Produção de bioetanol a partir de biomassa lignocelulósica de milho

Abstract

There is already a consensus on a new global agenda to increase the share of renewable sources, to become an economy based on a wide range of alternative energy sources, in which ethanol can be regarded as an important biofuel. Brazil is the second largest producer of ethanol, however, it is still necessary to diversify the production matrix to make it more attractive for replacement as an alternative fuel. Therefore, it is observed the need for studies with different raw materials, mainly the use of low-cost residues that have a high availability, such as lignocellulosic wastes from agriculture. In this context the aim of this work was to study the production of bioethanol as biofuel from corn lignocellulosic residue. For that, a pretreatment followed by enzymatic hydrolysis to obtain fermentable sugars was carried out. The best condition was the use of a solution of 100 g/L of biomass, concentration of 0.2 gCaO/gbiomass in incubation at 70 ºC and agitation of 200 rpm for a period of 24 hours. Then enzymatic hydrolysis was performed using commercial enzymes at concentrations of 2 % Ctec2 (m/m) and 0.5 % Htec2 (m/m), incubated at 50 °C and 200 rpm of stirring for 24 hours. Through this process, a solution with a concentration of 0.31 gsugars/gbiomass was obtained, being fermentable sugars quantified by HPLC. Thereafter, a new hydrolyzate was produced in order to be fermented by an industrial Saccharomyces cerevisiae strain (PE-2) and by a wild yeast strain, isolated from rotting corn and taxonomically identified as a new species from genus Wickerhamomyces. From these processes, a yield of 0.376 gethanol/gglucose was achieved, demonstrating the potential of this process for the bioethanol production.