- Email: [email protected]
00579 Screening analysis to detect adulterations in Brazilian gasoline samples using distillation curves
02 Liquid fuels (economics, business, marketing, policy) 05/00573 Clean coal conversion options using FischerTropsch technology Steynberg, A. P. and Nel, H. G. Fuel, 2004, 83, (6), 765-770. Material and energy balances were prepared for two coal conversion options for the co-production of liquid hydrocarbon products and electricity. The results are compared to the alternative approach of producing liquid hydrocarbons from natural gas. It is concluded that the capital cost for coal conversion must be higher but that cash operating costs may be similar. There are important synergistic effects so that facilities co-producing liquid hydrocarbons and electricity from coal are more efficient than facilities producing these products individually. There may be good strategic reasons to use clean coal conversion plants co-producing liquid hydrocarbons and electricity. Due to the huge capital investments required, some form of government assistance will be needed.
05/00574 Fischer-Tropsch synthesis over Co-SiO2 catalysts prepared by the sol-gel method Okabe, K. et al. Catalysis Today, 2004, 89, (4), 431-438. Fischer-Tropsch synthesis was carried out in slurry phase over uniformly dispersed Co-SiO2 catalysts prepared by the sol-gel method. When 0.01-1 wt.% of noble metals were added to the Co-SiO2 catalysts, a high and stable catalytic activity was obtained over 60 h of the reaction at 503 K and 1 MPa. The addition of noble metals increased the reducibility of surface Co on the catalysts, without changing the particle size of Co metal significantly. High dispersion of metallic Co species stabilized on SiO2 was responsible for stable activity. The uniform pore size of the catalysts was enlarged by varying the preparation conditions and by adding organic compounds such as N,N-dimethylformamide and formamide. Increased pore size resulted in decrease in CO conversion and selectivity for CO2, a byproduct, and an increase in the olefin/paraffin ratio of the products. By modifying the surface of wide pore silica with Co-SiO2 prepared by the sol-gel method, a bimodal pore structured catalyst was prepared. The bimodal catalyst showed high catalytic performance with reducing the amount of the expensive sol-gel Co-SiO2.
05/00575 Fracture response of pipelines subjected to large plastic deformation under tension Jayadevan, K. R. el al. International Journal of Pressure Vessels and Piping, 2004, 81, (9), 771-783. Economical design with sufficient fracture resistance is of utmost importance in any offshore pipeline project. High internal pressure combined with bending/tension, accompanied by large plastic strains, becomes a major design challenge for ensuring line integrity. Recent research efforts have pushed the design strain limits in compression to quite large values, but on the tension side, the limits are still very restrictive. The existing procedures for the fracture assessment of pipelines are based on simplified analytical methods and, these are derived for a load-based approach. Hence, application to surface cracked pipes under large deformation is doubtful. The aim of this paper is to understand and identify various parameters that influence the fracture response of cracks in pipelines. The evolution of CTOD of a line-pipe segment with an external circumferential surface crack is investigated under pure tensile loading as well as tension with internal pressure. Detailed 3D elastic-plastic finite element simulations are performed. The effects of crack depth, crack length, radius-tothickness ratio and material hardening on fracture response are examined. The results show a significant enhancement of applied CTOD with increase in magnitude of internal pressure. Further, the variation of applied CTOD with strain can be well approximated by a simple linear relationship.
05/00576 Hydrogels as adsorbents of organosulphur compounds currently found in diesel Aburto, J. et al. Chemical Engineering and Processing, 2004, 43, (12), 1587-1595. Hydrogels of chitosan were synthesized using glutaric dialdehyde as the crosslinking agent in an acetonitrile/water solution (1:4, v/v). These hydrogels recognized and adsorbed the dibenzothiophene sulfone (DBTS) against other related compounds found in diesel, e.g. dibenzothiophene (DBT), fluorene (FLE) and 4,6-dimethyl DBT (DMDBT). In order to improve the recognition and adsorption of DBTS, the latter compound served as a template for the building of recognition sites inside the hydrogel matrix through the use of the molecular imprinting technique (MIT). Despite the adsorption capacity of the molecular imprinted hydrogel (MIH) was not increased, the imprinting process of chitosan allowed both an enhancement of two orders of magnitude in ligand affinity constant and material homogeneity as seen by SEM. The change in swelling degree (Q) suggested the presence of a conformational memory of the hydrogel that might allow the design of stimuli-response but also tailored-made hydrogels responding at a required factor as temperature. The imprinting process improved ligand recognition and consequently hydrogel's specificity as
shown by a monolayer adsorption. In contrast, the adsorption isotherm of DBTS by the non-imprinted hydrogel showed a multi-layer adsorption due to non-specific interactions.
