Alcohol to jet (AtJ)
To produce alcohol-based biofuel (Alcohol to Jet, AtJ), hydrocarbon chains are produced from the alcohols with the aid of thermo-chemical reactions, and then the jet fraction is separated in a final step. In doing so, the required alcohols can be produced in a number of ways: One approach, for example, is to convert carbon monoxide into alcohol using micro-organisms. In another method, a sugar-containing solution is initially obtained from biomass and then the solution is subsequently converted into alcohol in a fermentation process. It is also possible to leave out the alcohol phase entirely: One example is the direct sugar to hydrocarbons (DSHC) method in which micro-organisms are used to process sugar molecules so that they can subsequently be converted directly into C15 hydrocarbons via hydrogenation.
Some companies are already developing the production of biojet on an AtJ basis beyond the demonstration phase. Given the limited number of production sites, so far there have still been no major breakthroughs made regarding the large-scale deployment of such technology. Alternative aviation fuel from AtJ production processes is in the testing phase with regard to the certification processes; certification is expected by the middle of 2014. Due to the early stage of development, AtJ methods are assigned an FRL rating of 2.