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02852 Kinetics of CO2 and CH4 sorption on high rank coal at ambient temperatures
16 Fuel science and technology (fundamental science, analysis, instrumentation) 99102945
Global kinetic analysis of complex materials
Burnham, A. K. and Braun, R. L. Proc. Conf North Am. Therm. Analysis Sot., 26, 1998, 676-681. Edited by Williams, K. R., Omnipress, Madison, Wisconsin Global kinetic models are reviewed using examples for synthetic polymers, kerogens and coal. Amongst the models reviewed are; lst-order, nth-order, nucleation models and models having Gaussian, Weibull and discrete activation energy distributions. The various models’ characteristics are given, some of which are similar. The parameter relationships among similar models are discussed. Guidance is given in how to select the correct model A t&S-sensor for online measurements in a coal gasification system
99102846
Vandecruys, F. et al. Solid State lonics, 1998, 112, (l-2), 95-102. An evaluation of two solid state H&sensors using Na-P-alumina as solid electrolyte and NazS as auxiliary layer. The sensors were analysed in a real coal gasifier and the results indicated that the sensors could survive the aggressive coal gasification atmosphere. The sensors reacted simultaneously and identically on changes of the HzS-pressure. The experimental EMFvalues were in agreement with theoretical EMF-values and therefore the H&concentrations calculated from the sensor signals agreed with the real ones.
Heating and calorimetry in single droplets and micro fluid reactors
99102547
Zieren, M. et al. Microreact Technol., Proc. Int Conf., 1, 1997 (Pub. 1998), 324-331. Edited by Ehrfeld, W., Springer, Berlin, Germany. The paper details four different devices prepared by micromachining technique, which incorporate different concepts and materials. All are feasible for heating and calorimetry in liquid flows at low rates of 51 ml/ min or in single droplets of l-50 ~1. The materials used, the device topology and the geometrical arrangement of heaters and sensing elements are all important in determining the heat management and calorimetric data. 99102845
High pressure
steam drying of single porous
oarticles
Golonka, K. et al. World Congr. Part. Technol. 3, [computer optical disk], 1998. 3196-3208. An experimental and theoretical study of the drying kinetics of single porous particles in superheated steam under a range of pressures and particle sizes. Specific focus is placed on brown coal. Apparatus was developed to measure moisture content and core temperature of single spherical porous particles in pressurized superheated steam. The drying process could then be mathematically modelled. Predictions of the model were compared with experimental data, with positive results. The findings of this work can be used in determining the rate limiting mechanism in pressurized steam-fluidized bed drying of porous material.
Hydrocarbon group-type analysis of high boiling petroleum distillates by HPLC
99lQ2049
Qiang, D. and Lu, W. /. of Pet. Sci. & Eng., 1999, 22, (l-3) 31-36. A high performance liquid chromatography (HPLC) system was developed for the group-type analysis of high boiling petroleum distillates (3% 500°C). By coupling with multi-column switching and gradient elution techniques, the high boiling distillates were separated into saturates, monoaromatics, diaromatics, polyaromatics (three to five rings) and resins (more than six condensed-ring aromatics and polar compounds). Employing moving-wire flame ionization detector for detection and data station for quantitation, the method was characterized by good separation, short analysis time and adaptability to high boiling samples. Its quantitative results showed a high repeatability and were well consistent with mass spectroscopy results for most high boiling distillates.
Impact of the price of energy on the use of conservation tillage in agriculture in the USA
99102650
Uri, N. D. Applied Energy, 1998, 60, (4), 225-240. In addressing concerns about the impact of agricultural production on the environment in the USA, the relationship between energy expenditure and the use of conservation tillage is of special importance. After establishing that a relationship exists between the price of energy and the use of conservation tillage via the Granger causality, the relationship is quantified. It is shown that while the real price of crude oil, the proxy used for the price of energy, does not affect the rate of adoption of conservation tillage, it does impact upon the extent to which it is used. Finally, there is no structural instability in the relationship between the relative use of conservation tillage and the real price of crude oil over the period 19631997.
