Emulsion Characterization Study for Improved Bilgewater Treatment and Management

Danielle Paynter | Naval Surface Warfare Center, Carderock Division



The primary objective of this project is to advance the current understanding of emulsion science for chemically stable emulsions formed in Armed Forces applications. While commercially available equipment can be implemented for bilgewater emulsion mitigation, there is little knowledge surrounding the physical, chemical and thermodynamic properties of the emulsions created in an Armed Forces vessel environment. Thus, targeted treatment and management of these fluids become conjecture and calls for a deliberate and thorough understanding of fundamental emulsion stability properties. This project focuses on three segments: (1) Scoping Study for Review of Armed Forces Vessels Oil-in-Water Emulsions, (2) Characterization of Prepared and Extracted Bilgewater Emulsions, and (3) Data Analysis, Interpretation and Publication.

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Technical Approach

Emulsions are created when two immiscible liquids are in solution with one liquid dispersed as small spherical droplets, usually between 10 nm to 100 μm in size. In the case of chemical emulsions, the dispersed droplets are maintained stable in solution by a surfactant that surrounds the droplet. Surfactants form a chemical barrier preventing the droplets from coalescing and phase separating. Emulsion formation and stability in the presence of surfactants is highly dependent on chemical, physical and thermodynamic properties of the solution. By studying these properties, a deeper fundamental understanding of emulsions stabilized by surfactants common on Armed Forces vessels can help guide current research and treatment technology selection. This research focuses on the systematic characterization of both prepared emulsions and extracted bilgewater to determine emulsion stability with time, salinity and temperature. To first determine the chemical composition of the emulsions, samples will be analyzed using nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectroscopy (LC-MS). Once the composition is known, physiochemical characteristics will be determined such as particle size distribution (via confocal laser scanning microscopy (CLSM) and dynamic light scattering), emulsion solubilization (via interfacial surface tension, contact angle, differential scanning calorimetry), and emulsion stability mechanisms (via zeta potential, CLSM and pH/conductivity microsensor profile measurements). With completion of the characterization techniques described above, both traditional and model based analysis methods will be employed for data interpretation and prediction to build a comprehensive picture of emulsion stability. From the data analysis, a series of peer reviewed publications are planned that will be compiled into a user friendly, plain language emulsion stability guide.

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Current bilgewater treatment methods do not rely on targeted techniques to increase the effectiveness of emulsion removal. Hence, this research focuses on discovering the underlying principles of emulsion formation and stability such that informed research decisions can be pursued. The purpose of this work is not to recommend treatment technologies once stability mechanism and strength is discovered. Rather, the purpose of this research is to contribute to the current research field; to assist researchers in selecting and targeting appropriate water treatment and technology research; to assist shipboard personnel in identifying which emulsions are creating treatment issues, which could potentially alter current activities and bilge management practices; and to inform decision makers which surfactants should be phased out or replaced with alternate options of comparable effectiveness but do not create stable bilgewater emulsions.

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Points of Contact

Principal Investigator

Ms. Danielle Paynter

Naval Surface Warfare Center Carderock Division

Phone: 301-227-5089