In accordance with the principles of green chemistry, the use of recycled materials in order to become the raw materials for the same or other process, minimizes or eliminates the generation of waste, reducing the use of materials and energy in process. Usually the alternatives explored are associated to farm products as, for example, the biomass derived of plants together with agricultural waste often lignocellulosic materials. The adsorbants used in this work derived of the tannin extraction from the Acacia mearnsii de Wildemann bark were pyrolyzed, chemically treated and appointed activated biochar (AB) and magnetic biochar (MB). Characterization by FT-IR, TGA, XDR, CHN and SEM allowed to display characteristics such as, for example, the presence of compounds originating from the biomass origin, tannins (TAN) in the BM and exhausted from the bark (CE) for BA. The adsorbents were effective in removing pesticides tiacloprid (TCL) and thiamethoxam (TMX) with values of adsorption capacity q = 0.73 and 0.40 mg g-1 for BM eq = 1.02 and 0.90 mg g-1 for BA, respectively. The removal percentage values were approximately 100% for two pesticides using BA, 72% and 42% using the WB, respectively, for the pesticides TMX and TCL. The kinetic model of pseudo-second order was the one that best fitted the results with values of q (exp) closest to q (calc) and good linearity coefficients ranging from 0.976 to 0.999. The study desorption of pesticides with water was performed in order to evaluate the possibility of the withdrawal of these pesticides for possible reuse of biochars. Attempting to desorption of adsorbed pesticides in biochar no significant results, thus evidencing the strong interaction between them. Thus, the study proposes the reuse of waste from an industrial process, which is the exhausted bark, for environmental purposes, as an alternative in removing pesticides besides assign any application to tannins extracted in the same process. / De acordo com o princípio da química verde, a utilização de materiais reciclados a fim de que se tornem matérias-primas para o mesmo processo ou para outro, minimiza ou elimina a geração de resíduos, diminuindo o uso de materiais e energia na produção. As principais alternativas atualmente exploradas estão relacionadas a produtos, como a biomassa de plantas em conjunto com resíduos agrícolas muitas vezes de materiais lignocelulósicos. Os adsorventes utilizados nesse trabalho, derivados da extração de taninos da casca da acácia negra (Acacia mearnsii de Wildemann) foram pirolisados, tratados quimicamente e nomeados de biocarvão ativado (BA) e biocarvão magnético (BM). A caracterização pelas técnicas de FT-IR, TGA, DRX, CHN e MEV permitiram visualizar características como a presença de compostos oriundos da sua biomassa de origem, taninos (TAN) no caso do BM, e a casca esgotada (CE) para o BA. Os adsorventes mostraram-se eficientes na remoção dos pesticidas tiacloprido (TCL) e tiametoxam (TMX) com valores de capacidade de adsorção, q = 0,73 e 0,40 mg g-1 para o BM e q = 1,02 e 0,90 mg g-1 para BA, respectivamente. Os valores de porcentagem de remoção foram aproximadamente 100% para os dois pesticidas usando o BA, 72% e 42% usando o BM, respectivamente, para os pesticidas TCL e TMX. O modelo cinético de pseudo-segunda ordem foi o que mais se ajustou aos resultados encontrados com valores de qe(exp) mais próximos do qe(calc) e bons coeficientes de linearidade variando entre 0,976-0,999. O estudo de dessorção dos pesticidas utilizando água foi realizado no intuito de avaliar a possibilidade da retirada desses pesticidas para possível reutilização dos biocarvões. A tentativa de dessorção dos pesticidas adsorvidos nos biocarvões não apresentou resultados significativos, constatando-se assim a forte interação entre eles. Assim, o estudo propõe a reutilização de um rejeito de um processo industrial, que é a casca esgotada, para fins ambientais, como uma alternativa na remoção de pesticidas além de atribuir outra aplicação aos taninos extraídos no mesmo processo.

