987 resultados para Biodiesel. Gas Chromatography. Castor Oil Biodiesel. Glycerin. MethylEsters. Methanol
Resumo:
Mode of access: Internet.
Resumo:
"MMS 91-0044."
Resumo:
The organic matter in five oil shales (three from the Kimmeridge Clay sequence, one from the Oxford Clay sequence and one from the Julia Creek deposits in Australia) has been isolated by acid demineralisation, separated into kerogens and bitumens by solvent extraction and then characterised in some detail by chromatographic, spectroscopic and degradative techniques. Kerogens cannot be characterised as easily as bitumens because of their insolubility, and hence before any detailed molecular information can be obtained from them they must be degraded into lower molecular weight, more soluble components. Unfortunately, the determination of kerogen structures has all too often involved degradations that were far too harsh and which lead to destruction of much of the structural information. For this reason a number of milder more selective degradative procedures have been tested and used to probe the structure of kerogens. These are: 1. Lithium aluminium hydride reduction. - This procedure is commonly used to remove pyrite from kerogens and it may also increase their solubility by reduction of labile functional groups. Although reduction of the kerogens was confirmed, increases in solubility were correlated with pyrite content and not kerogen reduction. 2. O-methylation in the presence of a phase transfer catalyst. - By the removal of hydrogen bond interactions via O-methylation, it was possible to determine the contribution of such secondary interactions to the insolubility of the kerogens. Problems were encountered with the use of the phase transfer catalyst. 3. Stepwise alkaline potassium permanganate oxidation. - Significant kerogen dissolution was achieved using this procedure but uncontrolled oxidation of initial oxidation products proved to be a problem. A comparison with the peroxytrifluoroaceticacid oxidation of these kerogens was made. 4. Peroxytrifluoroacetic acid oxidation. - This was used because it preferentially degrades aromatic rings whilst leaving any benzylic positions intact. Considerable conversion of the kerogens into soluble products was achieved with this procedure. At all stages of degradation the products were fully characterised where possible using a variety of techniques including elemental analysis, solution state 1H and 13C nuclear magnetic resonance, solid state 13C nuclear magnetic resonance, gel-permeationchromatography, gas chromatography-mass spectroscopy, fourier transform infra-red spectroscopy and some ultra violet-visible spectroscopy.
Resumo:
Sewage sludge was pyrolysed with 40% mixed wood, 40% rapeseed and 40% straw. The reason for the mixture of different biomass is to investigate the impact of co-pyrolysis on the upper phase of bio-oil in terms of changes to composition, elemental analysis, viscosity, water content, pH, higher heating value and acid number that could impact on their applications. The biomass was pyrolysed in a laboratory at 450 °C and bio-oil was collected from two cooling traps. The bio-oil obtained from co-pyrolysis of sewage sludge with wood, rapeseed and straw was analysed for composition using the gas chromatography mass spectrometry. The upper phase from the co-pyrolysis process was also characterised for ultimate analysis, higher heating values, water content, viscosity, pH and acid number. There was an increase in the amount of upper phase produced with co-pyrolysis of 40% rapeseed. It was also found that the upper phase from sewage sludge with mixed wood has the highest viscosity, acid number and lowest pH. The bio-oil containing 40% straw was found to have a pH of 6.5 with a very low acid number while the 40% rapeseed was found to have no acid number. Sewage sludge with 40% rapeseed was found to have the highest energy content of 34.8 MJ/kg, 40% straw has 32.5 MJ/kg while the 40% mixed wood pyrolysis oil has the lowest energy content of 31.3 MJ/kg. The 40% rapeseed fraction was found to have the highest water content of 8.2% compared to other fractions.
