15 research outputs found
Método para produção de petróleo em reservatórios depletados com contenção de água circulada
DepositadaÉ relatado um método para aumento da eficiência de recuperação de óleo de uma formação subterrânea, particularmente para poços que estejam em elevado estado de depleção. Preferencialmente para aumentar o volume da formação subterrânea contatada pela água na recuperação de óleo e promover urna redução seletiva, de longo alcance e duradoura na permeabilidade à água. Preferencialmente para reduzir os canais preferenciais e melhorar a eficiência de deslocamento, decorrente do deslocamento do óleo trapeado, pela partícula polimérica expandida e promover uma contenção da água circulada
EVALUATION OF AN HPHT UNIT COUPLED WITH NIR PROBE TO DETERMINE ASPHALTENES PRECIPITATION ONSET UNDER DIFFERENT PRESSURES
Asphaltenes are characterized as the crude oil fraction with the highest molar mass and polarity, presetting mainly (poly) aromatic groups. The flocculation and deposition of asphaltenes causes large losses to the oil industry. Understanding the phase behavior of asphaltenes under conditions closer to those found in reservoirs is important. Therefore, LMCP/UFRJ started operating a high-pressure high-temperature (HPHT) unit coupled to a near-infrared spectrometer probe that can use different flocculants. This work describes the development of a procedure as well as the validation of the results obtained from this unit. Due to the complex composition of crude oil, model systems (MS) were prepared with asphaltenes extracted with n-pentane (C5I) and n-heptane (C7I). The experiments were carried out at atmospheric pressure, titrated with n-heptane, and at 100 and 300 bar titrated with propane. As expected, C7I asphaltenes were more unstable, presenting lower precipitation onset than C5I asphaltenes under ambient conditions and higher pressures. However, for both MS, the stability increased with rising pressure when using propane as a solvent. The proposed method to evaluate asphaltenes precipitation onset was effective for MS in toluene and dead crude oil, and is a promising alternative for investigation of different types of crude oil
Síntese e sulfonação de resinas poliméricas macroporosas e avaliação na remoção de petróleo e de anilina em água
Resinas poliméricas porosas têm sido amplamente empregadas nos processos de tratamento de água devido a vantagens como elevada seletividade e possibilidade de regeneração e modificação química, permitindo a obtenção de um material com maior seletividade/especificidade. No presente estudo, resinas poliméricas porosas de metacrilato de metila-divinilbenzeno (MMA-DVB), estireno-divinilbenzeno (Sty-DVB) e estireno-divinilbenzeno sulfonada (S-Sty-DVB) foram sintetizadas, caracterizadas e avaliadas quanto à eficiência de remoção de petróleo e de anilina contidos na água. Nos testes empregando-se água oleosa, foram avaliadas colunas contendo somente um tipo de resina (Sty-DVB e S-Sty-DVB) e colunas contendo recheios mistos (MMA-DVB/S-Sty-DVB e Sty-DVB/S-Sty-DVB), frente à remoção de óleo e dos cátions sódio e cálcio presentes na água oleosa. As colunas com recheio misto apresentaram melhor desempenho, devido à diversidade de hidrofilicidade do sistema adsorvente, tendo sido possível remover uma gama mais extensa de contaminantes. A remoção de anilina presente na água foi possível com o uso da resina de estireno-divinilbenzeno sulfonada, em razão da reação ácido-base entre a anilina e os sítios ácidos da resina. Uma redução gradual, e não abrupta, da eficiência desta resina na remoção de anilina deve-se à interação de moléculas de anilina com o sal de anilínio formado após a saturação dos sitos ácidos da resina
Synthesis and characterization of isoprene oligomers to compare different production chemical processes
Abstract Three methods to obtain isoprene oligomers were evaluated: chemical degradation of non-vulcanized coagulated natural rubber; chemical degradation of natural rubber latex; and oligomerization of the isoprene monomer. The products were characterized by infrared spectrometry (FTIR), nuclear magnetic resonance (NMR) and size-exclusion chromatography (SEC). All the three processes were efficient and can be controlled in order to obtain products with desired molar mass. Among the degradation processes, the reaction with the non-vulcanized rubber led to the purest products, but this process has the disadvantage of relatively higher catalyst cost of the catalyst. Reactions of isoprene with free radical initiation produced oligomers under specific conditions: low isoprene concentration, low initiator concentration, and xylene as solvent. The results discussed here allows the readers to have a chemistry overview and experimental insights about different chemical routes to obtain isoprene oligomers, compiled together in the same work. It shall be helpful for applied chemistry researches
Exergy Load Distribution Analysis Applied to the Dehydration of Ethanol by Extractive Distillation
