Potential of the sustainable C1 fuels OME, DMC, and MeFo for particle-free combustion in SI and CI engines

Current efforts to reduce the use of fossil resources towards a CO₂-neutral energy and transport scenario 2050 involve the search for suitable energy platforms and corresponding synthetic fuels.C1 chemistry with methane and methanol (MeOH) as its well-established platform chemicals is not only an appropriate basis for a closed CO₂-cycle, but provides also a convenient feed for the synthesis of functional fuels for internal combustion engines (e.g. [Bu10]). Such C1-fuels have a molecular structure without C-C bonds and feature a high oxygen content, hence meet the most essential requirements for soot-less combustion [MP11], [Ma14].Primary requirements for synthetic fuels according to Maus et al. are in hierarchical sequence: CO₂-neutrality, availability of energy on a sustainable basis, low impact on environment, economic efficiency, and functionality (energy density) [Ma14]. Suitable fuels will have to be qualified in terms of long-term stability, low toxicity, good material compatibility, adequate evaporation and ignition properties, compatibility with infrastructure, and other material specific properties. This qualification needs to be defined bindingly for each fuel in corresponding standardisation.In this paper, an outlook on the next steps towards a broader use of C1 synthetic fuels will be given based on the work of multiple research projects currently being performed at the Technical University of Munich.