Submitted by LETICIA KAREN DOS SANTOS null (leticiaksantos@yahoo.com) on 2016-06-28T18:11:51Z No. of bitstreams: 1 Letícia_Dissertação.pdf: 3396409 bytes, checksum: 6fcb8261f964fb6c84ed2b04f91ef330 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-29T14:56:59Z (GMT) No. of bitstreams: 1 santos_lk_me_araiq.pdf: 3396409 bytes, checksum: 6fcb8261f964fb6c84ed2b04f91ef330 (MD5) / Made available in DSpace on 2016-06-29T14:56:59Z (GMT). No. of bitstreams: 1 santos_lk_me_araiq.pdf: 3396409 bytes, checksum: 6fcb8261f964fb6c84ed2b04f91ef330 (MD5) Previous issue date: 2016-06-10 / Fundação para o Desenvolvimento da UNESP (FUNDUNESP) / A produção de biodiesel a partir de Óleos e Gorduras Residuais (OGR), óleos brutos e outras matérias-primas com acidez elevada e alto teor de umidade, tem se tornado um desafio para a cadeia produtiva de biodiesel. Neste cenário surge como alternativa a hidroesterificação, processo que envolve duas etapas consecutivas: a hidrólise térmica seguida de esterificação o que permite o uso de qualquer matéria-prima graxa. Neste estudo foi avaliada a produção de biodiesel por hidroesterificação de óleo de palma bruto e de OGR. As reações de hidrólise foram conduzidas em reator de bancada de alta pressão e alta temperatura, utilizando-se planejamento fatorial 24 com ponto central. Para estimar os efeitos mais significativos na conversão percentual dos triacilgliceróis em ácidos graxos na reação de hidrólise, as variáveis avaliadas foram: razão molar água/óleo; temperatura; tempo; e velocidade de agitação. Tanto para óleo de palma como para o OGR, os efeitos mais significativos foram a temperatura e o tempo de reação. As condições ótimas obtidas na reação de hidrólise foram: razão molar água/óleo 100:1; temperatura de 250 °C; tempo de reação de 120 min; e agitação de 700 rpm. Os maiores rendimentos obtidos foram para o óleo de palma bruto 86,4% de ácidos graxos, enquanto para o OGR 95,7%. A conversão de ácidos graxos em ésteres metílicos para o óleo de palma bruto foi de 99,1% e para o OGR 98,0%. O processo de hidroesterificação é uma alternativa viável e sustentável na produção de biodiesel, pois favorece o uso de matérias-primas com baixo valor agregado e o reaproveitamento de óleos e gorduras residuais. Desta forma, o processo contribui não apenas na diminuição do efeito estufa e na redução de gases tóxicos na atmosfera, mas gera impactos positivos na matriz energética brasileira, menor impacto ambiental e atinge a dimensão social. / The biodiesel production from waste cooking oil (WCO), crude oils and other raw materials with high acidity and low content of moisture has become a challenge for the supply chain of biodiesel. Therefore, an alternative to this scenario is the hydroesterification, process that involves two consecutive steps, hydrolyze followed by esterification, that allows the use of any raw fat material. In this study, was investigate the biodiesel production by hydroesterification of the crude palm oil and WCO. The reactions were conducted in a reactor of high pressure and temperature, using a 24 with central point design of experiment. To estimate the most significant effects on the conversion of triacylglycerides of free fatty acids in hydrolyze reaction, the variable water/oil molar ratio; temperature; time and; agitation were analyzed. The most significant effects for hydrolysis where temperature and time. The conditions of the process evaluated as excellent were, 100:1 water/oil molar ratio, 250 °C, 120 min and 700 RPM. In terms of conversion, the best result for palm oil was 86,4% of free fatty acids and for WCO 95,7%. The conversion of fatty acids to methyl ester was 99,1% of the crude palm oil and 98,0% for the WCO. The results of this study showed the hydroesterification process as a viable and sustainable alternative to production of biodiesel, since it facilitates the use of low added value raw materials and recycling of waste oils and fats. Likewise, the process contributes not only to the reduction of the greenhouse effect and toxic gases in the atmosphere, but also generates positive impacts in the Brazilian energy matrix, lower environmental impact and affects the social dimension.

