993 resultados para OIL TYPE
Resumo:
De-inking sludge can be converted into useful forms of energy to provide economic and environmental benefits. In this study, pyrolysis oil produced from de-inking sludge through an intermediate pyrolysis technique was blended with biodiesel derived from waste cooking oil, and tested in a multi-cylinder indirect injection type CI engine. The physical and chemical properties of pyrolysis oil and its blends (20 and 30 vol.%) were measured and compared with those of fossil diesel and pure biodiesel (B100). Full engine power was achieved with both blends, and very little difference in engine performance and emission results were observed between 20% and 30% blends. At full engine load, the brake specific fuel consumption on a volume basis was around 6% higher for the blends when compared to fossil diesel. The brake thermal efficiencies were about 3-6% lower than biodiesel and were similar to fossil diesel. Exhaust gas emissions of the blends contained 4% higher CO2 and 6-12% lower NOx, as compared to fossil diesel. At full load, CO emissions of the blends were decreased by 5-10 times. The cylinder gas pressure diagram showed stable engine operation with the 20% blend, but indicated minor knocking with 30% blend. Peak cylinder pressure of the 30% blend was about 5-6% higher compared to fossil diesel. At full load, the peak burn rate of combustion from the 30% blend was about 26% and 12% higher than fossil diesel and biodiesel respectively. In comparison to fossil diesel the combustion duration was decreased for both blends; for 30% blend at full load, the duration was almost 12% lower. The study concludes that up to 20% blend of de-inking sludge pyrolysis oil with biodiesel can be used in an indirect injection CI engine without adding any ignition additives or surfactants.
Resumo:
This paper studies the characteristics of blends of biodiesel and a new type of SSPO (sewage sludge derived intermediate pyrolysis oil) in various ratios, and evaluates the application of such blends in an unmodified Lister diesel engine. The engine performance and exhaust emissions were investigated and compared to those of diesel and biodiesel. The engine injectors were inspected and tested after the experiment. The SSPO-biodiesel blends were found to have comparable heating values to biodiesel, but relatively high acidity and carbon residue. The diesel engine has operated with a 30/70 SSPO-biodiesel blend and a 50/50 blend for up to 10h and there was no apparent deterioration in operation observed. It is concluded that with 30% SSPO, the engine gives better overall performance and fuel consumption than with 50% SSPO. The exhaust temperatures of 30% SSPO and 50% SSPO are similar, but 30% SSPO gives relatively lower NO emission than 50% SSPO. The CO and smoke emissions are lower with 50% SSPO than with 30% SSPO. The injectors of the engine operated with SSPO blends were found to have heavy carbon deposition and noticeably reduced opening pressure, which may lead to deteriorated engine performance and exhaust emissions in extended operation. © 2013 Elsevier Ltd.
Resumo:
In this article we develop a simple model to describe the evolution of a depositional wax layer on the inner surface of a circular pipe transporting heated oil, which contains dissolved wax. When the outer pipe surface is cooled sufficiently, the growth of a wax layer is initiated on the inner pipe wall, and this evolves to a saturated steady state thickness. The model proposed is based on fundamental balances of heat flow from the oil, into the wax layer, and across the pipe wall. We present an analysis of the model, examine a relevant asymptotic limit in which the full details of the solution to the model are available and develop an efficient numerical method (based on the method of fundamental solutions) for producing approximations of the model solution. The mathematical structure of the model is that of a free boundary evolution problem of generalised Stefan type. © The Author, 2014.
Resumo:
In this article we develop a simple model to describe the evolution of a depositional wax layer on the inner surface of a circular pipe transporting heated oil, which contains dissolved wax. When the outer pipe surface is cooled sufficiently, the growth of a wax layer is initiated on the inner pipe wall, and this evolves to a saturated steady state thickness. The model proposed is based on fundamental balances of heat flow from the oil, into the wax layer, and across the pipe wall. We present an analysis of the model, examine a relevant asymptotic limit in which the full details of the solution to the model are available and develop an efficient numerical method (based on the method of fundamental solutions) for producing approximations of the model solution. The mathematical structure of the model is that of a free boundary evolution problem of generalised Stefan type. © The Author, 2014.
