization under nonoxidative conditions by TP techniques
03/01631 EPR study on petroleum cokes annealed at different temperatures and used in lithium and sodium batteries
Liu, H.-M. et al. Gaodeng Xuexiao Huaxue Xuebao, 2002, 23, (8), 15561561. (In Chinese) Over Mo/HZSM-5 catalysts, various carbonaceous depositions occurred during the course of methane dehydroaromatization (MDA). These species of surface carbon formed on HZSM-5 zeolite or MO/ HZSM-5 catalysts with different MO loadings were investigated by TPH, TPCO* and TPO in combination with thermal gravimetric analysis.(TG). The results of TG revealed that, the total amount of coke formed on 6Mo/MCM-22 during TPSR is larger than those formed on HZSM-5 zeolite, 2Mo HZSM-5 and lOMo/HZSM-5 catalysts. The TPO profiles recorded during the procedure of coke burning-off show hvo different temperature peaks. The results of TPO and TG after TPH suggested that, the TPH experiments only had an effect on the coke burnt-off at a high temperature, but didn’t result in the diminishing of the coke burnt-off at low temperature peak. On the other hand, the result of the coked catalyst after succeeding TPCOz experiments exhibited an obvious reduction in the areas of both the high and low temperature peaks, particularly in the area of the low temperature peak. The study on the catalysts with different MO loadings suggested that, the percentage of the coke burnt-off at a low temperature turned larger with the increase of MO loading, respectively. And the change trend of the coke burnt-off at a high temperature was opposite exactly. By using the experiments of TPSR, TPH, TPCO? and TG, quantity analysis of the coke and the kinetics of its burning-off process were done. The results show that, either TPH or TPC02 can diminish the starting temperature and decrease the activation energy, and there are some differences among the catalysts with various MO loadings.
Zhecheva, E. et al. Carbon, 2002, 40, (13), 2301-2306. EPR spectroscopy was used for characterization of petroleum cokes heat-treated in the temperature range of 480-2800°C and after their electrochemical reactions with lithium and sodium. Unpaired spins with localized character were detected for cokes treated below lOOo”C, while delocalized electrons were found to contribute to the EPR profile of cokes treated between 1400 and 2800°C. After electrochemical interaction of cokes with lithium, the EPR signal due to delocalized electrons undergoes a strong line narrowing combined with an increase in signal intensity. Localized paramagnetic centres interact with Li and Na, as a result of which there is a line narrowing and decrease in the signal intensity. A new narrow signal is detected for low-temperature cokes after reaction with lithium. The origin of this signal could be associated with ‘near-metallic’ lithium, which is accommodated in nonordinary carbon sites such as microcavities. The intensity of this signal is higher for samples treated at 6OO”C, where a higher hysteresis in the voltage versus composition curve is observed.
03101626 Combined effects of pressure and ionexchangeable metallic species on pyrolysis of Victorian lignite
Sathe, C. et al. Fuel, 2003, 82, (3), 343-350. A set of ion-exchanged samples prepared from Loy Yang lignite was pyrolysed in a wire-mesh reactor at elevated pressures from 1 to 36 bar. The tar yields from the pyrolysis of H-form (acid-washed) sample at a fast heating rate of 1000°C s-l were drastically reduced by increasing pressure to 6 bar and then remained unchanged with further increase in pressure to 36 bar. This behaviour of the tar yield was in sharp contrast to that from the raw lignite, which showed a minimum with increasing pressure. The sensitivities of the tar yields to changes in the heating rate were also suppressed by increasing pressure. The tar yields from Ca-form and Na-form samples (prepared by ion-exchanging Ca and Na on the H-form sample, respectively) were not very sensitive to changes in the heating rate and pressure up to 11 bar. At 20 bar, the tar yields from the Na-from sample nearly doubled whereas from the Caform sample nearly halved compared to those respective values at 1 bar. Although increasing pressure is thought to cause changes in the intra-particle mass transfer processes of volatile precursors, the rate of formation of volatile precursors tends to dictate the kind of mass transfer process responsible for the release of volatiles. Therefore, depending on the pyrolysis condition, bulk diffusion or forced flow would dominate the mass transfer processes for the release of volatiles. The introduction of cations is thought to result in irreversible changes in the lignite structure and not only control the process of formation but also the amount of volatile precursors and in turn alter the effects of pressure. Valence and catalytic activity of cations seem to play important roles in determining pyrolysis products distribution at elevated pressures.
