The Impact of Copper on the Liquid-Phase Oxidation of Jet Fuel for Advanced Aircraft

• Published in: Energy & fuels 2004-03, Vol.18 (2), p.490-496
• Main Authors: Morris, Robert E, Hughes, Janet M, Colbert, John E
• Format: Article
• Language: English
• Subjects: Applied sciences; Crude oil, natural gas and petroleum products; Energy; Exact sciences and technology; Fuels; Petroleum products, gas and fuels. Motor fuels, lubricants and asphalts
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef0301093

The fuel systems in advanced aircraft will subject the fuel to more severe thermal stress and increased recirculation than in current designs. This work was undertaken as part of a study to determine the impact of copper contamination on the suitability of current JP-5 fuels in such advanced aircraft systems. Three issues were addressed in this study:  (1) the impact of temperature and dissolved copper concentration on oxidation, (2) the catalytic activity of copper entrained in fuel sediment, and (3) the validity of the use of copper dopants to simulate exposure to copper-containing alloy surfaces. Examinations of liquid-phase oxidation by analyses of oxygen consumption and hydroperoxide formation rates were used to characterize the impact of copper to accelerate fuel oxidation in a flow system as a function of both temperature and copper concentration. From these measurements, the oxidation regime was represented graphically in a plot that expresses the impact of temperature and copper concentration on liquid-phase oxidation for that particular fuel. It was also found that if the time that the fuel was exposed to copper was relatively short, i.e., days or weeks, as opposed to months or years, it made no appreciable difference whether copper was introduced from exposure to copper-containing surfaces or from addition of a chemical compound. A stirred glass reactor was employed to measure the catalytic activity of copper entrained in fuel sediments on fuel autoxidation. It was found that the catalytic activity of copper-containing sediments was negligible at up to 150 °C.