Avaliação de materiais lignocelulósicos oriundos da produção e beneficiamento de soja visando à obtenção de bioetanol

Abstract

In order to reduce emissions of greenhouse gases and the world phosphorus industry, the objective of this study was use ethanol from the production and processing of soybeans, an abundant material in the state of Paraná, especially in the western region. However, for the use of the materials as carbon source, it was necessary the deconstruct of them. In this sense it was evaluated a DCC type statistical design of dilute acid pretreatment with different H2SO4 acid concentration (1%, 3% and 5% (m/v)), temperature (111°C, 116°C and 121°C) and reaction time (20 min, 30 min and 40 min), in order to obtain a better condition of hemicellulosic hydrolyzate, rich in fermentable sugars. The hydrolyzate obtained according to the program was submitted a fermentation with a Spathaspora passalidarum for ethanol production. A control experiment (constituted with synthetic medium), using commercial xylose was also evaluated to compare the results. According to the statistical design, the condition that provided the best result was 121°C, 20 min, with a concentration of 5% (m/v) of acid. In this condition, 16.07 g/L of xylose was reached. It was verified that the use of the hydrolyzate as fermentation medium provided 5.62 g/L ethanol, which was 60.68% lower than the production of it in synthetic medium. Regarding to the fermentation parameters, values of 0.183 g/g and 0.234 g/L.h were also found for the hydrolyzate medium and 0.392 g/g and 0.596 g/L.h for the control medium. As this work has an innovative character, as well as initial results, it is verified that these are promising, mainly as to the use of these materials to obtain cultivation media for bioproducts production, such as bioethanol or other value-added products.