03/01629 Determining the composition blends using Bayes theorem
of binary
coal
Lester, E. et (II. Fuel, 2003, 82. (2), 117-125. Binary coal blends were prepared using a typical UK steam coal with four different coals, which were then analysed using random vitrinite reflectance (Rrandom). D econvolution of the vitrinite reflectance data was attempted using Bayes Theorem in order to calculate the composition of each blend on a % vol/vol basis. Modifications were made to the initial Bayes algorithm to take into account experimental error. The effect of using increasing amounts of data on the blend predictions was also investigated. Accurate predictions were achieved when using more than 100 reflectance measurements from each component and iterating the Bayes algorithm more than 100 times.
03/01630 Environment-protecting coal fuel briauets
combustion
additive
for
Qu, Y. and Zhou, H. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,334,323 (Cl. ClOL9/10), 6 Feb 2002, Appl. 2,000,110,682. 5. (In Chinese) The title additive is composed of CaO 10-30, KMn04 3-15, Mn02 315, MgO 1-5, KC1 1-5, and Ba(NOx)z l-5 weight parts. The use of the additive can improve the heating value, and reduce noxious emissions.
03101632
interactions
between
coking
coals in blends
Sakurovs, R. Fuel, 2003, 82, (4), 439450. The thermoplastic behaviour of 78 binary blends of Australian coking coals was measured using proton magnetic resonance thermal analysis. Their measured extents of fusion were compared with the values calculated from measurements made on the component coals assuming additivity. Significant differences between calculated and measured results were found for most blends, though only at temperatures between 400 and 520°C: the coals interacted at these temperatures in a way that affected their fluidity. Both positive and negative differences were observed. The magnitude of the differences increased both with increasing differences in rank between the coals and differences in fluidity between the coals. A statistical study of the differences showed that material that became fluid in coal at temperatures below about 360°C did not appear to contribute to the interactions, which suggests that fluid material derived from liptinite plays a much smaller role in interactions than fluid material derived from vitrinite or inertinite. Additionally, the study indicated that the less fusible material in a blend slightly reduced the extent to which the associated more fusible material fused. It was not acting as an inert diluent. Fifteen blends of six Argonne premium coals were examined to see if the relationships found for Australian coals between the magnitude of the interaction and coal properties could be generalized. In most cases the agreement was good. However, at some temperatures, blends of Upper Freeport coal with lower rank coals were far less fluid than expected, suggesting that the fluidity of Upper Freeport coal is especially sensitive to these low rank coals. The general effect of interactions between coals of different ranks was to narrow the thermoplastic temperature range of the blend without reducing the maximum fluidity, in effect making the thermoplastic profile of the blend resemble the profile expected from an individual coal of the same average rank as the blend. The interactions are attributed to transfer of plasticising volatile material between the coals.
03101633 Low cost coal-based carbons and NO removal from exhaust gas
for combined
SOa
Izquierdo, M. T. et al. Fuel, 2003. 82, (2), 147-151. The aim of this paper is to show how a cheap carbonaceous material such as low rank coal-based carbon (or char) can be used in the combined SOdNO removal from exhaust qas at the linear gas velocity used in commercial systems (0.12 m s- ). Char is produced from carbonization and optionally activated with steam. This char is used in a first step to abate the SO2 concentration at the following conditions: lOO”C, space velocity of 3600 h-‘, 6% 02, 10% H20, 1000 ppmv S02, 1000 ppmv NO and N2 as remainder. In a second step, when the SO? concentration in the flue gas is low, NO is reduced to NZ and steam at the following experimental conditions: 15o”C, space velocity of 900 h-‘, 6% 02, 10% H20, O-500 ppmv SO2, 1000 ppmv NO, 1000 ppmv NH3 and N2 as remainder. It has been shown that the presence of NO has no effect on SO2 abatement during the first step of combined SOdNO removal system and that low SOz inlet concentration has a negligible effect on NO reduction in the second step. Moreover, this char can be thermally regenerated after use for various cycles without loss of activity. On the other hand, this regenerated char shows the highest NO removal activity (compared to parent chars, either carbonized or steam activated) which can be attributed to the activating effect of the sulfuric acid formed during the first step of the combined SO*/NO removal system.
