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Navegando Mestrado em Engenharia Química (IQ) por Por Orientador "Montano, Inti Doraci Cavalcanti"
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Item Pré-tratamento hidrotérmico do bagaço de malte (BSG) visando a produção de etanol de segunda geração(Universidade Federal de Goiás, 2019-02-26) Maione, Nicole Ribeiro; Rodrigues, Dasciana de Sousa; http://lattes.cnpq.br/8321796631800718; Montano, Inti Doraci Cavalcanti; http://lattes.cnpq.br/8547423775951223; Montano, Inti Doraci Cavalcanti; Rodrigues, Dasciana de Sousa; Freitas, Fernanda Ferreira; Delabona, Priscila da SilvaBrazil is the third largest producer of beer in the world and brewer’s spent grain (BSG) is the main residue of this industry. As a low-cost, available lignocellulosic material, it has become an attractive alternative for the production of biofuels and other chemicals. Thus, to be able to take advantage of BSG as a raw material it must first be pre-treated. Hydrothermal pre- treatment allows the removal of the fraction of hemicellulose present in the lignocellulosic material and brake the lignocellular crystallinity. In this work, initially was performed the characterization of the BSG in natura, obtaining 25.1% of cellulose, 20.9% of hemicellulose, 20.3% of lignin and 28.0% of proteins. Evaluating the effect of temperature and time of hydrothermal pretreatment, the best result was at 160°C and 60 min, with cellulose yield of 64.8% and removal of hemicellulose of 62.0%. In a second experiment, the temperature and solids content of the pretreatment and its effect on the enzymatic hydrolysis were analyzed, obtained better glucose yield, 74.1%, in the enzymatic hydrolysis of the pretreated at 180°C and 40 g of dry BSG, containing 0.020 g furfural, 0.062 g HMF and 0.902 g acetic acid (per 100 g dry BSG) which are inhibitors of the fermentation process. As the present study aimed at the production of 2G ethanol by fermentation, the condition of pretreatment 160 °C, 80 g was chosen for the pretreatment kinetic study, since it presented a high glucose yield, 66.3%, and a lower concentration of inhibitors of the fermentation process with 0.020 g Furfural 0.020 g HMF and 0.444 g acetic acid (per 100 g dry BSG). In a second condition, pretreatment kinetics were performed for comparison reasons (200°C / 80g). Samples were withdrawn at times 0, 5, 10, 20, 40 and 60 min. Results showed that the reaction time of 10 min obtained better cellulose yield in the solid fraction at 160°C and at 200°C the highest yield of cellulose was in 5 min. In the liquid fraction, the concentrations of oligomers did not change significantly when varied the reaction time at 160°C, while in the temperature of 200°C there was a considerable increase of oligomers in 5 minutes. The amounts of glucose released in the processes studied were not satisfactory high to consider hydrothermal pretreatment to BSG as feasible for the production of second generation ethanol.Item Otimização de reator batelada alimentada para hidrolise de palha de cana de açúcar aplicando a teoria do controle ótimo(Universidade Federal de Goiás, 2016-09-30) Pinto, Vitor Debiazzi Pereira; Suarez, Carlos Alberto Galeano; http://lattes.cnpq.br/5911055089145779; Montano, Inti Doraci Cavalcanti; http://lattes.cnpq.br/8547423775951223; Montano, Inti Doraci Cavalcanti; http://lattes.cnpq.br/8547423775951223; Suarez, Carlos Alberto Galeano; http://lattes.cnpq.br/5911055089145779; Sousa Junior, Ruy de; Freitas, Fernanda Ferreira; Horta, Antonio Carlos LuperniFrom the economic point of view it is important to process high charges of solid in enzimatic hydrolysis of the lignocellulosic residues for the production of 2G ethanol, but batch operation with high initial charges of substrate can cause inefficient mixture, damaging the reactional process. An attractive alternative is operating the reactors in fed batch. The aim of this work was to determine, applying the theory of optimal control, the optimal feeding profile of substrate in bench reactor. For this, it was tested two kinetic of Michaelis-Menten: pseudo-homogeneous Michaelis-Menten kinetic and Michaelis Menten kinetic with inhibition by the product, in the last kinetic was obtained the best fit to experimental data. The developed algorithm was run in Matlab® software and the simulation results were experimentally validated. Enzymatic hydrolysis assays were performed with hydrothermally pre-treated sugar cane straw followed by the alkaline delignification. It was obtained good fiting of the simulation data with respect to the experimental