Orientador: Gilbert Bannach / Banca: Egon Schnitzler / Banca: Roni Antonio Mendes / Resumo: A síntese de polímeros a partir de resíduos industriais e biomassa é o foco de muitas pesquisas realizadas atualmente, as quais buscam a sustentabilidade, viabilidade econômica e a preservação ambiental. Desta forma, um dos reagentes utilizados é o glicerol, proveniente da produção do biodiesel, este já é utilizado na síntese orgânica como solvente e como monômero na síntese de polímeros. Uma vantagem do glicerol é ser de baixo custo, considerado um composto verde, ou seja, apresenta baixo risco a saúde e ao meio ambiente. O foco do trabalho foi obter novos materiais de interesse tecnológico seguindo os conceitos da química verde e utilizando glicerol como principal reagente nas sínteses poliméricas; um dos sistemas abordados foi a fotopolimerização do glicerol com monômeros dimetacrilatos (uretano dimetacrilato, Bisfenol A dimetacrilato etoxilado, Bisfenol A dimetacrilato glicerolado e Dimetacrilato de trietilenoglicol) uma vez que é de conhecimento que o glicerol pode atuar como coiniciador radicalar na reação. Outro sistema proposto foi utilizando ácido acrílico com éster de glicerol no processo de fotopolimerização. Por fim, os dois últimos sistemas utilizam o glicerol para a obtenção de polímeros a partir de óleos vegetais. Na caracterização dos polímeros sintetizados foram utilizadas as técnicas termoanalíticas como Termogravimetria-Análise Térmica Diferencial Simultânea (TG-DTA) e Calorimetria Exploratória Diferencial (DSC), para a determinação da estabilidade térmica,... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Polymers synthesis from industrial waste and biomass is the aim of researchers nowadays that seek sustainability, economic viability, and environmental preservation. Thus, one of the used reactants is glycerol, from biodiesel production, which is used as a solvent in organic synthesis and monomer in polymers syntheses. One glycerol advantage is that it be cheap and considered a green compound, in the other words, it shows low health and environmental risk. The principal aim of this work is to get some new technological materials following green chemistry principles, and using glycerol as the principal reactant in polymer syntheses. The photopolymerization was used to get polymers from dimethacrylate monomers (urethane dimethacrylate, bisphenol A glycerolate dimethacrylate, bisphenol A ethoxylate dimethacrylate and triethylene glycol dimethacrylate) and glycerol, which could be used as radicalar coinitiator in its reaction. Another system in this work used acrylic acid and a glycerol ester in photopolymerization process. The last two system used the glycerol and vegetable oil to obtain polymers. To polymers characterization were used thermoanalytical techniques such as Simultaneous Thermogravimetry-Differential Thermal Analysis (TG-DTA) and Differential Scanning Calorimetry (DSC) to determination of thermal stability, degradation steps, thermal polymerization, glass transition, melt point, and volatilization, as well as Middle Infrared Spectroscopy (MIR) to studies about degre... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:35:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-04-10Bitstream added on 2014-06-13T20:46:06Z : No. of bitstreams: 1 sequinel_r_dr_araiq.pdf: 1034994 bytes, checksum: 847488302a85eccd70a146df5b912453 (MD5) / A glicerina bruta emergente da cadeia de produção de biodiesel contém alguns produtos intermediários da reação, resíduos de catalisador, água, metanol e vem se tornando o novo desafio do Programa Nacional de Produção e Uso do Biodiesel – PNPB. Neste trabalho foi realizada a caracterização completa de amostras de glicerina bruta, glicerina loira e glicerina bidestilada. Os parâmetros analisados foram aspecto, pH, teor de água, teor de metanol, teor de matéria orgânica não glicerol (MONG), teor de glicerol, além da realização de ensaio qualitativo para presença de elementos metálicos e não metálicos. De acordo com os resultados obtidos, as características físico químicas variaram muito de uma amostra para outra. Esta diferença foi principalmente observada em decorrência de processos de transesterificação problemáticos ou mesmo devido aos tratamentos de purificação a que são submetidas as amostras de glicerina. Enquanto uma amostra de glicerina loira contém em torno de 80% de glicerol, em uma amostra de glicerina bruta este valor pode ficar abaixo de 50%. Os resultados mostraram também ser possível a obtenção de glicerol com alto grau de pureza, acima de 97%, a partir de amostras de glicerina bruta. O grau de purificação vai depender da aplicação a que estas se destinam, entretanto, a utilização de processos de tratamento incompletos ou inadequados compromete a qualidade do produto. Deste modo, a determinação de todos os parâmetros citados neste trabalho é de suma importância para fornecer dados que possam ser úteis no estabelecimento de padrões de qualidade para a glicerina. No que diz respeito ao teor de metanol, como não foi encontrado um método oficial na literatura, foi validado um novo procedimento analítico para determinação deste parâmetro, utilizando a técnica de CG-HS. As condições cromatográficas utilizadas foram injetor... / The crude glycerin emerging from the biodiesel production process contains some intermediate products from reaction, residue of catalyst, moisture, methanol and for this reason is becoming the new challenge of the National Program of