Large Scale Comparative Testing of Corexit EC9500A, Finasol OSR 52, Accell Clean DWD, Marine D-Blue Clean, and ZI 400 at Ohmsett

Abstract

Abstract 2017-064In October of 2015, the U.S. Department of Interior’s Bureau of Safety and Environmental Enforcement (BSEE) conducted independent dispersant effectiveness testing to compare available formulations. Several products were tested at the Ohmsett facility. The study was conducted to better understand and compare the effectiveness of various dispersants under large scale test conditions. Five dispersants were selected from the EPA’s NCP Product Schedule and tested on a Gulf of Mexico crude oil: Corexit® EC9500A, Finasol® OSR 52, Accell® Clean DWD, Marine D-Blue Clean™ and ZI 400. To capture operational effectiveness, the dispersants were applied to a surface slick using Ohmsett’s spray bar, which simulated a boat spraying system. Data collected included droplet size distribution of the dispersed oil, measured at one and a half meters below the water’s surface and using two LISST-100x instruments from Sequoia Scientific. Dispersant Effectiveness (DE) was measured using the volume of the oil, which remained on the surface after the test as compared to the total volume dispensed onto the surface for the test. The performance of the products was quantified and compared to each other based on DE and the droplet size of dispersed oil. Overall, Finasol and Corexit demonstrated the best performance of the group of dispersants. Both dispersants were among the easiest to work with. Finasol and Corexit did not entrain any air while being pumped and maintained consistency throughout the tests. Accell, which demonstrated significant improvements when compared to the untreated oil, did exhibit operational difficulties during testing. Marine D and ZI 400 performed poorly relative to the other products tested.