data, with values of glucose final concentration close to 164.647 g/L (triplicate average) and in simulation the concentration was 174.93 g/L. Proving that the sugar cane straw, besides being a good feedstock cheap and abundant, it has a great energetic potential. Furthermore, the optimal control strategy was very efficient in optimization of the proposed problem.Item Fermentação de licor de hemicelulose advindo do pré-tratamento hidrotérmico do bagaço de malte com as leveduras Scheffersomyces stipitis e Pachysolen tannophilus para produção de etanol 2G(Universidade Federal de Goiás, 2019-08-30) Silva, Elizabeth Gonçalves da; Suarez, Carlos Alberto Galeano; http://lattes.cnpq.br/5911055089145779; Montano, Inti Doraci Cavalcanti; http://lattes.cnpq.br/8547423775951223; Montano, Inti Doraci Cavalcanti; Suarez, Carlos Alberto Galeano; Freitas, Fernanda Ferreira; Faria, Fabrícia Paula deEthanol is considered an important alternative energy source that contributes to alleviate energy problems and global warming caused by the accumulation of CO2 from burning fossil fuels. In this sense, the production of ethanol from lignocellulosic materials, known as second generation ethanol (2G), has stood out for presenting environmental advantages and economical. However, the economic viability of this process depends on the utilization of all fermentable fractions present in the different lignocellulosic materials under study, allowing the conversion of both cellulose (C6) and hemicellulose (C5) into ethanol. After the hydrolysis step of these materials is generated as main sugars, glucose and xylose, respectively. Xylose is not fermented by Saccharomyces cerevisiae (yeast widely used in 1G ethanol production), however Scheffersomyces stipitis and Pachysolen tannophilus are considered good biocatalysts for 2G fuel. This work evaluated xylose consumption and metabolites produced in different types of fermentation media. (YPX, MMX and hydrothermal pretreatment liquor from brewer’s spent grain supplemented) in aerobic system and with oxygen limitation. Using two pentose fermenting yeasts, S. stipitis and P. tannophilus, as an industrially viable alternative for the production of bioethanol in brewer’s spent grain hemicellulosic liquor, in order to determine between the two strains cited, a yeast with high ethanol/xylitol selectivity from the fermentation of this liquor through the conversion of xylose. The crops were performed in shaken flasks 500 mL volume filled with 200 mL of inoculated media at 200 rpm with a temperature of 30 ° C; and in 2 mL eppendorfs containing 1.5 mL of the inoculated media at 100 rpm and 30 °C. In cultures with aerobic conditions cell concentrations up to 10.64 g/L were achieved with the P. tannophilus strain in YPX media compared with the cell concentration of 5.42 g/L of the S. stipitis strain in YPX media but in oxygen limitation. At the end of the process were evaluated the kinetic parameters of each yeast in the different culture media and the values for maximum specific speed, xylose conversion factor in cells, xylose conversion factor in ethanol and xylitol were μmax = 0,21 h-1 to S. stipitis in the YPX media under aerobic conditions, Yx/s = 0,56 to P. tannophilus in the YPX media under aerobic conditions, YP/S(etanol) = 0,26 to S. stipitis in the YPX media under oxygen limitation, YP/S(xylitol) = 0,55 to S. stipitis in the MMX media under oxygen limitation. But for the researched environment, hemicellulose liquor from brewer’s spent grain supplemented with MMX components with 1.5 g/L urea obtained better responses for S. stipitis in relation to cell growth and ethanol production under aerobic conditions, already for ethanol production under conditions of oxygen limitation obtained better yield to P. tannophilus, as well as to the production factor of xylitol in the two oxygenation conditions studied. Therefore for better ethanol production the S. stipitis yeast had the highest YP/S(ethanol) = 0,1 under aerobic conditions, and for xylitol production the P. tannophilus strain is the most effective reaching YP/S(xylitol) = 0,46 under conditions of oxygen limitation. With the use of LHBMS media with urea at 6 g/L S. stipitis presented similarity with the conversion factors of urea (1.5 g/L) in the studied oxygen conditions, increasing only the accumulation of ethanol mainly in limitation of oxygen, reaching 3.9 g/L. In this media for P. tannophilus the yield was not plausible, prevailing the media with lower concentration of nitrogen source, because it favored the production of acetic acid, inhibiting the cellular metabolism of this yeast.