Production and Use of Biodiesel – PNPB. In this thesis it was performed a complete characterization of crude glycerin samples, blond glycerin samples and bi-distilled glycerin samples. All parameters analyzed were aspect, pH, water content, methanol content, material organic non-glycerol, glycerol content, as well as the qualitative determination of some metallic and non-metallic elements that may be present. According to the results obtained there was a great variation among the physic-chemical characteristics from the samples. This difference was mostly due to problematic transesterification process or due to some purification treatment which glycerin samples were submitted. While the glycerol content is around to 80% for a blond glycerin sample, this value may be bellow to 50% for crude glycerin samples. The results also showed it is possible to obtain glycerol of high purity grade, above to 97%, from crude glycerin samples. The desired purity grade depends on the future destination of the glycerin, however, the application of incomplete or inadequate treatment may compromise the quality of the product. Therefore, the determination of all physic-chemical parameters listed in this document becomes an important step to provide enough information to establish a quality standard for glycerin. Regarding the methanol content, since it was not found in literature an official method, it was developed and validated a new test procedure for this determination using GC-HS. The chromatographic conditions were PTV and FID temperatures at 300 °C. The oven temperature program was an initial hold at 50 °C for 3 min, followed... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:23:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-07-29Bitstream added on 2014-06-13T20:29:46Z : No. of bitstreams: 1 possato_lg_me_araiq.pdf: 1057064 bytes, checksum: 7e9daced79c0c4a6d80f9103825ca11a (MD5) / As propriedades catalíticas de zeólitas micro e micro-mesoporoas foram avaliadas pela desidratação do glicerol em fase gasosa. A dessilicação foi a metodologia utilizada para criar mesoporos nas zeólitas, diminuir as limitações difusionais e aumentar a conversão de glicerol devido a esse sistema hierárquico de poros criados no cristal zeolítico. A composição química e estrutural dos catalisadores foi estudada por difração de raios-X, isotermas de adsorção-dessorção de nitrogênio, TPD-NH3 e quimissorção de piridina seguida por espectroscopia IV. Embora o objetivo fosse dessilicar para criar mesoporosidade nos cristais zeolíticos, a dessilicação promoveu a firmação de alumínio extra-rede que afeta a conversão e a distribuição dos produtos. Os resultados mostram claramente que zeólitas mesoporosas permitem a rápida difusão e consequentemente melhoram a cinética da reação. Entretanto, uma atenção especial foi dada à dessilicação porque tratamentos severos afetam negativamente, interferindo na distribuição relativa dos sítios ácidos de Brønsted e Lewis e, consequentemente, na ineficiência catalítica promovida por esses materiais. Contudo, durante a reação catalítica, os mesoporos intra-cristalisnos permitem compostos carbonáceos serem depositados dentro dos mesmos, resultando em microporos menos bloqueados por coque e aumentando a sua estabilidade / The catalytic properties of monomodal microporous and bimodal micro-mesoporous zeolites were investigated in the gas-phase dehydration of glycerol. The desilication methodology used to produce the mesoporous zeolites minimized diffusion limitations and increased glycerol conversion in the catalytic reaction due to the hierarchical system of secondary pores created in the zeolite crystals. The chemical and structural properties of the catalyst were studied by X-ray diffraction, nitrogen adsorption–desorption isotherms, NH3-TPD and pyridine chemisorption followed by IR-spectroscopy. Although the aim was to desilicate to create mesoporosity in the zeolite crystals, the desilication promoted the formation of extra-framework aluminum species that affected the conversion of glycerol and the products distribution. The results clearly show that the mesoporous zeolites with designed mesopore structure allowed a rapid diffusion and consequently improved the reaction kinetics. However, especial attention must be given to the desilication procedure because the severity of the treatment negatively interfered on the Brønsted and Lewis acid sites relative concentration and, consequently, in the efficiency of the catalysis performed by these materials. On the other hand, during the catalytic reaction, the intracrystalline mesopores allowed carbonaceous compounds to be deposited herein, resulting in less blocked micropores and catalysts with higher long-term stability

