WorldWideScience

Sample records for copoliester alifatico aromatico

  1. Study of the electron beam irradiation effect on some properties of aromatic aliphatic copolyester films; Estudo do efeito da radiacao por feixe de eletrons nas propriedades de filmes de copoliester alifatico aromatico

    Energy Technology Data Exchange (ETDEWEB)

    Poveda, Patricia Negrini Siqueira

    2008-07-01

    Biodegradable and green plastics are the new tendency in the world. The effect of the electron beam irradiation in aromatic aliphatic copolyester and the blend with corn starch films (Ecoflex{sup R} and Ecobras{sup R}) were studied by tensile strength at break, elongation at break, Scanning Electronic Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), crosslinking degree and biodegradability. The measurements in both, the machine direction and the transverse direction were made for mechanical tests. It was found that, the electron irradiation caused an increase in the strength at break of the blend with corn starch film, when doses of up to 10 kGy were applied. A significant decrease of the elongation at break of the blend with corn starch was observed at doses of 10 kGy and 40 kGy. It was not found important change in tensile properties for aromatic aliphatic copolyester. Structural changes of the samples (crosslinking or degradation) by SEM were not observed. The FT-IR identified the characteristic peaks of each involved functional group (copolyester and corn starch). However, it was not found bands of oxidation of the samples. In the DSC, changes in the melting temperature of the irradiated Ecoflex{sup R} and Ecobras{sup R} samples, was not identified when compared with the samples of reference. However, it was verified a reduction in the melting enthalpy of the Ecobras{sup R} samples after irradiation. The Ecobras{sup R} material presented crosslinking, when submitted to doses of 10 kGy and 40 kGy. The Ecoflex{sup R} material did not present crosslinking when submitted to these doses. The biodegradability of the materials was evaluated by two methods of test: soil simulated and enzymatic. In both methods, the irradiated samples presented faster biodegradation than the references not irradiated. (author)

  2. High-resolution gas chromatographic analysis of polycyclic aromatic hydrocarbons and aliphatic hydrocarbons; Separacion por cromatografia de gases de alta eficiencia de hidrocarburos aromaticos policiclicos, (PAH) y alifaticos (AH) ambientales, empleado como fases estacionarias OV-1 y SE-54

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M.; Gonzalez, D.

    1988-07-01

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons and aliphatic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column in two different polar stationary phases OV-1 and SE-54. The limitation and the advantages of the procedure are discussed in terms of separation, sensitivity and precision. (Author) 20 refs.

  3. Analysis of TPH and Aliphatic and Aromatic Hydrocarbons Fractions in Environmental Interest Matrices; Analisis del TPH y las Fracciones de Hidrocarburos Alifaticos y Aromaticos en Matrices de Interes Medioambiental

    Energy Technology Data Exchange (ETDEWEB)

    Pindado, O.; Perez, R. M.; Garcia, S.

    2014-02-01

    Analytical methods to analyze TPH and several aliphatic and aromatic fractions present in soil and groundwater samples contaminated by hydrocarbons are showed. As a part of BIOXISOIL project, analyzing these parameters is fundamental and indispensable to know the initial contamination level, design an adequate method to decontaminate it and eventually assess decontamination accomplished. Analysis of both matrices involve different extraction stages such as microwave radiation, clean up steps based on solid phase extraction and finally a chromatograph analysis with flame ion detector. Analytical procedures have showed satisfactory analytical quality parameters and have been validated against several certified reference materials. (Author)

  4. Analysis of aliphatic and aromatic hydrocarbons in particulate matter in Madrid urban area. Analisis de hidrocarburos aromaticos policiclicos e hidrocarburos alifaticos en aerosoles de la zona urbana de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M.; Mendez, J.; Bomboi, M.T.

    1988-02-01

    Levels of n-alkanes and polycyclic aromatic hydrocarbons have been measured in the air particulate matter during six months, from January to June of 1987, in an urban area of Madrid. The hydrocarbons were collected on glass fiber filter by high volume sampling. The extraction was varried out by sohxlet and ultrasonic techniques. The extracts were clean-up on silica gel fractionation and the chromatographic analysis was performed by capillary coluymn gas chromatographic. Final results are discussed as well as the inmission values related to the possible emission sources.

  5. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosols of the urban area of Madrid; Estudio de las variaciones diarias en las concentraciones de algunos hidrocarburos alifaticos y aromatico; policiclicos, en aerosoles de la zona urbana de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M. M.; Perez-Pastor, R. M.; Bea, F. J.; Campos, A.; Gonzalez, D.

    1991-07-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)

  6. Petroleum hydrocarbon assessment in the sediments of the northeastern Havana littoral, Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Companioni Dams, Eloy Yordad; Nunez Clemente, Ana Catalina; Cora Medina, Miriam Odette [Laboratorio de Quimica Ambiental, Centro de Investigaciones del Petroleo, Habana (Cuba)]. E-mail: elocompa@yahoo.com; Gonzalez Brovo, Luis [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, Habana, (Cuba); Marbot Ramada, Rolando [Laboratorio de Quimica Analitica, Centro de Investigaciones del Petroleo, Habana (Cuba); Montes de Oca Porto, Rodny [Laboratorio Antidoping, Habana (Cuba); Rosabal Rodriguez, Maikel [Centro de Ingenieria y Manejo Ambiental de Bahias y Costas, Habana (Cuba); Diaz Diaz, Miguel angel [Laboratorio de Quimica Ambiental, Centro de Investigaciones del Petroleo, Habana (Cuba)

    2009-02-15

    As a part of a geochemical study, aliphatic and aromatic hydrocarbons were determined in surficial sediments, from a Cuban coastal zone located in the Northeastern Havana Littoral. Sediment samples were collected at 15 sites in this area, and then extracted and analyzed by gas chromatography with flame ionization and mass spectrometry detectors. Total concentration of both, aliphatic (AH) and aromatic (ArH) hydrocarbons, varied from 2.4 {+-} 0.2 to 105.1 {+-} 5.9 {mu}g/g (dry weight) and from 1.1 {+-} 0.2 to 38.4 {+-} 7.6 {mu}g/g (dry weight), respectively. The chromatography profile of AH was dominated by an unresolved complex mixture (UCM), and the presence of isoprenoid hydrocarbons, steranes and hopanes, indicated petroleum - related hydrocarbon inputs. The predominant concentration of phytoplanktonic molecular markers (pristane and nC17) in collected sediments, revealed the marine productivity in this sites. The anthropogenic contribution detected showed the impact of the petroleum exploration along this coastal area. [Spanish] Como parte de un estudio geoquimico se determinaron hidrocarburos alifaticos y aromaticos en sedimentos superficiales, de una zona costera situada en el Litoral Nordeste de La Habana. Las muestras de sedimento se colectaron en 15 estaciones de muestreo en esta area, y posteriormente se extrajeron y analizaron mediante cromatografia gaseosa con detectores de ionizacion a la llama y espectrometria de masas. Las concentraciones totales de hidrocarburos alifaticos (HA) e hidrocarburos aromaticos (HAr) variaron desde 2.4 {+-} 0.2 a 105.1 {+-} 5.9 {mu}g/g (peso eco) y desde 1.1 {+-} 0.2 a 38.4 {+-} 7.6 {mu}g/g (peso eco), respectivamente. El perfil cromatografico de los hidrocarburos alifaticos estuvo dominado por una mezcla compleja no resuelta (MCNR), y la presencia de hidrocarburos isoprenoides, esteranos y hopanos, indico el aporte de hidrocarburos derivados del petroleo. La concentracion predominante de marcadores moleculares

  7. EVALUACION DE LA CAPACIDAD ANTIOXIDANTE DE LOS COMPUESTOS AROMATICOS POLICICLICOS Y SUS DERIVADOS.

    OpenAIRE

    2004-01-01

    ¡a capacidad de los compuestos fenólicos de interactuar con radicales peroxilo es de interés tanto para entender sus procesos de oxidación como para evaluar su rol como antioxidantes en distintos sistemas. En la presente tesis se realizaron una serie de e 194p.