99162651 Investigation of heat transfer and coking characteristics of hydrocarbon fuels
Liang, K. et al. 1. Propul. Power, 1998, 14, (5) 789-796. Worldwide investigations of the cooling characteristics of hydrocarbon fuels are reviewed in this paper. Included are the results of Chinese experimental investigations. The heat transfer characteristics of methane, propane, no. 21 high-density kerosene, aerokerosene and rocket kerosene in stainless-steel and copper tubes were investigated accompanied by investigation of the deposit formation rates for kerosene in stainless-steel tubes. The test conditions were; pressures of 0.5-30 MPa, flow velocities of 2-106 m/s and
heat fluxes up to 66 MW/m’. Forced convective heat transfer correlations were obtained for liquid methane, propane, and kerosene. Heat fluxes at which test tubes burnt out were also investigated. The test results indicate that the heat transfer coefficients of methane and propane decrease at high wall temperatures. However, under similar conditions the coefficients of kerosene increase because of boiling. No coking was detected in methane tests, but coking temperature and coking rates were determined for kerosene in stainless-steel tubes.
Kinetics of COz and CH, sorption on high rank coal at amblent temperatures
99lO2552
Marecka, A. and Mianowski, A. Fuel, 1998, 77, (14), 1691-1696. The diffusional process in the system hard coal-gases in isothermal-isobaric conditions, is described by the novel kinetic equation presented in this paper. It enables an attempt at the analysis of the equilibrium states depending on changes in the specific surface areas of coal grains. For the purpose of illustration the model has been applied to the sorption of COz and CH4 on one type of highly metamorphized coal. The results of the considerations of the models were compared with the experimental kinetics of nitrogen sorption on type A zeolite. Further, the model’s relations with Fick’s II law are demonstrated.
A means of obtaining a full kinetic rate expression for the oxidation of a solid substrate from a single criticality data point
99lQ2653
Jones, J. C. Fuel, 1998, 77, (14) 1677-1678. A method is theoretically developed whereby kinetic rate parameters for the oxidation of a material, such as powdered coal or shredded wood, can be obtained from a determined single criticality data point. The data point can be determined, for example, from oven heating tests with a 10 cm cubic gauze container. The method is applied to two bituminous coals.
99162854 The measurement of small amounts of coke by a sensitive TGAFTIR technique
Li, B. and Gonzalez, R. D. Catal. Lett., 1998, 54, (l/2), 5-8. This report describes a useful, high-sensitivity thermogravimetry-Fourier transform IR (TGA-FTIR) method for quantifying small amounts of coke on a catalyst. Gases evolved from the sample during thermogravimetric analysis were transferred from the furnace by a purge gas to the flow cell of an FTIR. The intensity of the IR spectra of evolved gases was measured as a function of time and displayed as a chromatogram. Integration of the chromatograms was compared to that of a standard sample and gave the amount of coke deposited on the catalyst.
99102855
Method and apparatus for thermal analysis
Kimura, M. et al. Jpn. Kokai Tokkyo Koho, JP 10 260,147 (98 260,147) (Cl. GOlN25/00), 29 Sep 1998, JP Appl. 97/7,070, 17 Jan 1997, 17 pp. (In Japanese) When heating a sample, a heater with a low heat capacity can be used effectively by integrating a thin-film heater in a substrate. A method for measuring particle size distribution by using anisokinetic sampling
99102656
Tsuji, H. et al. World Congr. Part. Technol. 3, [computer optical disk], 1998, 333-34.5. An advanced size distribution measurement method has been developed. In this study it is theoretically investigated and experimentally applied to fly ash, pulverized coal, soot and dusts consisting of fly ash and soot. The ‘classification effect’ which occurs in anisokinetic sampling in which the sampling velocity deviates from the gas velocity is harnessed by this method. In this example, the measured concentration is not equal to that of the main flow. The velocity ratio, gas velocity/sampling velocity, has a linear relation with the concentration ratio, the ratio of the measured concentration to the true one. The slope of this straight line is defined by the size distribution and the inertia parameter. Thus, the size distribution can be derived from this relation.
99ia2857 Modeling and simulation of time varying slag flow in a Prenflo entrained-flow gasifier Seggiani, M. Fuel, 1998, 77, (14) 1611-1621. A Prenflo coal gasifier was monitored in order to develop a model capable of simulating the time varying phenomena connected to slag accumulation and flow on its walls. For this purpose the slag building simplified model has been integrated with a three-dimensional code which provides the temperature and concentration profiles of the gas phase within the gasifier. The integrated model has been used to evaluate the effects of changes of the gasifier operating conditions on the slag behaviour.
99102856 Molecular beam mass spectrometry measurement of 1-butene pyrolysis and combustion products: stable and active species profiles, and combustion modeling of benzene, phenol, anisole and cyclopentadiene thermodynamic parameters and elementary reaction kinetic mechanism Zhong, X. Di.rs. Abstr. Int., B, 1998,59, (4). 441 pp. Avail. UMI, Order No. DA9829021. The prolysis and combustion products of 1-butene were investigated using molecular beam mass spectrometry.
