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02082 Preparation chromia-zirconia catalysts for propane dehydrogenation
03 Gaseous fuels (transport, storage) sulfur in the end products was elemental sulfur. Throughout the experiment, biodesulfurization of sulfur waste using ABR system, showed that the process is extremely efficient, and the maximum sulfide removal rate was about 3.03 mmol S z 1 ~ h -1.
06/02078 Characteristics and origin of natural gases in the Kuqa Depression of Tarim Basin, NW China Zou, Y.-R. et al. Organic Geochemistry, 2006, 37, (3), 280 290. Significant gas condensate as well as some black oils have been discovered in the Kuqa Depression of Tarim Basin, north-west (NW) China. Dry gases with high ~513Cvalues occur in the Kelasu structural belt, wet, isotopically light gases in the Yiqikelik belt, whereas condensates are distributed mainly in the Front Uplift area. Kinetic modelling results show that the variation of methane and ethane isotopes with increasing vitrinite reflectance is independent of heating rates for a given source rock. Two maturity trends have been observed o n a C2/C~-~ C1 plot, one for thermogemc gases assocmted with coal, another for oil-associated gases with minor contribution from biogenic gas. It is most likely that the gases in the Kelasu belt and Front Uplift area were derived from the Jurassic coal measures and Triassic lacustrine shales, respectively, with those in the Yiqikelik belt being the mixtures of gases from the two sources. Both Jurassic coals and Triassic lacustrine shales appear to have contributed to the gases in the Kela 2 (KL2) and Dina 2 (DN2), the two largest gas fields in the Tarim Basin. 13
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06/02079 Determination of heavy metals and volatile aromatic compounds in used engine oils and sludges Rauckyte, T. et al. Fuel, 2006, 85, (4), 481-485. Assessment of contaminant releases during utilization of used oils is essential for the determination of environmental acceptability. These paper reports the results of the study examining a toxic metal leachability from used engine oil and sludge samples employing leaching test (TCLP). The leaching test indicated that lead in oil samples exceeded 5-ppm concentration level what qualified them as a toxic waste. The samples of contaminated sludge were found to contain high concentration of total lead, barium and chromium, but the leaching test showed concentration below regulatory limit. The total content of benzene, ethylbenzene, toluene, and xylenes (BETX), and naphthalene in used oil and sludge samples was also determined and was found not to be a significant factor to contamination.
06•02080 NOx formation in natural gas combustion - a new simplified reaction scheme for CFD calculations L6ffler, G. et al. Fuel, 2006, 85, (4), 513-523. Computational fluid dynamics (CFD) is a widely used tool in optimizing natural gas burners, for instance, for emission issues. Especially, a further reduction of NO,. emissions is of interest. However, due to computational efforts calculating three-dimensional turbulent flames, there is the necessity for simplified models in order to simulate the combustion reactions and the NO~ formation, respectively. Hitherto, models describing thermal NO and prompt NO formation, respectively, were applied in a post-processing step. Beforehand, the flow field including combustion has been determined in the three-dimensional geometry. However, in the former work, it was shown that prompt NO formation is of minor significance. For temperatures higher than 1600°C, thermal NO formation is dominating. At lower temperatures, the N:O/NO and NNH route have significant contribution. Though, the widely applied prompt NO model captures the observed trends acceptable, it lacks of physical bases. Besides low temperature NO formation is more related to N20/ NO and NNH route, it assumes the prompt NO formation to be proportional to the fuel concentratiom The detailed reaction mechanism show NO formation more related to fuel oxidation rate, i.e. radical concentration. Thus, in this work, a new simplified model combining thermal NO formation. N20/NO, and NNH route is proposed. It applies steady-state approximation for the intermediate species, i.e. N, N20, NNH, and NH. In this way, their concentrations can be obtained by four algebraic equations and rate of NO formation can be calculated without any model parameter, solely based on reaction kinetics. Moreover, the concentrations of O_,, N2, H> and H20 as well as the radicals O, H, OH, and HO2 have to be known from combustion calculations. The model was evaluated against the predictions of a detailed reaction mechanism, showing good agreement in a wide range of conditions. Neglecting prompt NO formation affects predicted NO emissions only under very fuel rich conditions. Under these circumstances, total NO formation is low, anyway. Thus, the performance of the presented model is not influenced by the lack of prompt NO formation.
