SIGNIFICANCE OF COPPER COMPLEX THERMAL-STABILITY IN THE USE OF METAL DEACTIVATORS AT ELEVATED-TEMPERATURES

A series of compounds were examined to determine which structural aspe cts were necessary to effectively block the catalytic activity of solu ble copper that promotes thermal deposition from jet fuel during JFTOT testing. The results indicated that salicylidene compounds such as th at currently used as a metal-deactivating additive are the most effect ive, with the copper coordinated with both the nitrogen and oxygen ato ms. The significance of the thermal stability of the copper complex of the metal-deactivator additive was revealed through thermal-desorptio n mass spectrometry and XPS examination of copper-rich JFTOT tube depo sits generated at high temperatures. Through JFTOT testing with heater tubes constructed from a variety of alloys, the impact of alloy compo sition on thermal deposition from jet fuel was demonstrated. These fin dings were used to construct a hypothesis that is consistent with the appearance of MDA induction periods in accelerated turbulent flow fuel tests.