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  • 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

Cultivo de microalgas para produção de bioetanol de terceira geração / Microalgae cultivation for third generation bioethanol production

Klein, Bruno Colling, 1987- 22 August 2018 (has links)
Orientadores: Maria Regina Wolf Maciel, Reinaldo Gaspar Bastos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-22T08:48:28Z (GMT). No. of bitstreams: 1 Klein_BrunoColling_M.pdf: 2562214 bytes, checksum: f891de86d253786cf5d2101fec1f3eba (MD5) Previous issue date: 2013 / Resumo: A busca por uma maior sustentabilidade tem levado a uma mudança em direção à utilização de fontes renováveis para geração de energia em detrimento do uso de combustíveis fósseis, visando a uma modificação na matriz energética global. A utilização da biomassa de microalgas para produção de biocombustíveis vem sendo vista como uma alternativa promissora, uma vez que o seu cultivo proporciona produtividades em carboidratos e lipídios superiores às matérias-primas vegetais convencionalmente utilizadas na obtenção de etanol e biodiesel. Neste contexto, o objetivo da presente dissertação de mestrado foi avaliar a produção de biomassa da microalga clorofícea Chlorella vulgaris em fotobiorreator de placa plana em diferentes condições de fluxo luminoso, concentração de CO2 na alimentação gasosa e concentração de NaNO3 no meio de cultivo, visando o acúmulo de carboidratos para obtenção de bioetanol de terceira geração. As influências das variáveis nutricionais e de processo sobre a eficiência fotossintética das microalgas também foram estimadas para determinação do estado fisiológico das culturas. A produtividade média de biomassa e a concentração máxima final das microalgas foram significativamente afetadas pela incidência de radiação luminosa e pela suplementação de CO2 gasoso, obtendo-se maiores produtividades de carboidratos em cultivos com alto fluxo luminoso e concentrações de CO2 intermediárias (7,5%). Também foi observado o efeito positivo do aumento do fotoperíodo sobre o crescimento das microalgas. Através de hidrólise ácida foi possível atingir concentrações de até 2 g L-1 de açúcares fermentescíveis no hidrolisado a partir de biomassa de microalgas cultivadas em meio com baixo teor de nitrogênio. A fermentação etanólica foi então conduzida com a levedura Dekkerabruxellensis capaz de converter diferentes hexoses e pentoses em bioetanol, dada a presença de ambos os tipos de açúcares no hidrolisado / Abstract: The search for industrial processes with higher sustainability has led to a change towards the utilization of renewable sources for energy generation in substitution of fossil fuels, aiming the modification of the global energy matrix. The utilization of microalgal biomass for the production of biofuels is viewed as a promising alternative, since its cultivation yields carbohydrate and lipid productivities superior to those of conventional sources used in the obtention of bioethanol and biodiesel. In this context, the goal of this master thesis was to evaluate the biomass production of the chlorophycean microalga Chlorella vulgaris in a flat plate photobioreactor under different conditions of light flux, CO2 concentration in the gas feed and NaNO3 concentration in the culture medium, aiming carbohydrate accumulation for the production of third generation bioethanol. The influences of both process and nutritional variables on the photosynthetic efficiency of microalgae were estimated for the determination of the physiological condition of the cultures. The mean biomass productivity and the maximum final microalgae concentration were significantly affected by the incidence of light radiation and by the supplementation of gaseous CO2, the highest carbohydrate productivities being obtained in cultivations with high light flux and intermediate CO2 concentrations (7,5%). It was also observed the positive effect of increasing the photoperiod over microalgae growth. Through acid hydrolysis, it was possible to attain fermentable sugar concentration of up to 2 g L-1 from biomass of microalgae cultivated in low-nitrogen medium. The ethanolic fermentation was then carried out with the Dekkerabruxellensis yeast, capable of converting different hexoses and pentoses into ethanol, due to the presence of both sugar types in the hydrolysate / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química
2

Isolation and characterization of alginate from Hong Kong brown seaweed: an evaluation of the potential use of the extracted alginate as food ingredient.

