Modeling of Oil Evaporation in an Aqueous Environment. Research on the Effects of Crude Oil Transfer and Upstream Refineries on Delaware Bay,

摘要

The goal of the overall research program is to provide information on the input of oil transfer operations in Delaware Bay for decision makers. The work reported here consists of the computer modeling of oil weathering in the early stage of a spill. A numerical model is developed to predict changes in oil characteristics,specific gravity,residues by weight and residues by volume of oil on water through evaporation known to dominate the early stage of weathering. The major driving forces for evaporation being considered include air temperature,wind speed,and size of slick. Laboratory experiments were conducted using No. 2fuel oil, Nigerian Crude,and Venezuelan Crude to calibrate the numerical model and to gain physical insight into the oil evaporation process. Based on the laboratory results,empirical relationships are proposed for determining the diffusion coefficient described in the first-order decay formula. Both numerical and laboratory results seemed to indicate that the effect of temperature on oil weathering is significant in the very early stage of weathering,but diminishes at a later time. The effect of wind speed is more uniform throughout the time duration being tested.