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In this research work, the catalytic performances of two manganese-based catalysts, manganese (III) acetylacetonate (Mn(acac)3) and manganese tallate (Mn-TO), were studied during the process of Ashalcha heavy oil oxidation under in situ combustion conditions. DSC analysis shows distinct thermal behavior of both ligated catalysts during low- and high-temperature oxidation phases (LTO and HTO); for example, the shifting in peak temperature (Tp) in the HTO at a heating rate of 10 °C/min was reduced by approximately 5.3% for Mn-TO and 2.24% for Mn(acac)3 when compared with uncatalyzed heavy oil. Combined isothermal kinetic analyses using the Friedman and Kissinger–Akahira–Sunose analytic methods have provided insights about activation energies and frequency factors over the whole conversion range, where the catalytic performance of Mn-TO showed low activation energies in both LTO and HTO (Eα of Mn-TO was approximately 13.33% (LTO) and 7.68% (HTO) less than with the heavy oil alone). In addition, calculations of the effective rate constant confirmed the increased oxidation rate trend of both catalysts, with Mn-TO exhibiting the highest values. The findings highlight the potential of these manganese-based catalysts, the Mn-TO catalyst in particular, in optimizing heavy oil oxidation processes. The overall results further contribute to developing more efficient ligand catalyst complexes for sustainable heavy oil recovery while continuously improving their efficient application during in situ combustion in the petroleum industry. [ABSTRACT FROM AUTHOR]

The present review paper discusses the different aspects related to the chemical transformation of oil components through ultrasound assistance. Ultrasound intensifies heat and mass transfer processes in oil production and treatment, which is used to separate water–oil emulsions, optimize pumping, clean the bottomhole zone, and more. The main reason for the positive effect of ultrasound is the cavitation phenomenon, which forms vapor–gas bubbles that cause changes in the structure and properties of dispersed phases, intensifying processes such as dissolution, extraction, and emulsification. The inhomogeneities in the medium being processed also reduce resistance to bubble formation and increase the intensity of technological processes. It is believed that ultrasonic treatment of heavy oil influences the colloid structure of oil. Such effects were observed in several studies. Despite the widespread use of ultrasound in oil processing, the chemical transformation of hydrocarbons during ultrasonic treatment remains an understudied area, particularly for heavy oil. Furthermore, the transformation mechanism of high-molecular-weight fragments of oil under ultrasonic energy is still poorly understood. Heavy oil can benefit greatly from ultrasonic treatment, both after production for pipeline transportation or plant processing and in the reservoir. This is due to the improved mobility of oil in rock and the chemical transformation of high-molecular components, such as resins, asphaltenes, and paraffins. These transformations contribute to the overall improvement of heavy oil processing, making it a crucial area for further research and development. In this review paper, we will explore the latest innovations in oil processing, specifically focusing on the chemical transformation of oil components through ultrasound assistance. This will include a comprehensive analysis of the underlying mechanisms of ultrasonic treatment and their impact on the chemical composition of oil. The review will also include a discussion of the current state of the art and future directions for research in this field, highlighting the potential for further advancements in the use of ultrasound in oil processing. [ABSTRACT FROM AUTHOR]

For the last few decades, the processes of heavy oil conversion have been generating considerable interest in terms of enhancing heavy oil recovery to improve recoverable hydrocarbon reserves. In the present Special Issue, several authors have studied thermally enhanced oil-recovery methods by investigating the thermal impact on the conversion of heavy oil and kerogen. The authors applied nuclear magnetic resonance (NMR) to determine the quantity of saturate, aromatic, resin, and asphaltene fractions in heavy oil. It is common knowledge that the world's economic growth is mainly based on hydrocarbon exploitation and processing, regardless of the political efforts towards developing renewable energy. [Extracted from the article]

