Orientador: Celso Eduardo Tuna / Resumo: A agroindústria nacional brasileira dispõe de uma grande variedade de unidades agrícolas que geram elevada quantidade de resíduos como o bagaço de cana-de-açúcar. Mesmo diante da crescente utilização desse material, o excedente ainda é da ordem de milhões de toneladas, causando problemas de estocagem e poluição ambiental. Devido a sua estrutura complexa e sua recalcitrância, a etapa de pré-tratamento representa o desafio mais crítico para a viabilização da utilização do bagaço de cana-de-açúcar dentro do contexto de uma biorrefinaria. O pré-tratamento busca facilitar o acesso aos componentes estruturais da biomassa, permitindo sua utilização na cadeia produtiva. Existem diferentes métodos de pré-tratamento como os físicos, químicos e biológicos ou uma combinação de todos esses, de modo que a geração de resíduos ambientalmente perigosos e/ou altos insumos energéticos é o gargalo. Neste sentido, rotas tecnológicas alternativas vem sendo estudadas e a cavitação hidrodinâmica desponta-se como uma promissora rota para o pré-tratamento de biomassa liberando grandes magnitudes de energia e induzindo a transformações físicas e químicas, favorecendo o rompimento da matriz carboidrato-lignina. Neste contexto, este trabalho empregou a cavitação hidrodinâmica para potencializar o pré-tratamento alcalino do bagaço de cana-de-açúcar. Para isto, projetou-se um reator de cavitação hidrodinâmica com tubo de Venturi utilizando como base uma abordagem computacional para a dinâmica dos fluidos. ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Brazilian national agroindustry has a large variety of agricultural units that generate high amounts of waste such as sugarcane bagasse. Even with the increasing use of this material, the surplus is still in the order of millions of tons, causing problems of stocking and environmental pollution. Due to its complex structure and recalcitrance, the pretreatment stage represents the most critical challenge for the feasibility of using sugarcane bagasse within the context of biorefinery. Pretreatment seeks to facilitate access to the structural components of biomass, allowing its use in the production chain. There are different pretreatment methods such as physical, chemical, physicochemical and biological or a combination of all of these, so that the generation of environmentally hazardous waste and / or high energy inputs is the bottleneck. In this sense, alternative technological routes have been studied and hydrodynamic cavitation emerges as a promising route for biomass pretreatment releasing large energy magnitudes and inducing physical and chemical transformations, favoring the rupture of the carbohydrate-lignin matrix. In this context, this thesis employed hydrodynamic cavitation as a physical means to improve the alkaline pre-treatment of sugarcane bagasse. The hydrodynamic cavitation reactor with Venturi tube was modeled by a computational approach to fluid dynamics, in order to evaluate the influence of the pressure ratio, the length and diameter of the throat and ... (Complete abstract click electronic access below) / Doutor

Orientador: Mauro Mitsuuchi Tashima / Resumo: A construção civil, setor responsável pela infraestrutura do ambiente antrópico, é de grande importância para o desenvolvimento de atividades sociais e econômicas, atuando, todavia, como geradora de impactos ambientais. Na presente pesquisa, com o objetivo de avaliar comparativamente o desempenho ambiental de argamassas confeccionadas com cimento Portland e argamassas com substituição deste por cinza do bagaço de cana-de-açúcar (CBC) nas proporções de 15 e 30%, é utilizado a Avaliação do Ciclo de Vida (ACV). A substituição do material mais consumido pela construção civil, por um resíduo da usina sucroalcooleira se enquadra nos princípios da economia circular (EC), contribuindo para o desenvolvimento sustentável no Brasil. Para a estrutura metodológica e a condução da presente ACV fez-se uso das recomendações normativas das NBR 14040 e 14044, onde o estudo é dividido em quatro etapas: definição do objetivo e escopo; inventário do ciclo de vida (ICV); avaliação dos impactos do ciclo de vida (AICV); e interpretação. Para a condução das etapas de ICV e AICV faz-se uso do software de ACV GaBi, versão 6.0 da base de dados do Ecoinvent 2.01 e do método de AICV ReCiPe 2008. Os impactos ambientais da produção da CBC são considerados no estudo para este ser valorizado como matéria-prima no sistema produtivo de argamassas, não como apenas um resíduo da produção sucroalcooleira. Assim, o traço de argamassa com substituição de 30% apresenta melhor desempenho para a categoria de Mudança cl... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Transitioning from an energy system based on fossil fuels to an energy system based on renewables is necessary to limit global warming and comes with both opportunities and challenges. National policies in Cuba look toward the domestic sugar industry for synergies in this transition, and bagasse is projected to play a key role in the future electricity system. Since bagasse only is available during the sugarcane harvesting season, it must be supplemented with other feedstock for power production year-round. Biomass can have important interactions with CLEWs and therefore a nexus approach is important to ensure policy coherence across sectors. This study investigates different pathways for the Cuban energy transition from a CLEWs perspective through a scenario analysis and uses OSeMOSYS as a tool. This study shows that national policies for increased food security, regrowth of the sugar industry, use of energy crops and increased electricity consumption to develop the country compete for land and water resources. While there are currently plenty of resources, compromises will be needed in the medium- to long-term in order to stay within natural boundaries. This is especially true for the water sector since precipitation is expected to decrease in the future due to climate