Evaluation of a hybrid chemistry approach for combustion of blended petroleum and bio-derived jet fuels

The hybrid chemistry modeling approach, termed HyChem, was used to explore the combustion chemistry of blended petroleum and bio-derived jet fuels. The pyrolysis products of conventional petroleum derived-fuels, such as Jet A, are dominated by ethylene and propene, whereas in many bio-derived fuels, such as alcohol to jet (ATJ) fuels, the fuel comprises highly branched alkanes and produces isobutene as a main pyrolysis product. We report here an investigation of blends of Jet A (designated A2) and an ATJ fuel (designated C1) with the central question of whether the HyChem models for neat fuels can be combined to model the blend combustion behaviors. The pyrolysis and oxidation of several blends of A2 and C1 were investigated. Flow reactor experiments were carried out at 1 atm, 1030 and 1140K, with equivalence ratios of 1.0 and 2.0. Shock tube measurements of blended fuel pyrolysis were performed at 1 atm from 1025 to 1325 K. Good agreement between measurements and model predictions was found showing that formation of the products in the blended fuels were predicted by a simple combination of the HyChem models for the two individual fuels, thus demonstrating that the HyChem models for two jet fuels of very different compositions are “additive.”