The study of asphaltene desorption from the iron surface with molecular dynamics method

In this work, we use molecular dynamics method to estimate the effects of various physical parameters such as: temperature, pressure and TiO2 nanoparticle in the desorption of asphaltene from the iron surface. To calculate the effect of these parameters in the desorption of asphaltene, the iron matrix is simulated at various temperatures (300 K, 325 K and 350 K), pressures (1.00 bar, 1.25 bar and 1.50 bar) and TiO2 atomic rate. In the first step of our simulations, the effect of temperature variation on the desorption of asphaltene molecules from iron matrix was investigated. In the second step, the effects of simulation box pressure were examined. Finally, TiO2 nanoparticles were added to the asphaltene solution and simulations done. In this step, the nanoparticles were added with various volume ratios at 300 K, and the asphaltene molecules distances from the iron matrix were reported. The study of TiO2 nanoparticles effect on the interaction of asphaltene molecules and iron matrix is the novelty of this research and includes practical hints. Our results show that the atomic force between asphaltene and iron surface would decrease with an increase in temperature and pressure of the simulation box. Further, TiO2 nanoparticles atomic rate is another important parameter in separation of asphaltene molecule from the iron surface. Numerically, a separation distance of asphaltene molecules from the iron surface in simulated structures with 1%, 2.5% and 5% nanoparticle rates are 13.6 Å, 17.8 Å and 15.2 Å, respectively. •Using of MDS to estimate the effects of nanoparticle in separation of asphaltene from metal surface.•Iron matrix is simulated at various temperatures and pressures.•Influence of temperature variation on the removal of asphaltene from metal matrix was investigated.•Effects of simulation box pressure were examined on asphaltene behavior.•Atomic force between asphaltene and metal matrix would decrease with an increase in temperature and pressure.