Investigation of the spreading tendency of emulsified oil slicks on open systems. (July 2022)

• Record Type: Journal Article
• Authors: Zhao, Lin; Nedwed, Tim; Daling, Per S.; Brandvik, Per Johan
• Is Part Of: Marine pollution bulletin. Volume 180(2022)
• Publication Date: 2022-07
• Subjects: Emulsions -- Spreading tendency -- Open water -- Oil spill; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2022.113739
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Properties and stability of water-in-oil emulsions influence oil behavior and response decisions. Closed-system lab protocols that assess emulsion stability cannot fully represent oil behavior in the open sea. We developed a novel test system that allows emulsions to spread over a laboratory flat pan. Nine highly weathered oils were studied and seven formed very stable emulsions in a closed-system. Results from our tests show that these oils underwent significant spreading unless the testing temperature were well below the oils' pour point. These findings indicate that emulsions may be less stable than laboratory tests indicate under some at-sea conditions (e.g. offshore in either high-energy or low-energy seas). Oil thinning due to spreading causes emulsions to break and the resulting thin oil film would be more susceptible to natural dispersion. Additional carefully designed laboratory and controlled field tests are needed to determine the operational relevance of our findings. Highlights: A novel test system was developed to study the spreading behavior of emulsified oil. Very stable emulsions formed in a closed-system underwent significant spreading. The spreading behavior seem directly linked to pour point and asphaltene content. Findings imply that emulsions formed at sea may be less stable at some conditions.