change and since sea level rise will contaminate groundwater. Another effect of climate change is soil degradation which would decrease yields. Increased energy and water inputs to the agricultural sector is known to increase yields in developing countries such as Cuba, which is why an adaptation strategy to maintain yields could be to increase these inputs. However, this would further amplify the pressure on water resources. Exceeding the exploitable internal renewable freshwater resources would then require water inputs from desalination plants which is an energy intensive process, which - if powered by an electricity system with a high share of biopower - could create a vicious cycle. / Omställningen från ett fossilbaserat energisystem till ett förnybart system är nödvändigt för att begränsa den globala uppvärmningen och innebär både möjligheter och utmaningar. Nationella policys i Kuba ser till landets sockerindustri för synergier i denna omställning, och bagass väntas spela en nyckelroll i det framtida elsystemet. Eftersom bagass endast är tillgängligt under sockerrörens skördesäsong måste den kompletteras med andra bränslen för att el ska kunna produceras året om. Biomassa kan ha betydande påverkan på CLEWs varför det är viktigt med en nexusanalys för att säkerställa samstämmighet av policys för olika sektorer. Denna studie undersöker olika tillvägagångssätt för den kubanska energiomställningen ur ett CLEWs-perspektiv genom en scenarioanalys i vilken OSeMOSYS används som modelleringsverktyg. Denna studie fann att nationella policys för ökad trygghet av matförsörjning, återuppbyggnad av sockerindustrin och ökad elkonsumtion för att utveckla landet konkurrerar om land- och vattenresurser. Det finns för närvarande gott om resurser, men på medel och lång sikt kommer kompromisser behövas för att stanna inom naturens gränser. Detta gäller särskilt för vattensektorn eftersom nederbörd väntas minska i framtiden till följd av klimatförändringar och eftersom höjningar av havsvattennivån kommer kontaminera grundvatten. Ytterligare påverkan från klimatförändringarna är markförstöring vilket minskar skörden. Ökad energi- och vattenanvändning i jordbrukssektorn ger vanligtvis högre skörd i utvecklingsländer såsom Kuba, vilket innebär att en anpassningsstrategi för att behålla skördenivån skulle kunna vara att öka dessa. Detta kan dock ytterligare förstärka belastningen på vattenresurserna. Att överskrida de utnyttjbara förnybara färskvattenresurserna skulle kräva avsaltning av vatten vilket är en energikrävande process, vilket - om energiförsörjningen kommer från ett system med mycket biomassa - skulle kunna skapa en ond cirkel.

Thesis (PhD (Process Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: A techno-economic feasibility study was performed to compare biological and thermochemical process routes for production of liquid biofuels from sugarcane bagasse in South Africa using process modelling. Processing of sugarcane bagasse for the production of bioethanol, pyrolysis oil or Fischer-Tropsch liquid fuels were identified as relevant for this case study. For each main process route, various modes or configurations were evaluated, and in total eleven process scenarios were modelled, for which fourteen economic models were developed to include different scales of biomass input. Although detailed process modelling of various biofuels processes has been performed for other (mainly first world) countries, comparative studies have been very limited and mainly focused on mature technology. This is the first techno-economic case study performed for South Africa to compare these process routes using data for sugarcane bagasse. The technical and economic performance of each process route was investigated using the following approach: Obtain reliable data sets from literature for processing of sugarcane bagasse via biological pretreatment, hydrolysis and fermentation, fast and vacuum pyrolysis, and equilibrium gasification to be sufficient for process modelling. Develop process models for eleven process scenarios to compare their energy efficiencies and product yields. In order to reflect currently available technology, conservative assumptions were made where necessary and the measured data collected from literature was used. The modelling was performed to reflect energy-self-sufficient processes by using the thermal energy available as a source of heat and electricity for the process. Develop economic models using cost data available in literature and price data and economic parameters applicable to South Africa. Compare the three process routes using technical and economic results obtained from the process and economic models and identify the most promising scenarios. For bioethanol production, experimental data was collected for three pretreatment methods, namely steam explosion, dilute acid and liquid hot water pretreatment performed at pretreatment solids concentrations of 50wt%, 10wt% and 5wt%, respectively. This was followed by enzymatic hydrolysis and separate co-fermentation. Pyrolysis data for production of bio-oil via fast and vacuum pyrolysis was also collected. For gasification, data was generated via equilibrium modelling based on literature that validated the method against experimental data for sugarcane bagasse gasification. The equilibrium model was used to determine optimum gasification conditions for either gasification efficiency or syngas composition, using sugarcane bagasse, fast pyrolysis slurry or vacuum pyrolysis slurry as feedstock. These results were integrated with a downstream process model for Fischer-Tropsch synthesis to evaluate the effect of upstream optimisation on the process energy efficiency and economics, and the inclusion of a shift reactor was also evaluated. The effect of process heat integration and boilers with steam turbine cycles to produce process heat and electricity, and possibly electricity by-product, was included for each process. This analysis assumed that certain process units could be