03101634 Study of pyrolysis and soft brown coal Karcz, Polish)
A. and Rozwadowski,
Fuel
and
Energy
of blends
A. Karbo,
Abstracts
2002,
of gas-coking 47, (6),
September
171-175.
2003
coal (In
267
02
Liquid
fuels
(sources,
properties,
recovery,,
High reactivity of domestic coke can be achieved by means of adding a small amount of soft brown coal to the coal blend. This addition, however, exerts a negative influence on mechanical properties of resulting coke. The results are presented of the examination of the plastic properties of coal blends produced from high volatile bituminous coal with the addition of various produced from high volatile bituminous coal with the addition of various amounts of brown coal (5, 10, 15 and 20%). Standard laboratory methods for plastic properties evaluation as well as an innovative test of rheological properties have been applied. The research focused on two kinds of coal, i.e. high volatile bituminous coal and soft brown coal from the Konin open strip mine. For both of these coal types as well as their blends the thermogravimetric tests have been carried out within the temperature range of 2O-900°C. Coal char samples of mechanical properties examined and reactivity test have been produced using the Jenkner retort. The obtained results show that the interaction of brown and hard coal occurring within the temperature range of coal blend plasticity has a crucial effect on the degree of agglomeration and, consequently, on mechanical properties of resulting coke. Along with the increase of brown coal percentage in the examined blend, rapid reduction of dilatation as well as an increase of devolatilization rate have been observed. Consequently, the porous structure of resulting coke underwent a significant transformation, which led to an increase of coke reactivity. It has also been stated, that the interaction of brown and hard coal occurring above the temperature of resolidification does not influence the mechanical properties of resulting coke. The devolatilization rates of brown coal and hard coal are similar above this temperature For this reason no local stresses arise. Moreover, it has been found that the bulk. density increase has beneficial effect on the mechanical properties as well as reactivity of coke produced from blends of bituminous and soft brown coal. The above mentioned effect is particularly powerful for blends with high percentage of brown coal.
03101635 of carbon
The nature of the surface and catalytic properties materials based on brown-coal semicokes
Tarkovskaya, I. A. (‘I (I/. C'krtrimkii Khimiwkskii Zhumul. 2002. 68, (5 6), 24-29. (In Russian) Catalytic properties of brown-coal semicokes and materials obtained after their modification by oxidation, sulfonation, and heat treatment have been studied. The ability of semicokes to catalyse reactions of esterification, hydrogen peroxide decomposition, oxidation of hydrocarbons, and dechlorination of solutions has been analysed against the pore structure, elemental composition, chemical nature of the surface, characteristics of IR and ESR spectra, electrical conditions, and other properties.
02 LIQUID FUELS Sources, properties, recovery 03/01636 composed chamber
Combustion characteristics of droplets of light cycle oil and diesel light oil in a hot-air
Xu, G. et al. Fuel, 2003, 82, (3), 319-330. Development of gas turbines fueled with light cycle oil (LCO) and oil mixture of LCO and diesel light oil (LO) requires an understanding of the droplet burning and vaporization characteristics of those oils. The present study is devoted to comparing the burning characteristics of isolated fuel droplets composed of an LCO and an LO. The tests were conducted in an atmospheric hot-air chamber preset at 1173 K, and the examined LCO had a lower cetane number but higher volatility and aromatics content compared to LO. It was demonstrated that the burning of the LCO droplet was sootier, while that of the LO droplet was more disruptive. At the tested temperature, coke formation was indistinct for both the oils, whereas slightly higher ignition delay time was shown for the LO droplet. The microexplosive burning more or less complicated the time-series droplet size d, an explicit burning rate constant, however, was still definable according to the d2-law to show the overall regression speed of the droplet surface area dz with burning time r. The rate constant exhibited little difference for smaller LCO and LO droplets but was greater for LO when the droplet was larger. The rate constant also gradually increased with increasing the initial droplet caused the relative size d/d,, to be unified diameter do, which (normalized) into a single curve by a burning time t/d," (1.0 < n < 2.0). Analysis revealed that this unification resulted from the respective overlaps of the unsteady and quasi-steady burning phases for 288
Fuel
and
Energy
Abstracts
September
2003
differently sized droplets. and analysts are generally III hot ambience\
03/01637 kerogen
Current
Further. It was clarified vahd to isolated liquid
that the umftcatron fuel droplet burning
views on the origin of Estonian
kukersite
Lille, U. Oil S/r&, 2002, IY. (I), 3- 18. A brief overview of current views on formation, characterization and classification of kerogens is given. On this background the results 01 geochemical investigations on G. i>ri.sccl-derived kerogens. in particular Estonian kukersite kerogen obtained during last two decades are analysed, and changes in views about the origin of kukersite kerogen are underlined.
