【作者】 李英峰；

【导师】 卢贵武； 张军；

【作者基本信息】 中国石油大学 ， 理论物理， 2007， 硕士

【摘要】 本课题用分子动力学模拟方法对沥青质缔合体进行了研究。首先,应用分子动力学方法分别在常温和加热条件下对沥青质缔合体的分子构型进行了模拟,并在加热条件下研究了五种溶剂对沥青质缔合体微观结构的影响。依据沥青质分子间距和氢键键长的变化规律分析讨论了不同溶剂对沥青质缔合体的解缔效果。随后,应用分子力学和分子动力学方法分别在常温和加热条件下模拟了不同溶剂对沥青质的分子构型、相互作用能和沥青质缔合体稳定性的影响。依据沥青质分子构型的变化和相互作用能分析讨论了沥青质缔合的微观机理和不同溶剂对沥青质缔合体的解缔效果。最后,依据模拟结果,筛选出了性能优良的抑制剂——硝基苯和苯,并对不同溶剂对沥青质缔合体的解缔作用机理进行了理论分析,指出了石油沥青质沉积抑制剂的研究方向。研究表明,范德瓦尔斯相互作用在沥青质缔合体内占据主导地位,分子间的π-π相互作用是促使沥青质缔合最主要的驱动力。更多还原

【Abstract】 In this paper, the Asphaltene Aggregate is studied using the Molecular Dynamics Simulation methods. Firstly, the molecular structures of the asphaltene aggregate were simulated under normal temperature and higher temperature, respectively, using molecular dynamics simulation method. And under higher temperature, the influences of five solvents on the micro-structure of the asphaltene aggregate were investigated. Based on the variation trends of the distances between the adjacent asphaltene molecules and the length of the hydrogen bond, the disassociating effects on the aggregation of different solvents are discussed.Secondly, using molecular mechanics and molecular dynamics method, the influences of different solvents on the molecular structure, interaction energy and the stability of the asphaltene aggregate were simulated at normal temperature and higher temperature, respectively. Based on the structural variation and the interaction energies of the asphaltene aggregate, the aggregating mechanism of the aggregate and the disassociating effects of different solvents are analyzed.Finally, according to the simulation results, nitrobenzene and benzene are chosen as the excellent inhibitors. A theoretical analysis is carried out on the disassociating mechanisms of different solvents on the aggregate, from which the devising direction of the inhibitors for asphaltene is suggested. It is found that VDW interaction play an important role on the stability of the asphaltene aggregate, and theπ-πinteraction was the leading force for the aggregate of asphaltene molecules.更多还原