Studies of Emissions From Oil Fires

Abstract

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.