O presente estudo visou avaliar alguns parâmetros de desempenho operacional das operações de enleiramento e enfardamento prismático de palhiço de cana-de-açúcar colhida mecanicamente, sem queima prévia, e de suas eficiências energéticas. Os ensaios de campo foram realizados em área da Cosan-Usina Costa Pinto, Município de Piracicaba, SP. A localização geográfica do centro do talhão é Latitude: 22 o 40’ 30’’ Sul, Longitude: 47 o 36’ 38’’ Oeste e Altitude de 605m. A variedade de cana-de-açúcar era a RB 82 5336, plantada em espaçamento de 1,40 m, em seu terceiro corte, com 11 meses de idade e apresentou uma produtividade média de colmos de 78,00 t.ha -1 . O canavial da área de estudo foi colhido por colhedora de cana-de-açúcar. O palhiço foi amostrado e analisado antes das operações de enleiramento e enfardamento. Foram obtidos, como resultados os índices médios de: folhas de 69,93%, frações de colmos de 21,44%, ponteiros de 2,27% e matéria estranha total de 6,36%. A produtividade média estimada apresentou uma grande variabilidade com coeficientes de variação 33,00%. Os valores médios obtidos do palhiço: de poderes caloríficos superiores de 18,43 MJ.kg -1 , inferior de 17,00 MJ.kg -1 e útil de 12,94 MJ.kg -1 . O potencial energético do palhiço determinado confirmou ser uma função varietal e apresentou valor médio de 342,48 GJ.ha -1 . Estimou-se para um hectare de palhiço o equivalente energético a 30,52 t de madeira, 15,16 t de carvão e de 11648,58 a 10104,17 L de óleo combustível. Foram realizados três tratamentos de enleiramentos: simples, duplo e triplo. A retirada de palhiço foi efetuada por meio de ancinho e de enfardadora prismática para fenação e foi viável do ponto de vista operacional e de eficiência energética, sendo que o enleiramento no tratamento de enleiramento simples apresentou os melhores resultados, com a maior capacidade efetiva média de 83,06 t.ha -1 , a menor média de consumo de combustível de 0,18 L.t -1 e eficiência energética positiva de 99,95%. Nas operações de enfardamento os fardos no tratamento de enleiramento triplo apresentaram a maior massa específica média de 221,11 kg.m -3 e as maiores médias de porcentagem de terra. As massas de terra no fardo aumentaram com enleiramentos sucessivos, e o tratamento de enleiramento triplo resultou em médias de terra nos fardo de 6,41%, contra 6,31% e 5,71% dos tratamentos de enleiramento duplo e simples, respectivamente. A operação de enfardamento do tratamento de enleiramento triplo foi a que obteve melhores resultados, apresentando as capacidades efetivas médias de 20,29 t.h -1 e 1,45 ha.h -1 e o consumo de combustível por tonelada de palhiço enfardado em 1,37 L.t -1 . A alta eficiência energética total de 99,53% indica que seja tecnicamente viável o recolhimento do palhiço. / This study was carried out aiming to evaluate some parameters of operational acting of windrowing and prismatic baling operations sugarcane trash picked mechanically without a previous burning and energy efficiency. The field tests were performed in a sugar cane trash field in Piracicaba, State of São Paulo, Brazil. The geographic location of the area is: latitude 22 o 40' 30' S, longitude 47 o 36' 38' W and altitude of 605m. The sugar-cane variety was RB 82 5336, planted in spacing of 1.40 m, in its third cut, with 11 months and it presented an average productivity of stalks of 78.00 t.ha -1 . The sugar cane field of the studied area was picked by a sugarcane harvester. Samples of the trash were analyzed before the windrowing and baling operations. From the trash analysis, before baling, the following average results were obtained: leaves indexes of 89.93%, 21,44% of stalks fractions, 2.27% of tops and 6.36% of total strange matter. The estimated productivity and index presented a great variability with coefficients of variation 33.00% and 68.00% respectively. From the sampled trash, were obtained average values of gross heat of 18.43 MJ.kg -1 , low heat of 17.00 MJ.kg -1 and useful heat of 12.94 MJ.kg -1 . The energy potential of the trash presented average value of 342.48 GJ.ha -1 confirmed to be a varietal function. It was considered for a hectare of trash the equivalent energy of 30,52 t of wood, 15,16 