Since the first oil crisis in 1972, automobile industry and academia is looking for means to reduce transportation's dependence on crude oil as well as its environmental impacts. Fuel consumption and emissions of combustion engines have been reduced technically and alternative propulsion technologies and fuels have been investigated.
Over the last years, research focused on a more holistic approach trying to analyze all relevant economic and material flows to be able to compare different fuels and propulsion technologies in an economic and environmental assessment. To do so, the fuel production phase from the resource to the fuel in the car's fuel tank (well-to-tank analysis) as well as the usage phase (tank-to-wheel analysis) have to be assessed. This is generally called the well-to-wheel (WTW) analysis. But the production, maintenance and disposal of the car have also to be included in the comparison. By calculating costs and environmental impacts of all these phases, it is possible to evaluate which alternative could make the most (cost) efficient contribution to environmental impact reduction in the automobile transportation sector.
This PhD project shall contribute to answer the question how energetic use of biomass for automotive mobility can be implemented in the most efficient way regarding technical, economic and environmental aspects.
Three fuels from biomass have been chosen: electricity, substitute natural gas (SNG) and Fischer-Tropsch (FT) diesel. Furthermore, three fossil fuels are used as references: electricity from the German electricity mix, natural gas and diesel. Fuels from biomass are compared among each other as well as to their fossil reference fuel.
Based on the analysis of passenger car use in Germany, two car types have been selected for the assessment: a smaller commuter car with shorter annual mileage and a bigger all-purpose car with higher annual mileage.
Two time frames with the base years 2020 and 2035 are considered to be able to include technologies in the comparison that are not available in mass production today.
One important result will be the greenhouse gas (GHG) reduction costs for each biomass based fuel combined with the GHG reduction potential. Additionally, if other important environmental impacts are identified, their reduction costs will be included in the comparison.
The PhD project is embedded in the project group "biomass" that currently focuses on the supply of biomass based fuels in different projects (see below). The results of these projects will be used in the PhD project to model the supply chains.