| 1 | Characterization of Average Molecular Structure of Heavy Oil Fractions by ~1H Nuclear Magnetic Resonance and X-ray Diffraction显示文摘The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of asphaltene molecules were estimated by combining 1 H nuclear magnetic resonance and X-ray diffraction analyses,and were also ob-tained from vapor pressure osmometry and elemental analysis.Heteroatoms,such as S,N,and O atoms,were considered in the construction of average molecular structure of heavy oils.Two important structural parameters were proposed,including the number of alkyl chain substituents to aromatic rings and the number of total rings with heteroatoms.Ultimately,the av-erage molecular structures of polycyclic aromatics,heavy resins and asphaltene molecules were constructed.The number of α-,β-,γ-,and aromatic hydrogen atoms of the constructed average molecular structures fits well with the number of hydro-gen atoms derived from the experimental spectral data. | Ren Wenpo Yang Chaohe Shan Honghong | 2011 | China Petroleum Processing & Petrochemical Technology2011，13，3： | 1 |
| 2 | Molecular size characterization of heavy oil fractions in vacuum and solution by molecular dynamic simulation显示文摘Two kinds of heavy oils were fractionated into eight fractions by Liquid-Solid Adsorption Chromatography,respectively,and samples were collected to measure properties.According to the elemental analysis,molecular weight and 1H-NMR data,average molecular structures of polycyclic aromatic and heavy resin were constructed with improved Brown-Ladner(B-L)method and several corrections.And then,the most stable conformations of polycyclic aromatic and heavy resin in vacuum and toluene solution were obtained by molecular dynamic simulation,and the molecular size was gotten via the radius of gyration analysis.The results showed that the radius of gyration of polycyclic aromatic and heavy resin was 0.55-0.70 nm in vacuum and 0.60-0.90 nm in toluene solution.With molecular weight increasing,the molecular size in vacuum and toluene solution also increased.Due to the swelling behavior of solvent,the alkyl side chains of heavy oil molecule in solution were more stretched.Thus,the molecular size in toluene solution was larger than that in vacuum. | Wenpo REN Honggang CHEN Chaohe YANG Honghong SHAN | 2010 | Frontiers of Chemical Science and Engineering2010，4，3： | 0 |
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