t of coal and from 11648,58 to 10104,17 L of fuel oil. Three different windrowing process were carried out, where the simple windrowing treatment consisted of a simple windrow formed by only one passage of the rake, the double of a windrow formed by two simple windrows and the triple by three simple windrows. The picking of sugarcane trash, by means of rake and prismatic baler was viable from the operational and of energy efficiency stand points. The windrowing in the treatment of simple windrowing presented the best results, with the effective capacity of 83.06 t.ha -1 , consumption of fuel of 0.18 L.t -1 and 99.95% of positive energy efficiency. In bales obtained in the treatment of triple windrowing presented the largest specific mass average of 221.11 kg.m -3 and the largest averages of soil percentage. The soil masses in the bales increased with successive windrowing, and the triple windrowing treatment resulted in 6.41% of soil in the bale, against 6.31% in treatments of double windrowing and 5.71% in the simple windrowing. The baling operation in the triple windrowing treatment obtained better results, presenting the effective capacities of 20.29 t.h -1 and 1.45 ha.h -1 and fuel consumption of for baled in 1.37 L.t -1 . The high total energy efficiency of 99.53% indicates that is technically viable the withdrawal of the trash.

Orientador: José Tomaz Vieira Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-19T10:41:26Z (GMT). No. of bitstreams: 1 Dalbem_JoseAntonio_M.pdf: 4137996 bytes, checksum: d9ffaa0145fff06b3a4f264c94e03244 (MD5) Previous issue date: 2007 / Resumo: O sucesso atual da cadeia sucro-alcooleira no Brasil, como largamente divulgado, tem como principal motivador o esforço tecnológico decorrente da implantação do pró-álcool na década de 70, com expressivo desenvolvimento das atividades agrícolas e industriais. Mas, considerando que as centenas de empresas do ramo sucro-alcooleiro nacionais buscam conhecimentos, equipamentos e insumos praticamente nas mesmas fontes, necessário se faz entender as razões pelas quais há uma ampla diferença de resultados em termos de eficiências de produção, tanto nas atividades agrícolas como nas industriais. As diferenças de solo, clima e cultura regionais, mesmo considerando as diferentes idades das usinas, não seriam suficientes para explicar tal variação de eficiências. Neste trabalho, pela experiência do autor como gestor em atividades de refino de petróleo, e por analogia com o observado nas atividades de refino no Brasil e no mundo, considera que diferentes práticas de gestão devem contribuir bastante para tais diferenças de resultados. Este trabalho, visando à confirmação dessa consideração, apresenta a análise de correlação comparativa entre práticas de gestão e resultados energéticos de usinas de açúcar e álcool. A análise foi aplicada em quatro usinas pré-selecionadas. A avaliação das práticas de gestão, para determinação da pontuação das usinas, seguiu os critérios da Fundação Nacional da Qualidade, mais especificamente a do Rumo a Excelência - 500 pontos, de 2006, de modo simplificado. Os resultados energéticos de eficiência de conversão de sacarose da cana-de-açúcar em produtos finais, medido pela eficiência industrial relativa Copersucar, e de eficiência de consumo de energia nos processos de produção de açúcar e álcool, medido pela sobra de bagaço, foram recebidos diretamente das usinas ou calculados a partir de dados fornecidos por elas. A pontuação obtida na avaliação simplificada pelos critérios da FNQ mostrou que as usinas pesquisadas têm bons sistemas de gestão. A análise comparativa entre as pontuações de gestão e as eficiências industriais, de conversão de açúcares e de consumo energético dos processos, mostrou que há relação direta entre elas. A eficiência de consumo dos processos aparenta ser bastante dependente da adoção ou não de estratégia de geração e venda de energia elétrica. Entretanto, considerando a pequena amostra de apenas quatro usinas, essas afirmações não podem ser generalizadas. Para assegurar confiabilidade nas conclusões das análises ela deve ser aplicada em uma amostragem maior de usinas / Abstract: The current success of sugar and alcohol plants