• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avalia??o da torta de maca?ba como insumo para produ??o de bioetanol / Evaluation of the macauba?s (macaw palm) coconut cake as an input for production of bioethanol

Santos, Hilton T?lio Lima dos 04 July 2011 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-19T13:34:45Z No. of bitstreams: 5 hil.pdf: 1837336 bytes, checksum: 915b40a5d9c4387507e76471c6ae2ca7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-20T11:01:25Z (GMT) No. of bitstreams: 5 hil.pdf: 1837336 bytes, checksum: 915b40a5d9c4387507e76471c6ae2ca7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) / Made available in DSpace on 2015-02-20T11:01:25Z (GMT). No. of bitstreams: 5 hil.pdf: 1837336 bytes, checksum: 915b40a5d9c4387507e76471c6ae2ca7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2110 bytes, checksum: b4c884761e4c6c296ab2179d378436d4 (MD5) Previous issue date: 2013-02-20 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Para a manuten??o das pr?ticas econ?micas e s?cio-culturais constru?das sobre a explora??o e transforma??o do petr?leo, faz-se necess?rio criar alternativas que n?o rompam de forma estanque com as pr?ticas industriais hoje vigentes. Nesse contexto, o uso de biomassas para a produ??o de combust?veis l?quidos que alimentem motores ? combust?o permite sustentar pr?ticas antigas com novos benef?cios. Dessa forma, a presente disserta??o teve por objetivo avaliar o potencial da torta de maca?ba, um coproduto da ind?stria de ?leos vegetais, como insumo para produ??o de bioetanol. Tal objetivo foi trabalhado atrav?s de estudos de sacarifica??o da torta de maca?ba com posterior processo fermentativo. A biomassa em quest?o foi caracterizada quimicamente, o que indicou a presen?a de aproximadamente 50% de carboidratos, distribu?dos em, 23,16 ? 0,95 % de amido, 11,49 ? 1,08% de celulose, 9,6 ? 0,79% de hemicelulose e 11,48 ? 0,62 % de a??cares sol?veis. Para a primeira interven??o da despolimeriza??o dos polissacar?deos presentes na torta de maca?ba foi realizado um planejamento experimental fatorial 25-1 com 5 fatores e 4 pontos centrais com as seguintes vari?veis: concentra??o de ?cido sulf?rico, tempo de pr?-tratamento ?cido, raz?o s?lido/l?quido, concentra??o de amiloglicosidase e concentra??o de celulase. Na sequ?ncia, o processo de sacarifica??o foi otimizado com o uso de delineamento composto central rotacional 23, com 3 fatores, 4 pontos centrais e 6 pontos axiais, onde foram avaliadas as concentra??es de ?cido sulf?rico, amiloglicosidase e celulase. Um hidrolisado obtido em condi??o otimizada com 92% de efici?ncia foi submetido ? destoxifica??o com carv?o ativado e, em seguida, foram realizados ensaios de fermentabilidade conduzidos como as leveduras Saccharomyces cerevisiae e Pichia stipitis. A levedura S. cerevisiae se mostrou resistente ao hidrolisado n?o destoxificado, apresentando YP/S de 0,49. P. stipitis mostrou-se suscept?vel ao meio n?o destoxificado, mas foi capaz de converter 99% dos a??cares redutores presentes no meio destoxificado. A torta de maca?ba apresentou potencial consider?vel para produ??o de bioetanol. A partir dos dados de bancada ? poss?vel estimar uma produ??o de 104l de etanol por tonelada de torta de maca?ba. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011. / ABSTRACT For the maintenance of economic and socio-cultural practices built on the exploitation and processing of oil it is necessary to create alternatives that do not break so tight with current industrial practices. In this context, the use of biomass to produce liquid fuels that are fed into to combustion engines allows to sustain old practices with new benefits. Thus, this dissertation aimed to evaluate the potential of macaw palm coconut cake, a co-product of vegetable oil industry, as an input for bioethanol production. This goal was worked out through studies of the process of saccharification of macaw palm coconut cake with subsequent fermentation. The biomass in question was characterized chemically, what indicated the presence of approximately 50% of carbohydrates, among which, 23,16 ? 0,95% of starch, 11,49 ? 1,08% of cellulose, 9,6 ? 0,79% of hemicellulose and 11,48 ? 0,62% of soluble sugars. For the first intervention of deconstruction of the polysaccharides present in the macauba cake it was held a 25-1 factorial experimental design with five factors and four central points with the following variables: concentration of sulfuric acid, time of acid pretreatment, solid / liquid ratio, amyloglucosidase and cellulose concentrations. Following, the saccharification process was optimized using central composite rotational design 23, with three factors, four central points and six axial points, whereas the concentrations of sulfuric acid, cellulose and amyloglucosidase were evaluated. A hydrolyzed obtained in optimum condition with 92% efficiency was subjected to detoxification with activated charcoal and then, fermentability assays were carried out with yeasts Saccharomyces cerevisiae and Pichia stipitis. The yeast S. cerevisiae has proved resilient to the non-detoxified hydrolyzate and presented YP/S of 0.49. P. stipitis was found to be susceptible to the non-detoxified medium, but it was able to convert 99% of reducing sugars present in the detoxified medium. The macaw palm coconut cake showed considerable potential for bioethanol production. From the lab bench data it is possible to estimate a production of 104 l of ethanol per ton of macaw palm coconut cake.
