Avaliação da hidrólise do sorgo granífero na produção de etanol e co-produtos

Abstract

The search for new sources of raw materials for biofuel production has been growing, along with the interest of recovering the biomass used in the production process. In this context, among the various renewable alternative biomasses available for ethanol production, grain sorghum stands out because its grains have high starch content, which can be hydrolyzed to sugars such as maltose, glucose and fructose and can therefore be easily fermented for ethanol production. In the current work, the characterization of the grain sorghum grains of five cultivars produced by Embrapa Maize and Sorghum of Sete Lagoas (BRS330, BRS373, 1G100, 1167052, 1167092) was first determined, quantifying the starch, oil, cellulose, hemicellulose A, hemicellulose B and moisture. The different sorghum hybrids had similar characteristics in terms of moisture 10% (g / 100g grain) and starch content 30% (g / 100g grain). It was also evaluated two different types of alcoholic fermentation, in the hydrolysis and fermentation process separated the 1% sulfuric acid stood out in the sugar production in 50 minutes of acid hydrolysis and 72 hours fermentation. Sorghum 1G100 presented the best performance in ethanol yield (28.23 L / 100 kg of grain) and practical yield (Yp = 83.34%). Concerning the simultaneous fermentation and saccharification process, the use of the amyloglucosidase enzyme in the enzymatic hydrolysis of the starch present in the grain sorghum grain was evaluated. It was found that the concentration of 1.5 U / g enzyme in the grains and 100 hours of fermentation provided greater hydrolysis of starch, highlighting sorghum 1167052 with ethanol yield (28.59 L / 100 kg grain) and practical yield (Yp = 100%). Sorghum hybrids showed superior biomass recovery in the enzymatic fermentation process with values close to 30%.