in Brazil, as widely diffused, was primarily encouraged by the technological effort secondary to the establishment of pro-alcohol in the 1970s, with remarkable development of agricultural and industrial activities. However, considering that the hundreds of national companies dealing with sugar and alcohol production search for knowledge, equipments and supplies nearly in the same sources, there is the need to understand the reason why there is a wide difference in production efficiency results, both in agricultural and industrial activities. Even considering the different periods of establishment of plants, the differences in regional soil, weather and culture would not be enough to explain these variable efficiencies. Considering the experience of the author as manager of petroleum refinement activities, and by comparison with performance observed in refinement activities in Brazil and in the world, the present study considers that different management practices should have appreciate contributions for such differences in results. This study presents a comparative correlation analysis between management practices and energy results of sugar and alcohol plants, with a view to confirm this consideration. The analysis was applied to four pre-selected plants. Evaluation of the management practices to determine the score of plants followed the criteria of the National Quality Foundation (FNQ), more specifically of Aiming at Excellence - 500 points, in 2006, in simplified manner. The energy results of efficiency of converting the sucrose from sugar cane in final products, evaluated in Copersucar relative industrial efficiency, and of relative energy consumption in the processes of sugar and alcohol production, evaluated in surplus bagasse, were directly supplied by the plants or calculated from data provided by them. The score achieved in the simplified evaluation by the FNQ criteria demonstrated that the plants investigated have good management systems. Comparative analysis of management scores with efficiency of sucrose conversion and surplus bagasse demonstrated a direct correlation among them. The relative energy consumption in industrial process seems to be quite a lot dependent of strategies for to generate and sell electric energy. However, considering the small sample of only four plants, these statements cannot be generalized. The analysis should be applied to a larger sample of plants in order to assure its reliability in the conclusions achieved / Mestrado / Mestre em Planejamento de Sistemas Energéticos

Orientador: Luis Augusto Barbosa Cortez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-21T11:11:59Z (GMT). No. of bitstreams: 1 Souza_RenataTorresGomesde_M.pdf: 3951716 bytes, checksum: bd5e04dc6012cdb85e0ddd68057c1917 (MD5) Previous issue date: 2012 / Resumo: Atualmente uma série de países está promovendo ações para que as energias alternativas renováveis tenham participação significativa em suas matrizes energéticas, sendo a cana-de-açúcar apontada como uma das principais fontes para o estado de São Paulo. Contribuindo para aumentar ainda mais o potencial da cana, o palhiço vem despertando interesse dos usineiros, uma vez que possui um importante equivalente energético quando comparado ao barril de petróleo. O reaproveitamento do palhiço dependerá em linhas gerais da rota tecnológica utilizada para converter a energia bruta em energia disponível (cogeração de energia é a rota mais difundida nas usinas); da viabilidade técnica do seu recolhimento (colheita integral é considerada de mais curto prazo); da viabilidade técnica do seu processamento; da viabilidade econômica considerando todos os custos, investimentos necessários e receitas provenientes da conversão do palhiço em energia. Portanto, esta pesquisa teve como objetivo contribuir com a criação de um modelo que permita determinar qual é o limite técnico para o processamento do palhiço adicional recolhido via colheita integral, respeitando o limite agronômico e considerando uma usina que queira melhor utilizar a sua capacidade instalada na recepção (01 hillo e 01 mesa alimentadora) e decida investir em uma estação de limpeza à seco. Além disso, o modelo se propôs a avaliar