03/O! 636 Cyclic carbon monoxide combustion-carbon fra;;de reductron for petroleum recovery by retorting
of oil
Peterson, 0. V. U.S. US 6,464.X60 (Cl. 20X-400; ClOGl/OO), IS Ott 2002, Appl. 610,842. Crude shale oil is recovered from crushed oil shale by a cyclic combustion-reaction process consisting of: (1) combustion of CO with relatively pure O2 to provide heat to pyrolyse the oil shale and produce recovered shale oil, carbonaceous residue in the unburned shale, and CO*, (2) reaction of the COz with the carbonaceous residue to recover CO. Heat recovered from cooling the retorted gases and liquids (to be processed into useable crude shale oil) can be recovered and returned to the combustion chamber. Calcium minerals present in the shale matrix react under the combustion conditions to produce calcite or calcium oxide lime. Combustion is carried out in a sealed chamber.
03101639
Detonations
in hydrocarbon
fuel blends
Austin,J. M. and Shepherd,J. E. Cvrnhustion cmdF/mw. 2003, 132.(12). 73-90. A study of detonations in high-molecular weight hydrocarbon fuels of interest to pulse detonation engine applications was performed in a 2X0-mm diameter, 7.3-m long facility. Detonation pressure, wave speed, and cell width measurements were made in JP-10 mixtures and in mixtures representative of the decomposition products of JP-10. Experiments were performed in vapor-phase JP-10 mixtures at 353 K over a range of equivalence ratios (0.7 5 0 C: 1.4), nitrogen dilutions (fuel-oxygen to fuel-air), and initial pressures (20-130 kPa). The cell widths of the JP-10 mixtures are found to be similar to those of propane mixtures. A fuel blend representative of thermally decomposed JP-10 was studied at 295 K. This blend consisted of hydrogen, carbon monoxide, methane, acetylene, ethylene, and hexane with varying fractions of oxygen and nitrogen. The measured cell width of the fuel blend-air mixture is about half that of JP-lo-air. The addition of components of the fuel blend (acetylene, ethylene, and methane) to JP-10 in air at 353 K was characterized. Nitrogen diluted mixtures of stoichiometric hexane-oxygen were studied and the cell widths for hexane-air and JP-lo-air are found to be comparable. The addition of lower molecular weight fuels (hydrogen. acetylene, ethylene, and carbon monoxide) to hexane-air was investigated. The measured cell width decreases, indicating increased sensitivity to detonation, with increasing fraction of hydrogen, acetylene, and ethylene, in order ot effectiveness. The addition of a small fraction of carbon monoxide produces a small decrease in the cell width, but addition of more than about 75% (by fuel mass) carbon monoxide results in a significant increase in cell width. Carbon monoxide is a principal intermediate product of hydrocarbon combustion yet there are relatively little cell width data available. Cell width measurements were made in carbon monoxide-air mixtures with the addition of hydrogen or hydrocarbons (acetylene, ethylene, and hexane). A linear relationship is found between the cell width and the reaction zone length when it is defined as the location of the peak in hydroxyl mole fraction.
