Hidrocarburos de petróleo en áreas marino costeras del Perú. 2004

Se han evaluado los hidrocarburos aromáticos en agua y en sedimento marino. En sedimentos de fondo como indicador del deterioro o estado de contaminación, se ha empleado el contenido de compuestos aromáticos.

Características químicas de solos da região de Janaúba, MG, irrigados com água de poços tubulares e do rio Gorutuba

Na região de Janaúba, norte de Minas Gerais, não obstante as altas produtividades alcançadas pela bananicultura da região no contexto de uma agricultura altamente tecnificada, com uso intenso de fertilizantes e controle sistemático de doenças e pragas, são comuns os relatos de produtores expressando preocupação com a queda de produtividade, particularmente quando se irriga com água de poços tubulares. Em razão disso, estudou-se o efeito de águas de irrigação provenientes de poços e do rio Gorutuba sobre propriedades químicas de solos sob bananais, onde foram coletadas amostras até 100 cm de profundidade em áreas adjacentes de sequeiro e irrigadas. Observou-se que o uso de águas de poços, de qualidade marginal, causou elevação do pH e dos teores de Ca2+ e Na+ dos solos, elevando as relações Ca/Mg e Ca/K, que se distanciaram da faixa ideal para a cultura da banana. Nos solos irrigados com água de poços houve aumento dos teores de P extraído com H2SO4, resultante da precipitação do P com o Ca veiculado com a água. Os valores de pH do extrato de saturação do solo foram mais elevados que aqueles registrados na análise de rotina, e a concentração de sais solúveis na solução do solo ocorreu em camadas intermediárias do perfil devido à lixiviação, com destaque para a camada de 30-40 cm dos solos irrigados com água de poços.

Petróleo y gas en África: viejas realidades, nuevos escenarios

[cat] En els últims temps es parla molt del nou paper dels hidrocarburs d'Àfrica, fins i tot s'al·ludeix a un oil rush o a un african oil scramble , que inevitablement desembocarà en una confrontació bipolar entre la Xina i els Estats Units, pel control de les reserves de petroli del subsòl del continent africà. Així, el propòsit d'aquest text és, en primer lloc, realitzar una anàlisi descriptiva que ajudi a valorar la hipòtesi d'aquest african oil scramble. A continuación, amb les dades obtingudes, es discutirà sobre la possibilitat de que aquest fenomen desemboqui en un escenari de confrontació xinoamericana. Aquesta especulació ens durà a concloure que hi ha suficients indicis per a argumentar que el joc petrolífer africà podria desenvolupar-se en un escenari marcat per la multilateralitat.

Remediação de um solo contaminado com petróleo por oxidação química

A remediação de uma amostra de Latossolo Vermelho-Amarelo contaminado artificialmente com petróleo (5.000 mg kg-1) foi estudada comparando diferentes oxidantes químicos: KMnO4 0,10 mol L-1; K2S2O8 0,10 mol L-1; H2O2 0,10 mol L-1; H2O2/Fe2+ 0,10/0,080 mol L-1 (reação de Fenton); e H2O2/Fe2+/UV 0,10/0,080 mol L-1 (reação de foto-Fenton). A remediação foi praticamente completa aos 30 min para o processo de foto-Fenton (99 %). Todos os outros oxidantes não atingiram essa taxa de dissipação até 180 min. O processo em que se usou H2O2 0,10 mol L-1 (70,51 %) foi o de menor eficiência. A adição de íons Fe aumentou a taxa de dissipação para 86,98 % (H2O2/Fe2+ 0,10/0,080 mol L-1). Os métodos convencionais apresentaram taxas de dissipação de 76,58 % (KMnO4 0,10 mol L-1) e 93,85 % (K2S2O8 0,10 mol L-1).

Petróleo y gas en África: viejas realidades, nuevos escenarios

[cat] En els últims temps es parla molt del nou paper dels hidrocarburs d'Àfrica, fins i tot s'al·ludeix a un oil rush o a un african oil scramble , que inevitablement desembocarà en una confrontació bipolar entre la Xina i els Estats Units, pel control de les reserves de petroli del subsòl del continent africà. Així, el propòsit d'aquest text és, en primer lloc, realitzar una anàlisi descriptiva que ajudi a valorar la hipòtesi d'aquest african oil scramble. A continuación, amb les dades obtingudes, es discutirà sobre la possibilitat de que aquest fenomen desemboqui en un escenari de confrontació xinoamericana. Aquesta especulació ens durà a concloure que hi ha suficients indicis per a argumentar que el joc petrolífer africà podria desenvolupar-se en un escenari marcat per la multilateralitat.

A indústria petroquímica no próximo século: como substituir o petróleo como matéria-prima?

The world reserves of petroleum will finish in about 100 years. For a tropical country like Brazil, biomass will be the natural substitute for petroleum. For the best utilization of biomass, it first needs to be separated into its principal components: cellulose, hemicelluloses, lignins, vegetable and essential oils, non-structural carbohydrates, bark and foliage. All feedstocks for the chemical industry can be obtained from these biomass components, as shown in the first part of this paper. In the second part we discuss how the major products from petrochemicals can be obtained from the different biomass components. We show that Brazil can use different strategies, compared to other countries, to obtain petrochemical products, which could result in innovations. However, it is necessary that the government starts to invest immediately in order to keep the petrochemical industries competitive with foreign industries, so that they continue to be one of Brazil's major employers.

