Oil evaporation is a fundamental physical process where volatile components of oil transform from a liquid to a gaseous state and disperse into the atmosphere. This process plays a significant role in determining the ultimate fate of most oils in the environment.
The Role of Evaporation in Oil's Fate
Evaporation is not merely a loss of oil volume; it is a critical step that profoundly influences the subsequent behavior and characteristics of spilled or released oil. According to reference [1], evaporation plays a strong role in the fate of most oils. A key consequence of this process is its prerequisite role in the formation of water-in-oil emulsions.
- Precursor to Emulsification: Almost all oils must undergo some degree of evaporation before they can form stable water-in-oil emulsions [1]. This initial loss of lighter components alters the oil's viscosity and surface properties, making it more susceptible to emulsification when mixed with water.
Impacts of Evaporation on Different Oil Types
The effects of evaporation vary dramatically depending on the oil's initial composition, particularly its "lightness" or "heaviness." As lighter, more volatile compounds evaporate, the remaining oil becomes progressively denser and more viscous.
Oil Type | Initial State | Evaporation Effect | Remaining State |
---|---|---|---|
Light Oils | Fluid | Significant loss of volatile compounds; density and viscosity increase dramatically. | Very viscous |
Heavy Oils | Viscous | Loss of remaining lighter components; becomes extremely dense and immobile. | Solid-like |
- Light Oils: For light oils, evaporation causes a very dramatic transformation. They will change significantly from a fluid consistency to a highly viscous state [1]. This change in viscosity can impact cleanup efforts and how the oil spreads or weathers.
- Heavy Oils: Heavy oils, which are already viscous, become even more severe after evaporation. They will become solid-like [1], making them extremely difficult to disperse, recover, or break down naturally. This transformation can lead to persistent residues that can impact coastlines and marine life for extended periods.
In essence, oil evaporation is a critical weathering process that not only reduces the volume of oil but, more importantly, alters its physical and chemical properties, dictating its environmental behavior and ultimate impact.