  8. Solubilidad de hidrocarburos aromaticos en soluciones acuosas de sales de amonio cuaternario

    OpenAIRE

    Angulo Mercado, Edgardo Ramón

    2011-01-01

    Las solubilidades del benceno, tolueno y terbutil benceno en agua y en soluciones de bromuro de trietil bencil amonio, fueron determinadas en un rango de temperaturas de 283.15 a 313.15 K. Los valores obtenidos son relativamente muy bajos y esto se debe a la formación de enlaces de H que el anillo aromático forma con los hidrógenos del agua. Además se produce un ligero incremento en la solubilidad cuando la temperatura aumenta. Sin embargo la solubilidad disminuye en la medida que aumenta el ...

  9. Incidence of aromatic compounds found in petroleums of the brazilian basins; Ocorrencia de compostos aromaticos em petroleos das bacias brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Iorio, Sonia Maria Badaro Mangueira; Guimaraes, Regina Celia Lourenco [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Setor de Pesquisa, Desenvolvimento e Engenharia de Abastecimento]. E-mail: soniab@cenpes.petrobras.com.br; reginag@cenpes.petrobras.com.br

    2001-12-01

    Petroleum exploration at different sedimentary basins, both inland and at sea, generates oils of variable chemical composition that can be of paraffin wax, naphtha or mixed base and, in some cases, even aromatic. Environmental and toxicological issues are considered of extreme importance throughout the world as well as in Brazil and PETROBRAS and require much attention. With marine platform operation there is great concern with oil spills and its impact on the environment, making and environmental hazard analysis mandatory. This analysis is performed by IBAMA, which requests Petrobras for information on the characteristics of the petroleum, among them its Toxicological properties that will serve to support this analysis, and then issues an operating permit for the platforms or other production systems and its consequent renovation. Toxicological properties are influenced by the presence of aromatic hydrocarbons, te most undesirable of all due to its high toxicity, which include: poly aromatics, phenol, benzene, toluene, ethylbenzene and xylene. The incidence of benzene, in special, is a great factor of concern and must be monitored due to labor issues. The objective here is to present the aromatic and benzene percentiles found tin the petroleums per basin (in groups of Petrobras Production and Exploration Business Units) emphasizing minimum, average and maximum values and comparing with other petroleum products produced around the world. A brief description is made of the method used to determine benzene and aromatics compounds. (author)

  10. Aromatic hydrocarbons of petroleum from the Sergipe-Alagoas basin; Hidrocarbonetos aromaticos de petroleos da Bacia Sergipe-Alagoas

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Daniel I. de; Lima, Sandovanio F. de; Silva, Valeria W.; Sant' Ana, Antonio E.G.; Reboucas, Lucia M.C. [Alagoas Univ., Maceio, AL (Brazil). Dept. de Quimica]. E-mail: lmcr@qui.ufal.br

    2003-07-01

    Analysis using capillary gas chromatography-mass spectrometry (GC-MS) were carried out on the aromatic and saturated fraction from 4 crude oil samples from Sergipe-Alagoas basin, Brazil. On the basis of GC/MS analysis saturated fraction (n-alkanes and the isoprenoid alkanes pristane and phytane) it is assumed that 1 oil was biodegraded and 3 oils were non biodegraded. Variations in the distributions of trimethyl naphthalenes (TMNs), tetramethyl naphthalenes (TeMNs) and pentamethyl naphthalenes (PMNs) were studied in the 4 crude oils. The percentage of phenanthrene (P), in the tricyclic aromatic fractions, was the same in 3 of the 4 oils studied. Their maturation is assessed on the basis of the distribution and abundance of tricyclic aromatic hydrocarbons that are more resistant to biodegradation than alkane-type biological markers. These crude oils may be classified, on the basis of the maturation parameter MPI 3, as moderately mature. The occurrence of two series of tri aromatic steranes, m/z 231 and m/z 245, were also studied. (author)

  11. Multilinear relations between {sup 13} C NMR chemical shifts of aliphatic halides; Relacoes lineares multiplas entre deslocamentos quimicos em RMN {sup 13} C de haletos alifaticos

    Energy Technology Data Exchange (ETDEWEB)

    Doyama, Julio Toshimi [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Quimica e Bioquimica; Tornero, Maria Teresinha Trovarelli [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Bioestatistica; Yoshida, Massayoshi [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Organica

    1999-07-01

    The {sup 13} C NMR chemical shifts of the {alpha}, {beta}, {gamma} and {delta} carbons of 17 sets of aliphatic halides (F, Cl, Br and I), including mono, bi and tricyclic compounds, can be reproduced by a linear equation composed with two constants and two variables: {delta}{sub RX} = A{sup *} {delta}{sub R-X2}, where A and B are constants derived from multilinear regression of {sup 13} C chemical shifts observed; {delta}{sub R-X}, the chemical shifts of aliphatic halide (R-X); and {delta}{sub R-X1}, {delta}{sub R-X2} the chemical shifts of other halides. It was observed a better correlation for aliphatic bromides (R-X) by using data of aliphatic fluorides (R-X 1) and aliphatic iodides (R-X 2), resulting R{sup 2} of 0.9989 and average absolute deviation (AVG) of 0.39 ppm. For the chlorides (R-X), the better correlation was observed by using data of bromides (R-X 1) was observed better correlation with data of bromides (R-X 1) and iodides (R-X 2), R{sup 2} of 0.997 and AVG of 1.10 ppm. For the iodides (R-X) was observed better correlation with data of fluorides (R-X 1) and bromides (R-X 2), R{sup 2} of 0.9972 and AVG of 0.60 ppm. (author)

  12. Ressonancia magnetica nuclear de 1H e de 13C de compostos alifaticos : estudos dos efeitos dos substituintes [alfa] atraves da analise de componentes principais (PCA)

    OpenAIRE

    Ljubica Tasic

    2002-01-01

    Resumo: Este trabalho apresenta os resultados dos estudos dos efeitos de doze substituintes a (Y = F, CI, Br, I, OMe, OEt, SMe, SEt, NMe2, NEt2, Me e Et) sobre os deslocamentos químicos de H e de C em compostos carbonílicos, carboxílicos e insaturados. A classe dos compostos carbonílicos é representada por acetonas, acetofenonas, cicloexanonas e cânforas. Por outro lado, os ácidos acéticos, acetatos (de metila, de etila e de fenila), tioacetatos de etila e N,N-dietilacetamidas representam a c...

