ASSESSING DISPERSANT EFFECTIVENESS FOR HEAVY FUEL OILS USING SMALL-SCALE LABORATORY TESTS

Abstract

ABSTRACT Four bench-scale dispersant tests were used to evaluate three dispersants, Corexit 9500, Superdispersant 25 and Agma Super-concentrate DR 379 with an IFO (Intermediate Fuel Oil) 180 and an IFO 380. Dispersant effectiveness was assessed using the Swirling Flask Test (SFT) and Baffled Flask Test (BFT) developed by the U.S, Environmental Protection Agency (EPA), the Exxon Dispersant Effectiveness Test (EXDET) developed by ExxonMobil, and the Warren Spring Laboratory (WSL) test utilized in the United Kingdom. This study allows comparisons among the small-scale laboratory tests and provides a basis to compare dispersant effectiveness data with findings from at-sea field trials and wave basin studies conducted with the same dispersants and oils. No single dispersant preformed with the highest effectiveness under all test methods, but the data demonstrate that viscous oils such as IFO 380s could be dispersed under the right conditions. The results show that laboratory tests with greater mixing energy yield the highest estimates of dispersant effectiveness.