物理化学学报 >> 2010, Vol. 26 >> Issue (01): 57-65.doi: 10.3866/PKU.WHXB20100126

胶体及界面化学 上一篇    下一篇

重质油胶体聚集结构的耗散粒子动力学模拟

张胜飞, 孙丽丽, 徐俊波, 周涵, 温浩   

  1. 中国科学院过程工程研究所多相复杂系统国家重点实验室, 北京 100190; 中国科学院研究生院, 北京 100049; 中国石油化工股份有限公司石油化工科学研究院, 北京 100083
  • 收稿日期:2009-08-26 修回日期:2009-10-15 发布日期:2009-12-29
  • 通讯作者: 温浩 E-mail:hwen@home.ipe.ac.cn

Dissipative Particle Dynamics Simulations on the Structure of Heavy Oil Aggregates

ZHANG Sheng-Fei, SUN Li-Li, XU Jun-Bo, ZHOU Han, WEN Hao   

  1. State Key Laboratory of Multi-Phase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China; Graduate University of Chinese Academy of Sciences, Beijing 100049, P. R. China; Research Institute of Petroleum Processing, SINOPEC, Beijing 100083, P. R. China
  • Received:2009-08-26 Revised:2009-10-15 Published:2009-12-29
  • Contact: WEN Hao E-mail:hwen@home.ipe.ac.cn

摘要:

重质油是以沥青质为胶核分散于饱和油分中形成的极其复杂的胶体体系. 本文采用耗散粒子动力学(DPD)方法研究重质油的胶体结构及其影响因素. 根据重质油各组分的分子结构特征, 构建了描述重质油组分的粗粒化模型化合物. 模拟结果表明, 本文构建的粗粒化模型能很好地反映重质油的胶体聚集结构. 沥青质分子结构对胶体聚集结构有序性有显著影响, 较高稠合程度的芳香环结构将使胶束结构有较高的有序性, 烷基侧链则表现出分散作用. 重质油中的胶质具有胶溶作用, 胶质与沥青质的浓度比存在一个极限, 当小于这个极限时, 重质油将出现聚沉.

关键词: 重质油, 胶体, 多分散体系, 自缔合, 超分子结构, 聚集结构, 耗散粒子动力学

Abstract:

Heavy oil is an extremely complex colloidal system where asphaltenes, as the core of micelles, are dispersed in the continuous phase of other saturated fractions. We used dissipative particle dynamics (DPD) to simulate the mesoscopic colloidal structure of heavy oil and to determine its effective factors. Coarse-grained DPD model molecules were constructed in accordance with molecular structures of the component fractions in heavy oil. A modification of the standard DPD program was used to calculate the motion of rigid polycyclic aromatic rings. The simulations show that the coarse-grained DPD models used in this paper predict the colloidal structure of heavy oil well. The ordered structure of micelles depends greatly on the molecular structure of asphaltenes. Higher ordered micelles contain highly fused aromatic rings whereas the alkyl side-chains exhibit dispersing behavior. Deflocculation of the resins was observed in the simulations. A critical concentration ratio for the resin and asphaltene exists. The coagulation of heavy oil occurs when the concentration ratio of resin and asphaltene is less than this critical value.

Key words: Heavy oil, Colloid, Polydispersed system, Self-association, Supermolecular structure, Aggregate structure, Dissipative particle dynamics

MSC2000: 

  • O641