TY - JOUR
T1 - Influence of asphaltene structural parameters on solubility
AU - Nguele, Ronald
AU - Mbouopda Poupi, Albert Brandt
AU - Anombogo, Ghislain A.Mouthe
AU - Alade, Olalekan S.
AU - Saibi, Hakim
N1 - Funding Information:
This work was supported by United Arab Emirates University (Fund Number 12S016).
Funding Information:
The authors extend their gratitude to Mitsubishi Chemicals for supplying the polymer used in this study. Japan Petroleum Exploration is also acknowledged for supplying the dead oils from which asphaltenes ( C ) and ( D ) were extracted. This research was funded by the Research Office of United Arab Emirates University (Fund 12S016).
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/3/1
Y1 - 2022/3/1
N2 - This paper investigates the influence of asphaltene's structural parameters on its solubility, including aromatic sheet diameter and aromaticity. Aromatic sheet diameter (La) was determined by integrating the D1 and G bands of Raman spectra. Aromaticity was determined by the ratio of the integrated Fourier Infrared peaks of aliphatic carbon relative to aromatic carbon. Asphaltenes were extracted from five dead crude oils. Two types of solubility tests were conducted, with asphaltenes dissolved in both nonpolar (aromatic hydrocarbons) and polar (cyclic ethers and aromatic amines) solvents and re-precipitated using pentane; in addition to a scenario where asphaltenes were dissolved in toluene and re-precipitated using nonpolar (alkanes) and polar titrants (esters). The largest La was estimated to be 7.34 nm, while the other asphaltenes have a La within the range of 1.52–2.35 nm. La increases monotonically with aromaticity, which was inversely proportional to the hydrogen bonding capability. In terms of dispersant polarity, π-π interactions dominated, evidenced by a better asphaltene stability, which increased with aromatic core size. A reverse trend was recorded with nonpolar precipitants due to hydrogen bonding. This study argues that to inhibit the aggregation of asphaltene with large La, polar inhibitors should be used.
AB - This paper investigates the influence of asphaltene's structural parameters on its solubility, including aromatic sheet diameter and aromaticity. Aromatic sheet diameter (La) was determined by integrating the D1 and G bands of Raman spectra. Aromaticity was determined by the ratio of the integrated Fourier Infrared peaks of aliphatic carbon relative to aromatic carbon. Asphaltenes were extracted from five dead crude oils. Two types of solubility tests were conducted, with asphaltenes dissolved in both nonpolar (aromatic hydrocarbons) and polar (cyclic ethers and aromatic amines) solvents and re-precipitated using pentane; in addition to a scenario where asphaltenes were dissolved in toluene and re-precipitated using nonpolar (alkanes) and polar titrants (esters). The largest La was estimated to be 7.34 nm, while the other asphaltenes have a La within the range of 1.52–2.35 nm. La increases monotonically with aromaticity, which was inversely proportional to the hydrogen bonding capability. In terms of dispersant polarity, π-π interactions dominated, evidenced by a better asphaltene stability, which increased with aromatic core size. A reverse trend was recorded with nonpolar precipitants due to hydrogen bonding. This study argues that to inhibit the aggregation of asphaltene with large La, polar inhibitors should be used.
KW - Asphaltene precipitation
KW - Asphaltene solubility
KW - Asphaltenes
KW - Structural parameters
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U2 - 10.1016/j.fuel.2021.122559
DO - 10.1016/j.fuel.2021.122559
M3 - Article
AN - SCOPUS:85118983548
SN - 0016-2361
VL - 311
JO - Fuel
JF - Fuel
M1 - 122559
ER -