CAPES / As modificações químicas do amido nativo causam alterações estruturais na molécula do polímero afetando suas propriedades físico-químicas o que os torna aptos para vários usos industriais. O ácido tartárico é um ácido orgânico dicarboxílico que pode modificar quimicamente a estrutura do amido e tem uso permitido em alimentos. Neste estudo, o amido de mandioca foi modificado com ácido tartárico e o efeito da concentração do ácido (4,5 - 8,0 g.100g-1) e do pH da reação (5,0 - 8,0) sobre as propriedades do amido foram avaliados utilizando um planejamento experimental 22 centrado na face. As propriedades físicoquímicas, funcionais e propriedades da pasta foram determinadas. Também foram avaliados os espectros no infravermelho com transformada de Fourier (FT-IR) e a morfologia dos grânulos por microscopia eletrônica de varredura (MEV). A modificação reduziu a viscosidade intrínseca e o teor de amilose à medida que se aumentou a concentração do ácido e diminuiu o pH. Em pH 5,0, observou-se maior percentual de tartarato mono éster e maior inchamento e solubilidade dos amidos. Em pH 6,5 e 8,0 a modificação causou a redução do inchamento e solubilidade, o aumento da resistência ao congelamento-escongelamento e houve melhoria nas propriedades de pasta (maior resistência térmica e mecânica). O FTIR confirmou qualitativamente a esterificação do amido pelo aparecimento de bandas associadas a grupos ésteres nos ensaios realizados em pH 5,0. A modificação não causou alterações evidentes na morfologia externa dos grânulos de amido como observado por MEV. Conclui-se que o efeito da concentração do ácido sobre as propriedades do amido foi menor que o efeito do pH onde menores alores de pH favorecem a reação de esterificação do amido e valores de pH mais elevados favoreceram o intercruzamento. / The chemical modification of native starch cause structural changes in the polymer molecule affecting their physic-chemical properties which make them suitable for various industrial uses. Tartaric acid is an organic dicarboxylic acid which can chemically modify the starch structure and its use is allowed in foods. In this study, the tapioca starch was modified with tartaric acid and the effect of acid concentration (4.5 to 8.0 g.100g-1) and the reaction pH (5.0 to 8.0) on the properties starch were evaluated using a 22 face-centered central composite design. The physico-chemical properties, functional, and pasting properties were determined. The infrared spectra Fourier transform (FT-IR) and the morphology of granules by scanning electron microscopy (SEM) was also evaluated. The modification reduced the intrinsic viscosity and the amylose contents with the increase of the acid concentration and decrease of pH. At pH 5.0, there was a higher percentage of mono tartarate ester and higher swelling and solubility of starches were observed. At pH 6.5 and 8.0, the modification caused a reduction in the swelling and solubility, increased resistance to freeze-thaw and improvement in the pasting properties (increased thermal and mechanical resistance). FT-IR confirmed qualitatively the esterification of starch by the appearance of bands attached to ester groups in the tests performed at pH 5.0. The modification did not cause obvious changes in the external morphology of the starch granules as observed by MEV. It was possible to conclude that the effect of acid concentration on the properties of the starch was less than the effect of pH where lower pH values favor the esterification of starch and higher pH values favor the crosslinked.

