RESUMO
This work focuses on the effect of subcritical water pretreatment conditions on agave bagasse chemical composition, biomass fractionation, and enzymatic hydrolysis obtained from the different tequila production processes. The pretreatment was carried out in a batch pressurized reactor within an isothermal regime. The operational conditions for subcritical water pretreatment were (150-190 °C) and (10-50 min). The best operational conditions were selected, based on the increased cellulose content (>50%) in the pretreated solid phase. The conditions for 190 °C for 50 and 30 min of pretreated agave bagasse solids were chosen for enzymatic hydrolysis susceptibility (15 FPU/g of the substrate). The maximum conversion yield (cellulose to glucose) during enzymatic hydrolysis achieved was up to 61.62% (5.86 g/L) in industrial bagasse at 72 h and initial saccharification rate was 0.34 g/(L*h) at 12 h. This study indicates that the agave bagasse is a promising raw material in the development of second-generation biorefineries.
Assuntos
Agave , Saccharum , Celulose , Hidrólise , ÁguaRESUMO
The aim of this work was to develop an economical bioprocess to produce the bio-ethanol from soybean molasses at laboratory, pilot and industrial scales. A strain of Saccharomyces cerevisiae (LPB-SC) was selected and fermentation conditions were defined at the laboratory scale, which included the medium with soluble solids concentration of 30% (w/v), without pH adjustment or supplementation with the mineral sources. The kinetic parameters - ethanol productivity of 8.08g/Lh, YP/S 45.4%, YX/S 0.815%, m 0.27h(-1) and microX 0.0189h(-1) - were determined in a bench scale bioreactor. Ethanol production yields after the scale-up were satisfactory, with small decreases from 169.8L at the laboratory scale to 163.6 and 162.7L of absolute ethanol per ton of dry molasses, obtained at pilot and industrial scales, respectively.