Integration options for high energy efficiency and improved economics in a wood-to-ethanol process

摘要

BackgroundThere is currently a steady increase in the use of wood-based fuels for heat and power production in Sweden. A major proportion of these fuels could serve as feedstock for ethanol production. In this study various options for the utilization of the solid residue formed during ethanol production from spruce, such as the production of pellets, electricity and heat for district heating, were compared in terms of overall energy efficiency and production cost. The effects of changes in the process performance, such as variations in the ethanol yield and/or the energy demand, were also studied. The process was based on SO2-catalysed steam pretreatment, which was followed by simultaneous saccharification and fermentation. A model including all the major process steps was implemented in the commercial flow-sheeting program Aspen Plus, the model input was based on data recently obtained on lab scale or in a process development unit.