a rentabilidade do investimento necessário para recuperação e processamento do palhiço adicional para fins de cogeração de energia, considerando todos os investimentos agrícolas e industriais para a rota via colheita integral, tendo como base de comparação o cenário atual de recebimento de palhiço por esta mesma rota. Os resultados apresentados para os dados simulados demonstram que a máxima quantidade de palha que uma Usina preparada com 01 hillo + 01 mesa alimentadora e 01 sistema de limpeza à seco pode receber é 7% (base mássica) do total da biomassa de entrada. Já respeitando o limite agronômico, o máximo de palha contida na biomassa de entrada da usina é de 5,26%. Portanto o cenário limite considerado de quantidade de palha contida na biomassa de entrada foi de 5,26%. A análise econômica indicou que o cenário de 5,26% foi o de maior rentabilidade (TIR,VPL, PAYBACK) quando comparado ao cenário com quantidade atual de recebimento de palha (1,56% base mássica) e ao cenário intermediário (3% base mássica), sendo que a existência do picador de palha inviabiliza qualquer cenário. Considerando uma distância lavoura usina de 25 km, nenhum cenário é considerado viável economicamente para uma remuneração de cogeração de energia inferior a R$150/ MWh. Vale ressaltar que os dados de entrada variam com a realidade de cada usina e que o modelo computacional está preparado para receber quaisquer dados / Abstract: Currently a lot of countries are promoting actions so that the renewable energy alternatives have significant participation in its energy mix, and the sugarcane is considered the main available source for Sao Paulo state. Contributing to further increase the sugarcane potential, sugarcane trash (tops, green and dry leaves) has become attractive for the owners, since it has as important energy equivalent when compared to the American oil barrel. The sugarcane trash reuse depends on the technological route used to convert the raw energy in available energy (cogeneration is the most widespread in mills), the technical feasibility of its recover (collected by mechanized unburned cane harvest is considered shorter-term) the technical feasibility of its processing; economic viability considering all costs, required investments and income from the conversion of sugarcane trash into energy. The objective of this work was to create one model to determine what is the technical limit to the additional processing of sugarcane trash collected by mechanized unburned cane harvest, respecting the agronomic limit, considering mill that wants to better use its capacity in reception (01 hillo and 01 cane feed table) and decides to invest in a dry factory trash separation plant. Furthermore, the model proposed to evaluate the investment profitability needed for recovery and processing of additional sugarcane trash for cogeneration of energy, considering all agricultural and industrial investments for collecting system of the sugarcane trash by mechanized unburned cane harvest, based on comparison of the current scenario receipt of sugarcane trash by the same route. The results presented for the simulated data show that the maximum straw amount which a plant prepared with 01 hillo, 01 cane feed table and 01 and the dry factory trash separations plant can receive is 7% (w / w) of total biomass input. Already within the limit agronomic maximum straw contained in biomass input of the plant is 5.26%. Therefore the scene considered to limit the amount of straw input contained in biomass was 5.26%. The economic analysis indicated that the scenario of 5.26% was the highest return (IRR, VPL, PAYBACK) when compared to the scenario with the current number of receiving straw (1.56% w / w) and the intermediate scenario (3 % w / w), and the existence of the straw chopper prevents any scenario. Considering a crop plant 25 km away, no scenario is economically viable for a considerable fee cogeneration power less than $ 150 / MWh. Note that the input data vary with the reality of each plant and that the computational model is ready to receive any data / Mestrado / Construções Rurais e Ambiencia / Mestra em Engenharia Agrícola

Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.

