Novel binary hydrogen donors for the improved pyrolytic stability of model paraffinic aviation turbine fuels

Development of advanced aviation jet fuels for high-Mach aircraft requires the fuel to be able to withstand higher heat loads (>400°C). As a result the fuel can experience both thermal oxidative and pyrolytic temperature regimes in the presence of dissolved oxygen. Hydrogen donors can be used to help retard the pyrolytic decomposition of linear alkanes. However, in the presence of dissolved oxygen, it is unclear if the addition of hydrogen donors will increase or decrease the pyrolytic decomposition of the alkanes in jet fuels.; The primary objective of this work is to develop novel hydrogen donors for the high-temperature stabilization of paraffinic fuels during pyrolytic decomposition in the presence of dissolved oxygen. Through a combined experimental approach of conducting flow reactor pyrolysis, batch reactor autoxidation, and computational modeling we have been able to examine the effect of dissolved oxygen during pyrolysis of tetradecane with the addition of tetralin, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydronaphth-1-ol, or alpha-tetralone.; Tetralone was found to be unique in its ability to resist oxidation during autoxidation and protect tetradecane during the intermediate temperature regime from detrimental reactions involving alkoxyloxyl and hydroxyl radicals, without itself contributing the pyrolytic degradation of tetradecane. Oxidation of tetralin during autoxidation can be significantly retarded by the addition of tetralone due to the radical and oxygen scavenging abilities of tetralone. A binary donor of tetralin and tetralone proved to be oxidation-resistant and significantly reduced the thermal decomposition of tetradecane during oxidative pyrolysis. The binary donor of tetralin and tetralone also exhibited higher stabilizing ability than either of the individual donors. This synergism has been attributed to the slight selectivities of tetralone and tetralin towards 1°- and 2°-radicals, respectively.