Greenhouse gas emissions in the transport sector can significantly be reduced by replacing fossil based fuels with green alternatives. Various alternative fuel concepts have been developed differing in used sustainable feedstock, synthesis technology and final fuel characteristics. Whether these fuels can succeed in the market will depend on the fuel net production costs, the expected cost reduction potentials and the political intention to mitigate climate change. Results of previous studies for the techno-economic assessment of alternative fuels are difficult to compare due to significant differences in the applied methodology, level of detail and key assumptions in terms of economic factors and market prices. In this work, a standardized methodology for techno-economic analysis of fuel production processes is presented and exemplarily applied on sustainable fuels from Fischer-Tropsch (FT) synthesis. The methodology was adapted from a best practice approach from chemical industry and consists of three main steps: A) literature survey on feasible production designs, B) flowsheet simulation and C) techno-economic assessment with the in-house software tool TEPET (Techno-Economic Process Evaluation Tool). It is shown that the standardized approach enables qualitative and quantitative statements regarding the technical and economic feasibility of fuel synthesis concepts including the identification of the appropriate fuel production concept due to predefined framework conditions. Results from the case study on green FT fuels reveal that Biomass-to-Liquid (BtL) concepts have lowest production costs at high electricity costs, whereas the Power-to-Liquid (PtL) and Power and Biomass-to-Liquid (PBtL) concepts are superior at low electricity prices. Fuel production costs in the range of 1.2 and 2.8 € 2014 /l were estimated.

Poly(oxymethylene) dimethyl ethers (OME) show promising fuel properties enabling drop-in into the existing infrastructure, especially as an alternative or additive to diesel fuel leading to a significant reduction in local...

HIGHLIGHTS:  Process model of the generation of synthetic fuels from CO 2 , power and H 2 O developed.  100 of H 2 yields 1260 / of liquid hydrocarbon product.  A Power-to-Liquid efficiency of 43.3% arises.  Heat integration can reduce the energy losses to 25.6%.

Liquid hydrocarbons are considered as an option to store renewable energy while decoupling the supply and demand of renewable resources. They can also be used as transportation fuel or as feedstock for the chemical industry and are characterized by a high energy density. A process concept using renewable energy from fluctuating wind power and CO 2 to produce liquid hydrocarbons was modeled by a flowsheet simulation in Aspen Plus®. The capacity of the plant was set to 1 of hydrogen input, using water electrolysis, reverse-water-gas-shift reaction (RWGS) and Fischer-Tropsch (FT) synthesis. A feed of 30 /ℎ of H 2 generated 56.3 /ℎ (12,856 /) of liquid hydrocarbons. A Power-to-Liquid efficiency of 44.6 % was calculated for the base case scenario. Net production cost ranged from 12.

The Future Fuels project combines research in several institutes of the German Aerospace Center (DLR) on the production and use of synthetic fuels for space, energy, transportation, and aviation. This article gives an overview of the research questions considered and results achieved so far and also provides insight into the multidimensional and interdisciplinary project approach. Various methods and models were used which are embedded in the research context and based on established approaches. The prospects for large-scale fuel production using renewable electricity and solar radiation played a key role in the project. Empirical and model-based investigations of the technological and cost-related aspects were supplemented by modelling of the integration into a future electricity system. The composition, properties, and the related performance and emissions of synthetic fuels play an important role both for potential oxygenated drop-in fuels in road transport and for the design and certification of alternative aviation fuels. In addition, possible green synthetic fuels as an alternative to highly toxic hydrazine were investigated with different tools and experiments using combustion chambers. The results provide new answers to many research questions. The experiences with the interdisciplinary approach of Future Fuels are relevant for the further development of research topics and co-operations in this field.Synthetic fuels based on renewable energies (RE) are widely seen as a key element to achieving climate-neutral transport (e.g., [1,2]). As liquid hydrocarbons have a high energy and power density, they are primarily discussed as fuels for (heavy) road vehicles, ships, and aircraft. Due to their low storage and transport losses, they are also conceivable as a complementary long-term electricity storage option [3]. The challenges of producing and implementing these fuels are manifold. Chemical processes and renewable electrical or thermal energy can be used to produce liquid hydrocarbons from various carbon sources and hydrogen (and sometimes oxygen). Synthetic fuels have several advantages: they can be easily integrated into our existing energy and mobility infrastructures, can be used in all areas of the transport sector, and they can be optimized with regard to their chemical properties. The main disadvantages are the high energy losses and production costs.In this research context, eleven research groups at the German Aerospace Center (DLR) are working together on the Future Fuels project on synthetic fuels. The aim of the interdisciplinary approach is to realize synergies and joint research activities, as well as new research impulses through different perspectives. The scientists and engineers are investigating how synthetic fuels can be produced using solar energy and electrolysis processes (Solar Fuels), and are developing concepts for the re-conversion of these fuels into electricity. They are working on emission-optimized fuels for transport and aviation (Designer Fuels), as well as advanced space ap...