沥青质在石英表面吸附行为的分子动力学模拟  

Molecular Dynamics Simulation of Asphaltene Adsorption on Quartz Surface

作　　者：于维钊[1] 乔贵民 张军[2] 胡松青 

机构地区：[1]中国石油大学石油工程学院,山东青岛266555 [2]中国石油大学理学院,山东青岛266555

出　　处：《石油学报（石油加工）》2012年第1期76-82,共7页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：中国石油科技创新基金项目(2010D-5006-0204);中国博士后科学基金项目(20100471576)资助

摘　　要：为考察沥青质分子在不同溶剂环境中在岩石表面的吸附情况,选用代表性的沥青质分子结构,采用分子动力学模拟的方法研究了正庚烷、甲苯和吡啶3种溶剂中沥青质分子在羟基化石英表面的吸附机理。沥青质分子的平衡吸附构型显示,在正庚烷中,沥青质分子以较强的弯曲构型吸附在石英表面上;在甲苯和吡啶中,沥青质分子自身构型变化减弱,向石英表面吸附的趋势也明显下降。沥青质分子在石英表面吸附能及其与溶剂相互作用能的计算结果表明,正庚烷中沥青质在石英表面的吸附强度最大,而在甲苯和吡啶中其在石英表面的吸附则较弱;库仑相互作用能是沥青质在石英表面吸附过程中的决定因素,而范德华相互作用能则在沥青质与溶剂相互作用中占主导地位。因此,分子动力学方法可对沥青质分子吸附的动力学过程进行有效模拟。For investigation of adsorption of asphaltene molecules on rock surface in various solvent environments,a typical asphaltene molecule was chosen,and its adsorption on hydroxylized silica surface in the solvent environment of n-heptane,toluene and pyridine was studied by molecular dynamics simulation.The equilibrium adsorption configurations of asphaltene molecule indicated that the molecule was adsorbed on silica surface with a tilt and bended configuration in n-heptane,while the structural changes of asphaltene molecule by adsorption in toluene and pyridine was relatively minor,and the adsorption tendency on silica surface in these two solvents was decreased.The calculation results of adsorption energy of asphaltene molecule on quartz surface and interaction energy of asphaltene with solvent molecules further demonstrated the strongest adsorption in n-heptane,and comparatively weaker ones in toluene and pyridine.The coulomb interaction had critical influence on the adsorption process,and the van der Waals interaction was dominant in the interaction of asphaltene with solvent molecules.Generally,molecular dynamics can be an effective approach for adsorption simulation of asphaltene molecules.

关 键 词：沥青质 吸附机理 分子动力学模拟 

分 类 号：O641[理学—物理化学]