Resumo:
Since the Exxon Valdez accident in 1987, renewed interest has come forth to better understand and predict the fate and transport of crude oil lost to marine environments. The short-term fate of an Arabian Crude oil was simulated in laboratory experiments using artificial seawater. The time-dependent changes in the rheological and chemical properties of the oil under the influence of natural weathering processes were characterized, including dispersion behavior of the oil under simulated ocean turbulence. Methodology included monitoring the changes in the chemical composition of the oil by Gas Chromatography/Mass Spectrometry (GCMS), toxicity evaluations for the oil dispersions by Microtox analysis, and quantification of dispersed soluble aromatics by fluorescence spectrometry. Results for this oil show a sharp initial increase in viscosity, due to evaporative losses of lower molecular weight hydrocarbons, with the formation of stable water-in-oil emulsions occurring within one week. Toxicity evaluations indicate a decreased EC-50 value (higher toxicity) occurring after the oil has weathered eight hours, with maximum toxicity being observed after weathering seven days. Particle charge distributions, determined by electrophoretic techniques using a Coulter DELSA 440, reveal that an unstable oil dispersion exists within the size range of 1.5 to 2.5 um, with recombination processes being observed between sequential laser runs of a single sample.
Organic and conventional fertilization effects on essential oil production of Melissa officinalis L.
Resumo:
In most countries along with various food products, fish sausage is supplied in different formulas. Unfortunately, in our country because of different reasons, production and supply of fish sausage in industrial level has not yet been successful and some efforts taken, has also been doomed to failure or not welcomed. Fat fish is a rich source of poly unsaturated fatty acids (PUFA) and co-3. In this research, efforts have been made to produce and enrich sausage with fish oil and maintenance of fatty acids has also been experimented using gas chromatography along with heating process. The stages of producing ground fish and fish sausage are as the following: Transferring and preparing fish, washing the cleared fish, filleting, separating fillet steak, washing and drying them, Refining meat, Producing and homogenizing mixture from basic ingredients in a cutter, filling, knotting and heat processing. The fish sausage produced by this method tried and welcomed by the subjects. In the product in which fish meat was used, the subjects was not recognized fish flavor and taste and when in addition to fish meat, fish oil was used during enrichment, the flavor and taste of fish was considered as highly acceptable. TVN measurement of the produced fish sausage was kept in the refrigerator in two month was at a maximum of 16.5, the amount of peroxide was at a maximum 1.5% after the period of two months. During this period the Colony count was at maximum of 19.5 x 104, the high maximum of the number of coliforms was 10/gr, and for mold and yeast 83/gr , but Escherichia coli, Staphylococcus aureus, Salmonella and Clostridium perfringens were not found. The protein of the resulting product was 15-18%, lipid at about 11-15% and moisture 60-65%. Comparing fatty acids, including unsaturated fatty acids in ground and oil fish used in producing fish sausage with those of fish sausage showed that the heat used in processing had the least effect on fatty acids of the meat and oil used here and the resulting fish sausage is considered as food for good health.
Resumo:
Neste trabalho desenvolveu-se a síntese de -cetoésteres, a partir da acilação do ácido de Meldrum usando diferentes ácidos graxos, com cadeias saturadas e insaturadas. Inicialmente, foi realizado o experimento utilizando o ácido palmítico (1e) como modelo para obtenção de cloreto de ácido graxo, usando ácido de Meldrum e piridina como catalisador. Porém, após um longo tempo de reação, o -cetoéster palmítico (4e) foi obtido com baixo rendimento, não ultrapassando os 20%. Posteriormente, os experimentos foram realizados utilizando o ácidos graxos 1e, ácido de Meldrum (2), DCC, DMAP, e piridina à temperatura ambiente sob a atmosfera de nitrogênio. No entanto, o protocolo utilizado resultou no β-cetoéster 4e com rendimentos moderados. Em seguida examinou-se o efeito da adição do ácido de Meldrum após a adição dos ácido graxos e DCC. Neste caso, após a adição do DCC aos ácido graxos 1a-j foi observada a formação imediata das O-aciluréias graxas. A seguir a adição de 2,0 equiv de ácido de Meldrum (2) em diclorometano, revelou a formação dos respectivos enol graxos 3a-j. Posteriormente, os β- cetoésteres 4a-j foram obtidos a partir da reação do enol com o metanol. Este protocolo modificado proporcionou o aumento nos rendimentos (74 a 84%) dos β-cetoéster 4a-j. Após, o β-cetoéster 4k foi sintetizado em 75% utilizando o ácido de Meldrum (2) e ácido ricinoléico (1k), obtido a partir do biodiesel de mamona, à temperatura ambiente e sob a atmosfera de nitrogênio. Portanto, foi desenvolvido um método simples para obter β-cetoésteres graxos, a partir do ácido de Meldrum com cadeias graxas diversificadas utilizando DCC e DMAP. Além disso, o presente trabalho relata pela primeira vez a síntese de novos β-cetoésteres graxos derivados dos ácidos oléico, elaídico, ricinoléico, linoléico e linolênico.
