Characterization of Thermo-Catalytically Reformed Diesel Injection and Ignition in Comparison to Conventional Diesel Fuels

It is widely known that with decreasing oil reserves on a global scale there is a need for alternative energy sources. Therefore, the introduction of various alternative fuels is of utmost importance. One way of producing alternative fuels is the Thermo-catalytic Reforming (TCR) process which was developed by the Fraunhofer-Institute for Environmental, Safety and Energy Technology (UMSICHT). For an application in conventional diesel engines, however, it is important to investigate the spray behavior of such TCR Diesel fuels in comparison to conventional Diesel fuels under engine-like operating conditions. Two different batches of TCR Diesel were compared with conventional Diesel fuels. The results show batch-dependent significant differences in the penetration length of liquid and vapor as well as in the spray area, which gives clear indications of altered mixture formation quality. Furthermore, ignition timing and ignition location were evaluated for reactive conditions using OH* chemiluminescence. The results also show clear differences to conventional fuels depending on the production batch. Overall, the differences found are so clear that a development towards less variation in the fuel properties seems sensible. The analytical methods used are suitable for investigating fuel differences before use in the engine.