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02425 Vapor pressure and normal boiling point predictions for pure methyl esters and biodiesel fuels
02 Liquid fuels (transport, refining, quality, storage) prediction of the flow field. The predicted gas species concentrations were found to be in a reasonable agreement with the measurements, except near the burner and in the vicinity of the furnace axis where discrepancies were found.
05/02420 Investigation of bubble-point vapor pressures for mixtures of an endothermic hydrocarbon fuel with ethanol Sun, H. et al. Fuel, 2005, 84, (7 8), 825-831. Bubble-point vapour pressures and equilibrium temperatures for several mixtures with different mass fractions of a kerosene-based endothermic hydrocarbon fuel (EHF) and ethanol were measured by comparative ebulliometry with inclined ebulliometers. Correlation between vapour pressures and equilibrium temperatures by the Antoine equation was given with satisfactory precision. The bubblepoint lines of pressure versus composition at different temperatures and temperature versus composition at different pressures were obtained. The pseudo binary systems of EHF + ethanol appear with very large positive deviations from Raoult's law. It follows that the addition of ethanol had a critical effect on the vapour pressure of fuels. Ethanol may be an effective oxygenated hydrocarbon additive to adjust the volatility of EHF.
05•02421 Recovery of bitumen from oilsands: gelation of ultra-fine clay in the primary separation vessel Tu, Y. et al. Fuel, 2005, 84, (6), 653-660. The bulk of bitumen recovery from oilsands takes place via a flotation/ settling process in the primary separation vessel (PSV). Under certain conditions, some oilsands slurries become non-segregating, i.e. both fines and coarse solids remain in suspension and little or no bitumen froth is generated. An ultra-fine (<0.3 gm) component of the oilsands fines fraction (<44 gin) is identified as having the potential to be the major contributor to the thickening (gelation), or sludging, phenomenon observed in some ores. In this work the authors determined the amounts of ultra-fines in oilsands from different depositional environments. Although a generally linear correlation exists between ultrafines and fines or clay contents, some samples were found to have a disproportionately high ultra-fines contribution relative to other oilsands. Waste units, in particular, were found to be extremely rich in the ultra-fines and clay-sized fractions. The study used a 2H N M R method to measure both the rate and degree of gelation of ultra-fines suspensions separated from oilsands. Sludging conditions are reached when the ultra-fines concentration is between about 1.5 and 2.0 w/w%. Measurement of ultra-fines gelation times showed them to be of the same order as slurry residence time in the PSV. Laboratory jar tests have demonstrated that poor segregation of oilsands components can be correlated with the gelation conditions determined by NMR measurements.
05•02422 Replacement of CH4 in the hydrate by use of liquid C02 Ota, M. et al. Energy Conversion and Management, 2005, 46, (11-12), 1680-1691. The dynamics of CH4 replacement in the CH4 hydrate with saturated liquid CO2 at 273.2 K was measured with a high pressure optical cell. The results showed that CH4 in the hydrate gradually moved to the liquid CO2 phase while CO2 in the liquid phase penetrated into the hydrate from the quantitative analysis. The decomposing process of the CH4 hydrate during the replacement was analysed with in situ R a m a n spectroscopy, which allowed us to distinguish the cage structure of the CH4 hydrate and discuss the microscopic view of the replacement in the hydrate. It was found that the decomposition of the medium cage (Mcage) in the CH4 hydrate proceeded faster than that of the small cage (S-cage). The observed rate difference could be related to the stability of the S-cage in the CH4 hydrate or the re-formation tendency of CH4 and water molecules in the S-cage after decomposing the hydrate structure, whereas the guest molecule exchange of CH4 with CO2 could occur in the M-cage. Based on the experimental data, the authors developed a kinetic model for calculation of the CH4 remaining in the hydrate considering the decomposition rate difference between the Mcage and S-cage in the CH4 hydrate. The results indicate that the driving force could be the fugacity difference between the fluid phase and the hydrate phase for the replacement process.