successfully scaled to commercial scales at the same yields and efficiencies determined by experimental and equilibrium modelling data. The most important process units that need to be proven on an industrial scale are pretreatment, hydrolysis and fermentation for bioethanol production, the fast pyrolysis and vacuum pyrolysis reactors, and the operation of a twostage gasifier with nickel catalyst at near equilibrium conditions. All of these process units have already been proven on a bench scale with sugarcane bagasse as feedstock. The economic models were based on a critical evaluation of equipment cost data available in literature, and a conservative approach was taken to reflect 1st plant technology. Data for the cost and availability of raw materials was obtained from the local industry and all price data and economic parameters (debt ratio, interest and tax rates) were applicable to the current situation in South Africa. A sensitivity analysis was performed to investigate the effects of likely market fluctuations on the process economics. A summary of the technical and economic performances of the most promising scenarios is shown in the table below. The bioethanol process models showed that the liquid hot water and dilute acid pretreatment scenarios are not energy self-sufficient and require additional fossil energy input to supply process energy needs. This is attributed to the excessive process steam requirements for pretreatment and conditioning due to the low pretreatment solid concentrations of 5wt% and 10wt%, respectively. The critical solids concentration during dilute acid pretreatment for an energy selfsufficient process was found to be 35%, although this was a theoretical scenario and the data needs to be verified experimentally. At a pretreatment level of 50% solids, steam explosion achieved the highest process thermal energy efficiency for bioethanol of 55.8%, and a liquid fuel energy efficiency of 40.9%. Both pyrolysis processes are energy self-sufficient, although some of the char produced by fast pyrolysis is used to supplement the higher process energy demand of fast compared to vacuum pyrolysis. The thermal process energy efficiencies of both pyrolysis processes are roughly 70% for the production of crude bio-oil that can be sold as a residual fuel oil. However, the liquid fuel energy efficiency of fast pyrolysis is 66.5%, compared to 57.5% for vacuum pyrolysis, since fast pyrolysis produces more bio-oil and less char than vacuum pyrolysis. / Centre for Renewable and Sustainable Energy Studies

Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: Climate change that results from greenhouse gases (GHG’s) released from the burning of fossil fuels, together with the rising price of oil, have sparked interest in renewable biofuels. The production of biofuels also presents potential socio-economic benefits. There are two types of technologies for bioethanol production: · First generation bioethanol is produced from food feedstocks such as juice of sugarcane. · Second generation bioethanol is produced from non-food feedstocks (lignocellulosic materials). This project is concerned with 1st and 2nd generation bioethanol production from sugarcane juice and bagasse and the integration of these technologies. This project comprises a combination of experimental and process modelling work to assess energy efficiencies and the economic viability of integrated and stand-alone processes in the sub-Saharan African context. First generation fermentation experiments were conducted and high ethanol concentrations of up to 113.7 g/L were obtained. It was concluded that a recombinant yeast strain may be able to replace a natural hexose fermenting yeast for 1st generation fermentations to reduce costs. 2nd generation fermentation experiments were performed and ethanol concentrations of close to 40 g/L were obtained. Combinations of 1st and 2nd generation fermentation experiments were performed to improve the 2nd generation fermentation. In one of the experiments it was concluded that the combination of 1st and 2nd generation fermentations significantly improved the 2nd generation fermentation with an overall ethanol concentration of 57.6 g/L in a shorter time than for the pure 2nd generation experiments. It was determined from washing and pressing experiments that pressing the pre-hydrolysate liquor out of the pre-treated bagasse will sufficiently lower the levels of inhibitors in a 2nd generation fermentation when using a hardened yeast. Some of the data from the 1st generation experiments were used along with literature data to model a first generation process in Aspen Plus® which processes 493 tons of cane per hour (tc/hr). Pinch heat integration was used to reduce the utility requirements. The process used the bagasse that was generated to co-produce steam and electricity. The excess electricity was sold for additional revenue. In one scenario the excess bagasse was determined at 57.5%. This bagasse was sold to a stand-alone 2nd generation plant. The first generation process produced 85.5 litres of ethanol per ton of cane (L/tc), the integrated process produced 128 L/tc while the stand-alone 2nd generation process produced 185 litres of ethanol per ton of bagasse (50% moisture) or 25.5 L/tc. The amount of excess electricity that was produced ranged from 14.3 to 70.2 kWh/tc. Economic analyses were performed using South African economic parameters to resemble the sub- Saharan African context. Data from the 1st generation process model and literature data for integrated 1st and 2nd generation and stand-alone 2nd generation processes were used for the analyses. It was found that the integrated plant is the most economically viable (IRR = 11.66%) while the 1st generation process basically broke even (IRR = 1.62%) and the 2nd generation process is unviable. This was as a result of high sugarcane prices and too few incentives for 2nd generation ethanol. / AFRIKAANSE OPSOMMING: Klimaatsverandering wat veroorsaak word deur kweekhuisgasse