Исследованы термоокислительные и трибоокислительные свойства композитов СВМПЭ/графен со сверхнизким содержанием графена. Композиты получали методом полимеризации in situ с содержанием наполнителя от 0,014 до 0,05% масс. Введение графена в СВМПЭ приводит к существенному улучшению трибоокислительных свойств, но практически не влияет на термоокисление. Это объясняется различными механизмами процессов термоокисления и трибоокисления в композите. The thermooxidative and tribooxidative properties of UHMWPE/graphene composites with an ultra-low graphene content are studied. Composites were prepared by in situ polymerization with a filler content of 0.014 to 0.05% by weight. The introduction of graphene into UHMWPE leads to a significant improvement in tribo-oxidative properties, but it practically does not affect on thermal oxidation. This is explained by various oxidation mechanisms that are implemented in the process of thermal oxidation and tribooxidation in the composite.

High activity of metal complex catalytic systems comprising nitrogenous bases and copper sulfates, acetates, and basic carbonate in oxidation of hydrogen sulfide and light mercaptans with atmospheric oxygen was established. Their activities are close to that observed for the chlorine-containing analogs, while no corrosion effect is exerted. An increase in the initial concentration of H 2 S has negligible effect on its conversion rate. Mercaptans do not affect the H 2 S oxidation rate, whereas an increase in the hydrogen sulfide concentration decelerates mercaptan oxidation. This is a diffusion-controlled reaction; hence, intensification of mixing of the catalyst with the hydrocarbons affords a 30–40% increase in the demercaptanization efficiency. The efficiencies displayed in demercaptanization processes by the catalytic systems and by the conventional scavengers neutralizing light sulfur impurities were compared.

The problem of disposal of toxic and corrosion-active sulfhydryl substances (deodorization), natural hydrocarbons is relevant to operational and environmental aspects. One method of removing these impurities is catalytic oxidation to non-toxic disulfide form. The message shows the results of a comparative study of the oxidation reaction of thiols by oxygen to disulfides in hydrocarbon media, catalyzed by complexes of copper salts (I, II) with various nitrogen-containing bases. As nitrogen-containing ligands, mono - and diethanolamine with different C4-C18 hydrocarbon radicals were used. It is established that water-soluble catalyst composition on the basis of monoethanolamine and the hydrocarbon-soluble complex of copper Cu(II) with N-octadecyldiethanolamine exhibits low activity in the oxidation of 1-octanethiol. It was found the activating effect of HCl on the activity of catalysts in various hydrocarbons (model mixture, vacuum gasoil, naphtha and gas condensate of the Karachaganak field), which allows for an exhaustive oxidation of thiols with the initial concentrations ≥1000 ppm. However, the introduction of hydrogen chloride is accompanied by the appearance of corrosion. The introduction of corrosion inhibitors have led to the complete deactivation of the catalysts. The high-performance catalytic system based on CuCl2/CuO was designed, for which we found the optimum ratio of catalyst/inhibitor, to eliminate the corrosion effect while maintaining a high level of activity. The kinetics of the oxidation reaction of the sulfhydryl derivatives by oxygen was studied. It was found that regardless of the nature of the hydrocarbon media, for all investigated catalysts a zero order on concentration of the thiol and close to first order on the catalyst concentration is observed. The use of developed catalysts and purification technology in the industry will reduce the environmental hazard during the transportation and storage of petroleum products.Forcitation:Pletneva I.V., Gavrilov Yu.A. Highly active catalysts for oxidation of thiols. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 70-73.

The results of studying the nonextractive oxidative demercaptanization of fuel oil derived from gascondensate in the presence of metal complex catalysts are presented in this work. The effect of the ratio of gaseous (air) and liquid (fuel oil) phases, catalyst concentration, time of contact, process temperature, and amount of total mercaptans on the degree of conversion of low molecular weight sulfur admixtures and quality of commercial products was evaluated.

The results of identification of the main operational properties of metallocomplex catalysts solutions for non-extractive oxidative sweetening of natural hydrocarbons and their products are provided in this article. These catalysts allow carrying out the catalytic oxidation of hydrogen sulfide and mercaptans in hydrocarbon media directly. This method allows to exclude from the technological cycle the need to use large volumes of extracting agents (aqueous alkaline solutions), which greatly simplifies the purification technology and eliminates the stage of recycling sulfuralkaline waste. These catalysts are oxidizing systems, which can have a negative impact on their storage and use. Therefore, it was necessary to determine the influence of the synthesis conditions and the composition of the catalyst solution on viscosity, pour point, surface tension and corrosion properties. The impact of storage duration and its conditions on the catalysts activity in the oxidation of H2S and light mercaptans in oil and oil products was studied. The results showed that the catalytic systems based on copper salts and amino alcohols correspond to the requirements for industrial applications.

Increasing environmental regulations according to the content of toxic volatile sulfur impurities in fuel oil requires improvement existing and development of new absorbers and ways of their application. The results of the study of oxidative demercaptanization of model mixtures containing hydrogen sulfide and hydrogen sulfide/ethyl mercaptan in the presence of metal complex catalysts are shown. It is established that the required degree of purification (conversion of hydrogen sulphide) is achieved at a ratio of kt/H2S=1.5, which is much lower than required when using scavenger. Experiments carried out at the refinery of "TAIF-NK" to remove hydrogen sulfide from fuel oil have shown the efficiency close to that obtained in experiments on model compounds. These catalysts are also effective in conversion of light mercaptans of fuel oil. Irreversible nature of transformation of hydrogen sulfide and thiols into nontoxical forms and no negative impact on the properties of the final product of this method is established.

To develop materials with new mechanical and improved rheological properties on the basis of common polyolefins, ultrahigh-molecular-weight PE and HDPE of medium molecular masses, the polymers have been modified with low-molecular-mass additives: crystalline organic disulfides (dithiaalkanes), liquid oligomer phenylmethylsiloxane, and oligooxypropylene glycol. It has been shown that the studied disulfide additives at low concentrations (up to 10% of the mass of PE) have no significant effect on the content and quality of the crystalline phase of HDPE. (The degree of crystallinity, enthalpy, and melting temperature change weakly.) In this case the plasticity of the modified PE improves: the tensile modulus and dynamic modulus decrease, whereas the elongation at break increases. In the presence of organic disulfides, the effective viscosity of the PE melt decreases. Unlike oligomeric phenylmethylsiloxane and oligooxypropylene glycol, dithiaalkanes are inert to the components of metallocomplex catalysts. Thus, the modification of PE with the aforementioned additives may be performed via their addition to the final polymer or in the course of the synthesis of the polymer.

Demercaptanization of sulfur compounds in crude oil in the presence of metal complex oxidation catalysts was studied. The adsorption capacities of the catalysts and industrial mercaptane scavengers were compared. The possibility of using these catalysts for the removal of light sulfur impurities in the field oil preparation was shown.