03/01640 Distinctive combustion droplet under microgravity
stages of single heavy oil
Ikegami, M. er ul. Fuel. 2003. 82, (3), 293~-304. This report presents an investigation on the combustion of single droplets comprised of heavy oil and oil mixtures blending diesel light oil (LO) and a heavy oil residue (HOR). The tests were conducted in a microgravity facility that offered 10 s of free-fall time. Fine wire thermocouples supported the droplets, resulting in a measurement of droplet temperature history. Additional data were the droplet and flame size history. The results identified four distinctive burning stages between ignition and extinction for heavy oil (C class) and HOR-LO blends. They are, in succession, the start-up, inner evaporation, thermal decomposition (pyrolysis) and polymerization stages. The start-up stage denoted an initial transient period, where the LO components burned from the droplet surface and the droplet temperature increased rapidly. The latter three stages featured pronounced droplet swellings and contractions caused by fuel evaporation and decomposition inside the droplet. An evaporation temperature demarcated the start-up stage from the inner evaporation
03/01631 EPR study on petroleum cokes annealed at different temperatures and used in lithium and sodium batteries
Liu, H.-M. et al. Gaodeng Xuexiao Huaxue Xuebao, 2002, 23, (8), 15561561. (In Chinese) Over Mo/HZSM-5 catalysts, various carbonaceous depositions occurred during the course of methane dehydroaromatization (MDA). These species of surface carbon formed on HZSM-5 zeolite or MO/ HZSM-5 catalysts with different MO loadings were investigated by TPH, TPCO* and TPO in combination with thermal gravimetric analysis.(TG). The results of TG revealed that, the total amount of coke formed on 6Mo/MCM-22 during TPSR is larger than those formed on HZSM-5 zeolite, 2Mo HZSM-5 and lOMo/HZSM-5 catalysts. The TPO profiles recorded during the procedure of coke burning-off show hvo different temperature peaks. The results of TPO and TG after TPH suggested that, the TPH experiments only had an effect on the coke burnt-off at a high temperature, but didn’t result in the diminishing of the coke burnt-off at low temperature peak. On the other hand, the result of the coked catalyst after succeeding TPCOz experiments exhibited an obvious reduction in the areas of both the high and low temperature peaks, particularly in the area of the low temperature peak. The study on the catalysts with different MO loadings suggested that, the percentage of the coke burnt-off at a low temperature turned larger with the increase of MO loading, respectively. And the change trend of the coke burnt-off at a high temperature was opposite exactly. By using the experiments of TPSR, TPH, TPCO? and TG, quantity analysis of the coke and the kinetics of its burning-off process were done. The results show that, either TPH or TPC02 can diminish the starting temperature and decrease the activation energy, and there are some differences among the catalysts with various MO loadings.
Zhecheva, E. et al. Carbon, 2002, 40, (13), 2301-2306. EPR spectroscopy was used for characterization of petroleum cokes heat-treated in the temperature range of 480-2800°C and after their electrochemical reactions with lithium and sodium. Unpaired spins with localized character were detected for cokes treated below lOOo”C, while delocalized electrons were found to contribute to the EPR profile of cokes treated between 1400 and 2800°C. After electrochemical interaction of cokes with lithium, the EPR signal due to delocalized electrons undergoes a strong line narrowing combined with an increase in signal intensity. Localized paramagnetic centres interact with Li and Na, as a result of which there is a line narrowing and decrease in the signal intensity. A new narrow signal is detected for low-temperature cokes after reaction with lithium. The origin of this signal could be associated with ‘near-metallic’ lithium, which is accommodated in nonordinary carbon sites such as microcavities. The intensity of this signal is higher for samples treated at 6OO”C, where a higher hysteresis in the voltage versus composition curve is observed.
03101626 Combined effects of pressure and ionexchangeable metallic species on pyrolysis of Victorian lignite
Sathe, C. et al. Fuel, 2003, 82, (3), 343-350. A set of ion-exchanged samples prepared from Loy Yang lignite was pyrolysed in a wire-mesh reactor at elevated pressures from 1 to 36 bar. The tar yields from the pyrolysis of H-form (acid-washed) sample at a fast heating rate of 1000°C s-l were drastically reduced by increasing pressure to 6 bar and then remained unchanged with further increase in pressure to 36 bar. This behaviour of the tar yield was in sharp contrast to that from the raw lignite, which showed a minimum with increasing pressure. The sensitivities of the tar yields to changes in the heating rate were also suppressed by increasing pressure. The tar yields from Ca-form and Na-form samples (prepared by ion-exchanging Ca and Na on the H-form sample, respectively) were not very sensitive to changes in the heating rate and pressure up to 11 bar. At 20 bar, the tar yields from the Na-from sample nearly doubled whereas from the Caform sample nearly halved compared to those respective values at 1 bar. Although increasing pressure is thought to cause changes in the intra-particle mass transfer processes of volatile precursors, the rate of formation of volatile precursors tends to dictate the kind of mass transfer process responsible for the release of volatiles. Therefore, depending on the pyrolysis condition, bulk diffusion or forced flow would dominate the mass transfer processes for the release of volatiles. The introduction of cations is thought to result in irreversible changes in the lignite structure and not only control the process of formation but also the amount of volatile precursors and in turn alter the effects of pressure. Valence and catalytic activity of cations seem to play important roles in determining pyrolysis products distribution at elevated pressures.
