Comparative material balances and preliminary technical analysis of the pilot scale sugarcane bagasse alkaline pretreatment to 2G ethanol production

Material balance and preliminary technical analyses of pilot scale sugarcane bagasse alkaline pretreatment, using sodium hydroxide with and without anthraquinone (AQ) addition were analyzed and compared to elucidate the carbohydrates and phenolic components flux in the streams. The lowest carbohydrates solubilization rates (9% wt for cellulose and 41% wt for hemicelluloses) were reached for the condition at 130 degrees C with AQ addition, however the highest lignin solubilization (87% wt) was accomplished for the condition using 170 degrees C with AQ addition. Preliminary technical analysis was carried out to evaluate the performance of the best pretreatment condition when integrated to a first and second generation ethanol plant, in a biorefinery concept, showing that 83.03 m(3)/h of ethanol can be produced by this process. Ethanol production (in L/ton biomass) for proposed process is 8.1% lower than the expected for short terms technologies concluding that upgrades on the process, as higher solids concentrations and lignin energy use or, principally, lignin valorization must be performed to allow viability of the process.