Influence of Ice Cavity Geometry Changes on Burning Behavior of Large Scale Crude Oil Fires

Several Arctic council reports conclude that oil spills are the most significant threat to the Arctic ecosystem. Some studies have shown that in-situ burning (ISB) on open water can remove more than 90 % of the spilled oil, and it is the most promising technology for an efficient response to oil spills in Arctic. However, few studies have been undertaken on the influence of ice on the efficiency of oil burn. Prior studies have shown the coupling between the mass loss rate () and the geometry change of the ice cavity in pool fires smaller than 25 cm [1, 2]. In this study, a series of experiments are performed to develop an understanding of the influence of the coupling of ice cavity geometry changes and burning behavior of larger sized pool fires. The experiment involves Alaska North Slope (ANS) crude oil ignited in ice cavities of diameters (25-100 cm) with depth 6-25 cm. It is found that both burning rate and radiative heat flux are enhanced because of the cavity expansion. However, the overall efficiency of the burn is significantly lowered due to formation of lateral cavities. At some stage during the burning process, the heated oil tends to penetrate into the ice forming a pocket. This lateral cavity causes 10 - 35% of the crude oil to be trapped inside and hence un-recoverable. Further understanding of the reasons that may cause this unique formation and measures to prevent the same are discussed.

References

[1] P.W. Bellino, A.S. Rangwala, M.R. Flynn, A study of in situburning of crude oil in an ice channel, Proceedings of the Combustion Institute, 34 (2013) 2539-2546.

[2] H.F. Farahani, X. Shi, A. Simeoni, A.S. Rangwala, A study on burning of crude oil in ice cavities, Proc. Combust. Inst., 35 (2014).

This study was funded by the Bureau of Safety and Environmental Enforcement, US Department of the Interior, Washington, D.C., under Contract Number E12PC00056. The contents do not necessarily reflect the views and policies of the BSEE, nor does mention of the trade names or commercial products constitute endorsement or recommendation for use.