Development of nanostructured catalysts for catalytic oxidative water purification from organic impurities, including phenolic compounds

The purpose of this work was to create magnetic nanocatalysts that could be used for the oxidation of organic water pollutants – phenol and its derivatives – and to determine the physicochemical characteristics of the catalysts. The development of such active nanocomposite catalysts would solve the environmental problem in the Republic of Kazakhstan in the field of wastewater treatment from organic impurities, including phenols, and would also contribute to the subsequent creation of domestic production of oxygen-containing compounds, since almost the entire spectrum of oxygen-containing compounds for various industries is imported into the Republic. Nanosized magnetic composites based on Fe and Co were obtained by chemical deposition, in some cases, using polyethyleneimine and polyvinylpyrrolidone. It was shown that the interaction between nanoparticles and the polymer takes place in the case of a CoFe2O4 catalyst stabilized with polyvinylpyrrolidone or polyethyleneimine, which may indicate the efficient formation of nanocomposites. According to the IR study, for the CoFe2O4 nanocomposite stabilized with polyvinylpyrrolidone, the absorption bands at 735, 663, 649, 626 cm–1 are natural vibrations for the composite nanoparticles embedded in a polyvinylpyrrolidone matrix. The synthesized nanocomposites were tested in the oxidation of phenol with oxygen. The results demonstrate that the catalysts are promising both for the purification of industrial wastewater from phenol and for the synthesis of oxygen-containing compounds in the liquid phase under mild conditions

Catalytic cracking of M-100 fuel oil: relationships between origin process parameters and conversion products

The development of technologies for processing oil residues is relevant and promising for Kazakhstan, since the main oil reserves of hydrocarbons in the country are in heavy oils. This paper describes the study of the influence of technological modes on the yield and hydrocarbon composition of products formed because of cracking of commercial fuel oil and fuel oil M-100 in the presence of air in the reactor. For catalysts preparation, natural Taizhuzgen zeolite and Narynkol clay were used. It was found that the introduction of air into the reaction zone, in which oxygen is the initiator of the cracking process, significantly increases the yield of the middle distillate fractions. In the presence of air, the yield of diene and cyclodiene hydrocarbons significantly increases compared to cracking in an inert atmosphere. According to the data of IR spectral analysis of M-100 grade oil fractions, in addition to normal alkanes, the final sample contains a significant amount of olefinic and aromatic hydrocarbons. On the optimal catalyst, owing to oxidative cracking of fuel oil, the following product compositions (in %) were established: Fuel oil M-100: gas – 0.8, gasoline – 1.1, light gas oil – 85.7, heavy residue – 11.9, loss – 0.5 and total – 100.0%; commodity Fuel oil (M-100): gas – 3.3, gasoline – 8.4, light gas oil – 84.3, heavy residue – 4.0, loss – 0 and total – 100.0%

Activity features of catalysts for thermocatalytic hydrogenation processing of polymer waste

The aim of this study was to obtain new catalysts for the processing of carbon-containing polymer waste based on polyethylene and polypropylene, represented mostly by lids from beverages bottled in plastic containers, which accumulate in huge quantities in landfills, by the method of thermocatalytic hydrogenation into liquid fuels and other products. The process was carried out in the presence of fuel oil as a binder, a source of hydrogen and additional hydrocarbons. Thus, two tasks can be solved simultaneously: recycling the polymer waste and obtaining the alternative raw materials from the polymer waste in order to save resources and improve the environmental situation in general. New catalysts based on activated zeolite modified with Mo(VI) and W(VI) salts of various concentrations for the thermocatalytic hydrogenation processing of waste plastics into motor fuels were synthesized. The composition, structure, morphology and adsorption properties of the catalysts were determined by different physicochemical methods. The suitability of the obtained catalysts for use in the thermocatalytic hydrogenation processing of plastic waste into fuels was determined. The catalysts were tested during the processing of a mixture of polyethylene-polypropylene: a paste-forming agent (fuel oil) at T=450 °C and a pressure of 0.6 MPa. The individual and group composition of gasoline, diesel and gas oil fractions was determined by chromatography coupled with mass spectrometry. The maximum yield of the gasoline fraction (16.9 wt.%) and diesel fraction (39.31 wt.%) was obtained on a 2%W(VI)/diatomite catalyst

Synthesis, Characterization of Magnetic Composites and Testing of Their Activity in Liquid-Phase Oxidation of Phenol with Oxygen

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

Catalysts Based on Iron Oxides for Wastewater Purification from Phenolic Compounds: Synthesis, Physicochemical Analysis, Determination of Catalytic Activity

In this work, the synthesis of magnetite nanoparticles and catalysts based on it stabilized with silicon and aluminum oxides was carried out. It is revealed that the stabilization of the magnetite surface by using aluminum and silicon oxides leads to a decrease in the size of magnetite nanocrystals in nanocomposites (particle diameter less than ~10 nm). The catalytic activity of the obtained catalysts was evaluated during the oxidation reaction of phenol, pyrocatechin and cresol with oxygen. It is well known that phenolic compounds are among the most dangerous water pollutants. The effect of phenol concentration and the effect of temperature (303–333 K) on the rate of oxidation of phenol to Fe3O4/SiO2 has been studied. It has been determined that the dependence of the oxidation rate of phenol on the initial concentration of phenol in solution is described by a first-order equation. At temperatures of 303–313 K, incomplete absorption of the calculated amount of oxygen is observed, and the analysis data indicate the non-selective oxidation of phenol. Intermediate products, such as catechin, hydroquinone, formic acid, oxidation products, were found. The results of UV and IR spectroscopy showed that catalysts based on magnetite Fe3O4 are effective in the oxidation of phenol with oxygen. In the UV spectrum of the product in the wavelength range 190–1100 nm, there is an absorption band at a wavelength of 240–245 nm and a weak band at 430 nm, which is characteristic of benzoquinone. In the IR spectrum of the product, absorption bands were detected in the region of 1644 cm−1, which is characteristic of the oscillations of the C=O bonds of the carbonyl group of benzoquinone. The peaks also found at 1353 cm−1 and 1229 cm−1 may be due to vibrations of the C-H and C-C bonds of the quinone ring. It was found that among the synthesized catalysts, the Fe3O4/SiO2 catalyst demonstrated the greatest activity in the reaction of liquid-phase oxidation of phenol

Isothermic and Kinetic Study on Removal of Methylene Blue Dye Using Anisomeles malabarica Silver Nanoparticles: An Efficient Adsorbent to Purify Dye-Contaminated Wastewater

Remediation of industrial discharged dyes to the water bodies is much needed in the current scenario. Here in this, we prepared silver nanoparticles using Anisomeles malabarica. The synthesized nanoparticles were characterized by Fourier transform infrared study, scanning electron microscopy, dynamic scanning calorimetry, and thermogravimetric analysis. All the characterization studies suggested that the formation of silver nanoparticles was successful. The synthesized silver nanoparticles were used as an adsorbent to adsorb the methylene blue. To achieve this, optimum pH of the adsorbent to adsorb the dye was studied, and it was found to be pH 7. The adsorbent dose to adsorb the dye was found to be 0.1 g/L. From the isotherm theoretical studies, it was found that the adsorption isotherm follows Langmuir adsorption, and the qmax was found to be 97.08. From the kinetic study, the rate of the reaction follows the pseudosecond-order kinetics with regression>0.9. From the study, it was inferred the nanoparticles synthesized can act as a good adsorbent and can be used to purify the wastewater contaminated with methylene blue