This review discusses recent research findings spanning the last two decades concerning ultrasonic technologies applicable to the oil, gas, and coal sectors. Various experiments conducted in laboratories have demonstrated the efficacy, cost-effectiveness, and environmental friendliness of ultrasound in recovering and processing oil, bitumen, coal, and oil shale. Ultrasound enhances formation permeability, coal gas permeability, and oil viscosity, particularly when delivered in short, powerful pulses at medium frequencies. Combining ultrasound with traditional recovery methods has shown promising results, boosting recovery efficiency by up to 100%. At the same time, ultrasonic treatment reduces the use of traditional reagents, thereby reducing environmental pollution. Moreover, ultrasound treatment shows potential in tasks such as separating oil–water emulsions, desulfurization, dewaxing oil, coal enrichment, and extracting valuable metals from metal-bearing shales through hydrometallurgical leaching. However, the widespread industrial implementation of ultrasonic technology necessitates further field and mathematical research.

The catalytic activity of transition metal compounds (Mo, V, and W) in the reaction of oxidative desulfurization of straight-run diesel fuel with hydrogen peroxide is studied. Oxidation with sodium...

Oxidative desulfurization of straight-run nonhydrotreated diesel fraction with hydrogen peroxide in the presence of Na2MoO4 or Na2WO4, dibenzyl peroxide, and potassium permanganate; by air bubbling;...

The development and improvement of methods for the synthesis of environmentally friendly catalysts based on base metals is currently an urgent and promising task of modern catalysis. Catalysts based on nanoscale magnetite and maghemite have fast adsorption–desorption kinetics and high chemical activity. The purpose of this work is to obtain magnetic composites, determine their physicochemical characteristics and verify their activity in the process of liquid-phase oxidation of phenol with oxygen. Magnetic nanocomposites were obtained by chemical co-deposition of salts of ferrous and trivalent iron. The synthesized magnetic composites were studied by X-ray diffractometry, energy dispersive X-ray fluorescence and Mössbauer spectroscopy, IR-Fourier spectroscopy and elemental analysis. To increase the catalytic activity in oxidative processes, the magnetite surfaces were modified using cobalt nitrate salt. Further, CoFe₂O₄ was stabilized by adding polyethylenimine (PEI) as a surfactant. Preliminary studies of the oxidation of phenol with oxygen, as the most typical environmental pollutant were carried out on the obtained Fe₃O₄, CoFe₂O₄, CoFe₂O₄/PEI catalysts. The spectrum of the reaction product shows the presence of CH in the aromatic ring and double C=C bonds, stretching vibrations of the C=O groups of carbonyl compounds; the band at 3059 cm⁻¹ corresponds to the presence of double C=C bonds and the band at 3424 cm⁻¹ to hydroquinone compounds. The band at 1678 cm⁻¹ and the intense band at 1646 cm⁻¹ refer to vibrations of the C=O bonds of the carbonyl group of benzoquinone. Peaks at 1366 cm⁻¹ and 1310 cm⁻¹ can be related to the vibrations of C–H and C–C bonds of the quinone ring. Thus, it was demonstrated that produced magnetic composites based on iron oxide are quite effective in the oxidation of phenol with oxygen.

Disubstituted pyridines, such as derivatives of 2,6-pyridinedicarboxylic acid, have ben synthesized and their peroxo complexes with tungsten and vanadyl ion have been prepared in situ. The activity of the complexes during the oxidation of sulfur-containing compounds of various diesel fractions has been shown.