One path to sustainable aviation is expected to be based on the utilization of synthetic jet fuels, which are produced using renewable electric energy. In this combination such fuels are called as electrofuels. The approach in C3.3 is to find a synthetic fuel in such a way that the combustion properties are improved, especially with respect to emissions like soot and nitrogen oxides. Here, new synthetic fuels will be seen in the focus with "tailor-made" properties, to prevent CO2 emissions and pollutant emissions at the same time.
The planned research project is focused on this second approach. For the purpose of soot and NOx reduction the lean prevaporized premixed (LPP) burner concept is seen as research vision, as prevaporization of liquid fuels and premixing with the combustion air allows to prevent any soot formation and for lean mixtures reduces the NOx emission significantly.
For experiments, a very flexible mixing and burner arrangement will be built up at ITV Hannover where the processes of prevaporization, premixing, pre-ignition and flashback can be investigated for very different fuels with quantitative variation of the fuel-air mixing ratio and the preheating temperature.
At PTB Braunschweig the relevant properties of the different new tailor-made fuels will be investigated, in conjunction with the development of such fuels from the partners at TU Braunschweig (groups of Schröder, Spieß, Raabe, Project ICA-C2.1). The combustion properties, e.g., ignition delay and soot tendency of the target fuels will be experimentally determined.
Additionally, chemical kinetic mechanisms will be developed and validated. The combustion and flame stabilization properties of several different liquid electrofuels will be investigated, which in cooperation with the ICA-C2.1 group will be analyzed such that both the synthetic production possibilities and the combustion properties are related together and that structure-property relationships can be established. According to the current knowledge the electrofuels will contain for instance aromatic and cyclic hydrocarbons, alcohols like propanol and butanol, furan derivatives (e.g., furan, methyl and dimethylfuran).