Novel ethanol production using biomass preprocessing to increase ethanol yield and reduce overall costs

Abstract Background Ethanol biorefineries need to lower their overall production costs become economically feasible. Two strategies achieve this are reduce using cheaper feedstocks or increase the ethanol yield. Low-cost usually have high non-structural components (NSC) content; therefore, a new process is necessary accommodate these and overcome negative effects of NSC. This study developed novel biorefinery including biomass preprocessing step that enabled use lower-cost while improving without detoxification (overliming). types poplar were used, low-quality whole-tree chips (WTC) high-quality clean pulp (CPC), determine if proposed effective with different NSC contents. Results Technical assessment showed acidic increased monomeric sugar recovery WTC from 73.2% (untreated) 87.5% due reduced buffering capacity poplar, improved solubilization during pretreatment, better enzymatic hydrolysis conversion. Preprocessing alone significantly fermentability liquid fraction 1–2% 49–56% for both overliming it 45%. Consequently, was can substitute step. The economic revealed via annual 10.5 million liters when compared CPC (base case scenario). Also, savings in total operating about $10 per year instead CPC, recycled water lowered its by 45-fold. Conclusions successful increasing decreasing costs, thus facilitating feasibility lignocellulosic biorefineries. Key factors achieving outcome included substituting preprocessing, enabling lower-quality feedstock, fermentation yield, preprocessing. In addition, implementation an evaporator-combustor downstream design, resulting low-loading waste stream be treated wastewater treatment plant simple configuration.