Evaporation rate of spills of hydrocarbons and petroleum mixtures.

Procedures are described for quantifying the rate of environmental evaporation of liquid mixtures such as crude oils and petroleum products under a variety of environmental conditions. Equations are derived from mass transfer theory, which relate the fraction evaporated to an evaporative exposure and Henry's law constant. The dimensionless evaporative exposure characterizes the exposure conditions of atmospheric turbulence, spill volume, and area. The dimensionless Henry's law constant is a function of the liquid composition and temperature and of the fraction of liquid which has evaporated. Experimental procedures are described for measuring evaporation characteristics of a liquid mixture and for producing samples of partially evaporated material.