Enhanced effectiveness of oil dispersants in destabilizing water-in-oil emulsions

• Published in: PloS one Vol. 14; no. 9; p. e0222460
• Main Authors: John, Gerald F, Hayworth, Joel S
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 16-09-2019; Public Library of Science (PLoS)
• Subjects: 1-Octanol; Alcohol; Asphaltenes; Biology and Life Sciences; Chemical properties; Crude oil; Destabilization; Dispersants; Dispersion; Emulsifiers; Emulsions; Emulsions - chemistry; Engineering and Technology; Enhanced oil recovery; Evaluation; Excipients - chemistry; Gulf of Mexico; Hydrogen bonds; Interface stability; Laboratories; Mud-water interfaces; Octanol; Offshore oil field equipment; Oil; Oil spills; Organic chemistry; Petroleum - analysis; Petroleum Pollution - analysis; Physical Sciences; Pollutants; Polycyclic Aromatic Hydrocarbons - chemistry; Research methodology; Resins; Shorelines; Solubility; Studies; Surface active agents; Surface-Active Agents - chemistry; Surfactants; Water; Water Pollutants, Chemical - chemistry; Weather; Gulf of Mexico; United States; Louisiana; Alabama; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0222460

Oil impacting the northern Gulf of Mexico shoreline from the 2010 Deepwater Horizon accident was predominantly in the form of water-in-oil emulsions (WOE), a chemically weathered, highly viscous, neutrally buoyant material. Once formed, WOE are extremely difficult to destabilize. Commercially-available oil dispersants are largely ineffective de-emulsifiers as a result of the inability of dispersant surfactants to displace asphaltenes stabilizing the oil-water interface. This study investigated the effectiveness of the commercially-available dispersant Corexit 9500A, modified to enhance its polar fraction, in destabilizing WOE. Results suggest that Corexit modified to include between 20-60% fractional amount of either polar additive (1-octanol or hexylamine) will produce a modest increase in WOE instability, with a Corexit to hexylamine ratio of approximately 80/20 providing the most effective enhanced destabilization. Results support the hypothesis that modifying the fraction of polar constituents in commercial dispersants will increase asphaltene solubility, decrease oil-water interface stability, and enhance WOE instability.