wat vrygestel word deur die verbranding van fossielbrandstowwe en die stygenede olieprys het belangstelling in hernubare biobrandstowwe laat opvlam. Die produksie van biobrandstowwe hou ook potensiële sosioekonomiese voordele in. Daar is twee tegnologieë vir bioetanol produksie: · Eerste generasie bioetanol word vanaf voedsel bronne soos suikersap geproduseer. · Tweede generasie bioetanol word van nie-voedsel bronne (lignosellulose materiaal) geproduseer. Hierdie projek handel oor 1ste en 2de generasie bioetanol produksie van suikersap en suikerriet bagasse en die integrasie van hierdie tegnologieë. Hierdie projek bestaan uit ‘n kombinasie van eksperimentele- en prosesmodellering werk om die energiedoeltreffendheid en ekonomise vatbaarheid van geïntegreerde en alleenstaande prosesse in die sub-Sahara konteks te ondersoek. Eerste generasie fermentasie eksperimente is uitgevoer en hoë etanol konsentrasies van tot 113.7 g/L is gekry. Dit was bepaal dat ‘n rekombinante gisras ‘n natuurilke heksose fermenterende gisras kan vervang vir 1ste generasie fermentasies om kostes te bespaar. 2de generasie fermentasie eksperimente is gedoen en etanol konsentrasies van amper 40 g/L is behaal. Kombinasies van 1ste en 2de generasie fermentasie-eksperimente was uitgevoer om die 2de generasie fermentasie te verbeter. In een van die eksperimente is dit bepaal dat die kombinasie van 1ste en 2de generasie fermentasie die 2de generasie fermentasie beduidend verbeter het met ‘n etanol konsentrasie van 57.6 g/L en dít in ‘n korter tyd as vir die suiwer 2de generasie eksperimente. Dit was bepaal vanuit pers- en was eksperimente dat om die pre-hidrolisaat vloeistof uit die stoombehandelde bagasse te pers, die vlak van inhibitore in ‘n 2de generasie fermentasie voldoende verlaag vir die gebruik van ‘n verharde gis. Van die data van die 1ste generasie eksperimente was saam met literatuurdata gebruik om ‘n 1ste generasie proses in Aspen Plus® te modelleer wat 493 ton suikerriet per uur prosesseer (tc/hr). Pinch hitte integrasie was gebruik om die dienste vereistes te verminder. In die proses word die bagasse gebruik om stoom en elektrisiteit te genereer. In een geval was die oortillge bagasse bepaal as 57.5%. Hierdie bagasse was verkoop aan ‘n alleenstaande 2de generasie aanleg. Die eerste generasie proses het 85.5 liter etanol per ton suikerriet geproduseer (L/tc), die geïntegreerde proses het 128 L/tc geproduseer terwyl die 2de generasie proses 185 liter etanol etanol per ton bagasse (50% vog) of 25.5 L/tc geproduseer het. Die hoeveelhede oortillige elektrisiteit wat geproduseer is wissel van 14.3 tot 70.2 kWh/tc. Ekonomiese analieses is gedoen met Suid-Afrikaanse ekonomiese parameters om die sub-Sahara Afrika-konteks uit te beeld. Data van die 1ste generasie prosesmodel en literatuurdata van geïntegreerde 1ste en 2de generasie en alleenstaande 2de generasie prosesse was vir die analieses gebruik. Dit is bepaal dat die geïntegreerde model die mees ekonomies vatbare model is (IRR = 11.66%) terwyl die 1ste generasie proses basies gelyk gebreek het (IRR = 1.62%) en die 2de generasie proses is ekonomies onvatbaar. Hierdie bevindinge is as gevolg van hoë suikerrietpryse en te min aansporings vir 2de generasie etanol.

A biomassa do bagaço da cana-de-açúcar é composta de material lignocelulósico, principalmente celulose e hemicelulose, os quais são constituídos por açúcares de alta energia que podem ser convertidos a etanol. No entanto, a associação recalcitrante dessa biomassa impõe um grande desafio para a produção de biocombustíveis de segunda geração, devido à dificuldade em recuperar esses açúcares sob a forma de monômeros com elevado grau de pureza. Na natureza, muitos microrganismos realizam a degradação da biomassa de plantas através da ação de múltiplas CAZymes. Dentre esses, os fungos filamentosos se destacam devido a sua capacidade de produzir misturas enzimáticas altamente específicas para os substratos com que se deparam e, por essa razão, são a principal fonte das enzimas utilizadas nos coquetéis enzimáticos comercializados, em especial a espécie T. reesei. Contudo, esses coquetéis precisam ser otimizados e, para tanto, é necessário investir no estudo de outros fungos, como o A. fumigatus. Apesar de patogênico, o mesmo é considerado um importante produtor de enzimas lignocelulolíticas, cujas eficiências são aumentadas devido ao efeito sinérgico entre elas. Dessa forma, uma melhor compreensão dos mecanismos utilizados por esse fungo durante a exposição a biomassas vegetais é necessária. Nesse sentido, a determinação das atividades de celulases e xilanases após diferentes tempos de incubação foi realizada nos sobrenadantes das culturas do A. fumigatus crescido em SEB e em frutose, resultando em valores 21, 59 e 271 vezes maiores para as celulases e 150, 541 e 74 vezes para as xilanases, após 24, 48 e 72 horas de cultivo, respectivamente, na presença do bagaço. Para verificar se as enzimas estavam efetivamente hidrolisando a biomassa, foi realizada a dosagem dos açúcares redutores nos sobrenadantes das culturas em SEB, tendo sido observado um aumento na concentração desses açúcares à medida que o tempo de exposição ao bagaço aumentava. Com o propósito de compreender o mecanismo envolvido na hidrólise do bagaço, foi realizada a análise transcricional do A. fumigatus por RNA-seq, quando esse fungo foi crescido na presença desse substrato, assim como em frutose. A análise dos dados revelou 144 CAZymes induzidas em SEB, frente a 65 reprimidas nessa biomassa. Dentre os genes induzidos, foram identificados muitos potencialmente envolvidos na desconstrução da lignocelulose, como aqueles que codificam endoglucanases, celobiohidrolases, glucosidades, xilanases, xilosidases, manosidases, LPMOs, pectinases, entre outros. Para verificar se essas proteínas estavam sendo secretadas pelo fungo, o secretoma do mesmo foi analisado por espectrometria de massas LC/MS. Com isso, identificou-se uma gama muito maior de proteínas na presença de SEB (130) em comparação ao