Bioethanol is likely to be a large contributor to the fuel sector of industry in the near future. Current research trends are geared towards utilizing food crops as substrate for bioethanol fermentation; however, this is the source of much controversy. Utilizing food crops for fuel purposes is anticipated to cause massive food shortages worldwide. Cellulose is the most abundant renewable resource on earth and is subject to a wide array of scientific study in order to utilize the glucose contained within it. Waste paper has a high degree of cellulose associated with it, which makes it an ideal target for cellulose biotechnology with the ultimate end goal of bioethanol production. This study focussed on producing the necessary enzymes to hydrolyse the cellulose found in waste paper and using the sugars produced to produce ethanol. The effects of various printing inks had on the production of sugars and the total envirorunental impact of the effluents produced during the production line were also examined. It was found that the fungus Trichoderma longibrachiatum DSM 769 grown in Mandel's medium with waste newspaper as the sole carbon source at 28 °C for 6 days produced extracellular cellulase enzymes with an activity of 0.203 ± 0.009 FPU.ml⁻¹, significantly higher activity as compared to other paper sources. This extracellular cellulase was used to hydrolyse waste newspaper and office paper, with office paper yielding the highest degree of sugar production with an end concentration of 5.80 ± 0.19 g/1 at 40 °C. Analysis by HPLC showed that although glucose was the major product at 4.35 ± 0.12 g/1, cellobiose was also produced in appreciable amounts (1.97 ± 0.71 g/1). The sugar solution was used as a substrate for Saccharomyces cerevisiae DSM 1333 and ethanol was produced at a level of 1.79 ± 0.26 g/1, the presence of which was confirmed by a 600 MHz NMR spectrum. It was found that cellobiose was not fermented by this strain of S. cerevisiae. Certain components of inks (the PAHs phenanthrene and naphthalene) were found to have a slight inhibitory effect (approximately 15% decrease) on the cellulase enzymes at very high concentrations (approximately 600 μg/1 in aqueous medium), while anthracene had no effect. Whole newsprint ink was shown not to sorb glucose. The environmental analysis of the effluents produced showed that in order for the effluents to be discharged into an aqueous ecosystem they would have to be diluted up to 200 times. They were also shown to have the potential to cause severe machinery damage if reused without proper treatment.

The cellulosome is a multimeric enzyme complex that has the ability to metabolise a wide variety of carbonaceous compounds. Cellulosomal composition may vary according to the microbe’s nutritional requirement and allows for the anaerobic degradation of complex substrates. The complex substrates of interest in this research study were sugarcane bagasse and pineapple fibre waste, as they represent two important lignocellulosic, South African agricultural crops. The effective degradation of complex plant biomass wastes may present a valuable source of renewable compounds for the production of a variety of biofuels, for example bioethanol, and a variety of biocomposites of industrial importance. The identification of renewable energy sources for the production of biofuels is becoming increasingly important, as a result of the rapid depletion of the fossil fuels that are traditionally used as energy sources. An effective means of completely degrading lignocellulose biomass still remains elusive due to the complex heterogeneity of the substrate structure, and the fact that the effective degradation of the substrate requires a consortium of enzymes. The cellulosome not only provides a variety of enzymes with varying specificities, but also promote a close proximity between the catalytic components (enzymes). The close proximity between the enzymes promotes the synergistic degradation of complex plant biomass for the production of valuable energy products. Previous synergy studies have focused predominantly on the synergistic associations between cellulases; however, the synergy between hemicellulases has occasionally been documented. This research project established the synergistic associations between two Clostridium cellulovorans hemicellulases that may be incorporated into the cellulosome and a cellulosomal endoglucanase that is conserved in all cellulosomes. This research study indicated that there was indeed a synergistic degradation of the complex plant biomass (sugarcane bagasse and pineapple fibre). The degrees of synergy and the ratio of the enzymes varied between the two complex substrates. The initial degradation of the bagasse required the presence of all the enzymes and proceeded at an enhanced rate under sulphidogenic conditions; however, there was a low production of fermentable sugars. The low quantity of fermentable sugars produced by the degradation of the bagasse may be related to the chemical composition of the substrate. The sugarcane contains a high percentage of lignin forming a protective layer around the holocellulose, thus the glycosidic bonds are shielded extensively from enzymatic attack. In comparison, the initial degradation of the pineapple fibre required the action of hemicellulases, and proceeded at an enhanced rate under sulphidogenic conditions. The initial degradation of the pineapple fibre produced a substantially larger quantity of fermentable sugars in comparison to the bagasse. The higher production of fermentable sugars from the degradation of the pineapple fibre may be explained by the fact that this substrate may have a lower percentage of lignin than the bagasse, thus allowing a larger percentage of the glycosidic bonds to be exposed to enzymatic attack. The data obtained also indicated that the glycosidic bonds from the hemicellulosic components of the pineapple fibre shielded the glycosidic bonds of the cellulose component. The identification of the chemical components of the different substrates may allow for the initial development of an ideal enzyme complex (designer cellulosome) with enzymes in an ideal ratio with optimal synergy that will effectively degrade the complex plant biomass substrate.