05•00577 Oxidation of dibenzothiophene by laccase or hydrogen peroxide and deep desulfurization of diesel fuel by the later Villasefior, F. et al. Fuel Processing Technology, 2004, 86, (1), 49-59. Enzymatic oxidation of dibenzothiophene (DBT) catalysed by laccase in the presence of 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) was compared with the chemical oxidation with hydrogen peroxide catalysed by phosphotungstic acid. Enzymatic oxidation with laccase (2.4 U/ml) of 25 ~M DBT with 1.5 m M ABTS required a molar ratio [O2]/[ABTS]=140 and 72 h at 40°C in a water-acetonitrile reaction mixture, showing a rate constant of k m = - 6 . 3 x 1 0 - 4 rain -1. Whereas peroxide oxidation of 10 m M DBT with 39 g M phosphotungstic acid required only a molar ratio [HzOz]/[DBT] = 2, showing a rate constant of k2 = -6.1 x 10-2 rain -l in a hexane-ethanol system. A sample of diesel fuel, containing 342 ppm of sulfur, was chemically oxidized by an excess of hydrogen peroxide and 119 /aM phosphotungstic acid dissolved in ethanol, in less than 3 h at 60°C and atmospheric pressure. No sulfur could be detected in these samples after an additional extraction with an equal volume of ethanol.
05/00578 Removal of hydrogen sulfide from light oil with solid base Duan, Y. et al. Fuel Processing Technology, 2004, 86, (3), 237 244. A novel solid base with activated carbon as supporter and alkali and earth-alkali compounds as active components has been developed for removal of hydrogen sulfide from light oils. The experimental results indicated that the solid base has excellent adsorption capacity for hydrogen sulfide. In addition, an additive added to feedstock that can promote significantly the removal of hydrogen sulfide for the solid base was also developed. The adsorption capacity of the solid base for hydrogen sulfide was evaluated with dynamic testing.
05100579 Screening analysis to detect adulterations in Brazilian gasoline samples using distillation curves de Oliveira, F. S. et al. Fuel, 2004, 83, (7-8), 917-923. Data on evaporated fraction temperatures obtained from the distillation curves of Brazilian gasolines were employed to identify adulterated samples by applying the Soft Independent Modelling of Class Analogy (SIMCA) model. Since 1977, different quantities of ethanol have been added to the gasoline sold in Brazil. The ethanol concentration is established by Brazil's Petroleum Regulatory Agency. Ethanol and heavy solvent prices are lower than that for gasoline, so they are often added to the fuel for purpose of gasoline adulteration. Presence of these species in high or low concentration creates modifications in distillation curves. The SIMCA chemometrics method was selected due to its offering the possibility of sample classification into to the defined class. The training set for the SIMCA model consisted of 34 samples and test set consisted of 16 gasoline samples, eight of which were adulterated. Five principal components were necessary to explain 95% of the total variance. All test set samples were correctly classified while four samples of the training set, which were in conformity with legislation, were misclassified as contaminated by SIMCA.
Economics, business, marketing, policy 05/00580 Hedgers, funds, and small speculators in the energy futures markets: an analysis of the CFTC's Commitments of Traders reports Sanders, D. R. et al. Energy Economics, 2004, 26, (3), 425-445. The Commodity Futures Trading Commission (CFTC)'s Commitments of Traders (COT) data are examined for crude oil, unleaded gasoline, heating oil, and natural gas futures contracts. The collection procedures for the COT data are first examined, followed by Granger causality tests to determine if relationships between trader positions and market prices exist. A positive correlation between returns and positions held by non-commercial traders, and a negative correlation between commercial positions and market returns, are found. Furthermore, positive returns result in a n increase in noncommercial net positions in the following week, whereas the net long positions held by commercial hedgers decline following price increases. However, traders' net positions do not lead market returns in general.