This study presents the analysis of the exergy load distribution in a separation process by extractive distillation for ethanol dehydration. The methodology carried out is divided into three parts: the calculation of the flow exergy considering the physical and chemical exergies of the distillation process; the calculation of the primary and transformed exergy contributions considering the consumed exergy; and finally, the overall process efficiency, which shows the real percentage of energy being used in the process. The simulation of an extractive distillation separation system is carried out using Aspen Plus®, from Aspen Tech Version 9. In general, heat transfer processes (heating or cooling) are the ones that generate the greatest exegetic destruction, which is why they must be the operations that must be optimized. As a result of our case study, the local exergy efficiency of the extractive distillation column is 13.80%, which is the operation with the greatest energy loss, and the overall exergy efficiency of the separation system is 30.67%. Then, in order to increase exergy efficiency, a sensitivity analysis is performed with the variation of the azeotrope feed, number of stages, reflux ratio, and solvent feed variation on ethanol purity to reach an overall efficiency of 33.53%. The purity of ethanol is classified as higher than that of the specified, 99.65%
Removal of Phenol from Aqueous Solutions by Polymeric Composites Containing Ni and Co Particles
Magnetic composites have a wide range of potential technological applications; however the evaluation of this material for extraction of phenolic compounds has not been sufficiently studied. Due to its high toxicity and solubility the removal of phenolic compounds from the aquatic environments has critical importance. In this work polymeric composites were prepared by anchoring Ni and Co particles on sulfonatedpoly(styrene-co-divinylbenzene) PS-DVB. The PS-DVB beads were synthesized by suspension polymerization and reacted with acetyl sulfate, aiming to obtain sulfonated copolymers. All materials were capable of removing phenol from aqueous solutions. The phenol adsorption kinetics was influenced by the polymer porosity and swelling capacity in water. The composite derivative of the more porous copolymer impregnated with nickel (C1SNi) was the most efficient in phenol removal, with the sorption equilibrium being established more rapidly than for the other composites. The pseudo second-order model was more adequate to describe the phenol adsorption process for the composite C1SNi. The Langmuir model describes successfully the phenol removal by this composite.CNPqCAPESFAPER
High throughput synthesis and characterization of PNIPAM-based kinetic hydrate inhibitors
� 2016 Libraries of kinetic hydrate inhibitors (KHIs) based on poly(N-isopropylacrylamide) (PNIPAM) were synthesized by post-synthetic modification of an existing PNIPAM copolymer. Unlike other synthetic routes this generates accurately controlled libraries of KHIs with similar molecular weight (M?w), molecular weight distribution, end groups and composition. This allows for accurate interpretation of the effect of each of these components and highlights key functional groups that can improve performance. This was assessed using a high throughput KHI ranking method based on its inhibition performance of Structure II (sII) forming cyclopentane (c-C5) hydrate under atmospheric pressure. Hydrate inhibition tests showed that performance of PNIPAM-based KHIs can be improved by careful inclusion of select groups. In addition, cloud point data demonstrates that polymers with higher deposition points could be generated using this method. The presence of side products has a pronounced effect on cloud point but minimal effect on hydrate inhibition performance. These data provide valuable insights into polymers that can improve the performance of KHIs. The method can also be applied to a number of structural motifs to develop chemicals to overcome issues associated with natural gas transport
Thermal resistance of magnetic polymeric composites based on styrene, divinylbenzene, and Ni and Co particles
Region 8q24 Is a Susceptibility Locus for Nonsyndromic Oral Clefting in Brazil
BACKGROUND: Nonsyndromic cleft lip with or without cleft palate is a relatively common craniofacial defect with multifactorial inheritance. The association of the rs987525 single nucleotide variant, located in a gene desert at 8q24.21 region, has been consistently replicated in European populations. We performed a structured association approach combined with transcriptional analysis of the MYC gene to dissect the role of rs987525 in oral clefting susceptibility in the ethnically admixed Brazilian population. METHODS: We performed the association study conditioned on the individual ancestry proportions in a sample of 563 patients and 336 controls, and in an independent sample of 221 patients and 261 controls. The correlation between rs987525 genotypes and MYC transcriptional levels in orbicularis oris muscle mesenchymal stem cells was also investigated in 42 patients and 4 controls. RESULTS: We found a significant association in the larger sample (p = 0.0016; OR = 1.80 [95% confidence interval {CI}, 1.21-2.69], for heterozygous genotype, and 2.71 [95% CI, 1.47-4.96] for homozygous genotype). We did not find a significant correlation between rs987525 genotypes and MYC transcriptional levels (p = 0.14; r = -0.22, Spearman Correlation). CONCLUSIONS: We present a positive association of rs987525 in the Brazilian population for the first time, and it is likely that the European contribution to our population is driving this association. We also cannot discard a role of rs987515 in MYC regulation, because this locus behaves as an expression quantitative locus of MYC in another tissue. Birth Defects Research (Part A) 94:464-468, 2012. (C) 2012 Wiley Periodicals, Inc.FAPESP/CEPID [98/14254-2]FAPESP/CEPIDCNPq [401952/2010-S]CNPqBrazilian Ministry of HealthBrazilian Ministry of Healt