  13. Morphology and thermal properties of PLA films plasticized with aliphatic oligoesters; Morfologia e propriedades termicas de filmes de PLA plastificados com oligoesteres alifaticos

    Energy Technology Data Exchange (ETDEWEB)

    Inacio, Erika M.; Dias, Marcos L., E-mail: erika.minacio@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Lima, Maria Celiana P. [Instituto Federal do Rio de Janeiro (IFRJ), Duque de Caxias, RJ (Brazil)

    2015-07-01

    The addition of plasticizers to poly(lactic acid) (PLA) is one of the known ways of changing its ductility, making possible the modification of its mechanical and thermal properties. In this work, it was synthesized two biodegradable aliphatic oligoesters: oligo(trimethylene sebacate) (OST) and oligo(trimethylene malonate) (OMT), and these oligomers were used as plasticizer in cast films of commercial film grade PLA at concentrations of 1, 5 and 10 wt% of each plasticizer. X-ray diffraction (XRD) was used to investigate the morphology and differential scanning calorimetry (DSC) was also used aiming the evaluation of the thermal properties of these films. The PLA films containing no plasticizer showed an amorphous behavior, and the addition of PMT on the PLA films acted, simultaneously, decreasing the Tg, and rising the material's crystallinity. In contrast, the increased addition of OST to the PLA films did not change the Tg, and equally, did not have a significant changes in the material's crystallinity. Therefore, it was possible to observe the effect of the concentration of oligomers on the crystallinity of the films as well as the no plasticizer effect of the OST. (author)

  14. Morphology and thermal properties of PLA films plasticised with aliphatic oligoesters; Morfologia e propriedades termicas de filmes de PLA plastificados com oligoesteres alifaticos

    Energy Technology Data Exchange (ETDEWEB)

    Inacio, Erika M.; Dias, Marcos L., E-mail: erika.minacio@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Lima, Maria Celiana P. [Instituto Federal do Rio de Janeiro (IFRJ), Duque de Caxias, RJ (Brazil)

    2013-07-01

    The addition of plasticizers to poly(lactic acid) (PLA) is one of the known ways of changing its ductility, making possible the modification of its mechanical and thermal properties. In this work, it was synthesized two biodegradable aliphatic oligoesters: oligo(trimethylene sebacate) (OST) and oligo(trimethylene malonate) (OMT), and these oligomers were used as plasticizer in cast films of commercial film grade PLA at concentrations of 1, 5 and 10 wt% of each plasticizer. X-ray diffraction (XRD) was used to investigate the morphology and differential scanning calorimetry (DSC) was also used aiming the evaluation of the thermal properties of these films. The PLA films containing no plasticizer showed an amorphous behavior, and the addition of PMT on the PLA films acted, simultaneously, decreasing the Tg, and rising the material's crystallinity. In contrast, the increased addition of OST to the PLA films did not change the Tg, and equally, did not have a significant changes in the material's crystallinity. Therefore, it was possible to observe the effect of the concentration of oligomers on the crystallinity of the films as well as the no plasticizer effect of the OST. (author)

  15. Characterization of the contamination produced by uncontrolled dumping of aromatic hydrocarbons; Caracterizacion de la contaminacion producida por el vertido incontrolado de hidrocarburos aromaticos

    Energy Technology Data Exchange (ETDEWEB)

    Navarro Flores, A.; Collado Fernandez, D.

    1996-08-01

    Uncontrolled dumping of aromatic hydrocarbons (m, o and p-xylen, ethylbenzene, etc) in the Tenes Valley aquifer (Besos river bassin) has produced a very important contamination of alluvial aquifer, that shows high concentrations of m, p xylen (41 mg/l) in groundwater, at a very vulnerable area. site characterization shows high concentrations of Fe, Mn and Ba in groundwater, originated by degradation of organic pollutants. Numerical simulation of plume movement shows a conditioned mobilization contaminants by biodegradation process. (Author) 11 refs.

  16. Alkylphenols and polycyclic aromatic hydrocarbons in bivalves from Comunidad Valenciana coastal waters; Alquilfenoles e hidrocarburos aromaticos policiclicos en bivalvos de las coastas de la comunidad Valenciana

    Energy Technology Data Exchange (ETDEWEB)

    Marti Ortega, N.; Aguado Garcia, D.; Bouzas Blanco, A.; Segovia Martinez, L.; Albargues Llamas, M.; Sevillano Cabeza, A.; Campins Falco, P.; Seco Torrecillas, A.; Ferrer Polo, J.

    2009-07-01

    This paper reports the results on alkylphenol and polycyclic aromatic hydrocarbons (PAH) pollution in mussels and cleans from Comunidad Valenciana coastal waters, in 2008. The significant presence of nonylphenol observed in both bivalves reflects an exposure to alkyl phenolic surfactants from the discharges of wastewater treatment plants that treat industrial and urban wastewaters, where the presence of alkylphenol polyethoxylated is common due to its extensive use (detergents, solubilizers...). The presence of low levels of PAH was observed in most of the studied areas. However, it must be highlighted that bivalves consumption does not imply any risk for human health. (Author) 21 refs.

  17. Development of a extensor oil with low content of polycyclic aromatic; Desenvolvimento de oleo extensor com baixo teor de policiclicos aromaticos

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Anie Daniela M.; Fontes, Anita Eleonora F.; Figueiredo, Joao Baptista [PETROBRAS, Rio de Janeiro, RJ (Brazil)] (and others)

    2008-07-01

    This paper presents the development of a substitute product for the aromatic oil used in rubber tires. The new oil must be in according to The European Community Directive 2005/69/EC, which has the start date in January first of 2010. The directive sets limits for specific levels of polyaromatics content in the oils for rubber tires because of the mutagenic and harmful to the reproduction characteristic of some of these substances. The process of aromatics extraction was conducted on several kinds of feedstocks to obtain a product with kinematic viscosity at 100 deg C in the 40-50 cSt range and polycyclics aromatics content until 3% in mass. It is important to know that the current oils have 20% in mass of polyaromatics content. The product developed is in according with the Directive specifications and contributes to the production of tires more suitable to the environment and human health. (author)

  18. Aromatic hydrocarbons from service stations in the sewer system in Cartagena, Columbia; Hidrocarburos aromaticos en la red de alcantarillado procedentes de estaciones de servicio en Cartagena (Colombia)

    Energy Technology Data Exchange (ETDEWEB)

    Cachorro Sanchez, P.; Gonzalez Garcia, H.; Luna Jara, J.