The sugar beet (Beta vulgaris) plant has in recent years been added to the Biofuel Industrial Strategy (Department of Minerals and Energy, 2007) by the South African government as a crop grown for the production of bio-ethanol. Sugar beet is commonly grown in Europe for the production of sucrose and has recently been cultivated in Cradock and the surrounding areas (Engineering News, 2008). The biofuel industry usually ferments the sucrose with Saccharomyces cerevisiae to yield bio-ethanol. However, researchers are presented with a critical role to increase current yields as there are concerns over the process costs from industrial biotechnologists. The beet factories produce a pulp by-product removed of all sucrose. The hemicellulose-rich pulp can be degraded by microbial enzymes to simple sugars that can be subsequently fermented to bio-ethanol. Thus, the pulp represents a potential source for second generation biofuel. The process of utilising microbial hemicellulases requires an initial chemical pre-treatment step to delignify the sugar beet pulp (SBP). An alkaline pre-treatment with ‘slake lime’ (calcium hydroxide) was investigated using a 23 factorial design and the factors examined were: lime load; temperature and time. The analysed results showed the highest release of reducing sugars at the pre-treatment conditions of: 0.4 g lime / g SBP; 40°C and 36 hours. A partial characterisation of the Clostridium cellulovorans hemicellulases was carried out to verify the optimal activity conditions stated in literature. The highest release of reducing sugars was measured at pH 6.5 – 7.0 and at 45°C for arabinofuranosidase A (ArfA); at pH 5.5 and 40°C for mannanase A (ManA) and pH 5.0 – 6.0 and 45°C for xylanase A (XynA). Temperature studies showed that a complete loss of enzymatic activity occurred after 11 hours for ManA; and 84-96 hours for ArfA. XynA was still active after 120 hours. The optimised lime pre-treated SBP was subsequently degraded using various combinations and percentages of C. cellulovorans ArfA, ManA and XynA to determine the maximal release of reducing sugars. Synergistically, the highest synergy was observed at 75% ArfA and 25% ManA, with a specific activity of 2.9 μmol/min/g protein. However, the highest release of sugars was observed at 4.2 μmol/min/g protein at 100% ArfA. This study has initiated the research within South Africa on SBP and its degradation by C. cellulovorans. Preliminary studies show that SBP has the potential to be utilised as a second generation biofuel source.