January 2000 (has links)
by Li Yung Yung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 105-121). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / ABSTRACT (ENGLISH VERSION) --- p.ii / ABSTRACT (CHINESE VERSION) --- p.iv / TABLE OF CONTENTS --- p.v / LIST OF TABLES --- p.x / LIST OF FIGURES --- p.xi / LIST OF ABBREVIATIONS --- p.xiii / Chapter CHAPTER ONE --- INTRODUCTION / Chapter 1.1 --- Seaweed --- p.1 / Chapter 1.1.1 --- General Introduction --- p.1 / Chapter 1.1.2 --- Classification and Use of Seaweed --- p.1 / Chapter 1.1.3 --- Phycocolloids --- p.2 / Chapter 1.1.4 --- Hong Kong Seaweed --- p.3 / Chapter 1.1.4.1 --- Sargassum Species --- p.3 / Chapter 1.1.4.2 --- Padina Species --- p.5 / Chapter 1.2 --- Source and Production of Alginate --- p.8 / Chapter 1.2.1 --- Function of Alginate in Seaweed --- p.8 / Chapter 1.2.2 --- Chemical Structure of Alginate --- p.8 / Chapter 1.2.3 --- Alginate Production --- p.9 / Chapter 1.2.4 --- Isolation of Alginate --- p.13 / Chapter 1.2.5 --- Commercial Methods --- p.13 / Chapter 1.3 --- Application of Alginate --- p.14 / Chapter 1.3.1 --- Industrial Application --- p.14 / Chapter 1.3.2 --- Pharmaceutical Application --- p.16 / Chapter 1.3.3 --- Food Application --- p.17 / Chapter 1.3.3.1 --- Uses of Alginate in Food --- p.17 / Chapter 1.3.3.2 --- Safety --- p.19 / Chapter 1.4 --- Structure and Function Relationship of Alginate --- p.19 / Chapter 1.4.1 --- Physico-Chemical Properties --- p.21 / Chapter 1.4.1.1 --- M/G ratio --- p.21 / Chapter 1.4.1.2 --- Solution Properties --- p.21 / Chapter 1.4.1.3 --- Viscosity --- p.23 / Chapter 1.4.1.4 --- Molecular Weight --- p.27 / Chapter 1.4.2 --- Functional Properties --- p.27 / Chapter 1.4.2.1 --- Emulsion --- p.27 / Chapter 1.4.2.2 --- Gel Properties --- p.27 / Chapter 1.4.2.3 --- Mechanism of Gelation --- p.29 / Chapter 1.4.2.4 --- Gel Strength and Syneresis --- p.30 / Chapter 1.5 --- Physiological Effects --- p.32 / Chapter 1.5.1 --- Dietary Fibre --- p.32 / Chapter 1.5.2 --- Minerals --- p.32 / Chapter 1.6 --- Significance of the Present Study --- p.33 / Chapter CHAPTER TWO --- MATERIALS AND METHODS / Chapter 2.1 --- Seaweed Collection --- p.36 / Chapter 2.2 --- Sample Preparation --- p.36 / Chapter 2.3 --- Alginate Extraction --- p.38 / Chapter 2.3.1 --- Method A --- p.38 / Chapter 2.3.2 --- Method B --- p.38 / Chapter 2.3.3 --- Commercial Alginate --- p.39 / Chapter 2.4 --- Chemical Composition of Alginate --- p.41 / Chapter 2.4.1 --- Alginate Content --- p.41 / Chapter 2.4.2 --- Moisture Content --- p.41 / Chapter 2.4.3 --- Crude Protein Content --- p.41 / Chapter 2.4.4 --- Ash Content --- p.42 / Chapter 2.4.5 --- Monosaccharide Composition --- p.42 / Chapter 2.4.5.1 --- Acid Deploymerisation --- p.42 / Chapter 2.4.5.2 --- Neutral and Amino Sugar Derivatization --- p.42 / Chapter 2.4.5.3 --- Determination of Neutral Sugars by Gas Chromatography --- p.43 / Chapter 2.4.5.4 --- Uronic Acid Content --- p.44 / Chapter 2.4.6 --- Uronic Acid Block Composition --- p.44 / Chapter 2.4.6.1 --- "MG, MM and GG Block Determination" --- p.44 / Chapter 2.4.6.2 --- M/G Ratio Determination --- p.45 / Chapter 2.4.6.3 --- Phenol-Sulfuric Acid Method --- p.45 / Chapter 2.5 --- Physico-Chemical Properties of Alginate --- p.46 / Chapter 2.5.1 --- Viscosity --- p.46 / Chapter 2.5.1.1 --- Ostwald Viscometer --- p.46 / Chapter 2.5.1.2 --- Brookfield Viscometer --- p.47 / Chapter 2.5.2 --- Molecular Weight --- p.47 / Chapter 2.5.2.1 --- From Intrinsic Viscosity --- p.47 / Chapter 2.5.2.2 --- Gel Permeation Chromatography-Laser Light Scattering (GPC-LLS) --- p.48 / Chapter 2.6 --- Functional Properties of Alginate --- p.49 / Chapter 2.6.1 --- Emulsifying Activity (EA) and Emulsion Stability (ES) --- p.49 / Chapter 2.6.2 --- Gel Formation --- p.49 / Chapter 2.6.3 --- Gel Strength and Syneresis --- p.50 / Chapter 2.6.4 --- Application in Food ´ؤ Fruit Jelly --- p.52 / Chapter 2.7 --- Data Analysis --- p.53 / Chapter CHAPTER THREE --- RESULTS AND DISCUSSION / Chapter 3.1 --- Proximate Composition of Selected Seaweed --- p.54 / Chapter 3.1.1 --- Moisture Content --- p.54 / Chapter 3.1.2 --- Ash Content --- p.56 / Chapter 3.1.3 --- Crude Protein Content --- p.57 / Chapter 3.1.4 --- Carbohydrate Content --- p.58 / Chapter 3.2 --- Chemical Composition of Alginate Extracted from Two Different Methods --- p.58 / Chapter 3.2.1 --- Percentage Yield --- p.59 / Chapter 3.2.2 --- Alginate Content --- p.61 / Chapter 3.2.3 --- Moisture Content --- p.62 / Chapter 3.2.4 --- Ash Content --- p.62 / Chapter 3.2.5 --- Residual Protein Content --- p.63 / Chapter 3.2.6 --- Monosaccharide Composition of Alginate --- p.63 / Chapter 3.2.7 --- M/G Ratio --- p.66 / Chapter 3.2.8 --- Summary --- p.69 / Chapter 3.3 --- Comparative Studies of Physico-Chemical Composition of Alginate from Sargassum and Padina Species --- p.71 / Chapter 3.3.1 --- Block Composition and M/G Ratio --- p.71 / Chapter 3.3.2 --- Viscosity --- p.75 / Chapter 3.3.2.1 --- Intrinsic Viscosity ´ؤ Capillary Viscometer --- p.75 / Chapter 3.3.2.2 --- Solution Viscosity - Brookfield Viscometer --- p.79 / Chapter 3.3.2.2.1 --- Effect of Temperature --- p.79 / Chapter 3.3.2.2.2 --- Effect of Concentration --- p.81 / Chapter 3.3.2.2.3 --- Shear Thinning and Time Independent Effect --- p.82 / Chapter 3.3.3 --- Molecular Weight --- p.88 / Chapter 3.3.3.1 --- From Intrinsic Viscosity --- p.88 / Chapter 3.3.3.2 --- Gel Permeation Chromatograph-Laser Light Scattering (GPC-LLS) --- p.90 / Chapter 3.4 --- Comparative Studies of the Functional Properties of Extracted Alginate with Commercial Alginate --- p.93 / Chapter 3.4.1 --- Emulsifying Activity (EA) and Emulsifying Stability (ES) --- p.93 / Chapter 3.4.2 --- Gelling Properties --- p.95 / Chapter 3.4.2.1 --- Effect of Calcium Concentrations --- p.95 / Chapter 3.4.2.2 --- Gel Strength and Syneresis --- p.97 / Chapter 3.4.3 --- Application in Food --- p.99 / Chapter CHAPTER FOUR --- CONCLUSIONS --- p.103 / REFERENCES --- p.105 / RELATED PUBLICATION --- p.120

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