    2000-07-01

    The results of this study are part of a project for characterising domestic and industrial waste flowing through the sewer system of Cartagena de Indias (Columbia). Characterisation was carried out in order to establish the contaminating load in the drinking water supply with a view to establishing a framework for compensatory taxes levied by the corresponding environmental agency. (Author)

  19. DESARROLLO DE METODOLOGIAS ANALITICAS PARA LA DETERMINACION DE HIODROCARBUROS AROMATICOS POLICICLICOS EN ALIMENTOS GRASOS MEDIANTE ESPECTROSCOPIA DE FLUORESCENCIA Y CALIBRACION MULTIVARIADA

    OpenAIRE

    ALARCON RODRIGUEZ, FRANCIS PAMELA

    2013-01-01

    Los hidrocarburos aromáticos policíclicos (PAHs), generados por combustión incompleta de materia orgánica, presentan particular interés debido a sus características cancerígenas y/o mutagénicas. Para el ser humano una de las vías de exposición a los PAHs es el consumo de alimentos grasos como los aceites vegetales. Los principales problemas de la determinación de PAHs en estas matrices oleosas son su baja concentración y la presencia de diversos interferentes. En general, su determin...

  20. Aromatic inputs derived from Candiota Coal: quick hydro pyrolysis results; Insumos aromaticos a partir do carvao de Candiota: resultados da hidropirolise rapida

    Energy Technology Data Exchange (ETDEWEB)

    Cencig, M.O.; Gomes, J.R.; Luengo, C.A. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica

    1984-12-31

    A coal hydro pyrolysis process has been built and operated at the Laboratory for Alternative Fuels, University of Campinas, Brazil, to obtain desired liquid and gaseous chemical and valuable liquid fuels. A bench, down flow reactor, processes up to 3 kg per hour of powdered coal in hydrogen atmosphere at high pressures (up to 50 atm). Reactor temperatures reach 800 deg C. Residual solids are quenched from the gaseous mainstream. Immediately afterwards, appropriate condensers remove the liquid products. On line gas chromatography is used for monitoring output gas composition after the reaction chamber. Condensed oils had a heating value of 8000 kCal per minute. Results of systematic testing during the last two years are presented. Hardware developments and future applications to biomass materials are also discussed. (author). 13 refs., 2 figs., 1 tab

  1. Process to remove aromatic and sulfur compounds from light solvents; Processo para remocao de compostos aromaticos e sulfurados de solventes leves

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Ricardo R. Cunha; Huziwara, Wilson K.; Santiago, Fernando Antonio D.; Brito, Carlos Otavio; Vieira, Jose Antonio Vidal; Souza, Paulo T.; Chaves, Beatriz M.C.; Lemos, Jose C.; Maeshiro, Keiji [PETROBRAS/CENPES, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2000-12-01

    The market demand for tailor-made non pollutant products and the increasing environmental restrictions increase the need to optimize and enhance treatment processes in the refining industry. These points well be used as a basis by PETROBRAS, to develop a process to obtain special solvents from direct distillation naphtha through the selective adsorption of the aromatic and sulfurous compounds present. Although the traditional way to remove these contaminating agents from solvents through hydrogenation, the joint work of the research, basic engineering and industrial areas has lead to the conception of a new reliable, safe, flexible and profitable process, which allows the processing of different loads to produce light solvents continuously in the range from C5 to C9 with very low contents of aromatic and sulfurous compounds. Among the main characteristics of the process we can mention the optimization of the adsorption beds capacity, high energetic integration, operational flexibility and high automation. Thanks to the high flexibility of the unit and to the fact that there is no need to use hydrogen this new process was selected for two new industrial units in the Refineries of Capuava - 6,000 m{sup 3}/month - and Canoas - 4,000 m{sup 3}/ month. These units are currently operating, thus validating this new technology. (author)

  2. Effect of ethanol on solubility enhancement of aromatic compounds presented in Brazilian gasoline; Efeito do etanol no aumento da solubilidade de compostos aromaticos presentes na gasolina brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Corseuil, Henry Xavier; Fernandes, Marilda [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Sanitaria e Ambiental]. E-mail: corseuil@ens.ufsc.br

    1999-06-01

    This study evaluates the potential effect of ethanol on solubility enhancement of monoaromatic compounds such as benzene, toluene and xylenes (BTX) in ethanol-amended gasoline spills. The analysis of several ratios of water-gasoline mixtures in equilibrium, corresponding to different ethanol fractions in the aqueous phase, indicates that ethanol enhances aqueous solubility of petroleum hydrocarbons. It was verified that, for ethanol fractions in the aqueous phase of 10%, BTX mass increases to 30%. This effect was greater for xylene (the more hydrophobic BTX compound), followed by toluene and benzene. (author)

  3. Methodology used for estimate the hydrogenation of aromatics in diesel oil; Metodologia para estimar a hidrogenacao de aromaticos em oleo diesel

    Energy Technology Data Exchange (ETDEWEB)

    Dauzacker, Erich Radeke [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Gerencia de Combustiveis]. E-mail:erichrd@cenpes.petrobras.com.br; Belato, Donizeti A. Silva [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Hidrorrefino e Processos Especiais; Pinto, Jose Carlos C.S.; Monteiro, Jose Luiz F. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao de Programas em Pos-Graduacao em Engenharia. Programa de Engenharia Quimica]. E-mail: pinto@peq.coppe.ufrj.br and monteiro@peq.coppe.ufrj.br

    2002-12-01

    This paper shows a methodology that allows the estimation of the aromatic concentration of hydrotreated diesel oil, based on untreated feedstock and under the operating conditions of a unit. The reversibility of aromatic hydrogenation reactions adds significant complexity to the process modeling, though, it is really important to take it into account, in order to reach more precise estimate of the aromatic concentration in products. Due to the restrictions imposed by diesel oil new specifications, the Hydrogenation of Aromatic process - HDA is becoming more and more important, because aromatic are straightly associated with ignition quality and particulate material emissions. (author)

  4. Comparative study of structural and thermal behavior of aromatic polyester;Estudo comparativo do comportamento termico e estrutral de poliesteres aromaticos

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Diego K.M., E-mail: diego_keller_1984@yahoo.com.b; Guimaraes, Danilo H.; Medeiros, Marina O. de A.; Jose, Nadia M. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Prado, Luis A.S. de A. [Technische Universitaet Hamburg (TUHH), Harburg (Germany). Inst. of Polymer and Composites

    2009-07-01

    Aromatic polyesters have been currently used for the production of PET bottles and polymer fibers. Currently, thermodynamic study is necessary for production of polymers with mechanical properties, thermal degradation and satisfactory. Many thermodynamic properties of polymer solutions, such as solubility, swelling, and balance of the properties Colligative can be expressed in terms of interaction parameter of polymer-solvent {chi}. The present work presents the objective synthesize, characterize and assess the degree of swelling of aromatic polyesters. The polyester formed from the reaction of glycerol and terephthalic acid/phthalic, using varying molar ratios to the glycerolterephthalic acid/phthalic acid (1,0-1,0, 1,0-1,5, 1,0 -- 2.0), by mixing with mechanical agitation and by use of tin catalyst. We studied the thermal and structural behavior through techniques: FTIR, TGA, DSC, XRD, SEM and swelling test. (author)

  5. Aislamiento y rendimiento del GMP mediante precipitacion de lactosuero con acido tricloroacetico

    National Research Council Canada - National Science Library

    Rojas V., Evelin; Valbuena C., Emiro; Torres F., Gabriel; Garcia de H., Aiza; Pinero G., Maria; Galindo A., Luz Mila

    2009-01-01

    ...) que se libera al lactosuero. El GMP presenta una estructura quimica particular donde predominan los aminoacidos con cadena lateral ramificada, no presenta aminoacidos aromaticos y contiene carbohidratos unidos a residuos de treonina...