06•02081 Numerical modelling of propane combustion in a high velocity oxygen-fuel thermal spray gun Kamnis, S. and Gu, S. Chemical Engineering and Processing, 2006, 45, (4), 246 253.
322
Fuel and Energy Abstracts
September 2006
High velocity oxygen-fuel (HVOF) thermal spraying is a relatively new technology compared to other protective coating methods. Powders sprayed by liquid fuel HVOF guns are able to achieve high impact velocities without overheating, which results in superior coatings. A computational fluid dynamic (CFD) model is developed to investigate propane combustion in the process of HVOF thermal spraying. The numerical methods are described for correct representation of various thermal-physical phenomena such as flame propagation, turbulent mixing and flow acceleration. The principal advantages and shortcomings of various models are discussed.
06•02082 Preparation, characterisation and activity of chromia-zirconia catalysts for propane dehydrogenation Cutrufello, M. G. et al. Thermochimiea Acta, 2005, 434, (1-2), 62-68. Dehydrogenation catalysts based on chromia supported on ZrO2, containing about 10 wt% of chromium and increasing amounts of potassium (up to 4 wt%), were prepared and characterized by chemical analysis, N2 adsorption-desorption at 77 K, X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), temperature programmed reduction (TPR) and adsorption microcalorimetry of ammonia. Increasing K amounts deeply modify the ammonia adsorption behaviour, with a progressive decrease in the acidic features, which are completely lost when the K content attains 1 wt%. Reduction of Cr species seems rather easy for chromia-zirconia and K-containing chromia-zirconia samples with K contents up to 0.5 wt%. The onset of reduction shifts to higher temperatures as the K concentration increases. Catalytic testing was performed under atmospheric pressure at 813 K. Pure zirconia is very poorly active in propane dehydrogenation; also virtually inactive are the samples with a K content _>1 wt%. Conversion decreases as the K amount increases up to 0.5 wt%, propene selectivity being close to 100 tool%. An induction period is observed for all the active samples, which attains a maximum in conversion before being deactivated by coking.
06102083 Separation and qualitative analysis of suspended matter in jet fuel Zeng, X. et al. Fuel, 2006, 85, (4), 486 491. Suspended matter in jet fuel was separated by filtration and analysed using scanning electron microscopy, energy-dispersive X-ray spectrometry, X-ray diffractometry, infrared spectrophotometry and gas chromatograph-mass spectrometry. The results showed that the components in the suspended matter include alkanes, esters with long molecular chains and multi-substituents, alcohols, ketones, alkenes and heteroatomic compounds containing nitrogen and sulfur. This work will assist in the ultimate determination of the chemical composition of the suspended matter and an understanding of its mode of formation.
Transport, storage 06•02084 Influence of old rectangular repair patches on the burst pressure of a gas pipeline Fazzini, P. G. and Otegui, J. L. International Journal of Pressure Vessels and Piping, 2006, 83, (1), 27-34. Seven full-scale hydrostatic burst tests were carried out on pipes extracted from an API 5LX52 gas pipeline that contained rectangular and elliptical fillet welded patches and other repairs of different geometries. All breaks took place after widespread yielding. This analysis shows that the patches that generate greater risks are those that: (1) were attached to the pipeline at very low pressure, (2) were placed to repair large defects, (3) are rectangular, long in the direction of the pipe, and narrow, (4) the quality of the weld is doubtful. Based on data reported by In Line Inspection (ILI), of the four conditions mentioned above, only the third can be assessed in order to quantify risks and to schedule replacements.