Resumo:
Why has Corporate Social Responsibility (CSR) yielded such disappointing outcomes in oil-rich sub-Saharan Africa? Over the past decades, a sizable body of literature has emerged which draws attention to the shortcomings of oil-related development and complementary CSR exercises in the region. Most critiques on the topic, however, assess specific interventions and/or policies but fail to evaluate the complex decision-making processes, dictated heavily by setting, which produce such actions altogether. This thesis attributes CSR outcomes in oil-rich sub-Saharan Africa to the unique context in which the decisions underpinning actions take place. In doing so, the analysis borrows ideas from a diverse body of literature spanning the international development, accounting, management and political science disciplines. To explore these ideas further, the thesis focuses on the case of Ghana. The most recent “addition” to sub-Saharan Africa’s oil club, Ghana provides a rare glimpse of how decisions underpinning CSR have been identified, evolved and reshaped from the outset. To provide a comprehensive picture of CSR in the sector and its impacts at the local level, interviews and focus groups were conducted with a range of stakeholder groups. As is the case throughout sub-Saharan Africa, in Ghana, oil production occurs in offshore “enclaves”, which are disconnected geographically from local communities. This thesis argues that these dynamics have important implications for CSR. Findings point to companies also being disconnected ideologically from local development needs, which, in part explains the questionable CSR that has become such a contentious issue in the debate on oil and development in sub-Saharan Africa in recent years. The enclave-type setting in which oil production occurs appears to have stifled creativity and innovation in the area of CSR. This, along with institutional weaknesses, regulatory deficiencies and the Government of Ghana’s failure to adequately respond to local-level concerns, has produced these outcomes.
Resumo:
This survey is devoted to some fractional extensions of the incomplete lumped formulation, the lumped formulation and the formulation of Lauwerier of the temperature field problem in oil strata. The method of integral transforms is used to solve the corresponding boundary value problems for the fractional heat equation. By using Caputo’s differintegration operator and the Laplace transform, new integral forms of the solutions are obtained. In each of the different cases the integrands are expressed in terms of a convolution of two special functions of Wright’s type.
Resumo:
Waste cooking oils can be converted into fuels to provide economical and environmental benefits. One option is to use such fuels in stationary engines for electricity generation, co-generation or tri-generation application. In this study, biodiesel derived from waste cooking oil was tested in an indirect injection type 3-cylinder Lister Petter biodiesel engine. We compared the combustion and emission characteristics with that of fossil diesel operation. The physical and chemical properties of pure biodiesel (B100) and its blends (20% and 60% vol.) were measured and compared with those of diesel. With pure biodiesel fuel, full engine power was achieved and the cylinder gas pressure diagram showed stable operation. At full load, peak cylinder pressure of B100 operation was almost similar to diesel and peak burn rate of combustion was about 13% higher than diesel. For biodiesel operation, occurrences of peak burn rates were delayed compared to diesel. Fuel line injection pressure was increased by 8.5-14.5% at all loads. In comparison to diesel, the start of combustion was delayed and 90% combustion occurred earlier. At full load, the total combustion duration of B100 operation was almost 16% lower than diesel. Biodiesel exhaust gas emissions contained 3% higher CO2 and 4% lower NOx, as compared to diesel. CO emissions were similar at low load condition, but were decreased by 15 times at full load. Oxygen emission decreased by around 1.5%. Exhaust gas temperatures were almost similar for both biodiesel and diesel operation. At full engine load, the brake specific fuel consumption (on a volume basis) and brake thermal efficiency were respectively about 2.5% and 5% higher compared to diesel. Full engine power was achieved with both blends, and little difference in engine performance and emission results were observed between 20% and 60% blends. The study concludes that biodiesel derived from waste cooking oil gave better efficiency and lower NOx emissions than standard diesel. Copyright © 2012 SAE International.
