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Desenvolvimento de um modelo da cinética enzimática da transesterifica o de óleos vegetais para produ o de biodiesel = Development of the enzymatic kinetics model of vegetable oils transesterification for biodiesel production  [cached]
Alexander Dimitrov Kroumov,Aparecido Nivaldo Módenes,Bruno München Wenzel
Acta Scientiarum : Technology , 2007,
Abstract: Atualmente, a tecnologia de produ o enzimática do biodiesel é mais uma alternativa em rela o aos métodos químicos que utilizam catalisadores ácidos ou básicos. A enzima lipase utilizada como catalisador desse processo pode ser obtida de microrganismoscomo Pseudomonas fluorescens, P. cepacia, Candida antarctica, dentre outros. Neste trabalho, propomos um mecanismo da transesterifica o de triglicerídeos catalisada por enzima lipase. O processo foi formalizado em três rea es consecutivas, nas quais s o formados osdiglicerídeos e monoglicerídeos. Outras três etapas intermediárias das rea es envolvendo a lipase foram consideradas. A identifica o dos parametros do modelo desenvolvido foi feita para condi es reacionais em que a alimenta o é feita na propor o estequiométrica dos reagentes. O modelo desenvolvido foi testado com dados experimentais em diversas condi es operacionais encontradas na literatura. Os resultados das simula es mostram boa flexibilidade do modelo, ajustando os dados em várias condi es de transesterifica oenzimática para produ o de biodiesel. Currently the technology of enzymatic production of biodiesel is more promising than that based on chemical methods, using acidic orbasic catalysts. The enzyme lipase used as catalyst in this process can be isolated from microorganisms such as Pseudomonas fluorescens, P. cepacia, Candida antarctica among others. In this work, a mechanism for the transesterification of triglycerides catalyzed by lipase for production of biodiesel is proposed. The process was modeled in three consecutive reactions where diglycerides and monoglycerides were formed. Other three intermediate stages involving lipase were considered. The identification of parameters with the developed model was performed for reaction conditions where stoichiometric amount of reagents were used. The developed modelwas tested for different operational conditions with experimental data found in the literature. The simulation results showed good model flexibility.
Parametros da rea??o de transesterifica??o etílica com óleo de milho para produ??o de biodiesel
Lima, A. L.;Lima, A. P.;Portela, F. M.;Santos, D. Q.;Neto, W. B.;Hernández-Terrones, M. G.;Fabris, J. D.;
Eclética Química , 2010, DOI: 10.1590/S0100-46702010000400013
Abstract: foram avaliados, a partir de um delineamento estatístico de um conjunto de ensaios experimentais, os efeitos (i) do tempo; (ii) da velocidade de rota??o; (iii) da raz?o etanol:triglicerídeos; (iv) do tipo e (v) da quantidade do catalisador e (vi) da temperatura da rea??o de transesterifica??o de triglicerídeos do óleo de milho com etanol. a magnitude do efeito devido a cada fator, individualmente, afetou o rendimento, em biodiesel, da rea??o, na seguinte ordem decrescente de efeito (desconsiderando-se o sinal algébrico): quantidade de catalisador > raz?o molar > tipo de catalisador > velocidade de rota??o > tempo > temperatura. avaliaram-se, também, as intera??es estatísticas entre as variáveis e suas correla??es com os fatores principais da rea??o.
Produ??o de biodiesel via transesterifica??o etílica com zeólitas básicas
Ghesti, Grace F.;Macedo, Julio L. de;Dias, José A.;Dias, Sílvia C. L.;
Química Nova , 2012, DOI: 10.1590/S0100-40422012000100022
Abstract: soybean oil transesterification with ethanol was carried out in a batch reactor using usy zeolites modified with barium and strontium (15 wt.%) as catalysts. a series of three catalytic cycles were performed for each zeolite without any loss of activity. the biodiesel product was analyzed by hplc and ft-raman, and the catalysts by pyridine and co2 adsorption. ba/usy provided higher conversions (> 97%) than sr/usy (< 75%). the increased catalytic activity of ba/usy was attributed to two different effects: a larger number of basic sites; and a lower interaction between barium species and husy br?nsted sites.
