基于分子动力学研究油泥在溶剂中溶解与扩散机理  

Molecular dynamics-based study of oil sludge dissolution and diffusion mechanisms in solvents

作　　者：刘宏宇 郭继香[1,2] 宋瀚轩 李皓 李哲 王一然 LIU Hongyu;GUO Jixiang;SONG Hanxuan;LI Hao;LI Zhe;WANG Yiran(Unconventional Petroleum Research Institute,China University of Petroleum,Beijing 102249,China;Key Laboratory of Heavy Oil,China University of Petroleum,Beijing 102249,China;Eastern Oil Storage and Transportation Co.,Ltd.,PipeChina Network Group,Xuzhou 221004,China)

机构地区：[1]中国石油大学(北京)非常规油气科学技术研究院,北京102249 [2]中国石油大学(北京)重质油重点实验室,北京102249 [3]国家管网集团东部原油储运有限公司,江苏徐州221004

出　　处：《应用化工》2024年第12期2798-2805,2816,共9页Applied Chemical Industry

基　　金：国家自然科学基金(52174047)(ZLZX2020-02-07-03)。

摘　　要：为实现储罐油泥高效清洗和油泥重质烃类物质有效回收,在微观尺度上揭示溶剂中油泥的溶解和扩散机理是至关重要的。通过建立分子动力学反应模型,表征了溶剂中油泥的溶解和扩散行为,分析了不同溶剂中油泥分子的微观相行为、溶解度参数、自扩散系数以及径向分布函数变化规律。研究表明油泥在溶剂中主要经历溶解和扩散两个过程,而油泥中同种分子间的高度聚集是限制油泥溶解和扩散的主要因素。极性溶剂甲基苯乙醚与非极性溶剂煤油可协同削弱油泥石蜡分子间聚集使得油泥分子的自扩散能力增强,甲基苯乙醚的芳环结构和醚键的氧原子是油泥沥青质分子解聚的关键。此外,油泥的溶解和扩散是吸热过程,随着反应温度的升高油泥溶解和扩散能力增强,分子间聚集度降低,油泥与溶剂间的互溶性增强。对溶剂中油泥溶解与扩散机理的研究可为原油储罐油泥化学清洗技术的改进提供理论支持。In order to achieve efficient cleaning of oil sludge in storage tanks and effective recovery of heavy hydrocarbons from oil sludge,it is crucial to reveal the dissolution and diffusion mechanism of oil sludge in solvents on a microscopic scale.The dissolution and diffusion behaviours of oil sludge in solvents are characterized by establishing a molecular dynamics reaction model,and the microscopic phase behaviours of oil sludge molecules in different solvents,solubility parameters,self-diffusion coefficients,and the changing law of radial distribution function are analyzed.The study shows that the oil sludge in the solvent mainly undergoes the two processes of dissolution and diffusion,and the high degree of aggregation between the same molecules in the oil sludge is the main factor limiting the dissolution and diffusion of the oil sludge.Polar solvent methylphenethyl ether and non-polar solvent paraffin can synergistically weaken the intermolecular aggregation of oil sludge paraffin so that the self-diffusion ability of oil sludge molecules can be enhanced,and the aryl ring structure of methylphenethyl ether and the oxygen atom of the ether bond are the key to the depolymerisation of oil sludge asphaltene molecules.In addition,the dissolution and diffusion of oil sludge is a heat-absorbing process,with the increase of reaction temperature oil sludge dissolution and diffusion ability to enhance the degree of intermolecular aggregation is reduced,the oil sludge and the solvent inter-solvent solubility is enhanced.This paper on the solvent sludge dissolution and diffusion mechanism of the study can provide theoretical support for the improvement of chemical cleaning technology of crude oil storage tank sludge.

关 键 词：储罐油泥 分子动力学 溶解 扩散 

分 类 号：TE82[石油与天然气工程—油气储运工程] TE992