基于柱色谱分离的阿曼减压渣油结构表征与溶解度参数测定

Structural characterization and determination of solubility parameters of Oman vacuum residue based on column chromatography separation

采用液-固色谱分离方法将阿曼减压渣油分离成饱和分、轻芳烃、中芳烃、重芳烃、轻胶质、中胶质、重胶质和沥青质8个组分,对各组分烃类组成和分子结构进行表征;同时采用基团贡献法计算各组分溶解度参数并与各组分性质进行关联。结果表明,芳香分和胶质组分中S分布相对均匀,绝大部分N(85.05%)、残炭(91.95%)和镍钒金属(99.85%)分布在重芳烃、胶质和沥青质中,金属和残炭脱除率分别在流出组分累计收率为53.8%和43.8%时存在明显下降拐点,对溶剂脱沥青工艺操作有重要指导意义;从饱和分到沥青质,各组分的密度ρi、摩尔体积Vi和溶解度参数δi依次增加;阿曼减压渣油的溶解度参数δVR为17.29MPa1/2,介于轻芳烃和中芳烃之间。相对于S、N、残炭值、H/C比和芳香度fA,溶解度参数δ与密度、总环数RT和分子量关联性较好,尤其与对数ln M呈现良好线性关系,可以近似看成分子量的单值函数δ=4.7282ln M–14.639。

Oman vacuum residues were separated into saturation,light aromatics,middle aromatics,heavy aromatics, light resins, middle resins, heavy resins, and asphaltene by liquid-solid chromatography method,and the hydrocarbon compositions and the molecular structure of each fraction were characterized. Meanwhile, solubility parameters were calculated by the group contribution method and the relation between properties and solubility parameter was correlated. The results indicated that the sulfur distribution of aromatic and resin fractions was relatively uniform,while the vast majority of N（85.05%）,CCR（91.95%）and metal（99.85%）were mainly enriched in heavy aromatics,resins and asphaltene;the removal rate of metal（Ni and V） and CCR decreased markedly at the total component yield of 53.8% and 43.8%,respectively,which was important to guide solvent deasphalting process. From saturate to asphaltene,the density（ρi）,molar volume（Vi）and solubility parameter（δi）increased. In addition,the δVR of Oman residue was 17.29 MPa1/2,between light aromatics and middle aromatics. Compared to S,N,CCR,H/C ratio,density,fA and RT,excellent linearity between δ and ln M was shown and the correlation equation was δ=4.7282 ln M–14.639.