A crescente demanda por lubrificantes obtidos a partir de fontes renováveis vem incentivando a pesquisa por alternativas sustentáveis. O objetivo principal deste trabalho foi investigar a síntese de sebacato de dioctila a partir da reação de esterificação entre o ácido sebácico e o 1-octanol empregando biocatalisadores e catalisador químico convencional (ácido sulfúrico). Alguns parâmetros reacionais foram estudados: tipo de lipase comercial imobilizada (Novozym 435, Lipozyme RM IM e Lipozyme TL IM), temperatura, razão molar ácido/álcool, concentração de lipase, métodos de remoção da água do meio reacional. A reutilização da lipase Novozym 435 também foi avaliada. A conversão da reação foi determinada por cromatografia em fase gasosa. A lipase Novozym 435 apresentou os melhores resultados: 100% de conversão de ácido sebácico quando foi empregada razão molar ácido:álcool de 1:5 e 5% m/m de lipase, após 150 minutos de reação a 100C. O emprego de peneira molecular e vácuo não aumentou a conversão do ácido sebácico. O produto final foi caracterizado com relação à viscosidade, ao índice de viscosidade, ao ponto de fulgor, ao ponto de fluidez e ao índice de neutralização, e apresentou comportamento semelhante a um óleo naftênico / The growing demand for lubricants derived from renewable sources has been encouraging the search for sustainable alternatives. The main objective of this study was to investigate the synthesis of dioctyl sebacate from esterification reaction between sebacic acid and 1-octanol, using biocatalysts and conventional chemical catalyst (sulfuric acid). Some reactions parameters were studied: type of commercial immobilized lipase (Novozym 435, Lipozyme RM IM and Lipozyme TL IM), temperature, molar ratio, lipase concentration, and methods of water removal from the reaction medium. The reuse of lipase Novozym 435 was also evaluated. The conversion of the reaction was determined by gas chromatography. Lipase Novozym 435 showed the best results, achieving 100% conversion of sebacic acid when employing a sebacic acid: 1-octanol molar ratio of 1:5 and 5 wt.% lipase after 150 minutes at 100C. The use of molecular sieve and vacuum did not enhance the acid sebacic conversion. The final product was characterized by viscosity, viscosity index, flash point, pour point and neutralization index; and it showed a pattern similar to a naphthenic oil

Orientadores: Telma Teixeira Franco, Gustavo Paim Valença / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-26T21:59:10Z (GMT). No. of bitstreams: 1 Ayres_BiancaMairaTeixeira_D.pdf: 23160216 bytes, checksum: 967289613483c430d41cd88562085d44 (MD5) Previous issue date: 2014 / Resumo: O objetivo deste trabalho foi a biocatálise de acrilatos de carboidratos, desde glicose até maltodextrina. Maltodextrinas (MD) são produtos da hidrólise do amido, caracterizadas por cadeias de 5 a 20 unidades de ?-D-glicose unidas por ligações ?-1,4 (principalmente). Análises por cromatografia de permeação em gel (HPSEC) caracterizou ampla distribuição de massa molar de amostras padrão ou industriais de MD, apresentando de 1 a 100 unidades de glicose (G1). O fracionamento por etanol para seleção de menores cadeias de glicose não foi efetivo pois variadas frações volumétricas de etanol forneceu contaminação de cadeias curtas no precipitado. Os principais fatores limitantes para a esterificação enzimática da MD com ácido acrílico são baixa solubilidade do substrato sacarídico, inibição por ácido acrílico, polaridade do solvente orgânico que permita atividade enzimática, a qual depende das características da lipase imobilizada como tipo de suporte e origem da lipase. Lipases disponíveis comercialmente na forma imobilizada de Thermomyces lanuginosa (TL IM) ou Candida antarctica (Novozyme 435) e, imobilização por adsorção das lipases de T.lanuginosa, C.antarctica, Candida rugosa e Rizomucor miehei em Accurel EP-100 foram investigadas em triagem associada de solventes orgânicos. Dioxano e Novozyme 435 foram a melhor associação que alcançou maior conversão de G1 e G2. Acrilatos de maltodextrina foram também observados sob incubação com TL IM em TBA. A solubilidade da MD é completa em água, piridina e DMSO, cerca de 1 kg L-1, mas as lipases não são ativas para esterificação nestes solventes. A água é um subproduto da esterificação e sua presença pode deslocar a reação em favor da hidrólise. A adição de DMSO como co-solvente para o sistema reacional contendo 2M2B ou TBA foi comprovado ser menos eficiente que sistemas com 100% dos solventes apolares. A maior área de taxa de aumento da produção direta