Fuel and Energy Abstracts
July 1999 297
Global kinetic analysis of complex materials
Burnham, A. K. and Braun, R. L. Proc. Conf North Am. Therm. Analysis Sot., 26, 1998, 676-681. Edited by Williams, K. R., Omnipress, Madison, Wisconsin Global kinetic models are reviewed using examples for synthetic polymers, kerogens and coal. Amongst the models reviewed are; lst-order, nth-order, nucleation models and models having Gaussian, Weibull and discrete activation energy distributions. The various models’ characteristics are given, some of which are similar. The parameter relationships among similar models are discussed. Guidance is given in how to select the correct model A t&S-sensor for online measurements in a coal gasification system
99102846
Vandecruys, F. et al. Solid State lonics, 1998, 112, (l-2), 95-102. An evaluation of two solid state H&sensors using Na-P-alumina as solid electrolyte and NazS as auxiliary layer. The sensors were analysed in a real coal gasifier and the results indicated that the sensors could survive the aggressive coal gasification atmosphere. The sensors reacted simultaneously and identically on changes of the HzS-pressure. The experimental EMFvalues were in agreement with theoretical EMF-values and therefore the H&concentrations calculated from the sensor signals agreed with the real ones.
Heating and calorimetry in single droplets and micro fluid reactors
99102547
Zieren, M. et al. Microreact Technol., Proc. Int Conf., 1, 1997 (Pub. 1998), 324-331. Edited by Ehrfeld, W., Springer, Berlin, Germany. The paper details four different devices prepared by micromachining technique, which incorporate different concepts and materials. All are feasible for heating and calorimetry in liquid flows at low rates of 51 ml/ min or in single droplets of l-50 ~1. The materials used, the device topology and the geometrical arrangement of heaters and sensing elements are all important in determining the heat management and calorimetric data. 99102845
High pressure
steam drying of single porous
oarticles
Golonka, K. et al. World Congr. Part. Technol. 3, [computer optical disk], 1998. 3196-3208. An experimental and theoretical study of the drying kinetics of single porous particles in superheated steam under a range of pressures and particle sizes. Specific focus is placed on brown coal. Apparatus was developed to measure moisture content and core temperature of single spherical porous particles in pressurized superheated steam. The drying process could then be mathematically modelled. Predictions of the model were compared with experimental data, with positive results. The findings of this work can be used in determining the rate limiting mechanism in pressurized steam-fluidized bed drying of porous material.
Hydrocarbon group-type analysis of high boiling petroleum distillates by HPLC
99lQ2049
Qiang, D. and Lu, W. /. of Pet. Sci. & Eng., 1999, 22, (l-3) 31-36. A high performance liquid chromatography (HPLC) system was developed for the group-type analysis of high boiling petroleum distillates (3% 500°C). By coupling with multi-column switching and gradient elution techniques, the high boiling distillates were separated into saturates, monoaromatics, diaromatics, polyaromatics (three to five rings) and resins (more than six condensed-ring aromatics and polar compounds). Employing moving-wire flame ionization detector for detection and data station for quantitation, the method was characterized by good separation, short analysis time and adaptability to high boiling samples. Its quantitative results showed a high repeatability and were well consistent with mass spectroscopy results for most high boiling distillates.
Impact of the price of energy on the use of conservation tillage in agriculture in the USA
99102650
Uri, N. D. Applied Energy, 1998, 60, (4), 225-240. In addressing concerns about the impact of agricultural production on the environment in the USA, the relationship between energy expenditure and the use of conservation tillage is of special importance. After establishing that a relationship exists between the price of energy and the use of conservation tillage via the Granger causality, the relationship is quantified. It is shown that while the real price of crude oil, the proxy used for the price of energy, does not affect the rate of adoption of conservation tillage, it does impact upon the extent to which it is used. Finally, there is no structural instability in the relationship between the relative use of conservation tillage and the real price of crude oil over the period 19631997.
99162651 Investigation of heat transfer and coking characteristics of hydrocarbon fuels
Liang, K. et al. 1. Propul. Power, 1998, 14, (5) 789-796. Worldwide investigations of the cooling characteristics of hydrocarbon fuels are reviewed in this paper. Included are the results of Chinese experimental investigations. The heat transfer characteristics of methane, propane, no. 21 high-density kerosene, aerokerosene and rocket kerosene in stainless-steel and copper tubes were investigated accompanied by investigation of the deposit formation rates for kerosene in stainless-steel tubes. The test conditions were; pressures of 0.5-30 MPa, flow velocities of 2-106 m/s and
heat fluxes up to 66 MW/m’. Forced convective heat transfer correlations were obtained for liquid methane, propane, and kerosene. Heat fluxes at which test tubes burnt out were also investigated. The test results indicate that the heat transfer coefficients of methane and propane decrease at high wall temperatures. However, under similar conditions the coefficients of kerosene increase because of boiling. No coking was detected in methane tests, but coking temperature and coking rates were determined for kerosene in stainless-steel tubes.
