文献类型：期刊文献

英文题名：Solvation of asphaltenes in supercritical water: A molecular dynamics study

作者：Xin, Shuang-Mei[1];Liu, Qing-Kun[1];Wang, Kai[1];Chen, Yi[1];Yuan, Pei-Qing[1];Cheng, Zhen-Min[1];Yuan, Wei-Kang[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2016

卷号：146

起止页码：115

外文期刊名：CHEMICAL ENGINEERING SCIENCE

收录：;EI(收录号：20161102092510);WOS:【SCI-EXPANDED(收录号:WOS:000373448100011)】；

基金：This work was supported by the Open Project of State Key Laboratory of Chemical Engineering (SKL-ChE-13C02) and the National Natural Science Foundation of China (Grant no. 21376075).

语种：英文

外文关键词：Asphaltenes; Supercritical water; Molecular dynamics; Solvation; Aggregation

摘要：To improve the understanding of the condensation of asphaltenes in supercritical water (SCW), the solvation of asphaltenes under SCW environments was investigated with molecular dynamics simulation. The simulation results indicate that the repulsive van der Waals interaction has a primary influence on the nature and the magnitude of the interaction between asphaltenes and SCW. A cavity short-range solvent structure surrounding asphaltenes thus is formed, and the solvation free energy (G(sol)) of asphaltenes in SCW has a positive sign in most cases. The scale of cavities and the value of G(sol) both are determined mainly by the bulk density of water. By the repulsive asphaltenes/SCW interaction and the attractive pi pi aromatic interaction, the aggregation of asphaltenes in SCW occurs spontaneously. The asphaltene clusters formed, containing asphaltene monomers and nanoaggregates, present a coke-like supramolecular structure. Benefiting from excellent diffusivity in SCW, the aggregation of asphaltenes in SCW can be accomplished rapidly. (C) 2016 Elsevier Ltd. All rights reserved.