05102423 The chemistry of minerals obtained from the combustion of Jordanian oil shale A1-Otoom, A. Y. et aI. Energy, 2005, 30, (5), 611-619. A characterization study was performed on the spent oil shale (oil shale ash) obtained from the combustion of Jordanian oil shale. This characterization utilized different analytical techniques. These include scanning electron microscope with energy dispersive spectrum analysis, X-ray fluorescence, X-ray diffraction and Qemscan. During the combustion process, minimal fragmentation was encountered since Jordanian oil shale contains large proportions of ash, which maintain the original structure of the oil shale particle. Different analytical techniques confirmed that the dominant phase of minerals in the oil
358
Fuel and Energy Abstracts
November 2005
shale is calcite, which transforms, in parts, into anhydrite during combustion. Sulphur was found to be mainly of an organic source. This sulphur is combusted to produce SO2 and then SOs, which controls the sulphation reaction of the calcite. The dominant phase in the ash was the anhydrite in addition to the calcite, clays and calcium phosphate.
05•02424 Thermal and geochemical characterization of Lokpanta oil shales, Nigeria Sonibare, O. O. et al. Energy Conversion and Management, 2005, 46, (15 16), 2335-2344. Thermal decomposition of Lokpanta oil shale from Nigeria was studied by non-isothermal thermogravimetry (TG) and differential thermal analysis (DTA). The experiments were performed in an inert environment with a temperature range of 25 to 600°C. The geochemical characteristics of the oil shale were also investigated by rock evaluation pyrolysis. Thermal breakdown of the kerogen content of the oil shale takes place mainly at the temperature range of 300 to 570°C. The estimated decomposable kerogen content of the oil shale ranges from 4.55 to 9.64 wt.%. The activation energies of the pyrolysis process vary from 73.2 to 75.0 kJ/mol. The D T A data reveals the exothermic nature of the decomposition process. The results fl'om the geochemical analysis indicate that the oil shale contains sufficient, good quality kerogen to generate both oil and gas upon pyrolysis.
05•02425 Vapor pressure and normal boiling point predictions for pure methyl esters and biodiesel fuels Yuan, W. et al. Fuel, 2005, 84, (7-8), 943-950. Temperature dependent vapour pressures of the methyl esters of 14 fatty acids that are commonly present in biodiesel fuels were predicted by the Antoine equation and a group contribution method. The predicted boiling points of these esters up to a pressure of 100 mmHg were within --1.0% of reported data for these two methods. Normal boiling points were determined from both the predicted vapour pressure and a correlation equation and the prediction errors were less than 5 K comparing to available published data. The vapour pressure and normal boiling points of 19 real-world biodiesel fuels were predicted and compared with reported data where available. The prediction errors of normal boiling points were less than 1.0%, and the predicted vapour pressures were also observed to closely match the reported data among the methyl esters of soybean oil, rapeseed oil and tallow. The predicted results showed that, except for coconut and butterfat, most of the methyl esters of the vegetable oils and animal fats had a normal boiling point in the range of 620-630 K. A sensitivity analysis indicated that the variation of fatty acid composition and the uncertainty of the normal boiling point of C18:2 were the main factors that affected the predicted normal boiling points of the biodiesel fuels.
Transport, refining, quality, storage 05/02426 A novel catalyst system based on quadruple silicoaluminophosphate and aluminosilicate zeolites for FCC gasoline upgrading Fan, Y. et al. Fuel, 2005, 84, (4), 435-442. To develop a novel catalyst system that has excellent olefin reduction capability for FCC gasoline without loss in octane number, different catalysts supported on multiple composite carriers consisting of SAPO11, HtS, H M O R and HZSM-5 were prepared and their catalytic performances for FCC gasoline upgrading were assessed. The pore structure and acidity of the catalysts were characterized by Nz adsorption and pyridine adsorption FTIR, respectively. Based on the results obtained over the catalysts supported on binary-zeolite carriers (H/3/HZSM-5, HMOR/HZSM-5 and SAPO-11/HZSM-5) using FCC gasoline as the feedstock, various multiple-zeolite supported catalysts were developed from different combinations of the binary-zeolite systems. It was found that the SAPO-11/HMOR/p/ZSM-5 quadruple composite zeolite supported catalyst gave higher liquid yield, improved gasoline RON, and lower coke deposit amount for the hydro-upgrading of FCC gasoline and thus can be considered as a potential catalyst system. A comprehensive analysis based on the catalytic activities and acidity measurements revealed that acid strength and acid type were two very important factors influencing hydroisomerization and aromatization activities, and the difference in catalyst acid strength determined which factor predominates.