Resumo:
As metas da União Europeia para 2020 em termos de biocombustíveis e biolíquidos traduziram-se, na última década, num destaque da indústria de biodiesel em Portugal. Inerente ao processo de produção biodiesel está um subproduto, o glicerol bruto, cujo estudo tem vindo a ser alvo de interesse na comunidade científica. O objetivo principal deste trabalho consistiu no estudo da gasificação do glicerol técnico e do glicerol bruto, usando vapor como agente oxidante. Pretendeu-se avaliar a composição do gás de produção obtido e os parâmetros de gasificação, como a percentagem de conversão de carbono e de hidrogénio, o rendimento de gás seco, a eficiência de gás frio e o poder calorífico do gás produzido. No estudo da gasificação do glicerol técnico avaliou-se o efeito da temperatura na performance do processo, entre 750 – 1000 ºC, e estudou-se ainda o efeito do caudal de alimentação ao reator (3,8 mL/min, 6,5 mL/min e 10,0 mL/min). Para o caudal mais baixo, estudou-se o efeito da razão de mistura glicerol/água (25/75, 40/60, 60/40 e 75/25) e para a razão de mistura 60/40 foi avaliada a influência da adição de ar como agente gasificante. O estudo da gasificação do glicerol bruto foi feito realizando ensaios de gasificação numa gama de temperaturas de 750 ºC a 1000 ºC, para uma razão de mistura glicerol/água (60/40) com o caudal de 3,8 mL/min e usando apenas vapor de água como agente de gasificação. Os ensaios foram realizados num reator de leito fixo de 500 mm de comprimento e 90 mm de diâmetro interno, composto por um leito de alumina com partículas de 5 mm de diâmetro. O aquecimento foi realizado com um forno elétrico de 4 kW. A amostra de gás de produção recolhida foi analisada por cromatografia gasosa com detector de termocondutividade. Os resultados obtidos na gasificação do glicerol técnico, revelaram que a temperatura é uma variável preponderante no desempenho do processo de gasificação. À exceção do poder calorífico superior, para o qual se obteve uma ligeira diminuição de valores com o aumento da temperatura, os valores mais elevados dos parâmetros de gasificação foram obtidos para temperaturas superiores a 900 ºC. Esta temperatura parece ser determinante no modelo cinético de gasificação do glicerol, condicionando a composição do gás de produção obtido. Concluiu-se ainda que, na gama de caudais testada, o caudal de alimentação ao reator não teve influência no processo de gasificação. Os ensaios realizados para avaliar o efeito da razão de mistura permitiram verificar que, o aumento da adição de água à alimentação se traduz na redução do teor de CO e de CH4 e no aumento do teor de H2 e CO2, no gás de produção. Para a razão de mistura 25/75 foram obtidos valores de 1,3 para o rácio H2/CO para temperaturas superiores a 900 ºC. A influência da adição de água tornou-se mais evidente nos ensaios de gasificação realizados a temperaturas superiores a 900 ºC. Verificou-se um aumento da conversão de carbono, do rendimento de gás seco e da eficiência do gás frio e uma ligeira diminuição do poder calorífico e da potência disponível, no gás de produção. Para as razões de misturas 60/40 e 40/60 obtiveram-se resultados, para os parâmetros de gasificação, da mesma ordem de grandeza e com valores intermédios entre os obtidos para as razões de mistura 25/75 e 75/25. Porém, quanto maior o teor de água alimentado maior o consumo de energia associado à vaporização da água. Assim, o aumento do teor de água na mistura só apresentará interesse industrial se o objetivo passar pela produção de hidrogénio. Quanto ao efeito da adição de ar como agente de gasificação, os resultados obtidos dão indicação que se poderão potenciar algumas reações exotérmicas que contribuirão para a redução do consumo energético global