  6. Azo coupling of 4-nitrophenyldiazonium chloride with aliphatic nucleophiles: an integrated organic synthesis and X-ray crystallography experiment; Acoplamento de cloreto de 4-nitrofenildiazonio com nucleofilos alifaticos: experimento integrado de sintese organica e cristalografia de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Silvio; Marques, Monique F.; Rocha, Valeria, E-mail: silviodc@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica; Lariucci, Carlito; Vencato, Ivo [Universidade Federal de Goiania (UFG), GO (Brazil). Instituto de Fisica

    2013-11-01

    This article describes an undergraduate experiment for the synthesis of p-nitrophenyldiazonium chloride and its coupling with acetylacetone and two enaminones, 4-phenylamino-pent-3-en-2-one and 4-amino-pent-3-en-2-one, in an adaptation of a previously reported synthetic protocol. The azo dyes 4-(E)-phenylamino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one and 4-(E)-amino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one were obtained, and the solid state structure of this latter azo compound was characterized by single crystal X-ray diffraction studies. This two-week integrated laboratory approach involves simple synthetic experiments and microwave chemistry in the organic laboratory plus crystallography analysis, suitable for novice students on undergraduate experimental chemistry courses. (author)

  7. Synthesis and chemical modification of polymeric resins for the treatment of cations and aromatic hydrocarbons in produced oily water; Sintese de modificacao quimica de resina polimerica e aplicacao na remocao de cations e hidrocarbonetos aromaticos presentes em agua produzida

    Energy Technology Data Exchange (ETDEWEB)

    Aversa, Thiago M.; Rodrigues, Monique F.; Vieira, Helida V.P.; Queiros, Yure G.C.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro, Instituto de Macromoleculas, Lab. de Macromoleculas e Coloides na Industria do Petroleo, Rio de Janeiro, RJ (Brazil)], e-mail: thiagoaversa@ima.ufrj.br

    2011-07-01

    The use of chemically modified resins in oily water treatment process is not very developed yet. Because of this, this work suggests to study the styrene and divinylbenzene sulfonation effect on oil and grease, aniline and calcium removal from the water. The aniline, oils and greases belong to a class of toxic organic compounds, with the Brazilian maximum limits established for disposal in CONAMA 393/2007, while the calcium ions belong to the group of cations of alkaline earth metals which improve hardness to the water, may cause fouling as carbonates and sulfates form. By using sulfonated resins in oily water treatment it is possible to remove not only oils and greases but also calcium and aniline. These kinds of polar compounds are removed because of the cation exchange capacity of resin. (author)

  8. A Simple Analytical Method Using HPLC with Fluorescence Detection to Determine Selected Polycyclic Aromatic Compounds in Filter Samples; Metodo Analitico Sencillo para la Determinacion de Compuestos Aromaticos Policiclicos en Muestras de Filtros mediante HPLC con Detector de Fluorescencia

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R. M.

    2014-06-01

    A study on the comparison and evaluation of a miniaturized extraction method for the determination of selected PACs in sample filters is presented. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the intermediate precision. (Author)

  9. Petrogenesis contamination of the Todos os Santos bay by aromatic polycyclic hydrocarbons: a contribution for the environmental diagnostic; Contaminacao petrogenica da Baia de Todos os Santos por hidrocarbonetos policiclicos aromaticos: uma contribuicao ao diagnostico ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Machado, J. Carlos V. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Tavares, Tania M. [Universidade Federal da Bahia (UFBA), Salvador (Brazil)

    1998-07-01

    This work studies the contamination degree of the meso and infra-coastline sediments of the Baia de Todos os Santos, Bahia, the largest of Brazil, by organic compounds, mainly of period origin. The assessment was proceeded through quantification of total polycyclic aromatic hydrocarbons (PAH's), by fluorimetric analysis in continuous flow. The levels of contamination were quantified taking in consideration the levels considered as critical by the published literature. The grading of the target sites with those of the control sites (background) were compared also. The main objective was to define the degree of contamination relative to different areas of the bay, correlating with the different activities, such as oil exploitation, industrial production, mainly of oil processing at the north of the bay, port and urban, specially near the city of Salvador, with 2 million of inhabitants. In some stations, specially in those classified as industrial, urban and heavy boats traffic, sediments showed contamination, resulting in grades up to 2000 times greater than the control sites. Some regions, mainly industrial and urban, showed high PHA's contamination, higher than 200 {mu}g/g. The majority of sediments in areas remaining as recreational until present days showed no contamination, lesser than {mu}g/g. (author)

  10. Aromatic hydrogenation with noble metal basis catalysts: support effect on the sensitivity to sulfur compounds; Hidrogenacao de aromaticos com catalisadores a base de metal nobre: efeito do suporte na sensibilidade a compostos sulfurados

    Energy Technology Data Exchange (ETDEWEB)

    Zotin, J.L.; Duarte, M.A.I.; Silva, C.L.T.; Fonseca, D.L.; Costa, D.; Mattos, E.B.C. [PETROBRAS, S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2000-07-01

    The production of high quality diesel oil, with lower contents of contaminants and better performance, demands a deep hydrogenation of the aromatics compounds present in this fuel. The process for aromatic saturation are usually based on noble metal catalysts which have high activity but are poisoned by sulfur compounds present in petroleum feedstocks. The tio-tolerance of these catalysts is a function, among others factors, of the nature of the metallic phase and its dispersion and of the nature of the support. In this paper, the effect of the support (silica-alumina or zeolite) on the sulfur tolerance of Pt Pd catalysts is studied. The hydrogenation of iso-propylbenzene in presence of sulfur concentration up to 500 ppm was used as model reaction. The catalyst supported on silica-alumina (SA) was 3 times more active than zeolite based catalyst (ZT), in absence of sulfur. However, this latter one was much more tolerant to sulfur poisoning, with an inhibition constant by sulfur 5 times lower than the one obtained for SA catalyst. These results are explained by the higher Broensted acidity of the zeolitic support, which is known to improve the tio-tolerance of metallic catalysts. (author)

  11. Analysis of polycyclic aromatic hydrocarbons I. Determination by gas chromatography with glass and fused silica capillary columns; Analisis de Hidrocarburos aromaticos policiclicos. I. Determinacion por cromatografia de gases con columnas capilares de vidrio de silice fundida

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M. M.; Gonzalez, D.

