沙中原油减压馏分油的分离及表征

采用溶剂脱蜡法和溶剂萃取法将沙中原油的减压馏分油分离为正构烷烃相、轻芳烃-饱和烃相、中芳烃相和重芳烃相等亚组分，采用气相色谱、气相色谱-质谱联用、固体核磁共振等方法分析了减压馏分油及其亚组分的基本性质、烃类组成和结构参数，同时考察了上述分离过程中各组分的分离百分率。结果表明：溶剂脱蜡法和溶剂萃取法分别分离减压馏分油中链烷烃和多环芳烃的选择性及分离效率均较高；采用溶剂脱蜡法得到的正构烷烃相中链烷烃含量在88.3％～95.2％之间，其碳数呈正态分布，链烷烃分离百分率在24.4%~36.8%之间，约是环烷烃分离百分率的12倍；采用两段溶剂萃取法得到的重芳烃相和中芳烃相具有随着馏分油变重CA降低，CN，CP，RA，RN增加，平均分子式中S和N原子数增加的规律，重芳烃相和中芳烃相中芳烃含量分别为85.4%~88.8%和73.2％～78.5％，三环及以上芳烃的分离百分率在72.8%~75.5%之间，分别是链烷烃和环烷烃分离百分率的5~8倍和4~5倍。

SEPARATION AND CHARACTERIZATION OF VACUUM CUTS OF SAUDI MIDDLE CRUDE OIL

The 3rd and 4th vacuum cuts of Saudi Arabia Middle crude oil were separated into four components: paraffins, light aromatics-saturates, middle aromatics and heavy aromatics by the solvent separation techniques (dewaxing and/or solvent extraction). The main properties, hydrocarbon types and structural parameters of VGOs and their components were characterized by GC, GC-MS and NMR, and the separation efficiency of the solvent separation methods was studied. The results show that 24.4%~36.8% of alkanes in VGOs come into the paraffins obtained by solvent dewaxing, about 12 times that of cycloalkanes, the alkane content in the paraffins is 88.3%~95.2% and the carbon number of the paraffins is normally distributed. The aromatic contents in heavy aromatics and middle aromatics components obtained by solvent extraction were 85.4%~88.8% and 73.2%~78.5%, respectively. As the components become heavier, the CN, CP, RA, RN and atoms of S and N in average molecular formula increase, but CA decreases. The separation percentage of aromatics with three and more rings was 72.8%~75.5%, about 5~8 times that of alkanes and 4~5 times that of cycloalkanes. So the selectivity and efficiency are high for separating alkanes and aromatics by solvent separation.