Molecular Dynamics Study Of The Petroleum-Derived Asphaltene Aggregate And The Choice Of Inhibitors

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.