crescimento em frutose (44), sendo a maioria CAZymes (59%). Todos esses resultados evidenciam o potencial do A. fumigatus na hidrólise do bagaço de cana-de-açúcar, podendo suas enzimas contribuir para a produção de coquetéis enzimáticos mais eficientes e, consequentemente, para a produção de etanol de segunda geração / Sugarcane bagasse biomass is composed of lignocellulosic material, mainly cellulose and hemicellulose, which are composed of high energy sugars that can be converted into ethanol. However, the recalcitrant association of this biomass imposes a major challenge for the production of second-generation biofuels, due to the difficulty in recovering these sugars in the form of monomers with high purity. In nature, many microorganisms perform the degradation of plant biomass through the action of multiple CAZymes. Among them, filamentous fungi stand out for their ability to produce highly specific enzymatic mixtures for the substrates they are in the presence of and, therefore, they are the main source of enzymes used in commercialized enzymatic cocktails, especially T. reesei. However, these cocktails need to be optimized and, for this reason, it is necessary to invest in the study of other fungi, such as the A. fumigatus. Although pathogenic, it is considered an important producer of lignocellulolytic enzymes, whose efficiencies are increased due to the synergistic effect between them. Thus, a better understanding about the mechanisms used by this fungus during exposure to plant biomass is necessary. In this sense, the determination of cellulases and xylanases activities after different incubation times was performed after collection of supernatants from A. fumigatus grown in SEB and fructose cultures, resulting in 21, 59 and 271-fold higher values for cellulases, and 150, 541 and 74-fold higher values for xylanases, after 24, 48 and 72 hours of cultivation, respectively, in presence of the bagasse. To verify if the enzymes were effectively hydrolyzing the biomass, the supernatants from SEB cultures were collected and the reducing sugars were quantified. An increase in the concentration of these sugars was observed as the exposure time to the bagasse increased. In order to understand the mechanism involved in bagasse hydrolysis, the transcriptional analysis of A. fumigatus grown in the presence of this substrate and in fructose was performed by RNA-seq. Data analysis revealed 144 CAZymes induced by SEB, compared to 65 repressed by this biomass. Among the induced genes, many potentially involved in the lignocellulose deconstruction, such as those encoding for endoglucanases, cellobiohydrolases, glucosidases, xylanases, xylosidases, mannosidases, LPMOs, pectinases, among others, were identified. To verify if these proteins were being secreted, the secretome of the fungus was analyzed by LC/MS mass spectrometry. Hence, a much larger range of proteins was identified in the presence of SEB (130) as compared to growth in fructose (44), most of them being CAZymes (59%). All these results show the potential of A. fumigatus in the hydrolysis of sugarcane bagasse and its enzymes can contribute to the production of more efficient enzymatic cocktails and, consequently, to the production of second-generation ethanol

São objetivos deste trabalho: (1) avaliar a produção de celulases pelo fungo termofílico Myceliophthora sp. M77, isolado no âmbito do programa BIOTA-FAPESP, cultivando-o em meios compostos por bagaço de cana-de-açúcar (B) e farelo de trigo (T) ou farelo de soja (S), portanto, cultivos em estado sólido; (2) avaliar a eficácia das enzimas na hidrólise de bagaço de cana-de-açúcar e celulose cristalina. Nos cultivos em frascos Erlenmeyer, o maior valor de concentração de celulases foi obtido em meio SB (10:90) (porcentagem em massa) com 80% de umidade inicial, 10,3 FPU.gms-1 após cinco dias de cultivo, valor este 120% superior ao valor de 4,8 U.gms-1, que foi a maior concentração de celulases registrada no cultivo em meio TB (20:80) com 60% de umidade inicial. O uso de aeração forçada no cultivo de Myceliophthora sp. M77 em meio SB (10:90) com 80% de umidade inicial, em reator de leito fixo, resultou aumento de 30% na concentração de celulase e na máxima produtividade em relação aos cultivos em frasco Erlenmeyer. Ensaios de hidrólise nas temperaturas de 50°C, 60°C e 70°C foram realizados para determinação da melhor temperatura de ação das celulases produzidas pelo fungo Myceliophthora sp. M77. Utilizou-se extrato obtido a partir do cultivo de Myceliophthora sp. M77 em meio SB (10:90) com umidade inicial de 60% a 45°C por 3 dias. Após 48h de hidrólise de bagaço de cana-de-açúcar pré-tratado por explosão a vapor, a conversão de celulose a glicose foi de 15% para T=50°C, 8% para T=60°C e 1,5% para T=70°C. Os resultados indicam que pode ocorrer desnaturação térmica a 60°C e 70°C para períodos superiores a 6 h e 2 h de hidrólise, respectivamente. Ensaios de hidrólise de bagaço de cana-de-açúcar pré-tratado por explosão a vapor, a 50°C, com adição de 10 FPU.gms-1 de celulases produzidas por Myceliopthora sp. M77 em meio SB (10:90) resultaram conversão de celulose a glicose 50% maior do que para o ensaio de hidrólise nas mesmas condições com enzimas produzidas em meio TB (40:60), indicando que a composição dos extratos enzimáticos produzidos em meio TB e SB são diferentes. A concentração inicial de glicose de 1 g.L-1 no extrato produzido em meio TB pode ter inibido a ação da enzima b-glicosidade. Já os extratos produzidos em meio SB apresentaram concentrações de glicose inicial inferiores a 0,15 g.L-1. Ensaios de hidrólise com enzimas aderidas ao meio de cultura sólido foram realizados com a finalidade de avaliar essa metodologia em comparação à hidrólise usual com enzimas extraídas do meio. Após 48 h, as conversões de celulose a glicose das hidrólises de celulose cristalina ou bagaço de cana-de-açúcar pré-tratado por explosão à vapor com enzimas aderidas ao meio de cultura foram ou superiores ou iguais àquelas obtidas nas hidrólises