Abstract
Oily wastes such as oily tank sludge and oil contaminated soil, are among the largest waste problems in oil producing countries. In this study, oilfield wastes were characterized, and their carbonization with superheated steam was examined as a low cost method for treatment and recovery of oil.
Oil concentrations of oily waste measured by IR method were 59,800-217,000 mg/kg, depending on the type of waste. In addition, contaminant oils also differed according to waste type. Oil based mud was composed mainly of saturated hydrocarbons in the range of C12-C28. For other oily wastes, the concentrations of heavy oil in the range of C28-C44, were roughly 10-20% higher than those of Bunker C. Combined resin and asphaltene ratios were in the range of 33.7-40.0%. Therefore, a treatment method suitable for the complete range of hydrocarbons was required; rather than methods such as biological decomposition, suitable only for partial, lighter range of hydrocarbons.
After carbonization treatment, oil concentration in residues ranged from N. D. to 65 mg/kg. Oil removal efficiency for all oily waste types exceeded 99.9%. Additionally, upwards of 63.6% of oil in the wastes were recovered, with the recovery ratio varying from one waste type to another.
Finally, these results indicate the effectiveness of carbonization with superheated steam method for oily waste treatment and recovery of oil.
