Systematic Study of Jet Fuel Thermal Oxidative Deposit Formation

This study expands on prior work investigating thermal oxidative deposit (TOD) formation in a Hydrocracked Jet Fuel component using quartz crystal microbalance (QCM). Building on earlier findings, the effects of additional basic and nonbasic nitrogen compounds, sulfur species in the absence of other polar compounds, disulfides as reactive sulfur species, and the addition of naphthenic acid on TOD behavior were systematically evaluated. Due to limited availability of the original Hydrocracked Jet Fuel component used in the 2022 study, a compositionally different Hydrocracked Jet Fuel component was used that showed similar behavior by QCM. This substitution enabled assessment of how bulk fuel composition influences TOD when trace heteroatom-containing species are held constant. Surrogate fuels were formulated with Hydrocracked Jet Fuel components and heteroatom concentrations representative of conventional jet fuel. QCM analysis revealed TOD trends consistent with conventional jet fuels. ASTM D3241 testing of the acid-free surrogate confirmed significant deposit formation utilizing the standard test method conditions.