Potential of LiNO3/Al2O3 Catalyst for Heterogeneous Transesterification of Palm Oil to Biodiesel  [cached]
Istadi Istadi,Bambang Pramudono,S. Suherman,S. Priyanto
Bulletin of Chemical Reaction Engineering & Catalysis , 2010, DOI: 10.9767/bcrec.5.1.777.51-56
Abstract: Production of biodiesel through transesterification process using heterogenous catalysts in order to avoid the saponification problem was studied. In this process, palm oil reacted with methanol to form a mixture of glycerol and biodiese over a solid basic catalyst. One type of the catalysts used in this research is basic catalyst of LiNO3/Al2O3. The parameters studied in this research are concentration of LiNO3 loading on Al2O3 and effect of different reaction time. The products was analyzed using Gas Chromatography to determine composition and yield of resulted methyl esters as well as conversion of palm oil to biodiesel. The major products in this transesterification reaction were biodiesel and glycerol. It can be concluded that the 20 wt% LiNO3/Al2O3 catalyst is potential for producing biodiesel from palm oil over transesterification reaction. Advantages of the usage of this catalyst is that the soap formation was not observed in this research. 2010 BCREC UNDIP. All rights reserved (Received: 24th April 2010, Revised: 20th May 2010; Accepted: 21st May 2010) [How to Cite: I. Istadi, B. Pramudono, S. Suherman, and S. Priyanto. (2010). Potential of LiNO3/Al2O3 Catalyst for Heterogeneous Transesterification of Palm Oil to Biodiesel. Bulletin of Chemical Reaction Engineering and Catalysis, 5(1): 51-56. doi:10.9767/bcrec.5.1.777.51-56] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.777.51-56 ]
PRODU O DE BIODIESEL POR BIOCATáLISE UTILIZANDO MéTODO ALTERNATIVO DE IMOBILIZA O DA LIPASE EM HIDROGEL
Fernanda Marder,Mariéli Milanesi Celin,Mariele da Silva Mazuim,Rosana de Cassia de Souza Schneider
Tecno-Lógica , 2008,
Abstract: A sociedade vem buscando alternativas para reduzir o processo de destrui o ambiental instalada no planeta, porém, a partirdo século passado, uma nova vis o sobre o uso indiscriminado dos recursos ambientais passou a ser discutido levando a utiliza ode tecnologias alternativas de produ o de combustíveis mais limpos, como o biodiesel, produzido a partir de óleos vegetais. Osprocessos enzimáticos constituem-se numa alternativa de produ o, por serem métodos biotecnológicos e menos impactantes aomeio ambiente, apresentando até ent o, elevado custo de produ o. Com o objetivo de diminuir custos e aumentar a eficiênciainvestigou-se a imobiliza o das enzimas por método alternativo e o emprego destes biocatalisadores na produ o de biodiesel. Aimobiliza o da lipase PS Amano foi realizada utilizando esferas formadas pela hidrata o de hidrogéis comerciais em solu oaquosa contendo a enzima. Com a enzima imobilizada realizou-se a transesterifica o, na qual obteve-se convers es em ésteresmetílicos com rendimento de até 70%, em solvente organico, no tempo de 24h, temperatura de 55°C, 100 rpm e 40 esferas dehidrogel com enzima imobilizada. O método de transesterifica o enzimática com as enzimas imobilizadas em hidrogéisapresentou-se como uma tecnologia alternativa e promissora para a obten o de biodiesel.
Produ??o de biodiesel através de transesterifica??o in situ de sementes de girassol via catálise homogênea e heterogênea
Gama, Paola Ervatti;Gil, Rosane Aguiar da Silva San;Lachter, Elizabeth Roditi;
Química Nova , 2010, DOI: 10.1590/S0100-40422010000900007
Abstract: the objective of this work is to show the results of the in situ transesterification of sunflower seed oil with methanol on basic homogeneous and heterogeneous catalysis for the production of biodiesel. in homogeneous catalysis, the activity of koh and k2co3 were evaluated using the same oil:methanol ratio of 1:90. koh showed to be more active than k2co3, leading to total conversion in biodiesel after 1h reaction time. in the heterogeneous catalysis the activity of k2co3/al2o3 was comparable to the activity of k2co3 bulk: 53.0 and 66.6% resp. the properties of samples of biodiesel produced by homogeneous and heterogeneous catalysis were evaluated and are in accordance with the recommended fuel properties.
Biodiesel produzido iodiesel com óleo de frango = Biodiesel manufactured with chicken oil  [cached]
Luis Fernando Souza Gomes,Samuel Nelson Melegari de Souza,Reinaldo Aparecido Bariccatti
Acta Scientiarum : Technology , 2008,
Abstract: O Brasil ocupa local de destaque no desenvolvimento e uso de fontesrenováveis de energia, por causa da sua grande extens o territorial, clima e várias alternativas. Uma destas é a produ o de biodiesel, o qual pode substituir o óleo diesel, diminuindo os impactos ao meio ambiente. Na cadeia produtiva de carne de frango, é gerado um resíduo, óleo de frango, com potencial para produ o de biodiesel. Neste trabalho, foram determinadas características físico-químicas que podem influenciar nas rea es de transesterifica o do óleo de frango. Foi levantado o potencial de produ o de óleo de frango nas cooperativas da regi o oeste do Estado do Paraná e rendimento embiodiesel. Brazil occupies a prominent place in the development and use of renewable energy sources, due to its great territorial extension, climate and myriad available alternatives. One of these it is biodiesel, which can substitute petroleum diesel, thus decreasing environmental impacts. In the productive chain of chicken meat, a residue – chicken oil – is generated, with potential for biodieselproduction. In this work, certain physical-chemical characteristics were determined that can influence in the transesterification reactions of chicken oil. The potential for production of chicken oil in the cooperatives of the western Paraná State and the yield of biodiesel were also determined.
