MOLECULAR DYNAMICS SIMULATION OF STRUCTURAL RELAXATION OF ASPHALTENE MACROMOLECULES

摘要

For asphaltene obtained from vacuum residues of three different kinds of crude oils (Khafji, Maya and Iranian-Light), the energy-minimum conformation calculated by molecular mechanics ― dynamics simulations showed that aggregated structures of asphaltene molecules through noncovalent interactions are the most stable conformation. Changes of aggregated structures by solvent soaking were investigated by using the molecular dynamics calculation. In quinoline, part of aggregates seemed to be dissociated at 573 K, while, in 1-methylnaphthalene it was not observed. The mechanism of coke formation originated from asphaltene aggregates during heating will be discussed on the basis of the solvent effect estimated by the simulation and the experimentally obtained data.