Abstract:

(C5-C7) asphaltene (soluble in n-heptane but insoluble in n-pentane) of Canada oilsand bitumen vacuum residue (VTB) was charactered and compared with n-pentane asphaltene and n-heptane asphaltene with the help of GPC, XRD, 1H-NMR, SEM measurements and HyperChem simulation. (C5-C7) asphaltene has a small yield of 9.80% and composes mainly small moleculars, whose average structure unit possesses the lowest aromaticity and aromatic ring number but maximum naphthenic ring number (2.60). The length of (C5-C7) asphaltene alkane chains connected with aromatic rings is 0.5 more carbons than the other two asphaltenes. There is no aromatic sheet stacking structures existing in (C5-C7) asphaltene, which is different from n-pentane and n-heptane asphaltenes. (C5-C7) asphaltene has the biggest stable energy (266.73 kJ/mol), leading to a worst stability, whose particles have a large dimension and smooth surface.

Key words: Oilsand bitumen, n-Pentane, n-Heptane, Asphaltene, Characterization

摘要： 利用GPC , XRD, 1 H -NMR, SEM 及H yperChem 模拟等技术手段对加拿大油砂沥青减压渣油VTB 中溶于正庚烷但不溶于正戊烷的沥青质((C5-C7)沥青质)的性质进行了考察, 并与正戊烷沥青质、正庚烷沥青质进行了比较。结果表明,(C5 -C7)沥青质的质量分数为9 .80 %, 主要由小分子组成, 其芳香片层没有形成堆积结构, 在三种沥青质中拥有最低的芳碳率和芳香环数, 但环烷环数的数目最多(2.60 个), 与芳香环相连的烷基链的长度要高于另外两种沥青质0 .5 个碳原子, 该种沥青质颗粒尺寸较大, 表面光滑、平整, 能量最高(266.73 kJ/mo l), 稳定性最差。

关键词: 油砂沥青 , 正戊烷 , 正庚烷 , 沥青质 , 性质表征