06•02085 Optimization of pipeline transport for COa sequestration Zhang, Z. X. et al. Energy Conversion and Management, 2006, 47, (6), 702 715. Coal-fired power generation will continue to provide energy to the world for the foreseeable future. However, this energy use is a significant contributor to increased atmospheric carbon dioxide concentration and, hence, global warming. Capture and disposal of carbon dioxide has received increased research and development attention in the past decade as the technology promises to be the most cost-effective for large-scale reductions in carbon dioxide emissions. This paper addresses carbon dioxide transport via pipeline from capture site to disposal site, in terms of system optimization, energy efficiency and overall economics. Technically, carbon dioxide can be transported through pipelines in the form of a gas, a supercritical fluid or in the subcooled liquid state. Operationally, most carbon dioxide
06/02078 Characteristics and origin of natural gases in the Kuqa Depression of Tarim Basin, NW China Zou, Y.-R. et al. Organic Geochemistry, 2006, 37, (3), 280 290. Significant gas condensate as well as some black oils have been discovered in the Kuqa Depression of Tarim Basin, north-west (NW) China. Dry gases with high ~513Cvalues occur in the Kelasu structural belt, wet, isotopically light gases in the Yiqikelik belt, whereas condensates are distributed mainly in the Front Uplift area. Kinetic modelling results show that the variation of methane and ethane isotopes with increasing vitrinite reflectance is independent of heating rates for a given source rock. Two maturity trends have been observed o n a C2/C~-~ C1 plot, one for thermogemc gases assocmted with coal, another for oil-associated gases with minor contribution from biogenic gas. It is most likely that the gases in the Kelasu belt and Front Uplift area were derived from the Jurassic coal measures and Triassic lacustrine shales, respectively, with those in the Yiqikelik belt being the mixtures of gases from the two sources. Both Jurassic coals and Triassic lacustrine shales appear to have contributed to the gases in the Kela 2 (KL2) and Dina 2 (DN2), the two largest gas fields in the Tarim Basin. 13
•
-
•
06/02079 Determination of heavy metals and volatile aromatic compounds in used engine oils and sludges Rauckyte, T. et al. Fuel, 2006, 85, (4), 481-485. Assessment of contaminant releases during utilization of used oils is essential for the determination of environmental acceptability. These paper reports the results of the study examining a toxic metal leachability from used engine oil and sludge samples employing leaching test (TCLP). The leaching test indicated that lead in oil samples exceeded 5-ppm concentration level what qualified them as a toxic waste. The samples of contaminated sludge were found to contain high concentration of total lead, barium and chromium, but the leaching test showed concentration below regulatory limit. The total content of benzene, ethylbenzene, toluene, and xylenes (BETX), and naphthalene in used oil and sludge samples was also determined and was found not to be a significant factor to contamination.
06•02080 NOx formation in natural gas combustion - a new simplified reaction scheme for CFD calculations L6ffler, G. et al. Fuel, 2006, 85, (4), 513-523. Computational fluid dynamics (CFD) is a widely used tool in optimizing natural gas burners, for instance, for emission issues. Especially, a further reduction of NO,. emissions is of interest. However, due to computational efforts calculating three-dimensional turbulent flames, there is the necessity for simplified models in order to simulate the combustion reactions and the NO~ formation, respectively. Hitherto, models describing thermal NO and prompt NO formation, respectively, were applied in a post-processing step. Beforehand, the flow field including combustion has been determined in the three-dimensional geometry. However, in the former work, it was shown that prompt NO formation is of minor significance. For temperatures higher than 1600°C, thermal NO formation is dominating. At lower temperatures, the N:O/NO and NNH route have significant contribution. Though, the widely applied prompt NO model captures the observed trends acceptable, it lacks of physical bases. Besides low temperature NO formation is more related to N20/ NO and NNH route, it assumes the prompt NO formation to be proportional to the fuel concentratiom The detailed reaction mechanism show NO formation more related to fuel oxidation rate, i.e. radical concentration. Thus, in this work, a new simplified model combining thermal NO formation. N20/NO, and NNH route is proposed. It applies steady-state approximation for the intermediate species, i.e. N, N20, NNH, and NH. In this way, their concentrations can be obtained by four algebraic equations and rate of NO formation can be calculated without any model parameter, solely based on reaction kinetics. Moreover, the concentrations of O_,, N2, H> and H20 as well as the radicals O, H, OH, and HO2 have to be known from combustion calculations. The model was evaluated against the predictions of a detailed reaction mechanism, showing good agreement in a wide range of conditions. Neglecting prompt NO formation affects predicted NO emissions only under very fuel rich conditions. Under these circumstances, total NO formation is low, anyway. Thus, the performance of the presented model is not influenced by the lack of prompt NO formation.