Resumo:
Waste biomass is generated during the conservation management of semi-natural habitats, and represents an unused resource and potential bioenergy feedstock that does not compete with food production. Thermogravimetric analysis was used to characterise a representative range of biomass generated during conservation management in Wales. Of the biomass types assessed, those dominated by rush (Juncus effuses) and bracken (Pteridium aquilinum) exhibited the highest and lowest volatile compositions respectively and were selected for bench scale conversion via fast pyrolysis. Each biomass type was ensiled and a sub-sample of silage was washed and pressed. Demineralization of conservation biomass through washing and pressing was associated with higher oil yields following fast pyrolysis. The oil yields were within the published range established for the dedicated energy crops miscanthus and willow. In order to examine the potential a multiple output energy system was developed with gross power production estimates following valorisation of the press fluid, char and oil. If used in multi fuel industrial burners the char and oil alone would displace 3.9 × 105 tonnes per year of No. 2 light oil using Welsh biomass from conservation management. Bioenergy and product development using these feedstocks could simultaneously support biodiversity management and displace fossil fuels, thereby reducing GHG emissions. Gross power generation predictions show good potential.
Resumo:
Deep fat frying process is one of the widely followed cooking practices throughout the world. Cooking oils serve as a medium for frying food for transferring heat and makes fried food tasty and palatable. Frying process is a most complex process involving numerous physicochemical changes which are complicated to understand. Frying leads to thermal degradation of oil through thermo-oxidation, hydrolysis, and polymerization. Hydrolysis results in formation of free fatty acids whereas oxidation process produces hydroperoxides and small molecular carbonyl compounds. This whole process leads to the formation of polar compounds and degradation of antioxidants that further degrades frying oil. Eventually, through mass transfer process these degradation products accumulate into fried food and reduce the nutritional quality of both oil and food. Thus, the frying process is of research interest calls for detailed systematic study which is chosen for the present study. The primary objective of this study is to understand the mechanism of degradation and characterization ofdegraded products which helps in arriving at the limits for frying oil utilization in terms of number of frying cycles. The mechanistic studies and the knowledge on the degraded products help to understand the way to retard the deterioration of oil for stability and enhancement of frying cycles. The study also explores the formation of the predominant polar compounds and their structural elucidation through mass spectrometry. Oxidation of oil is another important factor that ignites the degradation phenomena. One of the best ways to increase thermal stability of any oil is addition of potent antioxidants. But, most of the natural and synthetic antioxidants are unstable and ineffective at frying temperatures. Therefore, it is necessary to screen alternative antioxidants for their activity in the refined oils which are devoid of any added antioxidants. In this context, this study discussed the efficacy of several natural and synthetic antioxidants to retard the formation of polar compounds and thermooxidation during prolonged frying conditions. Similarly, the advantage of blending of two different oils to improve the thermal stability was explored. The present study brings out the total picture on the type of degradation products formed during frying and the ways of retarding the determination to improve upon the stability of the oil and enhancement of frying cycles.
Resumo:
The L-dopa is the immediate precursor of the neurotransmitter dopamine. Unlike dopamine, L-dopa easily enters the central nervous system and is used in the treatment of Parkinson's disease. A sensitive and selective method is presented for the voltammetric determination of L-dopa in pharmaceutical formulations using a carbon paste electrode modified with trinuclear ruthenium ammine complex [(NH3)(5)Ru-III-O-Ru-IV(NH3)(4)-O-Ru-III(NH3)(5)](6+) (Ru-red) incorporated in NaY zeolite. The parameters which influence on the electrode response (paste composition, potential scan rate, pH and interference) were also investigated. The optimum conditions were found to an electrode composition (m/m) of 25% zeolite containing 6.7% Ru, 50% graphite and 25% mineral oil in acetate buffer at pH 4.8. Voltammetric peak currents showed a linear response for L-dopa concentration in the range between 1.2 x 10(-4) and 1.0 x 10(-2) Mol l(-1) (r = 0.9988) with a detection limit of 8.5 x 10(-5) mol l(-1). The variation coefficient for a 1.0 x 10(-3) mol l(-1) L-dopa (n = 10) was 5.5%. The results obtained for L-dopa in pharmaceutical formulations (tablet) was in agreement with compared official method. In conclusion, this study has illustrated that the proposed electrode modified with Ru-red incorporated zeolite is suitable valuable for selective measurements of L-dopa. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
