Power-to-fuel as a key to sustainable transport systems - An analysis of diesel fuels produced from CO2 and renewable electricity

This paper outlines the role of the transportation sector in the energy system and the resulting challenges it will face in the context of the energy system transition (Energiewende). One option for surmounting this is the coupling of energy generation and the transportation sector using power-to-fuel (PTF) technologies. The present paper outlines a fundamental approach, as well as a basis for discussion, to the implementation of this option. The focus is on the potential of non-fossil and non-biological diesel fuels derived from hydrogen that is produced by renewable energy sources and CO2 and a possible implementation strategy. The physical and chemical properties of synthetic diesel fuels are compared to those of conventional diesel. In addition, the combustion and exhaust gas properties of various alternatives are contrasted, on the basis of which an analysis and evaluation of the potential of alternative diesel fuels is undertaken. This paper thus explores selection, production, and implementation strategies for promising future fuel alternatives for the transport sector. There are already techno-economic calculations - and in some cases pilot plants - for various pathways for synthesizing these fuels. However, in order to achieve a comparative evaluation of the various paths, standardized calculations are necessary. This evaluation creates the basis for an efficient implementation strategy for a future, ideally greenhouse gas-neutral, transportation sector, and thus to achieve the objectives of the Energiewende and Energy Roadmap 2050 set out by the European Commission. (C) 2017 Elsevier Ltd. All rights reserved.