06•02081 Numerical modelling of propane combustion in a high velocity oxygen-fuel thermal spray gun Kamnis, S. and Gu, S. Chemical Engineering and Processing, 2006, 45, (4), 246 253.
322
Fuel and Energy Abstracts
September 2006
High velocity oxygen-fuel (HVOF) thermal spraying is a relatively new technology compared to other protective coating methods. Powders sprayed by liquid fuel HVOF guns are able to achieve high impact velocities without overheating, which results in superior coatings. A computational fluid dynamic (CFD) model is developed to investigate propane combustion in the process of HVOF thermal spraying. The numerical methods are described for correct representation of various thermal-physical phenomena such as flame propagation, turbulent mixing and flow acceleration. The principal advantages and shortcomings of various models are discussed.
06•02082 Preparation, characterisation and activity of chromia-zirconia catalysts for propane dehydrogenation Cutrufello, M. G. et al. Thermochimiea Acta, 2005, 434, (1-2), 62-68. Dehydrogenation catalysts based on chromia supported on ZrO2, containing about 10 wt% of chromium and increasing amounts of potassium (up to 4 wt%), were prepared and characterized by chemical analysis, N2 adsorption-desorption at 77 K, X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), temperature programmed reduction (TPR) and adsorption microcalorimetry of ammonia. Increasing K amounts deeply modify the ammonia adsorption behaviour, with a progressive decrease in the acidic features, which are completely lost when the K content attains 1 wt%. Reduction of Cr species seems rather easy for chromia-zirconia and K-containing chromia-zirconia samples with K contents up to 0.5 wt%. The onset of reduction shifts to higher temperatures as the K concentration increases. Catalytic testing was performed under atmospheric pressure at 813 K. Pure zirconia is very poorly active in propane dehydrogenation; also virtually inactive are the samples with a K content _>1 wt%. Conversion decreases as the K amount increases up to 0.5 wt%, propene selectivity being close to 100 tool%. An induction period is observed for all the active samples, which attains a maximum in conversion before being deactivated by coking.
06102083 Separation and qualitative analysis of suspended matter in jet fuel Zeng, X. et al. Fuel, 2006, 85, (4), 486 491. Suspended matter in jet fuel was separated by filtration and analysed using scanning electron microscopy, energy-dispersive X-ray spectrometry, X-ray diffractometry, infrared spectrophotometry and gas chromatograph-mass spectrometry. The results showed that the components in the suspended matter include alkanes, esters with long molecular chains and multi-substituents, alcohols, ketones, alkenes and heteroatomic compounds containing nitrogen and sulfur. This work will assist in the ultimate determination of the chemical composition of the suspended matter and an understanding of its mode of formation.
Transport, storage 06•02084 Influence of old rectangular repair patches on the burst pressure of a gas pipeline Fazzini, P. G. and Otegui, J. L. International Journal of Pressure Vessels and Piping, 2006, 83, (1), 27-34. Seven full-scale hydrostatic burst tests were carried out on pipes extracted from an API 5LX52 gas pipeline that contained rectangular and elliptical fillet welded patches and other repairs of different geometries. All breaks took place after widespread yielding. This analysis shows that the patches that generate greater risks are those that: (1) were attached to the pipeline at very low pressure, (2) were placed to repair large defects, (3) are rectangular, long in the direction of the pipe, and narrow, (4) the quality of the weld is doubtful. Based on data reported by In Line Inspection (ILI), of the four conditions mentioned above, only the third can be assessed in order to quantify risks and to schedule replacements.
06•02085 Optimization of pipeline transport for COa sequestration Zhang, Z. X. et al. Energy Conversion and Management, 2006, 47, (6), 702 715. Coal-fired power generation will continue to provide energy to the world for the foreseeable future. However, this energy use is a significant contributor to increased atmospheric carbon dioxide concentration and, hence, global warming. Capture and disposal of carbon dioxide has received increased research and development attention in the past decade as the technology promises to be the most cost-effective for large-scale reductions in carbon dioxide emissions. This paper addresses carbon dioxide transport via pipeline from capture site to disposal site, in terms of system optimization, energy efficiency and overall economics. Technically, carbon dioxide can be transported through pipelines in the form of a gas, a supercritical fluid or in the subcooled liquid state. Operationally, most carbon dioxide