de acrilatos de maltodextrina foi alcançada com 2-metil-2- butanol como meio reacional. Analogicamente, a acrilação enzimática de n-butanol foi catalisada pela Novozyme 435. Diferentemente dos acrilatos de carboidratos, o produto acrilato de butila pôde ser quantificado por cromatografia em fase gasosa (CG). Sistemas de solventes e co-solventes (tolueno, ciclohexano, 2-metil-2-butanol (2M2B), álcool terc-butílico (TBA) e associações com parcial volume de dimetilsulfoxido (DMSO)) foram estudados para determinar o efeito destes na atividade enzimática específica. O uso de ciclohexano e tolueno resultaram em atividade da enzima três vezes maior que em TBA e 2M2B. n-Butanol e MD são substratos diferenciados pela solubilidade nos solventes orgânicos, os quais devem ser apolares ou pouco polares para permitir atividade catalítica. Uma reação secundária de acrilação com o solvente orgânico, TBA ou 2M2B, foi verificada por cromatografia gasosa acoplada à espectrometria de massas. A esterificação enzimática de maltose, de maltotriose e maltodextrina com ácido acrílico catalisada pela lipase Novozyme 435 em 2M2B foram analisadas por espectrometria de massas com ionização por eletrospray, ou acoplada à cromatografia líquida de alta eficiência. Essas análises confirmaram a presença de uma até quatro hidroxilas acriladas da maltose (G2) ou da maltotriose (G3). Um processo em duas etapas de biocatálise para produção de acrilatos de carboidratos foi investigado. Inicialmente, G1 ou G2 foram esterificadas enzimaticamente com propionato de vinila ou acrilato de etila por incubação com Novozyme 435 em dioxano. Em subsequente etapa, a cadeia glicosídica destes ésteres foram alongadas a partir da atividade da cicloglicosil transferase de Bacillus macerans com ?-ciclodextrina como doador de grupo glicosil. Cromatografia líquida de alta eficiência com detecção amperométrica e aerossol carregado e cromatografia em camada delgada foram utilizados para identificar os ésteres de oligossacarídeos. Cerca de 75% ou 55% de ?-ciclodextrina foi convertida com consumo de 40.5% de propionato de glicose (G1P) ou 86.3% de propionato de maltose (G2P) pela atividade da CGTase. A composição da solução final foi, desde 2 a 14 unidades de glicose com uma unidade acrilada ou propilada / Abstract: The aim of this work was the biocatalysis of the acrylates of carbohydrates, from glucose up to maltodextrins. Maltodetrins (MD) are starch hydrolysates consisting of ?-D-glucose units bounded by ?-1,4 glycosidic linkages (primarily). Analysis of standard or industrial samples of MD in gel permeation chromatography presented a huge molecular mass distribution, from 1 to 100 units of glucose (G1). An ethanol fractionation step for selection of narrow range of the chains of glucose was unsuccesfull because the precipitate and supernatant were contamined with small molecules. The main limitant factors for enzymatic esterification of MD with acrylic acid are the catering saccharidic substrate (increase its solubility) to the lipase, to avoid (or overcome) inhibition from acrylic acid, and to allow enzymatic activity, which depends on the characteristics of the immobilized lipases (type of support, source of the lipase) and solvent of the system. Commercial immobilized lipases from Thermomyces lanuginosa (TL IM) or Candida antarctica (Novozyme 435) and, lipases from T.lanuginosa, C.antarctica, Candida rugosa and Rizomucor miehei immobilized by absorption in Accurel EP-100 were investigated in a screening of organic solvents. Dioxane and Novozyme 435 were the best association for higher conversion of G1 and G2. TL IM in tert-butanol (TBA) was the only system, which produced acrylates of maltodextrina on TLC plates. The solubility of the MD is complete in water, pyridine and dimethylsulfoxide (DMSO), about 1 kg L-1, but lipases are not active for esterification in these solvents. The water is a byproduct of the esterification and shifts the reversible reaction toward the hydrolysis. The partial addition of the co- solvent DMSO to the reactional system containing 2-methyl-2-butanol (2M2B) or TBA was tested for partial solubilization of the maltodextrin. The systems with only one organic solvent were more efficient than the presence of DMSO. The highest area in high performance liquid chromatography (HPLC) for production of the MD acrylates was achieved with 2M2B as adjuvant. Analogically, the acrylation of n-butanol by Novozyme 435 was studied to better understand the enzymatic acrylation, since the quantification of the product butyl acrylate is possible by gas chromatography (GC). Solvent systems (toluene, cyclohexane, 2M2B, TBA and partial volume of DMSO) were studied to determine the effect of the solvents on the specific enzymatic activity. It was found that cyclohexane and toluene achieved 3-fold the enzyme activity that in TBA and 2M2B. However, n-butanol and MD as substrate are mainly differentiated regards to the solubility in non polar organic solvents which are more suitable for lipase activity. A side reaction of acrylation of the organic solvent, TBA or 2M2B, was verified by GC-Mass Spectrometry. Meanwhile, the enzymatic esterification of maltose, maltotriose and maltodextrin with acrylic acid by Novozyme 435 in 2M2B were analyzed in electrospray ionization (ESI) mass spectrometry (MS) associated to HPLC, which confirmed the presence of mono- until tetra- acrylated hydroxyls for maltose (G2) and maltotriose (G3). A two-step process of biocatalysis for producton of sugar acrylates was investigated. G1 or G2 was acylated with either vinyl propionate or ethyl acrylate by Novozyme 435 in dioxane. Then, the elongation of the chain by cyclodextrin glucanotransferase (CGTase) from Bacillus macerans with ?-cyclodextrin as acyl donor provided maltoligosaccharides esters. CGTase from Bacillus macerans converted these products from the first step and ?-cyclodextrin into oligosaccharide esters. HPLC coupled to charged aerosol detector and amperometric exchange and thin layer chromatography were used to identify the oligosaccharide esters. About 75% or 55% of ?-cyclodextrin was converted under consumption of 40.5% of glucose propionate (G1P) or 86.3% of maltose propionate (G2P) by CGTase activity. The composition of the final solution was since 2 to 14 glucose units with one acrylate or propionate moiety / Doutorado / Engenharia Química / Doutora em Engenharia Quimica

Gas chromatographic acquisition of representative 'Total' cellular fatty acid profiles from bacteria or bacteria-containing samples (e.g., environmental or clinical materials) tends to be dependent on the method used to released the fatty acids and convert them to derivatives suitable for analysis. Alkaline saponification or interesterification methods, while preserving acid-sensitive components such as cyclopropane fatty acids, are often insufficient to release amide-linked components, such as hydroxylated fatty acids. Acid-catalyzed hydrolyses or interesterifications, on the other hand, while more efficiently releasing the predominantly amide-linked hydroxylated components, have been shown to cause severe and unpredictable degradation of cyclopropane fatty acids. We report studies of a single-tube method involving sequential alkaline/acid release of fatty acids in which fatty acids released by the alkaline step are partitioned into an organic epiphase during the aqueous acid hydrolysis step. After hydrolysis, the epiphase and the released fatty acids are extracted into an hypophasic solvend and esterified at moderate temperature under relatively low acid concentrations. Under these conditions, cyclopropane as well as hydroxylated fatty acids are recovered in high yield.

7-Ketocholesterol (7KC) is a cytotoxic component of oxidized low density lipoproteins (OxLDLs) and induces apoptosis in macrophages by a mechanism involving the activation of cytosolic phospholipase A2 (cPLA 2). In the current study, we examined the role of ACAT in 7KC-induced and OxLDL-induced apoptosis in murine macrophages. An ACAT inhibitor, Sandoz 58-035, suppressed 7KC-induced apoptosis in P388D1 cells and both 7KC-induced and OxLDL-induced apoptosis in mouse peritoneal macrophages (MPMs). Furthermore, compared with wild-type MPMs, ACAT-1-deficient MPMs demonstrated significant resistance to both 7KC-induced and OxLDL-induced apoptosis. Macrophages treated with 7KC accumulated ACAT-derived [14C]cholesteryl and [ 3H]7-ketocholesteryl esters. Tandem LC-MS revealed that the 7KC esters contained primarily saturated and monounsaturated fatty acids. An inhibitor of CPLA2, arachidonyl trifluoromethyl ketone, prevented the accumulation of 7KC esters and inhibited 7KC-induced apoptosis in P388B1 cells. The decrease in 7KC ester accumulation produced by the inhibition of cPLA 2 was reversed by supplementing with either oleic or arachidonic acid (AA); however, only AA supplementation restored the induction of apoptosis by 7KC. These results suggest that 7KC not only initiates the apoptosis pathway by activating cPLA2, as we have reported previously, but also participates in the downstream signaling pathway when esterified by ACAT to form 7KC-arachidonate.