com enzimas extraídas do meio de cultura. Esse resultado mostra que existe a possibilidade de aplicação direta da enzima não extraída do meio de cultura sólido, com consequente redução do custo do processo de hidrólise do material celulósico para liberação de açúcares fermentescíveis. / The objectives of this study are: (1) to evaluate the production of cellulases by a thermophilic fungus, Myceliophthora sp. M77, isolated by the BIOTA-FAPESP program. The microorganism was cultivated in media composed by sugarcane bagasse (B) and wheat bran (T) or soybean meal (S), thus, solid state cultivation; (2) to evaluate the effectiveness of these enzymes in the hydrolysis of sugarcane bagasse and crystalline cellulose. The highest cellulases concentration in Erlenmeyer flasks cultures was achieved in medium SB (10:90) (w/w) with initial moisture of 80%, 10.3 FPU.gdm-1 after five days of cultivation, a value 120% higher than 4.8 U.gdm-1, which was the highest recorded cellulases concentration in culture using TB (20:80) with 60% of initial moisture. Applying forced aeration in the cultivation of Myceliophthora sp. M77 in medium SB (10:90) with 80% initial moisture, in fixed bed reactor, cellulases concentration and maximum productivity raised 30% relative to cultivation in Erlenmeyer flask. Hydrolysis assays at temperatures of 50°C, 60°C and 70°C were performed to evaluate the optimal temperature for application of cellulases produced by the fungus Myceliophthora sp. M77, since it is a thermophilic fungus. It was used the enzymatic extract produced from cultures in medium SB (10:90) with 60% initial moisture, at 50°C, for three days. After 48 h of hydrolysis of sugarcane bagasse pretreated by steam explosion, the conversion of cellulose to glucose was 15% for T = 50 ° C, 8% for T = 60 ° C and 1.5% T = 70 ° C. These results indicated that thermal denaturation may occur in hydrolysis at 60°C and 70°C for periods longer of 6 h and 2 h, respectively. Hydrolysis of sugarcane bagasse pretreated by steam explosion at 50°C with addition of 10 FPU.gdm-1 of cellulases produced by Myceliopthora sp. M77 in medium TB (40:60), resulted in conversion of cellulose to glucose 50% lower than hydrolysis with enzymes produced in medium SB (10:90), under the same conditions, indicating that the composition of enzyme extracts produced in TB and SB medium are different. The initial glucose concentration of 1 g.L-1 in the enzyme extract produced in TB medium can inhibit the action of the enzyme b-glucosidade. On the other hand, initial glucose concentration in the extract produced in medium SB was lower than 0.15 g.L-1. Hydrolysis using enzymes adhered to the solid culture medium were performed in order to compare this method to the usual hydrolysis with enzymes extracted from the medium. After 48 h, the cellulose conversion to glucose in the hydrolysis of sugarcane bagasse pretreated by steam explosion or crystalline cellulose were either greater than or equal to those obtained by hydrolysis with enzymes extracted from the culture medium. This result shows that there is the possibility of direct application of the enzyme still adhered to the solid culture medium, with consequent reduction of the process cost of cellulosic materials hydrolysis to release fermentable sugars.

A conversão de biomassa vegetal em produtos químicos e energia é essencial a fim de sustentar o nosso modo de vida atual. O bagaço de cana-de-açúcar, matériaprima disponível em abundância no Brasil, poderá tanto ajudar a suprir a crescente demanda pelo etanol combustível como ser empregado para obtenção de produtos de valor agregado, tais como xilitol, além de trazer vantagens econômicas para o setor sucroalcooleiro. O xilitol, um poliol com poder adoçante semelhante ao da sacarose e com propriedades peculiares, como metabolismo independente de insulina, anticariogenicidade e aplicações na área clínica, no tratamento de osteoporose e de doenças respiratórias, é obtido em escala comercial por catálise química de materiais lignocelulósicos. A produção biotecnológica de xilitol como alternativa ao processo químico vem sendo pesquisada e os resultados revelam que a presença de compostos tóxicos nos hidrolisados hemicelulósicos resultantes do processo de hidrólise ácida contribui para sua baixa fermentabilidade. Isto se deve à inibição do metabolismo microbiano causada principalmente por compostos tais como ácidos orgânicos, fenólicos e íons metálicos. No presente trabalho foi avaliado o efeito de diferentes fontes de carbono (xilose, glicose e mistura de xilose e glicose) empregadas no preparo do inóculo de Candida guilliermondii FTI 20037 sobre a bioconversão de xilose em xilitol a partir de fermentações em frascos Erlenmeyer de hidrolisados hemicelulósicos submetidos a procedimentos de destoxificação. A condição de favorecimento deste bioprocesso foi empregada para a avaliação da ampliação de escala em fermentadores de 2,4L para 16L, utilizando como critério de ampliação o KLa (igual a 15h-1). De acordo com os resultados, os máximos valores dos parâmetros fermentativos como fator de conversão de xilose em xilitol e produtividade em xilitol foram alcançados com a utilização de inóculo obtido em xilose durante fermentação do hidrolisado destoxificado por resinas (YP/S = 0,81 g g-1 e QP = 0,60 g L-1 h-1, respectivamente), embora o emprego de carvão ativado tenha gerado valores de rendimento próximos para as diferentes fontes de carbono (YP/S variando de 0,78 a 0,80 g g-1). Considerando o valor de fator de conversão e que o procedimento de destoxificação com carvão ativado é o de menor custo e de mais fácil manipulação em comparação ao processo com resinas, os experimentos de ampliação de escala da produção de xilitol por C. guilliermondii foram realizados nesta condição de destoxificação e empregando-se xilose como fonte de carbono para o inóculo. Nesta etapa ficou evidente a viabilidade de ampliação de escala de produção de xilitol de fermentador de 2,4L para 16L, já que os valores dos parâmetros