In this paper, we propose the synthesis of green amphiphilic catalysts based on two metals: Ni and Al. The amphiphilic characteristics of the obtained catalyst were provided by alkylbenzenesulfonic acid (ABSA). The end product was thoroughly characterized by the FTIR analysis method. The efficiency of both catalysts was tested by modeling the catalytic hydrothermal upgrading of heavy-oil samples from Ashal’cha field (Russia) in a high-pressure/high-temperature (HP/HT) reactor with a stirrer at a temperature of 250 °C. The physical and chemical properties of the heavy oils and their fractions were studied before and after the catalytic hydrothermal upgrading by analytical procedures such as SARA analysis, FTIR spectroscopy, GC–MS, elemental analysis, gas chromatography, etc. The results showed that both catalysts had a different influence on the viscosity-reduction degree. It was revealed that the contribution of Al ABSA to the viscosity reduction was the highest: more than 80% in contrast to the initial crude oil sample. The Al-based catalyst showed the best activity in hydrogenation and decarbonization, and hence the H/C ratio of the upgraded oil was at a maximum in the presence of Al ABSA.

The most widely applied methods to unlock heavy oil and natural bitumen resources in the world are still based on steam injection techniques. Improving the efficiency of hydrothermal processes poses a great challenge. The co-injection of various additives is practiced to lower the steam-to-oil ratio (SOR), viscosity alteration and to improve heavy oil properties. Organic solvents, non-condensable gases, air and surfactants are the preferred chemicals to be combined with steam. This study provides an investigation of the surfactant-assisted hydrothermal upgrading of heavy oil at 200 °C. The thermal stability and salt resistivity of two non-ionic surfactants (SA–3 and Biolub Green) were investigated. Moreover, the improved performance of the surfactants was established by performing an SARA analysis, elemental analysis, FT-IR spectroscopy, and EPR analysis, and by studying the viscosity reduction degree. The experimental results showed that surfactants lead to the in-depth destructive hydrogenation of the high-molecular components of heavy oil such as resins and asphaltenes. However, the content of light fractions increased. According to the results of the elemental analysis, the surfactants assist in the hydrodesulphurization of heavy oil. Overall, the physical and chemical consequences of hydrothermal upgrading in the presence of surfactants led to the irreversible viscosity reduction of heavy oil.

The concentration of carbon dioxide in the atmosphere has been increasing since immediately after the boom of industrialization. Novel technologies are required for carbon dioxide (CO2) capture, storage, and its chemical conversion into value-added products. In this study, we present a novel in situ CO2 utilization method via a hydrogenation process in the presence of nickel tallates during steam-based enhanced oil recovery. The light n-alkanes are the preferred products of in situ catalytic hydrogenation of CO2 due to their effective solubility, viscosity-reducing capacity, and hydrogen-donating capacity. A nickel tallate was evaluated for its carbon dioxide hydrogenation and oil-upgrading performance at 300 °C. The results showed that the content of saturated and aromatic fractions increased, while the content of heavier fragments decreased. Moreover, the relative content of normal C10–C20 alkanes doubled after the catalytic hydrogenation of CO2. Despite the noncatalytic hydrogenation of CO2, the viscosity was altered from 3309 mPa.s to 1775 mPa.s at a shear rate of 0.66 s−1. The addition of the catalyst further contributed to the reduction of the viscosity, down to 1167 mPa.s at the same shear rate. Thus, in situ catalytic hydrogenation of CO2 not only significantly reduces the concentration of anthropogenic carbon dioxide gas in the atmosphere, but it also enhances the oil-recovery factor by improving the quality of the upgraded crude oil and its mobility.

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