Stabilization of Bilgewater Emulsions by Shipboard Oils: Fid-Bau Portal

Stabilization of Bilgewater Emulsions by Shipboard Oils

Church, Jared / Daniels, Grant C. / Lundin, Jeffrey G. / Lee, Woo Hyoung / Paynter, Danielle

The removal of oil from bilgewater is necessary for compliance with national and international maritime regulations; however, the formation of stable oil-in-water emulsions makes oil separation difficult. Therefore, it is necessary to understand the physical and chemical properties of emulsions created in bilgewater. Recent experiments have demonstrated that synthetic bilgewater emulsions can be stabilized in the absence of surfactants or cleaners. Consequently, the objective of this study was to determine if compounds found in fuels and lubricating oils can significantly contribute to bilgewater emulsion stability. Surface tension, conductivity, emulsion stability, and GC-MS measurements were conducted to determine transportation of oil additives into the aqueous phase. Results revealed that small polar compounds in common shipboard fuels and lubricants were capable of migrating from the oil phase to the aqueous phase. In particular, it was found that oxygenated alkanes and monoaromatic compounds are likely responsible for the stabilization of bilgewater emulsions. These compounds were found in the highest concentrations in diesel fuel and were found to stabilize simulated bilgewater emulsions more than lubricating oils. Overall, this work shows shipboard oils can contribute to the stabilization of bilgewater emulsions, and further research is needed to determine the full impact of these additives.

This research finds that compounds found in fuel that transport to the aqueous phase can contribute to the formation of oil-in-water emulsions and should not be ignored when investigating bilgewater emulsion behavior and treatability.