03/01629 Determining the composition blends using Bayes theorem
of binary
coal
Lester, E. et (II. Fuel, 2003, 82. (2), 117-125. Binary coal blends were prepared using a typical UK steam coal with four different coals, which were then analysed using random vitrinite reflectance (Rrandom). D econvolution of the vitrinite reflectance data was attempted using Bayes Theorem in order to calculate the composition of each blend on a % vol/vol basis. Modifications were made to the initial Bayes algorithm to take into account experimental error. The effect of using increasing amounts of data on the blend predictions was also investigated. Accurate predictions were achieved when using more than 100 reflectance measurements from each component and iterating the Bayes algorithm more than 100 times.
03/01630 Environment-protecting coal fuel briauets
combustion
additive
for
Qu, Y. and Zhou, H. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,334,323 (Cl. ClOL9/10), 6 Feb 2002, Appl. 2,000,110,682. 5. (In Chinese) The title additive is composed of CaO 10-30, KMn04 3-15, Mn02 315, MgO 1-5, KC1 1-5, and Ba(NOx)z l-5 weight parts. The use of the additive can improve the heating value, and reduce noxious emissions.
03101632
interactions
between
coking
coals in blends
Sakurovs, R. Fuel, 2003, 82, (4), 439450. The thermoplastic behaviour of 78 binary blends of Australian coking coals was measured using proton magnetic resonance thermal analysis. Their measured extents of fusion were compared with the values calculated from measurements made on the component coals assuming additivity. Significant differences between calculated and measured results were found for most blends, though only at temperatures between 400 and 520°C: the coals interacted at these temperatures in a way that affected their fluidity. Both positive and negative differences were observed. The magnitude of the differences increased both with increasing differences in rank between the coals and differences in fluidity between the coals. A statistical study of the differences showed that material that became fluid in coal at temperatures below about 360°C did not appear to contribute to the interactions, which suggests that fluid material derived from liptinite plays a much smaller role in interactions than fluid material derived from vitrinite or inertinite. Additionally, the study indicated that the less fusible material in a blend slightly reduced the extent to which the associated more fusible material fused. It was not acting as an inert diluent. Fifteen blends of six Argonne premium coals were examined to see if the relationships found for Australian coals between the magnitude of the interaction and coal properties could be generalized. In most cases the agreement was good. However, at some temperatures, blends of Upper Freeport coal with lower rank coals were far less fluid than expected, suggesting that the fluidity of Upper Freeport coal is especially sensitive to these low rank coals. The general effect of interactions between coals of different ranks was to narrow the thermoplastic temperature range of the blend without reducing the maximum fluidity, in effect making the thermoplastic profile of the blend resemble the profile expected from an individual coal of the same average rank as the blend. The interactions are attributed to transfer of plasticising volatile material between the coals.
03101633 Low cost coal-based carbons and NO removal from exhaust gas
for combined
SOa
Izquierdo, M. T. et al. Fuel, 2003. 82, (2), 147-151. The aim of this paper is to show how a cheap carbonaceous material such as low rank coal-based carbon (or char) can be used in the combined SOdNO removal from exhaust qas at the linear gas velocity used in commercial systems (0.12 m s- ). Char is produced from carbonization and optionally activated with steam. This char is used in a first step to abate the SO2 concentration at the following conditions: lOO”C, space velocity of 3600 h-‘, 6% 02, 10% H20, 1000 ppmv S02, 1000 ppmv NO and N2 as remainder. In a second step, when the SO? concentration in the flue gas is low, NO is reduced to NZ and steam at the following experimental conditions: 15o”C, space velocity of 900 h-‘, 6% 02, 10% H20, O-500 ppmv SO2, 1000 ppmv NO, 1000 ppmv NH3 and N2 as remainder. It has been shown that the presence of NO has no effect on SO2 abatement during the first step of combined SOdNO removal system and that low SOz inlet concentration has a negligible effect on NO reduction in the second step. Moreover, this char can be thermally regenerated after use for various cycles without loss of activity. On the other hand, this regenerated char shows the highest NO removal activity (compared to parent chars, either carbonized or steam activated) which can be attributed to the activating effect of the sulfuric acid formed during the first step of the combined SO*/NO removal system.