A destilação simulada na indústria do petróleo

One of the most widely used physico-chemical characterizations of hydrocarbon mixtures is the determination of their boiling point distribution. Knowledge of the boiling range of crude oils and petroleum products is essential to ensure the correct specification of final products and to control refinery processes. Simulated distillation, a GC based process, has been playing this role for the past decades in the petroleum industry. The main purpose of this work is to show the fundamentals of this technique as well as its present trends.

Determinação das formas de nitrogênio e nitrogênio total em rochas-reservatório de petróleo por destilação com arraste de vapor e método do indofenol

Several extraction procedures are described for the determination of exchangeable and fixed ammonium, nitrate + nitrite, total exchangeable nitrogen and total nitrogen in certified reference soils and petroleum reservoir rock samples by steam distillation and indophenol method. After improvement of the original distillation system, an increase in worker safety, a reduction in time consumption, a decrease of 73% in blank value and an analysis without ammonia loss, which could possibly occur, were achieved. The precision (RSD < 8%, n = 3) and the detection limit (9 mg kg-1 NH4+-N) are better than those of published procedures.

Estudo sobre a adsorção do fluido de perfuração salgado contendo polímeros sobre SiO2

Polysaccharide-based drilling fluids have been often applied in horizontal wells of petroleum reservoirs in Campos, Rio de Janeiro. The present study aimed to understand the mechanism of adsorption and desorption of the drill-in fluid, xanthan, modified starch and lubricant on SiO2 by means of ellipsometry. The effect of pH and brine on the mean thickness (D) of adsorbed layer was systematically investigated. The adsorption was mainly favored under alkaline conditions. A model has been proposed to explain this effect. The adsorption isotherms determined separately for xanthan and starch on SiO2 surfaces could be fitted with the Langmuir model, which yielded similar adsorption constant values.

Utilização de solos locais para tratamento de efluentes do refino de petróleo contendo metais

The employment of local soils for extraction of metallic elements was evaluated through batch tests to treat wastewaters generated in a petroleum refinery plant in southern Brazil. Clay and organic carbon content and clay mineralogy provide these soils, in principle, with moderate metal retention capacity. The following retention order was established: Cr3+ > Pb2+ > Cu2+ > Hg2+ > Cd2+, with total amount of metals retained varying from 36 to 65 meq kg-1. The results show the high efficiency of local soils for extracting metals from liquid effluents through sorption and precipitation processes under acid pH conditions.

Remoção do íon amônio de águas produzidas na exploração de petróleo em áreas offshore por adsorção em clinoptilolita

This work describes the use of clinoptilolite for removal of ammonium ions present in waters produced at the Campos' Basin. Samples were previously treated in order to remove organic compounds and metals. Experiments were run in fixed- and fluidized-bed systems, at room temperature. The fluidized-bed systems did not remove efficiently the ammonium ion. The best operational conditions were obtained with clinoptilolite particle size in the range 0.30-0.50 mm, under ascendant flow (3 mL min-1), in a fixed-bed system. The best zeolite performance was found when it was pretreated with 0.5 mol L-1 NaOH. Na+ was the most important interfering ion due to its high concentration in the water. Clinoptilolite lost partially its capacity to retain ammonium ions after several regeneration cycles with NaOH.

Principais aplicações das microondas na produção e refino de petróleo

Microwave irradiation offers a clean, inexpensive, and convenient method of heating, which is an alternative way of introducing energy into chemical systems. In particular, applications of microwave irradiation technology for petroleum processing have been developed in the last twenty years. The main objective of this paper is to review the use of microwave irradiation technology as an alternative technique applied during petroleum refining and primary processing of petroleum fluids, presenting and discussing successful applications of this technology as a tool for petroleum emulsion separation and catalytic reactions normally found at hydrorefining plants.

Salinidade em petróleo bruto: otimização de metodologia e proposta de um novo método para extração de sais em petróleo

The quantity of salts in the crude oils depends on the origin and of the wells production and these salts cause several problems during the transport and the process of refine as corrosions, incrustations and deactivation of the employed catalysts in the refineries. In this study were implemented changes for improvements in the execution of ASTM D 6470 method and has also developed a new methodology of extraction system of salts using process of mechanical agitation without heating. The results of the optimization produce larger efficiency and safety to the process compared to the traditional ASTM method.

Análise de compostos sulfurados em efluentes gasosos de refinaria de petróleo

This work discusses an analytical procedure for analysis of sulfur compounds in treated petroleum refinery gaseous effluents using a sulfur chemiluminescence detector with dual plasma burner (SCD-DP). Calibration was accomplished by using standards and gaseous streams of known concentration of sulfur compounds. The response factors agree with the calibration table of ASTM standard D 5504 (2008). The detection range for sulfur compounds is in μg m-3. The analytical procedure allowed the construction of a chromatographic chart of sulfur compounds present in several refinery gaseous effluents. SO2 was the most difficult compound to be determined because of its high reactivity.

Ácidos naftênicos no petróleo

Brazilian petroleum is known by its high acidity due to the presence of acidic constituents, especially naphthenic acids (NA). The total characterization of the NA in petrochemical samples has been receiving special attention in research and comprises an analytical challenge, mainly due to the complexity of their mixtures. Gas chromatography with mass detector (GC/MS) is the technique of analysis more used, but recently comprehensive two-dimensional gas chromatography (GC × GC) has been used, due to its high resolution, peak capacity and sensitivity. The goal of this article is to discuss the techniques for sample preparation and analysis of NA in petroleum.