Efeito dos pré-tratamentos químicos e físicos do bagaço de cana-de-açúcar na hidrólise enzimática
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2013-01-28
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Universidade Estadual Paulista (Unesp)
Resumo
Com a crescente demanda por fontes alternativas de combustíveis, a produção de etanol a partir de materiais lignocelulósicos torna-se uma opção interessante. Esse processo permite o aumento da produção de etanol sem a necessidade de crescimento da área plantada dos cultivares utilizados. Para a produção do etanol celulósico é necessário o fracionamento da biomassa de forma a disponibilizar a maior quantidade de carboidratos possível para o processo de fermentação alcoólica, porém essa biomassa precisa de um pré-tratamento para desorganizar a estrutura recalcitrante do material. Neste sentido, o principal objetivo deste projeto foi avaliar os métodos de pré-tratamentos alcalino, utilizando hidróxido de cálcio, e hidrotérmico, utilizando água, nos bagaços de cana-de-açúcar in natura (obtido diretamente da moenda) e explodido (submetido a explosão a vapor). Foram testados os tempos de 7, 30 e 60 minutos em ambos os tratamentos a uma temperatura de 120 °C em autoclave. Foram realizados planejamentos fatoriais completos a fim de analisar a influência do hidróxido de cálcio e do tempo no desempenho da hidrólise, quantificando a liberação de glicose e açúcares redutores totais (ART). Dessa maneira foram realizadas análises da composição química do bagaço pré-tratado a fim de avaliar uma possível correlação entre as modificações na estrutura do material e a eficiência da hidrólise. Os resultados mostraram que os melhores rendimentos foram obtidos com o bagaço in natura pré-tratado com hidróxido de cálcio em todos os tempos testados, a hidrólise enzimática desse material resultou em um rendimento mais alto, de 3,2 a 4,3 vezes, em comparação com a hidrólise no bagaço in natura sem pré-tratamento. Um novo planejamento foi realizado, delineamento composto central superfície resposta, para determinar as...
Due to the growing demand for alternative sources of fuel, ethanol production from lignocellulosic materials became an interesting option. This process allows the increase of ethanol production without the need of growth of the planted area of the cultivars used. For the production of cellulosic ethanol is necessary to fractionate the biomass to provide the largest possible amount of carbohydrates to ethanol fermentation process, but this biomass needs a pretreatment to disrupt the recalcitrant structure of the material. In this sense, the main objective of this project was to evaluate the methods of alkaline pretreatments, using calcium hydroxide, and hydrothermal ,using water, in sugar cane bagasses in natura (obtained directly from the mill) and exploded (subjected to steam explosion). We tested different times (7, 30 and 60 minutes) in both treatments at a temperature of 120 °C in autoclave. Complete factorial designs were performed to examine the influence of calcium hydroxide and hydrolysis time performance by quantifying the release of glucose and total reducing sugars (TRS). Thus were analyzed the chemical composition of the pretreated bagasse to evaluate a possible correlation between changes in material structure and efficiency of hydrolysis. The results showed that the best yields were obtained with the in natura bagasse pretreated with calcium hydroxide at all times tested and the enzymatic hydrolysis increased from 3.2 to 4.3 fold compared to untreated in natura bagasse. A new schedule was conducted, a central composite design surface response, to determine the hydrolysis conditions which lead to maximal glucose release. In this step was done the hydrolysis of in natura bagasse subjected to alkaline pretreatment, with the addition of a nonionic surfactant (Tween 80). The best condition found in this optimization... (Complete abstract click electronic access below)
Due to the growing demand for alternative sources of fuel, ethanol production from lignocellulosic materials became an interesting option. This process allows the increase of ethanol production without the need of growth of the planted area of the cultivars used. For the production of cellulosic ethanol is necessary to fractionate the biomass to provide the largest possible amount of carbohydrates to ethanol fermentation process, but this biomass needs a pretreatment to disrupt the recalcitrant structure of the material. In this sense, the main objective of this project was to evaluate the methods of alkaline pretreatments, using calcium hydroxide, and hydrothermal ,using water, in sugar cane bagasses in natura (obtained directly from the mill) and exploded (subjected to steam explosion). We tested different times (7, 30 and 60 minutes) in both treatments at a temperature of 120 °C in autoclave. Complete factorial designs were performed to examine the influence of calcium hydroxide and hydrolysis time performance by quantifying the release of glucose and total reducing sugars (TRS). Thus were analyzed the chemical composition of the pretreated bagasse to evaluate a possible correlation between changes in material structure and efficiency of hydrolysis. The results showed that the best yields were obtained with the in natura bagasse pretreated with calcium hydroxide at all times tested and the enzymatic hydrolysis increased from 3.2 to 4.3 fold compared to untreated in natura bagasse. A new schedule was conducted, a central composite design surface response, to determine the hydrolysis conditions which lead to maximal glucose release. In this step was done the hydrolysis of in natura bagasse subjected to alkaline pretreatment, with the addition of a nonionic surfactant (Tween 80). The best condition found in this optimization... (Complete abstract click electronic access below)
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Biotecnologia, Bagaço de cana, Hidrolise, Enzimas, Bagasse
Como citar
GRIMALDI, Maira Prearo. Efeito dos pré-tratamentos químicos e físicos do bagaço de cana-de-açúcar na hidrólise enzimática. 2013. 75 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Química de Araraquara, 2013.