Comparison of detailed reaction mechanisms for an alternative Jet Fuel surrogate by Parametric Continuation

Introduction In the last years there is a growing interest in the development and study of alternative fuels across various transport industries. Aviation industry is no exception to this trend. Indeed, the International Air Transport Association (IATA) established the importance of sustainable low-carbon alternative aviation drop-in fuels in their recent Technology Roadmap [1] in order to replace conventional, petroleum-based energy sources. Recently the attention focused on two categories of alternative jet fuels: the psch (FT) synthetic paraffinic kerosenes (FT-SPK) and the hydrotreated renewable jet (HRJ) fuels, both of which have been certified for flight in a blended form with conventional jet fuels [2]. FT-SPK fuels are obtained from coal (Coal-To-Liquid, CTL), natural gas (Gas-To-Liquid, GTL), and biomass (Biomass-To-Liquid, BTL) by using the FT process (a catalytic chemical reaction converting CO and H2 into various hydrocarbons). HRJ is produced by hydroprocessing of plant oil sources (algae, camelina, jatropha, etc.) and animal fats (tallow) [3]. The basic ignition and oxidation characteristics over a wide range of operating conditions are the key to the use of this fuels as drop-in fuel [2]. Therefore, the numerical investigation of these characteristics becomes an invaluable analysis tool. Different reaction mechanisms have been specifically developed in order to model the jet fuels and alternative jet fuels combustion [4-6] or have been adopted to this purpose [7]. The understanding of the differences between these mechanisms can have a large impact on the numerical study of alternative jet fuels combustion. In this work three reaction mechanisms [4,6,7] will be compared by using a novel parametric continuation tool [8]. Particularly, the combustion of a GTL-air mixture in a perfectly stirred reactor (PSR) will be analyzed, highlighting the difference of the residence time required to get spontaneous ignition or extinction.