05/02427 Accurate measurement method for the residues in liquefied petroleum gas (LPG) Zhuang, Q. et al. Fuel, 2005, 84, (4), 443-446. A newly developed LPG residues measurement method is reported. First, residues in LPG are extracted into n-hexane. Then, the residues in n-hexane is analysed by gas chromatography. The method gives accurate results and good repeatability. It is powerful even at low
05/02420 Investigation of bubble-point vapor pressures for mixtures of an endothermic hydrocarbon fuel with ethanol Sun, H. et al. Fuel, 2005, 84, (7 8), 825-831. Bubble-point vapour pressures and equilibrium temperatures for several mixtures with different mass fractions of a kerosene-based endothermic hydrocarbon fuel (EHF) and ethanol were measured by comparative ebulliometry with inclined ebulliometers. Correlation between vapour pressures and equilibrium temperatures by the Antoine equation was given with satisfactory precision. The bubblepoint lines of pressure versus composition at different temperatures and temperature versus composition at different pressures were obtained. The pseudo binary systems of EHF + ethanol appear with very large positive deviations from Raoult's law. It follows that the addition of ethanol had a critical effect on the vapour pressure of fuels. Ethanol may be an effective oxygenated hydrocarbon additive to adjust the volatility of EHF.
05•02421 Recovery of bitumen from oilsands: gelation of ultra-fine clay in the primary separation vessel Tu, Y. et al. Fuel, 2005, 84, (6), 653-660. The bulk of bitumen recovery from oilsands takes place via a flotation/ settling process in the primary separation vessel (PSV). Under certain conditions, some oilsands slurries become non-segregating, i.e. both fines and coarse solids remain in suspension and little or no bitumen froth is generated. An ultra-fine (<0.3 gm) component of the oilsands fines fraction (<44 gin) is identified as having the potential to be the major contributor to the thickening (gelation), or sludging, phenomenon observed in some ores. In this work the authors determined the amounts of ultra-fines in oilsands from different depositional environments. Although a generally linear correlation exists between ultrafines and fines or clay contents, some samples were found to have a disproportionately high ultra-fines contribution relative to other oilsands. Waste units, in particular, were found to be extremely rich in the ultra-fines and clay-sized fractions. The study used a 2H N M R method to measure both the rate and degree of gelation of ultra-fines suspensions separated from oilsands. Sludging conditions are reached when the ultra-fines concentration is between about 1.5 and 2.0 w/w%. Measurement of ultra-fines gelation times showed them to be of the same order as slurry residence time in the PSV. Laboratory jar tests have demonstrated that poor segregation of oilsands components can be correlated with the gelation conditions determined by NMR measurements.
05•02422 Replacement of CH4 in the hydrate by use of liquid C02 Ota, M. et al. Energy Conversion and Management, 2005, 46, (11-12), 1680-1691. The dynamics of CH4 replacement in the CH4 hydrate with saturated liquid CO2 at 273.2 K was measured with a high pressure optical cell. The results showed that CH4 in the hydrate gradually moved to the liquid CO2 phase while CO2 in the liquid phase penetrated into the hydrate from the quantitative analysis. The decomposing process of the CH4 hydrate during the replacement was analysed with in situ R a m a n spectroscopy, which allowed us to distinguish the cage structure of the CH4 hydrate and discuss the microscopic view of the replacement in the hydrate. It was found that the decomposition of the medium cage (Mcage) in the CH4 hydrate proceeded faster than that of the small cage (S-cage). The observed rate difference could be related to the stability of the S-cage in the CH4 hydrate or the re-formation tendency of CH4 and water molecules in the S-cage after decomposing the hydrate structure, whereas the guest molecule exchange of CH4 with CO2 could occur in the M-cage. Based on the experimental data, the authors developed a kinetic model for calculation of the CH4 remaining in the hydrate considering the decomposition rate difference between the Mcage and S-cage in the CH4 hydrate. The results indicate that the driving force could be the fugacity difference between the fluid phase and the hydrate phase for the replacement process.
05102423 The chemistry of minerals obtained from the combustion of Jordanian oil shale A1-Otoom, A. Y. et aI. Energy, 2005, 30, (5), 611-619. A characterization study was performed on the spent oil shale (oil shale ash) obtained from the combustion of Jordanian oil shale. This characterization utilized different analytical techniques. These include scanning electron microscope with energy dispersive spectrum analysis, X-ray fluorescence, X-ray diffraction and Qemscan. During the combustion process, minimal fragmentation was encountered since Jordanian oil shale contains large proportions of ash, which maintain the original structure of the oil shale particle. Different analytical techniques confirmed that the dominant phase of minerals in the oil
358
Fuel and Energy Abstracts
November 2005
shale is calcite, which transforms, in parts, into anhydrite during combustion. Sulphur was found to be mainly of an organic source. This sulphur is combusted to produce SO2 and then SOs, which controls the sulphation reaction of the calcite. The dominant phase in the ash was the anhydrite in addition to the calcite, clays and calcium phosphate.