Soybean oil transesterification: Study of using Nb2O5.xH2O as catalyst in biodiesel production  [cached]
Deborah A. dos Santos,Valdemar Lacerda Júnior,Sandro José Greco,Reginaldo B. Santos
Orbital : the Electronic Journal of Chemistry , 2012,
Abstract: Economic and environmental reasons show a trend towards replacing fossil fuels with biofuels such as those from triglycerides. Biodiesel can be obtained from vegetable oils and animal fat through several processes such as transesterification, esterification, usually with methanol, ethanol or through pyrolysis, all of them in the presence of an acid or basis catalyst. The use of solid catalysts in biodiesel production has the following advantages: easy recovery and reuse, thus decreasing process costs and amount of waste generated.1 Some of the problems in the use of solid catalysts are: low concentration of active sites, microporosity, and leaching of active sites.2 Studies aiming at developing methodologies involving hydrated niobium oxide as catalyst in biodiesel production have been carried out by our research group.3,4 Parameters such as the use of assistant solvent to increase the boiling point of the mixture (toluene, ethylene glycol, and DMSO), pre-thermal treatment (calcinations) and catalyst molar concentration were initially assessed in esterification, oleic acid, and methanol reactions. From these studies we could observe that high temperatures and excessive alcohol favor esterification reactions. The best reaction conditions were then used as models and employed in transesterification reactions of soybean oil. DMSO (Dimethyl sulfoxide) was the solvent used to increase the reaction medium temperature without evaporating all the methanol. Transesterification reactions were carried out with soybean oil (0.5 g), methanol (0.85 g), DMSO (2.50 ml), and hydrated niobium oxide as catalyst in ratios of 20% and 100% (in relation to oil mass). Catalyst was employed without pretreatment and after pretreatment at 115 °C, 300 °C, and 500 °C. The reactions occurred at 170 °C, under reflux for 48 hours. A reaction without a catalyst was also carried out. All the reactions have shown conversion using CCD and they have been determined by 1H NMR spectroscopy.
Optimization of Biodiesel Production from Jatropha Oil By Heterogeneous Base Catalysed Transesterification  [PDF]
S.Hawash,,G.El Diwani,,E.Abdel Kader
International Journal of Engineering Science and Technology , 2011,
Abstract: Transesterification of Jatropha curcas oil (JCO) to biodiesel using Ca O as a solid base catalyst is studied. Effect of molar ratio of methanol to oil, water content, reaction time and mass ratio of catalyst to oil are investigated on bench scale. Experimental results revealed that a 12:1 molar ratio of methanol to oil, addition of 1.5% (w/v) Ca O catalyst , 70oC reaction temperature, 2% water content in the oil produced more than 95% biodiesel yield after 3 hours reaction time. Calcium oxide activated with ammonium carbonate was an efficient super base catalyst for a high yield transesterification reaction and the base strength of Ca O was more than 26.5 after dipping in ammonium carbonate solution followed by calcinations.Transesterification of Jatropha oil using supercritical methanol has been studied under different conditions of temperature (from 120oC to 250oC), pressures (from 5- 37 bars) using superbase catalyst Ca O and acid catalyst. The reaction products were analyzed for their content of glycerol by high performance liquid chromatography (HPLC)which indicated that the process of supercritical transesterification achieved a yield of more than 95% after 1 hour.
Preparation of Biodiesel of Undi seed with In-situ Transesterification  [PDF]
Sanjaykumar DALVI,Swati SONAWANE,Raghunath POKHARKAR
Leonardo Electronic Journal of Practices and Technologies , 2012,
Abstract: The biodiesel fraction from oil content of Undi (Calophyllum innophyllum L.) is found 60-70%. The extraction of oil is a primary step in any biodiesel production system. To escape this step in-situ transesterification method is used in which the Undi seed crush is directly converted into biodiesel with in-situ transesterification which is fatty acid methyl and ethyl ester composition. The single step reaction is eco-friendly as hexane like solvents not have been used for oil extraction. These components of biodiesel were analysed by GC-MS technique.
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