do processo. Por outro lado, o gás de produção apresentou um rácio H2/CO interessante do ponto de vista da sua aplicação industrial, superior em 35 % ao verificado para a gasificação efetuada apenas na presença de vapor. À exceção do decréscimo no valor do poder calorífico superior do gás de produção, os restantes parâmetros estudados apresentaram a mesma ordem de grandeza, dos obtidos para o estudo da mesma razão de mistura na ausência de ar. Relativamente ao estudo da gasificação do glicerol bruto, obtiveram-se valores de rácio H2/CO e eficiência de gás frio mais elevados que os valores obtidos para a mesma razão de mistura usando glicerol técnico. Os demais parâmetros de gasificação avaliados mostraram-se semelhantes entre as duas matérias-primas, verificando-se apenas uma ligeira diminuição no valor do poder calorífico superior do gás produzido com glicerol bruto. Os resultados obtidos demonstram a possibilidade de valorização energética do glicerol bruto resultante da produção de biodiesel.
Resumo:
The herbaceous shrub Tetradenia riparia has been traditionally used to treat inflammatory and infectious diseases. Recently, a study showed that T. riparia essential oil (TrEO) obtained in summer has antileishmanial effects, although these results could be influenced by seasonal variation. This study evaluated the activity of the TrEO obtained in different seasons against Leishmania (Leishmania) amazonensis , in vitro and in vivo. The compounds in the TrEO were analysed by gas chromatography-mass spectrometry; terpenoids were present and oxygenated sesquiterpenes were the majority compounds (55.28%). The cytotoxicity and nitric oxide (NO) production were also tested after TrEO treatment. The TrEO from all seasons showed a 50% growth inhibitory concentration for promastigotes of about 15 ng/mL; at 30 ng/mL and 3 ng/mL, the TrEO reduced intracellular amastigote infection, independently of season. The TrEO from plants harvested in summer had the highest 50% cytotoxic concentration, 1,476 ng/mL for J774.A1 macrophages, and in spring (90.94 ng/mL) for murine macrophages. NO production did not change in samples of the TrEO from different seasons. The antileishmanial effect in vivo consisted of a reduction of the parasite load in the spleen. These results suggest that the TrEO has potential effects on L. (L.) amazonensis, consonant with its traditional use to treat parasitic diseases.
Resumo:
Purpose: To investigate the antimicrobial and anti-biofilm activities of essential oil from Mentha pulegium L. (EOMP) on multi-drug resistant (MDR) isolates of A. baumannii , as well as its phytochemical composition, antioxidant properties and cytotoxic activity. Methods: The phytochemical composition of EOMP was analyzed by gas chromatography, while its antimicrobial activities were determined by disc diffusion and broth micro-dilution methods. Minimal biofilm inhibition concentration (MBIC) and minimal biofilm eradication concentration (MBEC) tests were used for assessment of its anti-biofilm properties. Viability in the biofilm was studied using 2,3-bis (2- methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay, while colorimetric assay was used to assess its cytotoxicity on L929 cells. Results: D-isomenthone, pulegone, isopulegone, menthol and piperitenone were the major components of the plant extract. EOMP produced > 22 mm inhibition zone for the isolates, with minimum inhibitory concentration (MIC) and MBIC of 0.6 - 2.5 and 0.6 - 1.25 μL/mL, respectively, while MBEC was ≥ 10 μL/msL. EOMP damaged biofilm structures formed by A. baumannii strains at MIC by 26 – 91 %. Conclusion: These results suggest that EOMP contains agents that may be useful in the development of new drugs against A. baumannii infections.