05•02424 Thermal and geochemical characterization of Lokpanta oil shales, Nigeria Sonibare, O. O. et al. Energy Conversion and Management, 2005, 46, (15 16), 2335-2344. Thermal decomposition of Lokpanta oil shale from Nigeria was studied by non-isothermal thermogravimetry (TG) and differential thermal analysis (DTA). The experiments were performed in an inert environment with a temperature range of 25 to 600°C. The geochemical characteristics of the oil shale were also investigated by rock evaluation pyrolysis. Thermal breakdown of the kerogen content of the oil shale takes place mainly at the temperature range of 300 to 570°C. The estimated decomposable kerogen content of the oil shale ranges from 4.55 to 9.64 wt.%. The activation energies of the pyrolysis process vary from 73.2 to 75.0 kJ/mol. The D T A data reveals the exothermic nature of the decomposition process. The results fl'om the geochemical analysis indicate that the oil shale contains sufficient, good quality kerogen to generate both oil and gas upon pyrolysis.
05•02425 Vapor pressure and normal boiling point predictions for pure methyl esters and biodiesel fuels Yuan, W. et al. Fuel, 2005, 84, (7-8), 943-950. Temperature dependent vapour pressures of the methyl esters of 14 fatty acids that are commonly present in biodiesel fuels were predicted by the Antoine equation and a group contribution method. The predicted boiling points of these esters up to a pressure of 100 mmHg were within --1.0% of reported data for these two methods. Normal boiling points were determined from both the predicted vapour pressure and a correlation equation and the prediction errors were less than 5 K comparing to available published data. The vapour pressure and normal boiling points of 19 real-world biodiesel fuels were predicted and compared with reported data where available. The prediction errors of normal boiling points were less than 1.0%, and the predicted vapour pressures were also observed to closely match the reported data among the methyl esters of soybean oil, rapeseed oil and tallow. The predicted results showed that, except for coconut and butterfat, most of the methyl esters of the vegetable oils and animal fats had a normal boiling point in the range of 620-630 K. A sensitivity analysis indicated that the variation of fatty acid composition and the uncertainty of the normal boiling point of C18:2 were the main factors that affected the predicted normal boiling points of the biodiesel fuels.
Transport, refining, quality, storage 05/02426 A novel catalyst system based on quadruple silicoaluminophosphate and aluminosilicate zeolites for FCC gasoline upgrading Fan, Y. et al. Fuel, 2005, 84, (4), 435-442. To develop a novel catalyst system that has excellent olefin reduction capability for FCC gasoline without loss in octane number, different catalysts supported on multiple composite carriers consisting of SAPO11, HtS, H M O R and HZSM-5 were prepared and their catalytic performances for FCC gasoline upgrading were assessed. The pore structure and acidity of the catalysts were characterized by Nz adsorption and pyridine adsorption FTIR, respectively. Based on the results obtained over the catalysts supported on binary-zeolite carriers (H/3/HZSM-5, HMOR/HZSM-5 and SAPO-11/HZSM-5) using FCC gasoline as the feedstock, various multiple-zeolite supported catalysts were developed from different combinations of the binary-zeolite systems. It was found that the SAPO-11/HMOR/p/ZSM-5 quadruple composite zeolite supported catalyst gave higher liquid yield, improved gasoline RON, and lower coke deposit amount for the hydro-upgrading of FCC gasoline and thus can be considered as a potential catalyst system. A comprehensive analysis based on the catalytic activities and acidity measurements revealed that acid strength and acid type were two very important factors influencing hydroisomerization and aromatization activities, and the difference in catalyst acid strength determined which factor predominates.
05/02427 Accurate measurement method for the residues in liquefied petroleum gas (LPG) Zhuang, Q. et al. Fuel, 2005, 84, (4), 443-446. A newly developed LPG residues measurement method is reported. First, residues in LPG are extracted into n-hexane. Then, the residues in n-hexane is analysed by gas chromatography. The method gives accurate results and good repeatability. It is powerful even at low