By employing interpretive policy analysis this thesis aims to assess, measure, and explain policy capacity for government and non-government organizations involved in reclaiming Alberta's oil sands. Using this type of analysis to assess policy capacity is a novel approach for understanding reclamation policy; and therefore, this research will provide a unique contribution to the literature surrounding reclamation policy. The oil sands region in northeast Alberta, Canada is an area of interest for a few reasons; primarily because of the vast reserves of bitumen and the environmental cost associated with developing this resource. An increase in global oil demand has established incentive for industry to seek out and develop new reserves. Alberta's oil sands are one of the largest remaining reserves in the world, and there is significant interest in increasing production in this region. Furthermore, tensions in several oil exporting nations in the Middle East remain unresolved, and this has garnered additional support for a supply side solution to North American oil demands. This solution relies upon the development of reserves in both the United States and Canada. These compounding factors have contributed to the increased development in the oil sands of northeastern Alberta. Essentially, a rapid expansion of oil sands operations is ongoing, and is the source of significant disturbance across the region. This disturbance, and the promises of reclamation, is a source of contentious debates amongst stakeholders and continues to be highly visible in the media. If oil sands operations are to retain their social license to operate, it is critical that reclamation efforts be effective. One concern non-governmental organizations (NGOs) expressed criticizes the current monitoring and enforcement of regulatory programs in the oil sands. Alberta's NGOs have suggested the data made available to them originates from industrial sources, and is generally unchecked by government. In an effort to discern the overall status of reclamation in the oil sands this study explores several factors essential to policy capacity: work environment, training, employee attitudes, perceived capacity, policy tools, evidence based work, and networking. Data was collected through key informant interviews with senior policy professionals in government and non-government agencies in Alberta. The following are agencies of interest in this research: Canadian Association of Petroleum Producers (CAPP); Alberta Environment and Sustainable Resource Development (AESRD); Alberta Energy Regulator (AER); Cumulative Environmental Management Association (CEMA); Alberta Environment Monitoring, Evaluation, and Reporting Agency (AEMERA); Wood Buffalo Environmental Association (WBEA). The aim of this research is to explain how and why reclamation policy is conducted in Alberta's oil sands. This will illuminate government capacity, NGO capacity, and the interaction of these two agency typologies. In addition to answering research questions, another goal of this project is to show interpretive analysis of policy capacity can be used to measure and predict policy effectiveness. The oil sands of Alberta will be the focus of this project, however, future projects could focus on any government policy scenario utilizing evidence-based approaches.
Resumo:
ABSTRACT. The objective of this study was to investigate the effect of different sowing dates on the yield, 100-grain weight, oil, protein and isoflavone contents of food-type soybean breeding lines UEL 110, UEL 115 and UEL 123 and a cultivar BRS 257. The materials were seeded on four sowing dates, and the experiment was conducted in a randomized block design with four replications. The productivity and 100- grain weight varied with the sowing dates and soybean genotypes. The protein content ranged from 36.40 to 42.44%, and the oil content ranged from 18.29 to 22.71%. No significant interaction was found between the genotype and sowing dates for the protein content. The isoflavone content also varied with the sowing dates and soybean genotypes. The cultivar BRS 257 had the highest isoflavone content, including the β- glucoside, malonyl glucoside and aglycones forms. The different sowing dates influenced the productivity, 100-grain weight, oil and protein content and isoflavone levels. Higher temperatures and lower rainfall during the grain filling decreased the productivity and isoflavone content and increased the protein content. For all sowing dates, the BRS 257 soybean food-type cultivar showed the highest isoflavone content, indicating that the effect of genotype is more important. Keywords: soybean, oil, protein, isoflavones. RESUMO. O objetivo deste trabalho foi investigar o efeito das diferentes épocas de semeadura na produtividade, massa de 100 grãos, teor de proteínas, óleo e isoflavonas de linhagens de soja tipo alimento UEL 110, UEL 115 e UEL 123 e cultivar BRS 257. O material foi semeado em quatro épocas de semeadura e o experimento foi conduzido em blocos casualizados com quatro repetições. A produtividade e a massa de 100 grãos variaram com a época de semeadura e com os diferentes genótipos. O teor de proteínas variou de 36,40 a 42,44% e o de óleo de 18,29 a 22,71%. Não foi encontrada interação entre genótipo e épocas de semeadura para o teor de proteínas. O teor de isoflavonas variou com as épocas de semeadura e com os genótipos. A cultivar BRS 257 apresentou maior teor de β-glicosídeos, malonil-glicosídeos e agliconas. As diferentes épocas de semeadura influenciam a produtividade, massa de 100 grãos, conteúdo de óleo, proteínas e isoflavonas. Altas temperaturas e baixas precipitações durante o enchimento dos grãos reduzem a produtividade e teor de isoflavonas e aumentam o teor de proteínas. A cultivar BRS 257 apresenta o maior teor de isoflavonas indicando que o efeito genético é mais importante.