The generation of hydrogen from unconventional oil is expected to increase significantly during the next decade. It is commonly known that hydrogen is an environmentally friendly alternative fuel, and its production would partially cover the gap in energy market requirements. However, developing new cheap catalysts for its production from crude oil is still a challenging area in the field of petroleum and the petrochemical industry. This study presents a new approach to synthesizing and applying promising catalysts based on Ni, Co, and Ni-Co alloys that are supported by aluminum oxide Al2O3 in the production of hydrogen from extra-heavy crude oil in the Tahe Oil Field (China), in the presence of supercritical water (SCW). The obtained catalysts were characterized via scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, transmission electron microscopy (TEM), and, X-ray diffraction analysis (XRD). The obtained XRD data showed 3.22% of Co2+ in the Co/Al2O4 catalyst, 10.89% of Ni2+ in the Ni/Al2O4 catalyst, and 1.51% of Co2+ and 2.42% of Ni2+ in the Ni-CoAl2O3 bimetallic catalyst. The BET measurements of the obtained catalysts showed a surface area ranging from 3.04 to 162 m2/g, an average particle size ranging from 0.037 to 0.944 µm, and micropore volumes ranging from 0.000377 to 0.004882 cm3/g. The thermal, SCW, and catalytic upgrading processes of the studied samples were conducted in a discontinuous autoclave reactor for 2 h at a temperature of 420 °C. The obtained results revealed that thermal upgrading yielded 1.059 mol.% of H2, and SCW led to 6.132 mol.% of H2; meanwhile, the presence of Ni-CoAl2O3 provided the maximal rate of hydrogen generation with 11.783 mol.%. Moreover, Ni-CoAl2O3 and NiAl2O3 catalysts have been found to possess good affinity and selectivity toward H2 (11.783 mol.%) and methane CH4 (40.541 mol.%). According to our results, the presence of SCW increases the yield of upgraded oil (from 34.68 wt.% to 58.83 wt.%) while decreasing the amount of coke (from 51.02 wt.% to 33.64 wt.%) due to the significant amount of hydrogen generation in the reaction zone, which reduces free-radical recombination, and thus, improves oil recovery. Moreover, the combination of SCW and the synthetized catalysts resulted in a significant decrease in asphaltene content in the upgraded oil, from 28% to 2%, as a result of the good redistribution of hydrogen over carbons (H/C) during the upgrading processes, where it increased from 1.39 to 1.41 in the presence of SCW and reached 1.63 in the presence of the Ni-CoAl2O3 catalyst. According to the XRD results of the transformed form of catalysts (CoNi3S4), after thermal processing, heteroatom removal from extra-heavy crude oil via oxidative and adsorptive desulfurization processes is promoted. These findings contribute to the expanding body of knowledge on hydrogen production from in situ unconventional oil upgrading. [ABSTRACT FROM AUTHOR]

Our knowledge of electromagnetic heating's effect on heavy oil upgrading is largely based on very limited data. The aim of the present research was thus to study in detail the effect of microwave exposure in the absence and presence of nanosized magnetite on the composition of heavy oil. The obtained data reveal that the use of nanosized magnetite improves not only microwave radiation application as a result of its absorption and release of thermal energy but also that these nanoparticles have a catalytic ability to break carbon–heteroatom bonds in the composition of resins and asphaltene molecules. In fact, the overall reduction in asphaltenes or resins does not always adequately describe very important changes in asphaltene composition. Even a small fraction of broken carbon–heteroatom bonds can lead to an increase in the mobility of asphaltenes. Moreover, this study has shed light on the important evidence for asphaltenes' transformation, which was found to be the formation of light aromatic compounds, such as alkylbenzenes, naphthalenes and phenanthrenes. These compounds were fixed in the composition of the aromatic fraction. We believe that these compounds could be the fragments obtained from asphaltenes' degradation. The evidence from this study points toward the idea that asphaltenes' destruction is crucial for increasing oil mobility in the reservoir rock during its thermal stimulation. [ABSTRACT FROM AUTHOR]