Development of a De-oiling System for Seabed Sediments

Abstract

In northeastern Japan, a large number of fuel-oil tanks were destroyed by the tsunami that followed the March 2011 earthquake, with the spilled oil settling on the seabed in coastal areas. To remove the oil from the seabed, a de-oiling system was developed using superheated steam, and the efficacy and cost of the process assessed. The system was designed to process seabed sediments at a speed of 20 kg/h and supply steam at a temperature of 300 °C was capable of removing contaminated oil from seabed sediments. The de-oiling capacity of the system was maximized at a processing speed 30 kg/h of seabed sediment. The system proved effective in the de-oiling of contaminated seabed sediments, with estimated operating costs of ~20,000 JPN/m3 at a steam temperature of 300 °C and processing speed of 30 kg/h.