Orientador: José Eduardo de Oliveira / Coorientador: Leonardo Pezza / Banca: Sandra Imaculada Mantiguer / Banca: José Fernando Machado Menten / Banca: Fabio da Silva Vinhado / Banca: Paulo Roberto de Oliveira / Resumo: A glicerina bruta emergente da cadeia de produção de biodiesel contém alguns produtos intermediários da reação, resíduos de catalisador, água, metanol e vem se tornando o novo desafio do Programa Nacional de Produção e Uso do Biodiesel - PNPB. Neste trabalho foi realizada a caracterização completa de amostras de glicerina bruta, glicerina loira e glicerina bidestilada. Os parâmetros analisados foram aspecto, pH, teor de água, teor de metanol, teor de matéria orgânica não glicerol (MONG), teor de glicerol, além da realização de ensaio qualitativo para presença de elementos metálicos e não metálicos. De acordo com os resultados obtidos, as características físico químicas variaram muito de uma amostra para outra. Esta diferença foi principalmente observada em decorrência de processos de transesterificação problemáticos ou mesmo devido aos tratamentos de purificação a que são submetidas as amostras de glicerina. Enquanto uma amostra de glicerina loira contém em torno de 80% de glicerol, em uma amostra de glicerina bruta este valor pode ficar abaixo de 50%. Os resultados mostraram também ser possível a obtenção de glicerol com alto grau de pureza, acima de 97%, a partir de amostras de glicerina bruta. O grau de purificação vai depender da aplicação a que estas se destinam, entretanto, a utilização de processos de tratamento incompletos ou inadequados compromete a qualidade do produto. Deste modo, a determinação de todos os parâmetros citados neste trabalho é de suma importância para fornecer dados que possam ser úteis no estabelecimento de padrões de qualidade para a glicerina. No que diz respeito ao teor de metanol, como não foi encontrado um método oficial na literatura, foi validado um novo procedimento analítico para determinação deste parâmetro, utilizando a técnica de CG-HS. As condições cromatográficas utilizadas foram injetor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The crude glycerin emerging from the biodiesel production process contains some intermediate products from reaction, residue of catalyst, moisture, methanol and for this reason is becoming the new challenge of the National Program of Production and Use of Biodiesel - PNPB. In this thesis it was performed a complete characterization of crude glycerin samples, blond glycerin samples and bi-distilled glycerin samples. All parameters analyzed were aspect, pH, water content, methanol content, material organic non-glycerol, glycerol content, as well as the qualitative determination of some metallic and non-metallic elements that may be present. According to the results obtained there was a great variation among the physic-chemical characteristics from the samples. This difference was mostly due to problematic transesterification process or due to some purification treatment which glycerin samples were submitted. While the glycerol content is around to 80% for a blond glycerin sample, this value may be bellow to 50% for crude glycerin samples. The results also showed it is possible to obtain glycerol of high purity grade, above to 97%, from crude glycerin samples. The desired purity grade depends on the future destination of the glycerin, however, the application of incomplete or inadequate treatment may compromise the quality of the product. Therefore, the determination of all physic-chemical parameters listed in this document becomes an important step to provide enough information to establish a quality standard for glycerin. Regarding the methanol content, since it was not found in literature an official method, it was developed and validated a new test procedure for this determination using GC-HS. The chromatographic conditions were PTV and FID temperatures at 300 °C. The oven temperature program was an initial hold at 50 °C for 3 min, followed... (Complete abstract click electronic access below) / Doutor

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Doctor of Philosophy / Department of Animal Sciences and Industry / James S. Drouillard / Two trials were conducted to evaluate the effects of crude glycerin in feedlot cattle. The objectives of this research were to determine the effects of crude glycerin on animal performance, carcass characteristics, ruminal metabolism, and diet digestibility when fed in steam-flaked corn finishing diets. Trial one utilized crossbred heifers (n = 373) fed finishing diets containing 0, 2, 4, 8, 12, or 16% crude glycerin. Feeding heifers crude glycerin at 8% or less of the diet resulted in improvements in body weight gain and feed efficiency. Dry matter intake decreased linearly (P < 0.001) when glycerin was included at increasing levels from 0 to 16%. Average daily gains of heifers fed crude glycerin increased when glycerin was fed at 2, 4, or 8% of diet DM, but reductions in ADG were noted when glycerin increased to 12 or 16% (linear, P = 0.013; quadratic, P = 0.010). Feeding glycerin had a quadratic effect on G:F, and was optimal when fed at 2% of DM (P = 0.46). Hot carcass weights increased when glycerin was fed at 2, 4, and 8% of the diet, but decreases in HCW were observed with 12 and 16% crude glycerin (linear, P = 0.009; quadratic, P = 0.006). Low concentrations of glycerin can be fed without negatively impacting animal performances. Trial two consisted of a 3 × 3 Latin Square and utilized cannulated crossbred steers (n = 9) fed finishing diets containing 0, 2, or 4% crude glycerin. Apparent total tract digestibilities of DM, OM, starch, CP, and crude fat were unaffected by the addition of glycerin at 0, 2, or 4% of cannulated steer diets (linear, P > 0.51). Apparent total tract digestibilities of NDF tended to decrease as glycerin concentrations increased to 2 and 4% (linear, P <0.13). Ruminal pH increased as glycerin concentrations increased (linear, P < 0.05), and concentrations of butyrate and valerate decreased (linear, P < 0.03). Acetate production also tended to decrease when glycerin increased from 0 to 2 or 4% of the diet (linear, P =0.06). Collectively, these results suggest that glycerin may negatively influence fiber digestion.