    1987-07-01

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column. The limitations and the advantages of the procedure are discussed in terms of separation efficiency, sensitivity and precision. (Author) 17 refs.

  12. Preparation of manganese salts of carboxylic acids labelled with ''54Mn and comparison with ''54 MnCl{sub 2} in liquid scintillation counting; Preparacion de sales manganosas de acidos alifaticos monocarboxilicos marcados con ''54 MnCl{sub 2} en medidas por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Arcos Merino, J. M. los; Grau Malonda, A.

    1992-07-01

    Procedures for liquid scintillation sample preparation of manganese dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene. HISafe II. PCS, instagel. Dioxane-naphtalene and Toluene-alcohol. For comparison, Inorganic 54 MnCl-2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (Author)

  13. Colombian cracker feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-06

    Colombia`s Promotora de Olefinas Aromaticos del Caribe will soon select a consulting group to develop a $500,000 feasibility study for an olefins plant at Mamonal, Cartagena. The project will involve investments of $1.2 billion and will be based on natural gas from the Cusiana field, being developed by Ecopetrol and BP. Several groups are competing for the study; SRI International, Japan Consulting Institute, Muse, Stancil, Chem Systems, and KBC Advanced Technologies.

  14. Optimization of the Analytical Method Using HPLC with Fluorescence Detection to Determine Selected Polycyclic Aromatic Compounds in Clean Water Samples; Optimizacion del Metodo Analitico mediante HPLC con Detector de Fluorescencia para la Determinacion de Ciertos Compuestos Aromaticos Policiclicos en Muestras de Aguas Limpias

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.

    2013-10-01

    A study on the comparison and evaluation of 3 miniaturized extraction methods for the determination of selected PACs in clear waters is presented. Three types of liquid-liquid extraction were used for chromatographic analysis by HPLC with fluorescence detection. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the scope of the methods developed at low and high levels of concentration and intermediate precision. (Author)

  15. Polycyclic aromatic hydrocarbons (PAHS) contamination in aquatic environments adjacent to areas of multiple uses: to whom is that environmental liability?; Contaminacao por hidrocarbonetos aromaticos policiclicos (HPAS) em ambientes aquaticos adjacentes a areas de multiplos usos: a quem corresponde esse passivo ambiental?

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Marina R.D.; Mirlean, Nicolai; Machado, Maria Isabel C.S. [Fundacao Universidade Federal do Rio Grande (FURG), RS (Brazil); Caramao, Elina B. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2004-07-01

    Contamination often can be related to different activities, especially in areas with multiple uses. In these cases, studies are necessary to correctly evaluate the origin of contaminants. Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that have two main sources: pyrolytic and petrogenic processes. In Rio Grande City, located at the margins of Patos Lagoon estuary, south Brazil, there are several navigation and industrial activities. This work has the objective to determinate the origins of PAHs and to evaluate the contribution of different sources to the aquatic contamination. The sampling stations were classified according to three main types: industrial effluent, sewage and runoff. We collected sediments from the bottom of effluent channels and from the respective estuarine environments. The material was sieved (0,063 mm), dried, extracted in soxhlet apparatus with methylene chloride and GC-MS analyzed. The results showed that pyrolytic compounds were predominant, indicating the contribution of diffuse sources. This type of study was successful in relating PAHs with their sources, confirming the role of urban and other industries activities in this case of contamination, superimposed to the midstream e downstream activities of petroleum industry. (author)

  16. Analytical Procedure Development to Determine Polycyclic Aromatic Compounds in the PM{sub 2}.5-PM{sub 1}0 Fraction of Atmospheric Aerosols; Desarrollo de una Metodologia Analitica para la Determinacion de Compuestos Aromaticos Policiclicos en las Fracciones PM{sub 2}.5-PM{sub 1}0 del Aerosol Atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Barrado, A. I.; Garcia, S.; Perez, R. M.

    2013-06-01

    This paper presents an optimized and validated analytical methodology for the determination of various polycyclic aromatic compounds in ambient air using liquid chromatography with fluorescence detection. This analysis method was applied to samples obtained during more than one year in an area of Madrid. Selected compounds have included thirteen polycyclic hydrocarbons considered priorities by the EPA, and hydroxylated derivatives, which have been less investigated in air samples by liquid chromatography with fluorescence detection. We have characterized and compared the concentration ranges of compounds identified and studied seasonal and monthly variations. In addition, the techniques have been applied to study multivariate correlations, factor analysis and cluster analysis to extract as much information as possible for interpretation and more complete and accurate characterization of the results and their relationship with meteorological parameters and physicochemical. (Author) 50 refs.

  17. Methodology of preparing and evaluation of water, containing aromatic hydrocarbons, presents in a petroleum composition, for treatment in adsorption columns, containing polymeric resins; Metodologia de preparo e avaliacao de aguas contendo hidrocarbonetos aromaticos presentes na composicao do petroleo para o tratamento em colunas de adsorcao contendo resinas polimericas

    Energy Technology Data Exchange (ETDEWEB)

    Queiros, Yure G.C.; Lucas, Elizabete F. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas]. E-mail: yuregomes@hotmail.com; elucas@ima.ufrj.br; Barbosa, Celina C.R. [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)]. E-mail: celina@ima.ufrj.br; Furtado, Claudio Furtado; Barbosa, Luis C.F. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento Leopoldo Americo Miguez de Mello]. E-mail: lcesar@cenpes.petrobras.com.br

    2003-07-01

    This work deals with the analysis of aromatic components present in small amounts in oily waters produced by oil wells. The methodology for preparing this kind of water with simulation of reservoir conditions, as well as its storage, has been studied. Fluorimetry was the technique of choice for the component's analysis, with good results in terms of analytical speed and efficiency. The passage of toluene-containing solutions through adsorption columns based on polymeric packing shows satisfactory preliminary results as regards the retention of this aromatic hydrocarbon, where the compound detection level after the treatment attained values near to zero concentration. (author)

  18. Development and validation of analytical methodology for determination of polycyclic aromatic hydrocarbons (PAHS) in sediments. Assesment of Pedroso Park dam, Santo Andre, SP; Desenvolvimento e validacao de metodologia analitica para determinacao de hidrocarbonetos policiclicos aromaticos (HPAS) em sedimentos. Avaliacao da represa do Parque Pedroso, Santo Andre, SP

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Carlos Fernando de

    2009-07-01

    The polycyclic aromatic hydrocarbons (PAHs), by being considered persistent contaminants, by their ubiquity in the environment and by the recognition of their genotoxicity, have stimulated research activities in order to determine and evaluate their sources, transport, processing, biological effects and accumulation in compartments of aquatic and terrestrial ecosystems. In this work, the matrix studied was sediment collected at Pedroso Park's dam at Santo Andre, SP. The analytical technique employed was liquid chromatography in reverse phase with a UV/Vis detector. Statistics treatment of the data was established during the process of developing the methodology for which there was reliable results. The steps involved were evaluated using the concept of Validation of Chemical Testing. The parameters selected for the analytical validation were selectivity, linearity, Working Range, Sensitivity, Accuracy, Precision, Limit of Detection, Limit of quantification and robustness. These parameters showed satisfactory results, allowing the application of the methodology, and is a simple method that allows the minimization of contamination and loss of compounds by over-handling. For the PAHs tested were no found positive results, above the limit of detection, in any of the samples collected in the first phase. But, at the second collection, were found small changes mainly acenaphthylene, fluorene and benzo[a]anthracene. Although the area is preserved, it is possible to realize little signs of contamination. (author)