03101634 Study of pyrolysis and soft brown coal Karcz, Polish)
A. and Rozwadowski,
Fuel
and
Energy
of blends
A. Karbo,
Abstracts
2002,
of gas-coking 47, (6),
September
171-175.
2003
coal (In
267
02
Liquid
fuels
(sources,
properties,
recovery,,
High reactivity of domestic coke can be achieved by means of adding a small amount of soft brown coal to the coal blend. This addition, however, exerts a negative influence on mechanical properties of resulting coke. The results are presented of the examination of the plastic properties of coal blends produced from high volatile bituminous coal with the addition of various produced from high volatile bituminous coal with the addition of various amounts of brown coal (5, 10, 15 and 20%). Standard laboratory methods for plastic properties evaluation as well as an innovative test of rheological properties have been applied. The research focused on two kinds of coal, i.e. high volatile bituminous coal and soft brown coal from the Konin open strip mine. For both of these coal types as well as their blends the thermogravimetric tests have been carried out within the temperature range of 2O-900°C. Coal char samples of mechanical properties examined and reactivity test have been produced using the Jenkner retort. The obtained results show that the interaction of brown and hard coal occurring within the temperature range of coal blend plasticity has a crucial effect on the degree of agglomeration and, consequently, on mechanical properties of resulting coke. Along with the increase of brown coal percentage in the examined blend, rapid reduction of dilatation as well as an increase of devolatilization rate have been observed. Consequently, the porous structure of resulting coke underwent a significant transformation, which led to an increase of coke reactivity. It has also been stated, that the interaction of brown and hard coal occurring above the temperature of resolidification does not influence the mechanical properties of resulting coke. The devolatilization rates of brown coal and hard coal are similar above this temperature For this reason no local stresses arise. Moreover, it has been found that the bulk. density increase has beneficial effect on the mechanical properties as well as reactivity of coke produced from blends of bituminous and soft brown coal. The above mentioned effect is particularly powerful for blends with high percentage of brown coal.
03101635 of carbon
The nature of the surface and catalytic properties materials based on brown-coal semicokes
Tarkovskaya, I. A. (‘I (I/. C'krtrimkii Khimiwkskii Zhumul. 2002. 68, (5 6), 24-29. (In Russian) Catalytic properties of brown-coal semicokes and materials obtained after their modification by oxidation, sulfonation, and heat treatment have been studied. The ability of semicokes to catalyse reactions of esterification, hydrogen peroxide decomposition, oxidation of hydrocarbons, and dechlorination of solutions has been analysed against the pore structure, elemental composition, chemical nature of the surface, characteristics of IR and ESR spectra, electrical conditions, and other properties.
02 LIQUID FUELS Sources, properties, recovery 03/01636 composed chamber
Combustion characteristics of droplets of light cycle oil and diesel light oil in a hot-air
Xu, G. et al. Fuel, 2003, 82, (3), 319-330. Development of gas turbines fueled with light cycle oil (LCO) and oil mixture of LCO and diesel light oil (LO) requires an understanding of the droplet burning and vaporization characteristics of those oils. The present study is devoted to comparing the burning characteristics of isolated fuel droplets composed of an LCO and an LO. The tests were conducted in an atmospheric hot-air chamber preset at 1173 K, and the examined LCO had a lower cetane number but higher volatility and aromatics content compared to LO. It was demonstrated that the burning of the LCO droplet was sootier, while that of the LO droplet was more disruptive. At the tested temperature, coke formation was indistinct for both the oils, whereas slightly higher ignition delay time was shown for the LO droplet. The microexplosive burning more or less complicated the time-series droplet size d, an explicit burning rate constant, however, was still definable according to the d2-law to show the overall regression speed of the droplet surface area dz with burning time r. The rate constant exhibited little difference for smaller LCO and LO droplets but was greater for LO when the droplet was larger. The rate constant also gradually increased with increasing the initial droplet caused the relative size d/d,, to be unified diameter do, which (normalized) into a single curve by a burning time t/d," (1.0 < n < 2.0). Analysis revealed that this unification resulted from the respective overlaps of the unsteady and quasi-steady burning phases for 288
Fuel
and
Energy
Abstracts
September
2003
differently sized droplets. and analysts are generally III hot ambience\
03/01637 kerogen
Current
Further. It was clarified vahd to isolated liquid
that the umftcatron fuel droplet burning
views on the origin of Estonian
kukersite
Lille, U. Oil S/r&, 2002, IY. (I), 3- 18. A brief overview of current views on formation, characterization and classification of kerogens is given. On this background the results 01 geochemical investigations on G. i>ri.sccl-derived kerogens. in particular Estonian kukersite kerogen obtained during last two decades are analysed, and changes in views about the origin of kukersite kerogen are underlined.