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This dissertation aims to expand our knowledge of glycerol-driven engineered biological nitrogen removal processes by elucidating the link between operational controls and the structure and function of the microbial ecology grown under stoichiometrically-limited and excess glycerol conditions. Specific objectives were to: 1. Develop and experimentally evaluate an improved metric for denitratation performance that can be objectively compared across studies; 2. characterize the process kinetics, nitrogen conversion efficiencies, and microbial ecology of a glycerol-driven, stoichiometrically-limited denitratation process; 3. elucidate the impact of kinetic limitation on microbial community structure and function in a glycerol-driven, stoichiometrically-limited denitratation process; 4. explore the biological mechanisms contributing to nitrite (NO2-) accumulation in a glycerol-driven denitratating microbial community; and, 5. characterize the nitrogen conversion efficiencies and microbial ecology that favor dissimilatory nitrate reduction to ammonium (DNRA) in a glycerol-driven denitrification process at stoichiometric excess. Accordingly, a nitrate (NO3-) conversion ratio (NaCR) was first proposed as an improved metric of denitratation performance metric. Previous metrics used throughout literature were deemed insufficient as they provided an incomplete and subjective representation of denitratation performance by not accounting for residual NO3- remaining in the system following the selective reduction of NO3- to NO2-. The NaCR represented a singular metric that better signifies true denitratation performance and can be compared across studies regardless of carbon source or system configuration. Second, a glycerol-driven denitratation process was optimized according to different operational controls. Steady-state reactor operation and in situ and ex situ batch assays indicated that the influent chemical oxygen demand to NO3- (COD:NO3--N) ratio was determined to influence process kinetics and nitrogen conversion efficiencies leading to significant NO2- accumulation. A singular microbial community structure correlated to system performance was identified. Third, the application of kinetic limitation (by imposing different solids retention times [SRTs]) at a given influent COD:NO3--N ratio was demonstrated as an effective mechanism in the selection for a denitratating microbial ecology capable of significant NO2- accumulation. Steady-state reactor operation was used to characterize process kinetics and nitrogen conversion ratios supporting the determination of the optimal SRT for reactor operation. Analysis of the microbial community structure elucidated the impacts of kinetic limitation on the microbial ecology which were correlated to system performance. Functional denitrification gene transcripts were found to be significantly different under kinetic limitation, indicating that NO2- accumulation was driven more by differences in microbial community structure as opposed to differential expression at different operating SRTs. Fourth, ex situ batch assays were used to elucidate the microbial transcriptional response to the presence of varied sequences of electron acceptors. The microbial community was found to be enriched with NO3--respirers, or microorganisms incapable of NO2- reduction, and progressive onset denitrifiers, which express functional denitrification genes in sequence. The presence or re-introduction of NO3- in a NO2--reducing community was found to elicit an immediate transcriptional change and shift of electron flow to NO3- reductase. Electron competition as the primary contribution to NO2- accumulation was confirmed through the artificial inactivation of NO3- reductase. Lastly, an influent COD:NO3--N ratio was applied in stoichiometric excess to create the conditions necessary to support DNRA over denitrification. System performance at steady-state was found to vary under different kinetic regimes. The induction of DNRA was found to be far more complex than simply providing glycerol in stoichiometric excess. Additionally, glycerol does not appear to be an optimal COD source for DNRA under these conditions. In sum, the optimization of engineered biological nitrogen removal processes through the manipulation of process kinetics and the resulting impacts on nitrogen conversion efficiencies and microbial community structure and function was investigated in detail. From an engineering perspective, this knowledge can help guide the design and operation of biological nitrogen removal processes to systematically maximize the accumulation of targeted nitrogenous products or mitigate unintentional and undesired products.

No description available.