05•00581 industry
Model contracts: a survey of the global petroleum
Martin, A. T. Journal of Energy & Natural Resources Law, 2004, 22, (3), 281-340.
Fuel and Energy Abstracts March 2005
87
05/00574 Fischer-Tropsch synthesis over Co-SiO2 catalysts prepared by the sol-gel method Okabe, K. et al. Catalysis Today, 2004, 89, (4), 431-438. Fischer-Tropsch synthesis was carried out in slurry phase over uniformly dispersed Co-SiO2 catalysts prepared by the sol-gel method. When 0.01-1 wt.% of noble metals were added to the Co-SiO2 catalysts, a high and stable catalytic activity was obtained over 60 h of the reaction at 503 K and 1 MPa. The addition of noble metals increased the reducibility of surface Co on the catalysts, without changing the particle size of Co metal significantly. High dispersion of metallic Co species stabilized on SiO2 was responsible for stable activity. The uniform pore size of the catalysts was enlarged by varying the preparation conditions and by adding organic compounds such as N,N-dimethylformamide and formamide. Increased pore size resulted in decrease in CO conversion and selectivity for CO2, a byproduct, and an increase in the olefin/paraffin ratio of the products. By modifying the surface of wide pore silica with Co-SiO2 prepared by the sol-gel method, a bimodal pore structured catalyst was prepared. The bimodal catalyst showed high catalytic performance with reducing the amount of the expensive sol-gel Co-SiO2.
05/00575 Fracture response of pipelines subjected to large plastic deformation under tension Jayadevan, K. R. el al. International Journal of Pressure Vessels and Piping, 2004, 81, (9), 771-783. Economical design with sufficient fracture resistance is of utmost importance in any offshore pipeline project. High internal pressure combined with bending/tension, accompanied by large plastic strains, becomes a major design challenge for ensuring line integrity. Recent research efforts have pushed the design strain limits in compression to quite large values, but on the tension side, the limits are still very restrictive. The existing procedures for the fracture assessment of pipelines are based on simplified analytical methods and, these are derived for a load-based approach. Hence, application to surface cracked pipes under large deformation is doubtful. The aim of this paper is to understand and identify various parameters that influence the fracture response of cracks in pipelines. The evolution of CTOD of a line-pipe segment with an external circumferential surface crack is investigated under pure tensile loading as well as tension with internal pressure. Detailed 3D elastic-plastic finite element simulations are performed. The effects of crack depth, crack length, radius-tothickness ratio and material hardening on fracture response are examined. The results show a significant enhancement of applied CTOD with increase in magnitude of internal pressure. Further, the variation of applied CTOD with strain can be well approximated by a simple linear relationship.
05/00576 Hydrogels as adsorbents of organosulphur compounds currently found in diesel Aburto, J. et al. Chemical Engineering and Processing, 2004, 43, (12), 1587-1595. Hydrogels of chitosan were synthesized using glutaric dialdehyde as the crosslinking agent in an acetonitrile/water solution (1:4, v/v). These hydrogels recognized and adsorbed the dibenzothiophene sulfone (DBTS) against other related compounds found in diesel, e.g. dibenzothiophene (DBT), fluorene (FLE) and 4,6-dimethyl DBT (DMDBT). In order to improve the recognition and adsorption of DBTS, the latter compound served as a template for the building of recognition sites inside the hydrogel matrix through the use of the molecular imprinting technique (MIT). Despite the adsorption capacity of the molecular imprinted hydrogel (MIH) was not increased, the imprinting process of chitosan allowed both an enhancement of two orders of magnitude in ligand affinity constant and material homogeneity as seen by SEM. The change in swelling degree (Q) suggested the presence of a conformational memory of the hydrogel that might allow the design of stimuli-response but also tailored-made hydrogels responding at a required factor as temperature. The imprinting process improved ligand recognition and consequently hydrogel's specificity as
shown by a monolayer adsorption. In contrast, the adsorption isotherm of DBTS by the non-imprinted hydrogel showed a multi-layer adsorption due to non-specific interactions.
