A molecular mechanics and molecular dynamics study of the structural organization of Cu(II), Ni(II), Co(II), and Fe(II) stearates as potential catalysts for in situ upgrading of heavy oil

Abstract

Metal stearates may show a substantial catalytic effect in the thermal methods of in situ upgrading of heavy oil. Their good solubility in oil makes it possible to efficiently distribute them over oil reservoirs. Furthermore, in situ synthesis of metal oxide and metal sulfide nanoparticles is possible under conditions of steam injection or other thermal treatments. The initial molecular structure and arrangement of molecules of copper, nickel, cobalt, and iron transition metal stearates are elucidated using the molecular mechanics and molecular dynamics methods. All the simulated complexes are arranged into lamellar layers with additional arrangement of aliphatic chains and metal atoms in two-dimensional periodic arrays. According to the molecular dynamics simulation data, the disordering of hydrocarbon chains and the overall molecular organization takes place at high temperatures. The simulated structures can be further used for studying the solubility of the studied metal stearates in hydrocarbons and the mechanisms of nanoparticle formation from them under conditions used for in situ upgrading of heavy oil.