Molecular size characterization of heavy oil fractions in vacuum and solution by molecular dynamic simulation

Frontiers of Chemical Engineering in China - 2010
Wenpo Ren1, Honggang Chen1, Chaohe Yang1, Honghong Shan1
1State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao, China

Tóm tắt

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.

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Tài liệu tham khảo

Zhu H Y, He M Y, Zhu J Q. Reside cracking and bulky molecule cracking abilities. Petroleum Refinery Engineering, 2000, 30 (8): 47–51 (in Chinese)

Qi Y P, Chen S L, Dong P, Xu K Q, Shen B J. Novel macroporous residua FCC catalysts. Journal of Fuel Chemistry and Technology, 2006, 34 (6): 685–689 (in Chinese)

Nortz R L, Baltus R E. Determination of the macroscopic structure of heavy oils by measuring hydrodynamic properties. Ind Eng Chem Res, 1990, 29 (9): 1968–1976

Kyriacou K C, Baltus R E, Rahimi P. Characterization of oil residual fractions using intrinsic viscosity measurements. Fuel, 1988, 67 (1): 109–113

Yang C H, Xu C M, Du F, Lin S X. Primary study on the macroscopic size chracterization of heavy oil. Acta Petrolei Sinica (Petroleum Progcessing Section), 1998, 14 (3): 6–9 (in Chinese)

Buch L, Groenzin H, Buenrostro-Gonzalez E, Andern S I, Lira-Galeana C, Mullins O C. Molecular size of asphaltene fractions obtained from residuum hydrotreatment. Fuel, 2003, 82 (9): 1075–1084

Groenzin H, Mullins O C. Molecular size of asphaltene solubility fractions. Energy & Fuels, 2003, 17 (2): 498–503

Badre S, Goncalves C C, Norinaga K, Gustavsona G, Mullins O C. Molecular size and weight of asphaltene and asphaltene solubility fractions from coals, crude oils and bitumen. Fuel, 2006, 85 (1): 1–11

Andrews A B, Guerra R E, Mullins O C, Sen P N. Diffusivity of asphaltene molecules by fluorescence correlation spectroscopy. J Phys Chem A, 2006, 110 (26): 8093–8097

Schneider M H, Andrews A B, Mitra-Kirtley S, Mullins O C. Asphaltene molecular size by fluorescence correlation spectroscopy. Energy & Fuels, 2007, 21 (5): 2875–2882

Norinaga K, Wargardalam V J, Takasugi S, Lino M, Matsukawa S. Measurement of self-diffusion coefficient of asphaltene in pyridine by pulsed field gradient spin-echo 1h nmr. Energy & Fuels, 2001, 15 (5): 1317–1318

Mohamed R S, Ramos A C S. Aggregation behavior of two asphaltenic fractions in aromatic solvents. Energy & Fuels, 1999, 13 (2): 323–327

Rogel E, Leon O, Torres G, Espidel J. Aggregation of asphaltenes in organic solvents using surface tension measurements. Fuel, 2000, 79 (11): 1389–1394

Yarranton H W, Alboudwarej H, Jakher R. Investigation of asphaltene association with vapor pressure osmometry and interfacial tension measurements. Ind Eng Chem Res, 2000, 39 (8): 2916–2924

Gao J S, Xu C M, Kotlyar L S, Chung K H. Molecular simulation of heavy components present in Athabasca bitumen pitch. Journal of Chemical Industry and Engineering, 2003, 54 (1): 9–17 (in Chinese)

Pan Y Q, Wang D X, Gao J S. The accurate calculating method for molecular dimensions of heavy oil character molecules. Acta Petrolei Sinica (Petroleum Processing Section), 2007, 23 (4): 63–67 (in Chinese)

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Frontiers of Chemical Engineering in China

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