Resumo:
When the offshore oil and gas supplies exhaust, most offshore platforms are decommissioned and removed. The purpose of this paper is to evaluate the fatigue damage that will occur during the service life of a jacket-type offshore platform using different fatigue approaches in particular locations. The locations considered for this metocean climate impact study were Norway (North Sea), Portugal (Atlantic Ocean - Leixões) and Italy (Adriatic Sea). A finite element model was created by the means of Sesam and two different fatigue analysis, deterministic and spectral, were applied. For the fatigue assessment, an appropriate description of the site-specific wave environment, during the jacket platform service life, must be accomplished. This description is usually provided by a wave scatter diagram. Wave scatter diagrams usually represent the long-term wave environment during a (typical) year and are based on several years of site-specific data to ensure that they adequately represent the wave environment at the location of the structure. In this thesis, the comparison between these fatigue approaches will serve as a pilot study for planned reliability analysis in decommissioned offshore platforms in order to maximize the reuse of these platforms for future wind generation systems.
Resumo:
In this study, 103 unrelated South-American patients with mucopolysaccharidosis type II (MPS II) were investigated aiming at the identification of iduronate-2-sulfatase (IDS) disease causing mutations and the possibility of some insights on the genotype-phenotype correlation The strategy used for genotyping involved the identification of the previously reported inversion/disruption of the IDS gene by PCR and screening for other mutations by PCR/SSCP. The exons with altered mobility on SSCP were sequenced, as well as all the exons of patients with no SSCP alteration. By using this strategy, we were able to find the pathogenic mutation in all patients. Alterations such as inversion/disruption and partial/total deletions of the IDS gene were found in 20/103 (19%) patients. Small insertions/deletions/indels (<22 bp) and point mutations were identified in 83/103 (88%) patients, including 30 novel mutations; except for a higher frequency of small duplications in relation to small deletions, the frequencies of major and minor alterations found in our sample are in accordance with those described in the literature.
Resumo:
In the current study, a new approach has been developed for correcting the effect that moisture reduction after virgin olive oil (VOO) filtration exerts on the apparent increase of the secoiridoid content by using an internal standard during extraction. Firstly, two main Spanish varieties (Picual and Hojiblanca) were submitted to industrial filtration of VOOs. Afterwards, the moisture content was determined in unfiltered and filtered VOOs, and liquid-liquid extraction of phenolic compounds was performed using different internal standards. The resulting extracts were analyzed by HPLC-ESI-TOF/MS, in order to gain maximum information concerning the phenolic profiles of the samples under study. The reduction effect of filtration on the moisture content, phenolic alcohols, and flavones was confirmed at the industrial scale. Oleuropein was chosen as internal standard and, for the first time, the apparent increase of secoiridoids in filtered VOO was corrected, using a correction coefficient (Cc) calculated from the variation of internal standard area in filtered and unfiltered VOO during extraction. This approach gave the real concentration of secoiridoids in filtered VOO, and clarified the effect of the filtration step on the phenolic fraction. This finding is of great importance for future studies that seek to quantify phenolic compounds in VOOs.