Resumo:
Purpose: To determine borneol and other chemical compounds of essential oil derived from the exudate of Dryobalanops aromatica aromatica in Malaysia. Methods: Exudate was collected from D. aromatica and subjected to fractional distillation to obtain essential oil. Gas chromatography-mass spectrometry (GC-MS) was performed to characterize the composition of the isolated essential oil. Results: Essential oil (7.58 %) was obtained with the highest yield (3.24 %) in the first 2 h of fractional distillation. Thirty compounds which accounted for 97.56 % of total essential oil composition were identified by GC-MS, and they include sesquiterpenes (46.87 %), monoterpenes (31.05 %), oxygenated monoterpenes (16.76 %) and oxygenated sesquiterpenes (2.13 %). Borneol (0.74 %) was also detected in the essential oil. Conclusion: Borneol and other terpenoid compounds are present in the essential oil of the exudate of D. aromatica
Resumo:
This study investigates fast pyrolysis bio-oils produced from alkali-metal-impregnated biomass (beech wood). The impregnation aim is to study the catalytic cracking of the pyrolysis vapors as a result of potassium or phosphorus. It is recognized that potassium and phosphorus in biomass can have a major impact on the thermal conversion processes. When biomass is pyrolyzed in the presence of alkali metal cations, catalytic cracking of the pyrolysis liquids occurs in the vapor phase, reducing the organic liquids produced and increasing yields of water, char, and gas, resulting in a bio-oil that has a lower calorific value and an increased chance of phase separation. Beech wood was impregnated with potassium or phosphorus (K impregnation and P impregnation, respectively) in the range of 0.10-2.00 wt %. Analytical pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) was used to examine the pyrolysis products during thermal degradation, and thermogravimetric analysis (TGA) was used to examine the distribution of char and volatiles. Both potassium and phosphorus are seen to catalyze the pyrolytic decomposition of biomass and modify the yields of products. 3-Furaldehyde and levoglucosenone become more dominant products upon P impregnation, pointing to rearrangement and dehydration routes during the pyrolysis process. Potassium has a significant influence on cellulose and hemicellulose decomposition, not just on the formation of levoglucosan but also other species, such as 2(5H)-furanone or hydroxymethyl-cyclopentene derivatives. Fast pyrolysis processing has also been undertaken using a laboratory-scale continuously fed bubbling fluidized-bed reactor with a nominal capacity of 1 kg h-1 at the reaction temperature of 525 °C. An increase in the viscosity of the bio-oil during the stability assessment tests was observed with an increasing percentage of impregnation for both additives. This is because bio-oil undergoes polymerization while placed in storage as a result of the inorganic content. The majority of inorganics are concentrated in the char, but small amounts are entrained in the pyrolysis vapors and, therefore, end up in the bio-oil.
An empirical investigation of the impact of global energy transition on Nigerian oil and gas exports
Resumo:
18 months embargo on the thesis and check appendix for copy right materials
Resumo:
Sunflower is one of the most important oilseed crops and produces a high-quality edible oil. Balance of fatty acids in standard sunflower oil shows preponderance of linoleic rather than oleic acid, and conditions during seed development, such as temperature, changes the oleic/linoleic ratio of the oil. This work aimed to evaluate the environmental effect on fatty acid profile in a group of standard and high oleic varieties and hybrids. Seeds were produced during regular season crop and during off-season crop featuring different temperatures from anthesis to maturity. Fatty acid composition was determined by gas chromatography. Levels of oleic acid, in standard oil genotypes, raised as the crop developed in warmer environment while levels of linoleic acid decreased, and the opposite was observed when the crop was grown under lower temperature. High oleic genotypes were less sensitive to environment switching and showed lower variation on fatty acid composition.