2

Palma forrageira (Opuntia ficus indica e Nopalea cochenillifera) como mat?ria-prima para produ??o de etanol celul?sico e enzimas celulol?ticas

Souza Filho, Pedro Ferreira de 09 May 2014 (has links)
Made available in DSpace on 2014-12-17T15:01:34Z (GMT). No. of bitstreams: 1 PedroFSF_DISSERT.pdf: 2707475 bytes, checksum: 2a6ef9226a3d6d607615f74305bb9e07 (MD5) Previous issue date: 2014-05-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The need for new sources of energy and the concern about the environment have pushed the search for renewable energy sources such as ethanol. The use of lignocellulosic biomass as substrate appears as an important alternative because of the abundance of this raw material and for it does not compete with food production. However, the process still meets difficulties of implementation, including the cost for production of enzymes that degrade cellulose to fermentable sugars. The aim of this study was to evaluate the behavior of the species of cactus pear Opuntia ficus indica and Nopalea cochenillifera, commonly found in northeastern Brazil, as raw materials for the production of: 1) cellulosic ethanol by simultaneous saccharification and fermentation (SSF) process, using two different strains of Saccharomyces cerevisiae (PE-2 and LNF CA-11), and 2) cellulolytic enzymes by semi-solid state fermentation (SSSF) using the filamentous fungus Penicillium chrysogenum. Before alcoholic fermentation process, the material was conditioned and pretreated by three different strategies: alkaline hydrogen peroxide, alkaline using NaOH and acid using H2SO4 followed by alkaline delignification with NaOH. Analysis of composition, crystallinity and enzymatic digestibility were carried out with the material before and after pretreatment. In addition, scanning electron microscopy images were used to compare qualitatively the material and observe the effects of pretreatments. An experimental design 2? with triplicate at the central point was used to evaluate the influence of temperature (30, 40 and 45 ?C) and the initial charge of substrate (3, 4 and 5% cellulose) in the SSF process using the material obtained through the best condition and testing both strains of S. cerevisiae, one of them flocculent (LNF CA-11). For cellulase production, the filamentous fungus P. chrysogenum was tested with N. cochenillifera in the raw condition (without pretreatment) and pretrated hydrothermically, varying the pH of the fermentative medium (3, 5 and 7). The characterization of cactus pear resulted in 31.55% cellulose, 17.12% hemicellulose and 10.25% lignin for N. cochenillifera and 34.86% cellulose, 19.97% hemicellulose and 15.72% lignin for O. ficus indica. It has also been determined, to N. cochenillifera and O. ficus indica, the content of pectin (5.44% and 5.55% of calcium pectate, respectively), extractives (26.90% and 9.69%, respectively) and ashes (5.40% and 5.95%). Pretreatment using alkaline hydrogen peroxide resulted in the best cellulose recovery results (86.16% for N. cochenillifera and 93.59% for O. ficus indica) and delignification (48.79% and 23.84% for N. cochenillifera and O. ficus indica, respectively). This pretreatment was also the only one which did not increase the crystallinity index of the samples, in the case of O. ficus indica. However, when analyzing the enzymatic digestibility of cellulose, alkali pretreatment was the one which showed the best yields and therefore it was chosen for the tests in SSF. The experiments showed higher yield of conversion of cellulose to ethanol by PE-2 strain using the pretreated N. cochenillifera (93.81%) at 40 ?C using 4% initial charge of cellulose. N. cochenillifera gave better yields than O. ficus indica and PE-2 strain showed better performance than CA-11. N. cochenillifera proved to be a substrate that can be used in the SSSF for enzymes production, reaching