  19. Volatile aromatic compounds in Mexico City atmosphere: levels and source apportionment

    Energy Technology Data Exchange (ETDEWEB)

    Mugica, V. [Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D.F. (Mexico); Ruiz, M.E. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Watson, J.; Chow, J. [Desert Research Institute, Reno, Nevada (United States)

    2003-01-01

    Samples of ambient air were simultaneously collected at three different sites of Mexico City in March of 1997 in order to quantify the most abundant volatile aromatic compounds and estimate the source contributions by application of the chemical mass balance model (CMB). Volatile aromatic compounds were around 20% of the total of non-methane hydrocarbons present in morning air samples. The most abundant volatile aromatic species in urban air were toluene and xylenes followed by 1, 2, 4 trimethylbenzene, benzene, ethylbenzene, metaethyltoluene, 1, 3, 5 trimethylbenzene, styrene, n propylbenzene, and isopropylbenzene. Sampling campaigns were carried out at crossroads, a bus station, a parking place, and areas where solvents and petroleum distillates are used, with the objective of determining people's exposure to volatile aromatic compounds. The CMB was applied for estimating the contribution of different sources to the presence of each one of the most abundant aromatic compounds. Motor vehicle exhaust was the main source of all aromatic compounds, especially gasoline exhaust, although diesel exhausts and asphalt operations also accounted for toluene, xylenes, ethylbenzene, propylbenzenes, and styrene. Graphic arts and paint applications had an important impact on the presence of toluene. [Spanish] Se colectaron simultaneamente muestras de aire ambiente en tres sitios de la Ciudad de Mexico durante el mes de marzo de 1997 con el fin de conocer las concentraciones y el origen de compuestos aromaticos utilizando el modelo de balance de masa de especies quimicas (CMB). Los compuestos aromaticos volatiles representaron alrededor del 20% del total de hidrocarburos no metalicos presentes en las muestras matutinas colectadas. Las especies aromaticas volatiles mas abundantes en el ambiente fueron el tolueno y los xilenos, seguidos por 1, 2, 4 trimetilbenceno, benceno, etilbenceno, metaetiltolueno, nporpilbenceno, isopropilbenceno, 1, 3, 5 trimetilbenceno y estireno. Se

  20. Condensed aromatic rings and E{sub 4}/E{sub 6} ratio: humic acids in gleysoils studied by NMR CP/MAS{sup 13}C, and dipolar dephasing; Aneis aromaticos condensados e relacao E{sub 4}/E{sub 6}: estudo de acidos humicos de gleissolos por RMN de {sup 13}C no estado solido utilizando a tecnica CP/MAS desacoplamento defasado

    Energy Technology Data Exchange (ETDEWEB)

    Saab, Sergio da Costa [Universidade Estadual de Ponta Grossa, PR (Brazil). Dept. de Fisica]. E-mail: scsaab@uepg.br; Martin-Neto, Ladislau [Empresa Brasileira de Pesquisa Agropecuaria, Sao Carlos, SP (Brazil)

    2007-03-15

    In this work, seven samples of humic acids extracted from gleysoils were investigated. These studies, using NMR CP/MAS {sup 13}C techniques, did not show significant correlation between the E{sub 4}/E{sub 6} ratio and the degree of aromaticity. However, dipolar dephasing (DD) measurements of condensed aromatic or substituted carbons showed a negative correlation of 0.94. Also, there was a good correlation between the amount of semiquinone free radicals measured by the EPR technique and condensed aromatic rings measured by NMR CP/MAS {sup 13}C with the DD technique. The content of semiquinone free radicals was quantified by EPR spectroscopy and was correlated with the humification (degree of aromaticity) of the humic substances. The results indicated that the E{sub 4}/E{sub 6} ratio identifies the degree of aromatic rings condensation. It was also found that the degree of aromaticity, measured by NMR, as frequently presented in the literature (by conventional CP/MAS), underestimates aromatic rings in condensed structures. (author)

  1. A theory of phase separation in asphaltene-micellar solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco Sanchez, Juan H. [Instituto Mexicano del Petroleo, Mexico D.F. (Mexico)

    2001-08-01

    A theory of phase separation in micellar solutions of asphaltene in aromatic hydrocarbons was reported in this paper, based on both the approach of the phase behavior of amphiphile/water micelles, and the self-association of asphaltene in aromatic core. Several experimental techniques have been used by different investigators showing the existence of some kind of critical micellar concentration (CMC) on asphaltenes in aromatic solutions. So, at least asphaltene-monomer and asphaltene-micellar phases are experimentally demonstrated facts. These two phases are the main purpose in this report on a theoretical model. Some results show the temperature versus asphaltene concentration phase diagram. The phase diagram is examined against the limited critical micelle concentration data for asphaltenes-in-toluene systems. Such phase diagram is also qualitatively examined against an experimental demonstration of phase separation. The asphaltene-micelle growth depends on the parameter K responsible for the shape and size of it. At the same time, parameter K depends on both the number of asphaltene-monomer associated in the asphaltene-micelle, and the chemical potentials in the interior and in the periphery of the micelle. An expression for getting the number of asphaltene-monomers self-associated in the asphaltene-micelle was obtained. [Spanish] Se reporta una teoria de separacion de fases en soluciones micelares de asfalteno en hidrocarburos aromaticos, basada tanto en la conducta de fase de micelas formadas por anififilos en agua como en la autoasociacion de asfaltenos en nucleos aromaticos. Se han usado diversas tecnicas experimentales por diferentes investigadores que demuestran la existancia de algun tipo de concentracion micelar critica (CMC) de soluciones de asfaltenos en aromaticos. Entonces, al menos las fases de asfalteno-monomerico y de asfalteno-micelar son hechos experimentalmente demostrados. Esta dos fases son el principal proposito de este reporte en un modelo

  2. Direct synthesis of metal complexes starting from zero-valent metals

    Energy Technology Data Exchange (ETDEWEB)

    Gojon-Zorrilla, Gabriel; Kharisov, Boris I. [Universidad Autonoma de Nuevo Leon, Monterrey, Nuevo Leon (Mexico); Garnovskii, Alexander D. [Institute of Physical and Organic Chemistry (Russian Federation)

    1996-06-01

    The recent (1980-1994) literature on metal-vapor synthesis of coordination and organometallic compounds is reviewed. An account is given of the high-and low-temperature reactions between free metal atoms and a large variety of substrates, mainly alkenes, alkynes, dienes, arenes, funtionalized arenes, alkyl halides {beta}-diketones and simple inorganic molecules. The main experimental methods are described, as well as the results obtained thereby. It is shown that in many instances these methods present significant advantages over conventional synthetic procedures, offering unique access to some metal complexes. [Spanish] Se reviso la literatura reciente (1980-1994) sobre la sintesis de compuestos de coordinacion y compuestos organometalicos a partir de vapores metalicos. Se examinan las reacciones de los atomos metalicos libres con una gran variedad de substratos, principalmente alquenos, alquinos, dienos, hidrocarburos aromaticos y sus derivados, haluros de alquilo y arilo, {beta}-dicetonas y moleculas inorganicas simples. Se presentan los principales metodos experimentales, asi como los resultados obtenidos; se concluye que la crisintesis presenta en muchos casos ventajas significativas sobre los procedimientos sinteticos tradicionales, constituyendo frecuentemente la unica opcion disponible.

