Investigation on thermal oxidation coking inhibition of aviation kerosene RP-3 using additives and surface modification method

The thermal oxidation stability of aviation fuel is a significant area of interest and can be enhanced by several approaches. In this paper, the inhibitory effects of additives, surface treatments, and their synergistic application on the thermal oxidation process of RP-3 aviation kerosene have been investigated experimentally. On a flowing experimental device, the influences of three additives, antioxidant, metal deactivator and detergent dispersant on deposition were studied. The test pressure, inlet temperature and experiment time are 5 MPa, 127 ℃ and 1 h respectively. The effects of four surface treatment methods, including high-temperature oxidation, phosphating, pickling passivation and electrolytic passivation, on the deposition inhibition were investigated on a static experimental device. The test pressure of the static experimental device is identical to that of the flowing experimental device. The kerosene volume is 600 mL. It is discovered that high temperature oxidation and electrolytic passivation can both satisfactorily inhibit the formation of deposition. Furthermore, electrolytic passivation tubes experiments were conducted over short (1 h) and long (5 h) periods of time on the flowing experimental device. The results indicated that the passivation layer has a significant inhibition effect in a short time frame, but it is easy to lose the passivation effect in a long-time experiment due to the corrosion of kerosene. Finally, on the flowing experimental device, the experiment of additives and surface treatment coupling to suppress coking was conducted. According to the data, coupling measures can successfully inhibit deposition in the peak region, but coking does deteriorate to some extent in the high temperature region. The developed additive BHTD-E50D can maximumly inhibit the RP-3 deposition by 73.51 %.