values of 1.00 U/g of CMCase and 0.85 FPU/g. The pretreatment was not effective to increase the enzymatic activity values / A necessidade de novas fontes de energia e a preocupa??o com o meio-ambiente t?m impulsionado a pesquisa por fontes renov?veis de energia, como o etanol. O uso de biomassa lignocelul?sica como substrato aparece como uma importante alternativa devido ? abund?ncia desta mat?ria-prima e por n?o concorrer com a produ??o de alimentos. Entretanto, o processo ainda encontra dificuldades de implementa??o, entre elas o custo para produ??o das enzimas que degradam a celulose em a??cares fermentesc?veis. O objetivo deste trabalho foi avaliar o comportamento das esp?cies de palma forrageira Opuntia ficus indica (gigante) e Nopalea cochenillifera (mi?da), comumente encontradas na regi?o Nordeste do Brasil, como mat?rias-primas para produ??o de: 1) etanol celul?sico pelo processo de sacarifica??o e fermenta??o simult?neas (SFS) usando duas cepas diferentes de Saccharomyces cerevisiae (PE-2 e LNF CA-11) e 2) enzimas celulol?ticas atrav?s da fermenta??o em estado semiss?lido (FES) usando o fungo filamentoso Penicillium chrysogenum. Antes do processo de fermenta??o alco?lica, o material foi condicionado e pr?-tratado por tr?s diferentes estrat?gias: per?xido de hidrog?nio alcalino, alcalino usando NaOH e ?cido usando H2SO4 seguido de deslignifica??o alcalina com NaOH. An?lises de composi??o, cristalinidade e digestibilidade enzim?tica foram feitas com o material antes e depois do pr?-tratamento. Adicionalmente, imagens de microscopia eletr?nica de varredura foram usadas para comparar qualitativamente o material e observar os efeitos dos pr?-tratamentos. Um planejamento fatorial 2? com triplicata no ponto central foi utilizado para avaliar a influ?ncia da temperatura (30, 40 e 45 ?C) e da carga inicial de substrato (3, 4 e 5% de celulose) no processo SFS, usando o material obtido nas melhores condi??es de pr?-tratamento e testando duas cepas de S. cerevisiae, sendo uma delas floculante (LNF CA-11). Para a produ??o de celulase, o fungo filamentoso P. chrysogenum foi testado com a esp?cie de palma N. cochenillifera no estado in-natura (sem pr?-tratamento) e submetida a um pr?-tratamento hidrot?rmico, variando-se o pH do meio fermentativo (3, 5 e 7). A caracteriza??o das palmas forrageiras resultou em 31,55% de celulose, 17,12% de hemicelulose e 10,25% de lignina para a esp?cie N. cochenillifera e 34,86% de celulose, 19,97% de hemicelulose e 15,72% de lignina para a esp?cie O. ficus indica. Analisou-se ainda, para as palmas mi?da e gigante, o teor de pectina (5,44% e 5,55% de pectato de c?lcio, respectivamente), extrativos (26,90% e 9,69%, respectivamente) e cinzas (5,40% e 5,95%). O pr?-tratamento usando per?xido de hidrog?nio alcalino apresentou os melhores resultados de recupera??o de celulose (86,16% para a palma mi?da e 93,59% para a palma gigante) e de deslignifica??o (48,79% e 23,84% para as palmas mi?da e gigante, respectivamente). Este pr?-tratamento foi tamb?m o ?nico a n?o elevar o ?ndice de cristalinidade das amostras, no caso da palma gigante. Entretanto, quando analisada a digestibilidade enzim?tica da celulose, o pr?-tratamento alcalino foi o que proporcionou os melhores rendimentos e, portanto, este foi o escolhido para os testes de SFS. Os experimentos demonstraram maior rendimento da convers?o de celulose em etanol pela cepa PE-2 usando a palma mi?da pr?-tratada (93,81%) a 40 ?C e usando 4% de carga inicial de celulose. A palma mi?da demonstrou melhores rendimentos que a gigante e a cepa PE-2 resultou melhor desempenho que a CA-11. A palma mi?da se mostrou um substrato poss?vel de ser usado na FES para produ??o de enzimas, alcan?ando valores de 1,00 U/g de CMCase e 0,85 FPU/g. O pr?-tratamento n?o se mostrou eficaz para aumentar os valores de atividade enzim?tica

Page generated in 0.0433 seconds