Utilizing an Oil-soluble Iron and Sodium-based Catalyst for Catalytic Hydrogenation of Carbon Dioxide in Heavy Oil

The hydrogenation of CO2 can be carried out down in the heavy oil reservoir formations, which are developed by steam-based production methods. However, the proper catalysts must be delivered into the reservoir rocks to increase the efficiency of the hydrogenation processes. This study investigates the catalytic efficiency of iron particles on the upgrading performance of heavy oil sample in CO2 atmosphere. It was demonstrated that iron particles dopped with sodium nanoparticles further accelerates the destructive hydrogenation reactions. The results of gas composition evolved after upgrading experiments showed that iron nanoparticles doped with sodium nanoparticles contributed to the reduction of H2S by two-fold and CO2 from 2.1 kg/ton to 1.1 kg/ton of oil, which shows the activity of Na-FexOy on desulfurization and hydrogenation of carbon dioxide. The obtained results of SARA analysis revealed increase in the content of light fractions from 61.8 %wt. to 66.4 %wt., and decrease in the content of resins by almost 15%. Remarkably, the dynamic viscosity was reduced from 2859 mPa.s (origin oil) down to 2400 mPa.s (iron particles) and 1700 mP.s (iron doped with sodium), while non-catalytic upgrading increased the viscosity of the heavy oil sample up to 3100 mPa.s. Taken together, these findings can be considered as a first step towards enhancing our understanding of in-situ carbon dioxide utilization and oil upgrading techniques via hybrid approaches.