Kinetics of COz and CH, sorption on high rank coal at amblent temperatures
99lO2552
Marecka, A. and Mianowski, A. Fuel, 1998, 77, (14), 1691-1696. The diffusional process in the system hard coal-gases in isothermal-isobaric conditions, is described by the novel kinetic equation presented in this paper. It enables an attempt at the analysis of the equilibrium states depending on changes in the specific surface areas of coal grains. For the purpose of illustration the model has been applied to the sorption of COz and CH4 on one type of highly metamorphized coal. The results of the considerations of the models were compared with the experimental kinetics of nitrogen sorption on type A zeolite. Further, the model’s relations with Fick’s II law are demonstrated.
A means of obtaining a full kinetic rate expression for the oxidation of a solid substrate from a single criticality data point
99lQ2653
Jones, J. C. Fuel, 1998, 77, (14) 1677-1678. A method is theoretically developed whereby kinetic rate parameters for the oxidation of a material, such as powdered coal or shredded wood, can be obtained from a determined single criticality data point. The data point can be determined, for example, from oven heating tests with a 10 cm cubic gauze container. The method is applied to two bituminous coals.
99162854 The measurement of small amounts of coke by a sensitive TGAFTIR technique
Li, B. and Gonzalez, R. D. Catal. Lett., 1998, 54, (l/2), 5-8. This report describes a useful, high-sensitivity thermogravimetry-Fourier transform IR (TGA-FTIR) method for quantifying small amounts of coke on a catalyst. Gases evolved from the sample during thermogravimetric analysis were transferred from the furnace by a purge gas to the flow cell of an FTIR. The intensity of the IR spectra of evolved gases was measured as a function of time and displayed as a chromatogram. Integration of the chromatograms was compared to that of a standard sample and gave the amount of coke deposited on the catalyst.
99102855
Method and apparatus for thermal analysis
Kimura, M. et al. Jpn. Kokai Tokkyo Koho, JP 10 260,147 (98 260,147) (Cl. GOlN25/00), 29 Sep 1998, JP Appl. 97/7,070, 17 Jan 1997, 17 pp. (In Japanese) When heating a sample, a heater with a low heat capacity can be used effectively by integrating a thin-film heater in a substrate. A method for measuring particle size distribution by using anisokinetic sampling
99102656
Tsuji, H. et al. World Congr. Part. Technol. 3, [computer optical disk], 1998, 333-34.5. An advanced size distribution measurement method has been developed. In this study it is theoretically investigated and experimentally applied to fly ash, pulverized coal, soot and dusts consisting of fly ash and soot. The ‘classification effect’ which occurs in anisokinetic sampling in which the sampling velocity deviates from the gas velocity is harnessed by this method. In this example, the measured concentration is not equal to that of the main flow. The velocity ratio, gas velocity/sampling velocity, has a linear relation with the concentration ratio, the ratio of the measured concentration to the true one. The slope of this straight line is defined by the size distribution and the inertia parameter. Thus, the size distribution can be derived from this relation.
99ia2857 Modeling and simulation of time varying slag flow in a Prenflo entrained-flow gasifier Seggiani, M. Fuel, 1998, 77, (14) 1611-1621. A Prenflo coal gasifier was monitored in order to develop a model capable of simulating the time varying phenomena connected to slag accumulation and flow on its walls. For this purpose the slag building simplified model has been integrated with a three-dimensional code which provides the temperature and concentration profiles of the gas phase within the gasifier. The integrated model has been used to evaluate the effects of changes of the gasifier operating conditions on the slag behaviour.
99102856 Molecular beam mass spectrometry measurement of 1-butene pyrolysis and combustion products: stable and active species profiles, and combustion modeling of benzene, phenol, anisole and cyclopentadiene thermodynamic parameters and elementary reaction kinetic mechanism Zhong, X. Di.rs. Abstr. Int., B, 1998,59, (4). 441 pp. Avail. UMI, Order No. DA9829021. The prolysis and combustion products of 1-butene were investigated using molecular beam mass spectrometry.
Fuel and Energy Abstracts
July 1999 297