Studies of Emissions From Oil Fires

Abstract

Over 45 mesoscale burns were conducted to study various aspects of diesel and crude oil burning in situ,. Extensive sampling and monitoring of these burns were conducted at downwind stations, upwind stations, and in the smoke plume. Particulate samples were taken in air and analyzed for polycyclic aromatic hydrocarbons (PAHs). PAHs were found to be lower in the soot than in the starting oil, although higher concentrations of the larger molecular PAHs were found in the soot and residue, especially for diesel burns. Overall, the amount of PAHs in the soot and residue were about 2 to 8% of that in the starting oil. This implies a destruction of PAHS by 92 to 98%. Particulates in the air were measured by several means and were found to be greater than recommended exposure levels up to 500 meters downwind at ground level, depending on the size and type of fire. Diesel fires emit much more particulate matter and have longer exposure zones. Combustion gases including carbon dioxide and carbon monoxide are below exposure level maximums. Volatile organic compound (VOC) emissions are extensive from fires, but the levels were less than from an evaporating crude oil spill. Over 140 compounds were identified and quantified. Carbonyls, including aldehydes and ketones, were found to below human health concern levels. Emission data from over 45 experimental burns have been used to develop prediction equations for over 150 specific compounds or emission categories. These are used to calculate safe distances and levels of concern for a standard burn size of 500 square meters, an amount that would typically be contained in a boom. The safe distance for a crude oil burn of this size is about 500 m and for a diesel burn, much further.

Aerostat Sampling of PCDD/PCDF Emissions from the Gulf Oil Spill In Situ Burns

“…Measurement of PCDD/PCDF above background levels is in contrast with conclusions from limited, previous data from in situ ocean (6,7) and mesoscale laboratory oil spill burns (4). Their conclusions may have been reached based on insufficient sampling due to positioning their sampler outside of the plume at sea/ground level, low sample volume, high trip blank concentrations, and high detection limits (6).…”

“…Few measurements of PCDD/PCDF have been made from oil fires and only one (2) to our knowledge from an at-sea burn similar to those of the Gulf in situ burns. Results from two samples at sea level were reported as indistinguishable from background levels, leading to the conclusion that PCDD/PCDF were not formed from oil spill burns (6,7). Similar conclusions were reached during experimental, mesoscale burns (4) when ground-based emission samples were compared against upwind sampling.…”

“…The single, composite background PCDD/PCDF sample was collected intermittently over six days, primarily during nighttime, for a total of 24 h 8 min (1448 min) resulting in a total sample volume of 170.9 m 3 . As with the trip and field blanks, the only detected congener in the background sample was that of the standard contaminant (1,2,3,4,7,.…”

Screening Level Assessment of Risks Due to Dioxin Emissions from Burning Oil from the BP Deepwater Horizon Gulf of Mexico Spill

“…Very little information was found on the generation of dioxins from "in situ" open burning of oil in water bodies. In a comprehensive review of in situ burn tests, Fingas (4) noted that limited measurements of PCDD/Fs in particulates downwind of such burning found only background levels, which led him to conclude that dioxins were not being produced by the burning of crude oil or diesel oil.…”