Made available in DSpace on 2017-06-01T18:20:25Z (GMT). No. of bitstreams: 1 dissertacao_fernando_luiz.pdf: 33790100 bytes, checksum: c4cc04374bb2b0dcd638242804eebd1f (MD5) Previous issue date: 2009-03-24 / The recovery of by-products like glycerin and cake from oilseeds, resulting in the production of biodiesel, has been the main alternative to make this biofuel competitive compared to petroleum and diesel oil. This alternative can be associated with a beneficial integration of processes, such as use of glycerin as a solvent for separation of ethanol-water mixture in plants alcohol. Thus, the use of glycerin in place of ethylene glycol, a substance of fossil origin was tested. The glycerin eliminates the azeotrope formed by modification of the liquid-vapor equilibrium of ethanol-water mixture, increasing the difference in volatility between these components. To verify the operating conditions suitable for the process of extractive distillation for ethanol dehydration, experiments were performed in laboratory scale, using a central composite rotational design (CCRD). The independent variables were the molar fraction glycerol / water and the degree of vacuum, the latter as a way to avoid thermal decomposition of glycerol into acrolein. The analysis of the response surfaces showed that the molar fraction glycerin / ethanol becomes appropriate than 0.4 and the absolute pressure of the system is adequate around 380 mm Hg. In this way it was possible to obtain a statistical model for simulation and prediction of appropriate conditions to the process for developing a technology that prior actions to preserve the environment. / A valorização dos subprodutos como a glicerina e a torta de oleaginosas, originados no processo de produção de biodiesel, tem sido a principal alternativa para tornar esse biocombustível competitivo em relação ao diesel de petróleo. Essa alternativa pode estar associada a uma vantajosa integração de processos, como é o caso de utilização da glicerina como solvente para separação da mistura etanol-água em usinas de álcool. Para isso, estudou-se a utilização da glicerina em substituição ao etilenoglicol, esta última substância de origem fóssil. A glicerina elimina o azeótropo formado pela modificação do equilíbrio líquido-vapor da mistura etanol-água, aumentando a diferença de volatilidade entre esses componentes. Para verificação das condições operacionais adequadas ao processo de destilação extrativa de desidratação do etanol, foram realizados experimentos em escala de laboratório, com auxílio de um Delineamento Composto Central Rotacional (DCCR). As variáveis independentes foram a fração molar glicerina/água e o grau de vácuo, este último como forma de se evitar a decomposição térmica da glicerina em acroleína. A análise das superfícies de resposta mostrou que a fração molar glicerina/etanol torna-se adequada acima de 0,4 e que a pressão absoluta do sistema torna-se adequada em torno de 380 mm Hg. Com isto, obteve-se um modelo estatístico de simulação e a previsão de condições adequadas ao processo, para o desenvolvimento de uma tecnologia que privilegie as ações de preservação ao meio ambiente.

Thesis (Ph. D. (Microbiology)) -- University of Limpopo, 2020 / The use of lignocellulosic biomass for bioethanol production is largely dependent on cost effective production of cellulase enzymes and most importantly, the availability of cellulases with sufficient β-glucosidase activity for complete hydrolysis of cellulose to glucose. Commercial cellulase preparations are often inefficient in the complete hydrolysis of cellulose to glucose. The addition of β-glucosidases to commercial cellulase preparations may enhance cellulolytic activity in the saccharification of cellulose to fermentable sugars. A β-glucosidase producing thermophilic bacterium, Anoxybacillus sp. KTC2 was isolated from a hot geyser in the Zambezi Valley, Zimbabwe. The bacterium identified through biochemical tests and 16S rDNA sequencing, had an optimal growth temperature and pH of 60˚C and pH 8, respectively. The β-glucosidase enzyme had an optimal temperature of 60˚C and a broad pH range for activity, between 4.5 and 7.5 with an optimum at pH 7. The β-glucosidase enzyme retained almost 100% activity after 24 hours’ incubation at 50˚C. The Anoxybacillus sp. KTC2 β-glucosidase was partially purified and a partial amino acid sequence obtained through MALDI-TOF analysis. The whole genome of Anoxybacillus sp KTC2 β-glucosidase was sequenced and a β-glucosidase gene identified. The deduced amino acid sequence corresponded to the peptide sequences obtained through MALDI-TOF, confirming the presence of the a β glucosidase on the genome of Anoxybacillus sp KTC2. Analysis of the deduced amino acid sequence revealed that the β-glucosidase enzyme belongs to the GH family 1. The β-glucosidase gene was isolated by PCR and successfully cloned into an E. coli expression system. The saccharification efficiency of the β-glucosidase enzyme was evaluated through the creation of enzyme cocktails with the commercial cellulase preparation, CelluclastTM. CelluclastTM with the Anoxybacillus sp KTC2 β-glucosidase were used to hydrolyse pure Avicel cellulose, at 50˚C over a 96 hour reaction time. The Anoxybacillus sp KTC2 β-glucosidase enabled a 25% decrease in the total cellulose loading without a decrease in the amount of glucose released. / University of Limpopo staff development programme and VLIR