05•00577 Oxidation of dibenzothiophene by laccase or hydrogen peroxide and deep desulfurization of diesel fuel by the later Villasefior, F. et al. Fuel Processing Technology, 2004, 86, (1), 49-59. Enzymatic oxidation of dibenzothiophene (DBT) catalysed by laccase in the presence of 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) was compared with the chemical oxidation with hydrogen peroxide catalysed by phosphotungstic acid. Enzymatic oxidation with laccase (2.4 U/ml) of 25 ~M DBT with 1.5 m M ABTS required a molar ratio [O2]/[ABTS]=140 and 72 h at 40°C in a water-acetonitrile reaction mixture, showing a rate constant of k m = - 6 . 3 x 1 0 - 4 rain -1. Whereas peroxide oxidation of 10 m M DBT with 39 g M phosphotungstic acid required only a molar ratio [HzOz]/[DBT] = 2, showing a rate constant of k2 = -6.1 x 10-2 rain -l in a hexane-ethanol system. A sample of diesel fuel, containing 342 ppm of sulfur, was chemically oxidized by an excess of hydrogen peroxide and 119 /aM phosphotungstic acid dissolved in ethanol, in less than 3 h at 60°C and atmospheric pressure. No sulfur could be detected in these samples after an additional extraction with an equal volume of ethanol.
05/00578 Removal of hydrogen sulfide from light oil with solid base Duan, Y. et al. Fuel Processing Technology, 2004, 86, (3), 237 244. A novel solid base with activated carbon as supporter and alkali and earth-alkali compounds as active components has been developed for removal of hydrogen sulfide from light oils. The experimental results indicated that the solid base has excellent adsorption capacity for hydrogen sulfide. In addition, an additive added to feedstock that can promote significantly the removal of hydrogen sulfide for the solid base was also developed. The adsorption capacity of the solid base for hydrogen sulfide was evaluated with dynamic testing.
05100579 Screening analysis to detect adulterations in Brazilian gasoline samples using distillation curves de Oliveira, F. S. et al. Fuel, 2004, 83, (7-8), 917-923. Data on evaporated fraction temperatures obtained from the distillation curves of Brazilian gasolines were employed to identify adulterated samples by applying the Soft Independent Modelling of Class Analogy (SIMCA) model. Since 1977, different quantities of ethanol have been added to the gasoline sold in Brazil. The ethanol concentration is established by Brazil's Petroleum Regulatory Agency. Ethanol and heavy solvent prices are lower than that for gasoline, so they are often added to the fuel for purpose of gasoline adulteration. Presence of these species in high or low concentration creates modifications in distillation curves. The SIMCA chemometrics method was selected due to its offering the possibility of sample classification into to the defined class. The training set for the SIMCA model consisted of 34 samples and test set consisted of 16 gasoline samples, eight of which were adulterated. Five principal components were necessary to explain 95% of the total variance. All test set samples were correctly classified while four samples of the training set, which were in conformity with legislation, were misclassified as contaminated by SIMCA.
Economics, business, marketing, policy 05/00580 Hedgers, funds, and small speculators in the energy futures markets: an analysis of the CFTC's Commitments of Traders reports Sanders, D. R. et al. Energy Economics, 2004, 26, (3), 425-445. The Commodity Futures Trading Commission (CFTC)'s Commitments of Traders (COT) data are examined for crude oil, unleaded gasoline, heating oil, and natural gas futures contracts. The collection procedures for the COT data are first examined, followed by Granger causality tests to determine if relationships between trader positions and market prices exist. A positive correlation between returns and positions held by non-commercial traders, and a negative correlation between commercial positions and market returns, are found. Furthermore, positive returns result in a n increase in noncommercial net positions in the following week, whereas the net long positions held by commercial hedgers decline following price increases. However, traders' net positions do not lead market returns in general.
05•00581 industry
Model contracts: a survey of the global petroleum
Martin, A. T. Journal of Energy & Natural Resources Law, 2004, 22, (3), 281-340.
Fuel and Energy Abstracts March 2005
87