No description available.

Yes / Methyl Decanoate (MeDC) is a Fatty Acid Methyl Ester (FAME) and is an important chemical compound with global production of 31 million tons per year. However, synthesis of methyl decanoate (MeDC) via esterification of Decanoic Acid (DeC) with methanol by reactive distillation is operationally challenging due to difficulty of keeping the reactants together in the reaction zone as methanol being the lightest component in the mixture can separate itself easily form the other reactant deteriorating significantly the conversion of DeC using either conventional batch or continuous distillation column. This is probably the main reason for not applying the conventional route for MeDC synthesis. Whether Semi-batch Distillation column (SBD) and the recently developed Integrated Conventional Batch Distillation column (i-CBD) offer the possibility of revisiting such chemical reactions for the synthesis of MeDC is the focus of this paper. The minimum energy consumption (Qtot) as the performance measure is used to evaluate the performances of each of these reactive column configurations for different range of methyl decanoate purity and the amount of product. It is observed that the use of i-CBD column provides much better performance than SBD column in terms of the production time and the maximum energy savings when excess methanol is used in the feed. However, the SBD column is found to perform better than the i-CBD column when both reactants in the feed are in equal amount. Also, the optimization results for a given separation task show that the performance of two-reflux intervals strategy is superior to the single-reflux interval in terms of operating batch time, and energy usage rate in the SBD process at equimolar ratio.

Yes / Although batch reactive distillation process outperforms traditional reactor-distillation processes due to simultaneous reaction and separation of products for many reaction systems, synthesis of Methyl lactate (ML) through esterification of lactic acid (LA) with methanol in such process is very challenging due to difficulty of keeping the reactants together when one of the reactants (in this case methanol) has the lowest boiling point than the reaction products. To overcome this challenge, two novel reactive distillation column configurations are proposed in this work and are investigated in detail. These are: (1) integrated conventional batch distillation column (i-CBD) with recycled methanol and (2) integrated semi-batch and conventional batch distillation columns (i-SBD) with methanol recovery and recycle. Performances of each of these configurations are evaluated in terms of profitability for a defined separation task. In i-SBD column, an additional constraint is included to avoid overflow of the reboiler due to continuous feeding of methanol into the reboiler as the reboiler is initially charged to its maximum capacity. This study clearly indicates that both integrated column configurations outperform the traditional column configurations (batch or semi-batch) in terms of batch time, energy consumption, conversion of LA to ML, and the achievable profit.

Yes / The production of methyl decanoate (MeDC) through esterification of decanoic acid (DeC) with methanol by reactive distillation is operationally challenging and energy-intensive due to the complicated behaviour of the reaction system and the difficulty of retaining the reactants together in the reaction region. Methanol being the lightest component in the mixture can separate itself from the reactant DeC as the distillation proceeds which will cause a massive reduction in the conversion of DeC utilizing either a batch or continuous distillation process. Aiming to overcome this type of the potential problem, novel integrated divided-wall batch reactive distillation configuration (i-DWBD) with recycling from the distillate tank is established in this study and is examined in detail. This study has clearly demonstrated that the integrated divided-wall batch reactive distillation column (i-DWBD) is superior to the traditional conventional batch distillation (CBD) and both the divided-wall (DWBD), and split reflux divided-wall (sr-DWBD) batch reactive distillation configurations in terms of maximum achievable purity of MeDC and higher conversion of DeC into MeDC. In addition, significant batch time and energy savings are possible when the i-DWBD is operated in multi-reflux mode.