fermentativos avaliados foram semelhantes entre os fermentadores (valores médios: YP/S ≈ 0,68 g g-1 e QP ≈ 0,28 g L-1 h-1). No entanto, tais valores foram inferiores aos obtidos em frascos Erlenmeyer, possivelmente devido às condições de disponibilidade de oxigênio diferirem nos fermentadores de bancada, uma vez que o oxigênio é o parâmetro mais crítico neste bioprocesso. / The conversion of vegetable biomass into chemicals and energy is essential to sustain our current style of life. Sugarcane bagasse, a raw material abundantly available in Brazil, greatly contributes to the supply of the evergrowing demand for ethanol. Furthermore, biomass can be employed for obtaining value-added products, such as xylitol, as well as bring economical advantages for the sugar-ethanol sector. Xylitol, a polyol with sweetener power similar to that of saccharose and peculiar properties such as insulin-independent metabolism, anticariogenic power, and applications in the clinical area, in the treatment of osteoporosis and respiratory diseases, is obtained on a commercial scale by chemical catalysis of lignocellulosic materials. The biotechnological production of xylitol as an alternative to the chemical process has been researched and the results reveal that the presence of toxic compounds in hemicelllosics hydrolysates resulting from acid hydrolysis process contributes to its low fermentability. Such toxicity could be due to the inhibition of microbial metabolism promoted mainly by compounds such as organic acids, phenols and metallic ions. In the present work, the effect of different carbon sources (xylose, glucose and a mixture of xylose and glucose) used in the inoculum preparation of Candida guilliermondii FTI 20037 for the xylose-to-xylitol bioconversion by fermentation of hemicellulosics hydrolysates submitted to detoxification procedures in Erlenmeyer flasks was evaluated. The best condition for this bioprocess was employed to evaluate the scale up from the 2.4L to 16L fermentors, using KLa (equal to 15h-1) as scale-up criteria. According to the results the highest values of fermentative parameters such as xylitol yield and productivity were achieved with the use of inoculum cultivated on xylose during the fermentation of hydrolysate detoxified with resins (YP/S = 0.81 g g-1 and QP = 0.60 g L-1 h-1, respectively), although with the use of charcoal the yield value was similar (YP/S ranging for 0.78 to 0.80 g g-1), regardless of the carbon source employed. Considering the value of xylitol yield and that detoxification with activated charcoal is less expensive and more easily manipulated when compared to detoxification procedure with resins, the experiments for scale up xylitol production by C. guilliermondii were performed in such detoxification condition with xylose as the carbon source for the inoculum. At this stage it was evident the scale up xylitol production from a fermenter of 2.4L to 16L was feasible, since the values of fermentative parameters evaluated were similar to those of the fermentors (medium values YP/S ≈ 0.68 g g-1 e QP ≈ 0.28 g L-1 h-1). However, these values were lower than those obtained in Erlenmeyer flasks, maybe due to conditions of oxygen availability for they differ from those in fermentors, since oxygen is the most critical parameter in this bioprocess.

O presente trabalho teve como objetivo estudar a viabilidade da utilização de cinzas de resíduos agroindustriais (bagaço de cana-de-açúcar, cama de frango e casca de arroz) como aditivos minerais substitutos ao cimento Portland, na produção de compósitos fibrosos e concreto leve. As cinzas foram obtidas através da queima e moagem controlada dos resíduos, e tiveram suas características químicas e físicas analisadas. Além do \"compósito referência\" (0% de substituição), os compósitos fibrosos foram produzidos com teores de substituição de cimento Portland de 10%, 15% e 20%, e os concretos leves foram produzidos com 10% de substituição. Foram realizados ensaios físicos e mecânicos nos compósitos fibrosos e concreto leve. Os resultados mostraram que as cinzas de casca de arroz apresentaram propriedades pozolânicas e que podem ser empregadas para a produção dos compósitos fibrosos e concretos leve. No estudo com compósitos fibrosos, os resultados físicos e mecânicos em sua maioria indicaram que a cinza de casca de arroz apresentou os melhores resultados. Como não apresentaram propriedades pozolânicas, as cinzas de bagaço de cana-de-açúcar e cama de frango, mesmo apresentando bons resultados, podem ser utilizadas como \"micro-fillers\". No estudo com concreto leve, a cinza de casca de arroz também se apresentou como melhor substituto para o cimento Portland por apresentar os melhores resultados nos ensaios realizados. / This research examines the viability of the use of waste agro industrials ashes (sugar cane bagasse, poultry litter and rice husk) and mineral additives substitutes to Portland cement in the production of composite fiber and lightweight concrete. The ashes were obtained through controlled burns and milling waste, and had their chemical and physical characteristics analyzed. Besides the \"composite reference\" (0% substitution), the fiber composites were produced with levels of replacement of Portland cement, 10%, 15% and 20%, and lightweight concrete were produced with 10% of replacement. Were tested on physical and mechanical fiber composites and lightweight concrete. The results showed that the ashes of rice husk had pozolanic properties and can be used for the production of fiber composite and lightweight concrete. In the study with fiber composites, the results physical and mechanical mostly indicated that the rice husk ash showed the best results. As there had pozolanics properties, the ashes of sugar cane bagasse and poultry litter, even showing good results, can be used as \"micro-fillers\". In the study with lightweight concrete, the ash of rice husk is also presented as a better replacement for Portland cement by presenting the best results in tests.