03/O! 636 Cyclic carbon monoxide combustion-carbon fra;;de reductron for petroleum recovery by retorting
of oil
Peterson, 0. V. U.S. US 6,464.X60 (Cl. 20X-400; ClOGl/OO), IS Ott 2002, Appl. 610,842. Crude shale oil is recovered from crushed oil shale by a cyclic combustion-reaction process consisting of: (1) combustion of CO with relatively pure O2 to provide heat to pyrolyse the oil shale and produce recovered shale oil, carbonaceous residue in the unburned shale, and CO*, (2) reaction of the COz with the carbonaceous residue to recover CO. Heat recovered from cooling the retorted gases and liquids (to be processed into useable crude shale oil) can be recovered and returned to the combustion chamber. Calcium minerals present in the shale matrix react under the combustion conditions to produce calcite or calcium oxide lime. Combustion is carried out in a sealed chamber.
03101639
Detonations
in hydrocarbon
fuel blends
Austin,J. M. and Shepherd,J. E. Cvrnhustion cmdF/mw. 2003, 132.(12). 73-90. A study of detonations in high-molecular weight hydrocarbon fuels of interest to pulse detonation engine applications was performed in a 2X0-mm diameter, 7.3-m long facility. Detonation pressure, wave speed, and cell width measurements were made in JP-10 mixtures and in mixtures representative of the decomposition products of JP-10. Experiments were performed in vapor-phase JP-10 mixtures at 353 K over a range of equivalence ratios (0.7 5 0 C: 1.4), nitrogen dilutions (fuel-oxygen to fuel-air), and initial pressures (20-130 kPa). The cell widths of the JP-10 mixtures are found to be similar to those of propane mixtures. A fuel blend representative of thermally decomposed JP-10 was studied at 295 K. This blend consisted of hydrogen, carbon monoxide, methane, acetylene, ethylene, and hexane with varying fractions of oxygen and nitrogen. The measured cell width of the fuel blend-air mixture is about half that of JP-lo-air. The addition of components of the fuel blend (acetylene, ethylene, and methane) to JP-10 in air at 353 K was characterized. Nitrogen diluted mixtures of stoichiometric hexane-oxygen were studied and the cell widths for hexane-air and JP-lo-air are found to be comparable. The addition of lower molecular weight fuels (hydrogen. acetylene, ethylene, and carbon monoxide) to hexane-air was investigated. The measured cell width decreases, indicating increased sensitivity to detonation, with increasing fraction of hydrogen, acetylene, and ethylene, in order ot effectiveness. The addition of a small fraction of carbon monoxide produces a small decrease in the cell width, but addition of more than about 75% (by fuel mass) carbon monoxide results in a significant increase in cell width. Carbon monoxide is a principal intermediate product of hydrocarbon combustion yet there are relatively little cell width data available. Cell width measurements were made in carbon monoxide-air mixtures with the addition of hydrogen or hydrocarbons (acetylene, ethylene, and hexane). A linear relationship is found between the cell width and the reaction zone length when it is defined as the location of the peak in hydroxyl mole fraction.
03/01640 Distinctive combustion droplet under microgravity
stages of single heavy oil
Ikegami, M. er ul. Fuel. 2003. 82, (3), 293~-304. This report presents an investigation on the combustion of single droplets comprised of heavy oil and oil mixtures blending diesel light oil (LO) and a heavy oil residue (HOR). The tests were conducted in a microgravity facility that offered 10 s of free-fall time. Fine wire thermocouples supported the droplets, resulting in a measurement of droplet temperature history. Additional data were the droplet and flame size history. The results identified four distinctive burning stages between ignition and extinction for heavy oil (C class) and HOR-LO blends. They are, in succession, the start-up, inner evaporation, thermal decomposition (pyrolysis) and polymerization stages. The start-up stage denoted an initial transient period, where the LO components burned from the droplet surface and the droplet temperature increased rapidly. The latter three stages featured pronounced droplet swellings and contractions caused by fuel evaporation and decomposition inside the droplet. An evaporation temperature demarcated the start-up stage from the inner evaporation