Study of Extraction Oil Based on Oil Properties from High Viscosity Tank Bottom Oily Sludge
Due to the high viscosity,high density,and high carbon-to-hydrogen ratio(C/H)characteristics of high-viscosity tank bottom sludge,which complicate the separation of oil,water,and solids,result in high heavy component content in recovered oil,and lead to the formation of secondary sludge when returned to central facilities or refineries,this article uses the residual oil content,water content,heavy metal content in tailings,and the composition of the four components of recovered oil(saturated,aromatic,resin,and asphaltene fractions)as evaluation indicators.This study investigated the effect of countercurrent extraction using n-hexane and toluene as extractants for fractionating and classifying the sludge.The results shown that after extraction with n-hexane,the oil content in the sludge was reduced to 12.95%,and the water content to 16.43%.The extracted oil was mainly composed of saturated and aromatic fractions,accounting for 89.73%.Following extraction with toluene,the oil content in the sludge was further reduced to 0.22%,and the water content to 4.5%.The extracted oil was mainly composed of resin and asphaltene fractions,accounting for 54.27%,with the removal of heavy components primarily occurring in the toluene extraction stage.After the two-stage treatment,the removal rates of heavy metals such as Cd,Pb,Cr,As,Cu,Zn,and Ni in the tailings were 73.7%,78.3%,83.6%,75%,75%,85.7%,and 80.4%,respectively.The extracted oil fractions can be reused based on light and heavy components.
high viscosity tank bottom oily sludgesource-separated extractionlight componentheavy componentheavy metal
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维普