O bagaço de cana-de-açúcar é um resíduo gerado no processo de produção de açúcar e álcool pelas usinas. O histórico de uso desse material aponta para a queima visando à produção de vapor e energia para o processo. As necessidades ambientais e econômicas ligadas tanto à emissão de gases estufa quanto as áreas agricultáveis apontam para um melhor aproveitamento desse resíduo que é constituído de cerca de 50% de celulose, 28% de hemiceluloses (também chamadas polioses), 21% de lignina e 1% de inorgânicos. Dentro desse contexto este trabalho visou à utilização da celulose do bagaço para a obtenção de açúcares fermentescíveis para a produção de etanol de 2ª geração. O bagaço foi desmedulado e a fração fibra foi pré-hidrólisada visando eliminar as hemiceluloses. Em seguida a fração fibra pré-hidrolisada foi deslignificada através de polpação soda antraquinona (SAQ). A polpa celulósica da fração fibra do bagaço foi hidrolisada em ácido sulfúrico e ácido clorídrico através do método \"ELA\", extremely low acid. Esse método utiliza ácido mineral muito diluído, altas temperaturas e pressões. As temperaturas de hidrólise utilizadas compreenderam a faixa de 180 a 230°C e as concentrações de ácido sulfúrico e ácido clorídrico utilizadas foram 0,07%, 0,14% e 0,28% e 0,05%, 0,10% e 0,20%, respectivamente. A razão sólido-líquido empregada foi 1:20 (m/v) e os reatores utilizados foram de aço inox 316L. A perda de massa após os experimentos de hidrólise foi quantificada e a composição dos hidrolisados foi analisada por cromatografia líquida de alta eficiência (CLAE). Paralelamente um estudo de degradação de glicose em ácido sulfúrico e ácido clorídrico foi conduzido com o objetivo de minimizar a degradação de glicose e conseqüentemente aumentar o seu rendimento. Através desse estudo também foi possível comparar o efeito de cada ácido na cinética de degradação de glicose. A faixa de temperatura utilizada foi de 200 a 220°C e a faixa de concentração de ácido sulfúrico e ácido clorídrico foi a mesma empregada nos estudos de hidrólise ácida. As constantes de velocidade de ordem um obtidas através de regressões lineares dos dados de perda de massa foram utilizadas para calcular a energia de ativação de Arrhenius. As energias de ativação médias obtidas para a reação com H2SO4 e HCl foram 184.9 e 183.5 kJ/mol, respectivamente. O rendimento máximo de glicose para a hidrólise da polpa celulósica em H2SO4 foi 69,8% e em HCl foi 70,2%. As constantes de velocidade de ordem um obtidas através de regressões lineares dos dados de glicose residual para a degradação de glicose também foram utilizadas para calcular a energia de ativação de Arrhenius. As energias de ativação médias para a decomposição de glicose em H2SO4 e HCl foram 124.5 e 142.9 kJ/mol, respectivamente. Através dos estudos realizados foi possível concluir que HCl foi um catalisador mais efetivo que o H2SO4 com base no valor das constantes de velocidade determinadas e nos rendimentos máximos de glicose obtidos. Porém, o HCl é menos vantajoso economicamente que o H2SO4 e os íons cloreto são responsáveis por tornar esse ácido mais corrosivo que o H2SO4. / Sugarcane bagasse is a residue from sugar and alcohol production process. In the industry of sugar and alcohol this residue is burned to produce steam and energy for the process. The environmental and economic needs related to both emission of greenhouse gases and the increase of sugarcane planted area point to be a better utilization of the bagasse. The approximate composition of sugarcane bagasse is 50% cellulose, 28% hemicelluloses, 21% lignin and 1% inorganic compounds. From this view point, this work aimed to use cellulose from sugarcane bagasse to obtain fermentable sugars to produce second generation ethanol. Depithed bagasse was pre-hydrolyzed to remove hemicelluloses. Afterwards, pre-hydrolyzed depithed bagasse was pulped using soda-anthraquinone (SAQ) method to remove lignin. Cellulosic pulp was hydrolyzed employing the ELA conditions. Sulphuric acid and hydrochloric acid were chosen as hydrolysis catalysts. The ELA uses mineral acid in extremely low concentration, high temperatures and pressures. The temperature range chosen for kinetic study was from 180 to 230°C. The H2SO4 concentration was 0.07%, 0.14%, and 0.28% and HCl concentration was 0.05%, 0.10%, and 0.20%. In hydrolysis experiments the solid-liquid ratio employed was 1:20. Reactors resistant to acid corrosion made by 316L-stainless steel were used in the experiments. The weight loss after the hydrolysis experiments was determined and the hydrolysate composition was analyzed by high performance liquid chromatography (HPLC). A study of glucose decomposition in both acid catalysts was also carried out. The aim of this study was to minimize glucose degradation and acquire data to compare the effect of catalyst type on glucose degradation. The temperature range employed was from 200 to 220°C and the catalysts concentration was the same described above. First-order rate constants for hydrolysis of cellulosic pulp were obtained from linear regressions using data from weight loss. These rate constants were also used to calculate Arrhenius activation energy. The average activation energies for H2SO4 and HCl were 184.9 and 183.5 kJ/mol, respectively. The maximum glucose yields obtained in H2SO4 and HCl were 69.8% and 70.2%, respectively. First-order rate constants for glucose decomposition were also obtained from linear regressions and also used to calculate Arrhenius activation energy. The average activation energies for glucose decomposition in H2SO4 and HCl were 124.5 e 142.9 kJ/mol, respectively. From the results of kinetic studies was possible to conclude that HCl was a more efficient catalyst than H2SO4. Moreover, HCl is more expensive than H2SO4 and chloride ions are responsible for making HCl more corrosive than H2SO4.