Estudo da fermentação do bagaço de cana para obtenção de etanol de segunda geração.

Abstract

In the last decades, the search for and development of efficient and low-cost technologies for the production of bioethanol is constant. The use of the hydrolysis to convert the carbohydrates present in lignocellulosic materials is an alternative to obtain such product. This process is more difficult than conventional methods, since it is necessary to produce the sugar through the hydrolysis of the raw material, besides a physical or chemical pretreatment is necessary in order to prepare the biomass, making it accessible for The subsequent chemical or biological step. This work has the objective of evaluating the aeration of cane bagasse fermentation using the yeast Saccharomyces cerevisea in order to produce second generation ethanol. The experiments were performed in triplicate. In a beaker with distilled water and sulfuric acid was added sugarcane bagasse, then the mixture was submitted to stirring and water bath for two hours, this being the acid hydrolysis step. Before proceeding to the second step of the process, the biomass underwent the vacuum filtration process, in sequence, in the liquid fraction obtained was added sodium hydroxide for pH correction, making the proper medium for the yeast chosen, for this work was The selected yeast LNF CA-11, which was activated by aeration. In the fermentation stage, in which the sugar obtained in alcohol occurs, two musts were initially prepared, where only one of them was subjected to air injection. At the beginning of the fermentation process musts 1 and 2 had the ART concentrations at 3.23 and 3.28 g / L, consecutive. Quantification was done using the DNS method (dinitrosalicylic acid) with spectrophotometer. The best results were obtained in the wort that was submitted to aeration, in which the average efficiency was 42.37%, since in the wort without aeration the efficiency results were 17.4%. Concluding, then, that the yeast was better adapted to the must with air injection. In future works, it is intended to use other yeasts to assist in the fermentation, aiming at a greater efficiency, since Saccharomyces cerevisea only ferments C6 sugars. Keywords: bioethanol