Controllable oxidation for oil recovery: Low temperature oxidative decomposition of heavy oil on a MnO2 catalyst

Heavy oil is a readily available alternative energy resource with a reserve that is more than twice that of conventional light oil. In situ combustion is one of the most promising strategies for heavy oil exploitation, and the modulating of the oxidation behavior of heavy oil is an efficient way to expand the applicability of the in situ combustion method. MnO2 nanoparticles were employed to facilitate the cracking of heavy compounds, promote heat production, and improve recovery efficiency. The oxidative decomposition rate of heavy oil was doubled in the low temperature interval, and the heat release rate was accelerated in the high temperature interval. The increased weight loss at low temperature was attributed to the decomposition of heavy components. The detection of incomplete oxidation products by mass spectroscopy under excessive oxygen flow at high temperature indicated a diffusion controlled process of oil combustion. The same amount of CO2 from the combustion of less fuel demonstrated an increased oxidation degree of the products. The apparent activation energies of the oxidation reactions were decreased by 10–30 kJ/mol at low temperature and 20–40 kJ/mol at high temperature by the addition of MnO2. MnO2 can render in situ combustion more feasible for various oil reservoirs, and is also promising for other thermal recovery processes for improved oil recovery.

Graphical AbstractMnO2 nanoparticles were employed to facilitate the cracking of heavy compounds, promote heat production, and improve recovery efficiency.Figure optionsDownload as PowerPoint slide