高黏罐底油泥分质提油工艺研究

Study of Extraction Oil Based on Oil Properties from High Viscosity Tank Bottom Oily Sludge

针对高黏罐底油泥高黏度、高密度、高碳氢比(C/H)等特点而造成的油水固三相分离困难、回收油重组分含量高、返回联合站或炼厂易生成二次油泥等问题,文章以尾渣含油率、含水率、重金属含量及回收油四组分(饱和分、芳香分、胶质与沥青质)组成为考核指标,研究了以正己烷与甲苯为萃取剂对其进行分质分级逆流萃取的处理效果。结果表明:经正己烷萃取后油泥含油率降至12.95%,含水率降至16.43%,其所提取的油分以饱和分与芳香分为主,占比为89.73%;经甲苯萃取后油泥含油率进一步降至0.22%,含水率降至4.5%,所提取的油分以胶质与沥青质为主,占比为54.27%,重组分的去除主要在甲苯萃取段完成。经二段处理后尾渣中的Cd、Pb、Cr、As、Cu、Zn、Ni等重金属的去除率依次为73.7%,78.3%,83.6%,75%,75%,85.7%,80.4%。萃取油分可按轻组分、重组分分质回用。

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.