  3. Development of a chromatographic method for the study of the stability and compatibility of Mexican fuel oils; Desarrollo de un metodo cromatografico para el estudio de estabilidad y compatibilidad de combustoleos mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Blass Amador, Georgina; Panama Tirado, Luz Angelica [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-11-01

    compatibility of fuel oil mixes. [Espanol] En Mexico, la mayoria de la energia electrica producida proviene del uso de combustibles residuales pesados conocidos como combustoleos los cuales han sufrido disminuciones en la calidad debido a una combinacion de factores, entre los que destaca el de los cambios en el proceso de refinacion. Es necesario desarrollar metodos que sean capaces de indicar la inestabilidad (formacion de sedimento o incremento en viscosidad durante el almacenamiento o calentamiento) o incompatibilidad (formacion de sedimento al mezclar dos o mas) de los combustoleos utilizados en las centrales termoelectricas. El objetivo de este trabajo fue el desarrollar una prueba alternativa para el estudio de la compatibilidad y/o estabilidad de combustoleos mexicanos empleando cromatografia de liquidos de alta resolucion (CLAR) y asi poder determinar aspectos estructurales del combustoleo que determinan su estabilidad. Dado que la formacion de sedimentos ocurre cuando el poder disolvente del combustible es inadecuado para mantener los asfaltenos en solucion, es importante conocer la medida del poder disolvente o aromaticidad del diluyente; asi pues, la primera parte de este trabajo se centro en la determinacion del perfil de compuestos aromaticos de los diluyentes de los combustoleos, la otra parte se dedico a la determinacion del perfil de distribucion de los pesos moleculares de los asfaltenos presentes en los combustoleos. Los perfiles de la fraccion aromatica, asi como los de distribucion de pesos moleculares se determinaron empleando cromatografia de liquidos, en la que se empleo una variedad de columnas y de disolventes. Se efectuo una combinacion de pruebas de rutina tales como contenido de asfaltenos, equivalencia de tolueno, viscosidad, etcetera con el fin de obtener correlaciones con el metodo cromatografico desarrollado. En este articulo se discute solo la seccion correspondiente a la obtencion del perfil de contenidos de aromaticos de los combustoleos. Se

  4. Use of rum and sugar cane bagasse in the removal of hydrocarbons in contaminated soil; Uso de cachaza y bagazo de cana de azucar en la remocion de hidrocarburos en suelo contaminado

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-02-15

    The objective of this work was to determine the removal efficiency of polycyclic aromatic hydrocarbons (PAH) and total petroleum hydrocarbons (TPH) from soil contaminated with hydrocarbons using two different types of agricultural residues, filter cake mud and the sugarcane bagasse pith, as amendment and bulking agents. To test these approaches, a microcosms test was applied to soil contaminated with 14 300 mg kg-1 of TPH and 23.14 mg kg-1 of PAH. The soil treatments consisted of the following ratios of soil to residue (%/%): 100:0, 98:2, 98:4 and 98:6, and macronutrient addition was based on a carbon/nitrogen/phosphorus ratio (C:N:P, %/ % / %) of 100:10:1. Statistical analysis indicated that there were significant differences between the filter cake mud and the sugarcane bagasse pith treatments, in which the TPH removal efficiency was 60.1% using sugar cane bagasse pith and 51.4% with filter cake mud. A filter cake mud ratio of 96:4 produced the highest observed removal efficiency of PAH (43%), and a sugarcane bagasse pith ratio of 98:2 resulted in a PAH removal efficiency of 41%. Filter cake mud treatment could be an alternative for use in the bioremediation process of soils polluted with hydrocarbons. [Spanish] El objetivo del presente trabajo fue determinar la eficiencia de remocion de hidrocarburos aromaticos policiclicos (HAP) y de hidrocarburos totales del petroleo (HTP) de un suelo contaminado con petroleo crudo, utilizando dos tipos de residuos agroindustriales, la cachaza y el bagazo de cana de azucar como enmiendas y texturizante. Para ello, se realizaron pruebas en microcosmos de cultivos solidos para la biorremediacion de un suelo contaminado con 14300 mg kg-1 de HTP y 23.14 mg kg-1 de HAP. Las relaciones suelo: residuo utilizadas en las pruebas fueron las siguientes (%): 100:0, 98:2, 96:4 y 94:6, y la adicion de macronutrimentos con base en la relacion carbono/nitrogeno/fosforo (%%%) de 100:10:1. El analisis estadistico indico que hay diferencias

  5. Health risk analysis of a Mexico South-west oil installation; Analisis de riesgo a la salud de una instalacion petrolera del Suroeste de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Iturbide-Arguelles, R; Flores-Serrano, R. Ma; Torres-Bustillos, L.G [Instituto de Ingenieria, Universidad Autonoma de Mexico (Mexico)]. E-mail: ria@pumas.iingen.unam.mx

    2006-01-15

    ) en concentraciones de ND a 59,000 mg/kg. No se detecto la presencia de benceno, tolueno, etilbenceno y xileno (BTEX), metil terbutil eter (MTBE) ni metil-teramil eter (MTE). De los 16 hidrocarburos aromaticos policiclicos (HAP) analizados, solo se encontro la presencia de naftaleno en un punto, a una concentracion por debajo de 1 mg/kg. Se identifico la presencia de Fe, Pb y Zn en el suelo, pero los indices de geo-acumulacion calculados sugieren que se trata de concentraciones naturales del suelo y no contaminacion alguna. Se encontraron HTP en las aguas subterraneas, solo en un de los 6 pozos por arriba del nivel recomendado de 10mg/l. Tambien se encontro que el Fe excede el valor sugerido de 0.3 mg/l en 5 de los 6 pozos estudiados. Se encontro que el pH de las aguas subterraneas no esta relacionado con el nivel de metales encontrados (Fe y Zn), pero si con el contenido de HTP. El analisis de riesgo a la salud indico que las concentraciones de naftaleno y zinc, presentes en el suelo y agua subterranea, no representan un riesgo para la salud de los habitantes de las colonias aledanas ni para los trabajadores de la TAD. Sin embargo, dados los altos niveles de concentracion de HTP al norte de la TAD, se recomendo el saneamiento de un volumen de aproximadamente 8,000 m{sup 3} mediante el proceso de biopilas.