Economic Evaluation of Pretreatment alternatives for Ethanol production from Sugar Cane Bagasse

Abstract

Sugar cane bagasse is a lignocellulosic residue in the cane sugar industry whose use as raw material for ethanol production has been proposed. This work presents an economic evaluation of the pre-treatment alternatives using this biomass, based on a two-step approach. The first pretreatment step consisted in dilute sulphuric acid hydrolysis, where the acid concentration, the process time and the solid to liquid ratio were selected as independent variables. The pretreatment experiments were performed in a pilot scale reactor following a 2k experimental design. The second step, performed on solids issued from the first stage, was an organosolv pre-treatment, in which the ratio ethanol-water as solvent, the process time and the NaOH concentration (used as a catalyst) were chosen as independent variables for a Placket-Burmann saturated fractional experimental design. The pretreated solids were further submitted to enzymatic hydrolysis (lab scale) to evaluate pre-treatment performance. Enzymatic hydrolysis results were used to evaluate invests and production costs by applying economic estimation methods. The possibilities of feasibility and the technological scheme layout based on the pretreatment and enzymatic hydrolysis are presented