Studies on the evaporation of crude oil and petroleum products: I. the relationship between evaporation rate and time

The time dependance of evaporation was studied for several crude oils and petroleum oil products. Evaporation was determined by weight loss measured on a balance and recorded constantly on a computer. Examination of the data shows that most oil and petroleum products evaporate at a logarithmic rate with respect to time. This is attributed to the overall logarithmic appearance of many components evaporating at different linear rates. Petroleum products with fewer chemical components, such as diesel fuel, evaporate at a rate which can be best modelled as a square root of time. The particular behaviour is shown to be a result of the number of components evaporating by experimentation with artificial oils consisting of 1 to 15 components. Oils with greater than 7 components evaporating at one time can be modelled with logarithmic equations; those with 3 to 7 components, with square root equations. (C) 1997 Elsevier Science B.V.