Technical and Economic Optimization of Biomass-to-Liquid Processes Using Exergoeconomic Analysis

Kurzfassung

Decarbonization of the transport sector as proclaimed in the COP 21 targets requires the transition from fossil to renewable energy sources. While electric vehicles may become a viable option to reach these goals in private car traffic, it is expected that aviation, shipping and heavy duty transportation will continue to rely on liquid fuels. Biofuels can replace a large share of fossil fuel in these sectors. Currently, advanced biofuels are characterized by high fuel production costs, resulting in low competitiveness on the fuel market. In order to reduce production costs, it is indispensable to identify and quantify cost reduction potentials within biofuel production processes. For this purpose, it is important to understand and illustrate the cost flows and cost incurrence in Biomass-to-Liquid (BtL) applications. This can efficiently be done applying exergoeconomic methods, which initially have been developed to optimize power and heat production in terms of economic feasibility. In this study, the exergoeconomic methodology, consisting of a detailed exergy analysis and techno-economic assessment, is applied on the production of green Fischer-Tropsch biofuels from biomass and electrical power. Arising costs are broken down in avoidable and unavoidable fractions as well as in costs related to capital investments (CAPEX) or efficiency losses. As a result, recommendations are given were financial support for technology development will result in highest fuel cost reduction. Detailed cost flow diagrams of the investigated green Fischer-Tropsch processes will be presented and discussed.