Environmental Assessment of Emerging Bio-based Production - Possibilities in a Future Bio-economy

The bio-economy has been put forward as a strategy to increase economic growth without this leading to increased emissions of greenhouse gases. A key concept behind the bio-economy is the increased use of biomass for applications such as the production of bio-based chemicals and materials but also an increased importance for biotechnology and biorefinery systems in the production of these products. Recently, negative environmental concerns of increased biomass production have been brought into focus. However, these effects can to a large extent be avoided and this thesis aims at providing more knowledge of how a sustainable transition to a bio-economy can be achieved. The research objectives were to identify and evaluate factors of certain importance for the environmental performance of bio-based chemicals and to assess possibilities for the design of sustainable biorefinery systems. In general terms, a biorefinery is a facility in which biomass feedstock is converted into a spectrum of high-value products, such as bio-based chemicals and energy carriers. There are vast possibilities for the combination of feedstock, conversion processes and potential biorefinery products. In this thesis, case studies have been performed on some concepts of particular relevance for Swedish conditions. Environmental performance of bio-based chemicals was studied using life cycle assessment (LCA). For the analysis of design and siting options for biorefineries, techno-economic assessment methods were applied. The results of the LCAs show that the parameters causing the main impact on the environmental performance of bio-based chemicals are the choice of feedstock and the efficiency of the conversion process. The techno-economic assessment showed that factors with great influence on the design and location of biorefineries are raw material supply, possibilities to integrate biorefineries with the existing technical infrastructure in order to achieve high energy-efficiency and profitability. The profitability depends mainly on the possibility to optimise the output of high-value products. Biorefineries thus provide a way to both utilise biomass efficiently and to add value to this use. Development in biotechnology will be important to increase the output of value, which implies a potential for innovation in this field. There are also possibilities for the establishment of new business partnerships between actors necessary for an emerging biorefinery sector within a growing bio-economy