Biomass refining for sustainable development : analysis and directions

Abstract

To understand the contribution of biomass refining to sustainable development, the technical, environmental and economic aspects are summarized in this thesis. This work begins from life cycle assessment (LCA) of bioethanol from lignocellulosic feedstocks such as corn stover, sugarcane and bagasse, and switchgrass. The findings from these studies present a clear example of problem shifting – solving the problems of oil depletion and ozone layer depletion at the expenses of increasing agricultural related emissions. Then this work continues with energy analyses of bioethanol from lignocellulosic feedstocks in comparison with selected literature studies. The results indicate that a single-product (ethanol) system can be optimized only to a certain extent due to the fixed process options and relatively low price of ethanol. Therefore, the last part of this thesis focuses on design and system analysis of a lignocellulosic feedstock biorefinery producing fuel, chemicals and power in one plant, and analyzes the environmental and economic potential of such a refinery. The outcomes demonstrate that multi-product biorefining is indeed more feasible and profitable than single-output productions such as ethanol plant. Social aspects are beyond the scope of this study.