Jasur Shukurov, Normurot Fayzullaev

In the article, more than 20 catalysts were tested for synthesis gas dimethyl ether. Among them, catalysts containing Al₂O₃*CuO*ZnO*ZrO₂//HSZ and Cr₂O₃*Al₂O₃*ZnO//HSZ were proven to have high catalytic activity and productivity. In the presence of these catalysts, it was found that during the reaction, coke and tars are formed in minimal amount, and the catalyst works without changing its catalytic activity for a long time. Therefore, Al₂O₃*CuO*ZnO*ZrO₂//HSZ and Cr₂O₃*Al₂O₃*ZnO//HSZ catalysts with the following composition were used for methanol synthesis. Two-flow devices were used to conduct catalytic experiments: 2-4 MPa in the pressure range and 0.2-0.6 MPA (low-pressure device) in the range. Catalyst activation was conducted in a nitrogen-hydrogen stream (≈2 Vol.% H₂ at N₂, consumption ≈2 l/h). Contact Time, s∙kg_cat/l defined by the formula: τ=3600m/V_kir, conversion of methanol to dimethyl ether (DME) calculated by the formula: Х_СН3ОН = 2С_DME∙100(2С_DME+ С_м). The conversion of methanol to DME rises as contact duration increases (volumetric velocity decreases). Pressure reduction reduces the rate of methanol production but does not affect methanol dehydration. As a result, the higher the methanol synthesis, the lower the pressure at the same contact time.

Yuldashev Khayot Khurmatovich, Kodirova Dilshodxon Tulanovna, Mansurov Yulbarskhon Nabiyevich

In this work, samples of the Ce_0.72Zr_0.18Pr_0.1O₂ support and systems deposited on their surface with 0.5, 1.0 and 2.0% (wt.) of platinum were obtained. Studies were carried out on the catalytic properties of the samples during the oxidation of carbon monoxide by gas chromatography. The research on the catalytic activity of the obtained samples in the oxidation of carbon monoxide was carried out in a flow reactor under appropriate conditions. The study of the catalysts showed high activity in the oxidation of CO in the presence of platinum.

Ibragim R. Askarov, Sultanoy Kh. Mikhmanova, Nodira Kh. Abdurakhimova, Isakov Khayatulla

The contents of seeds and pods of melons were extracted with water and the amount of polysaccharides was studied. Based on the results obtained, it was determined that Water-soluble polysaccharide- (WSP), 7.5%, Pectin substances (PS)- 2.5% and Hemicelluloses (HMC) - 2.1%. When studying the composition of the seeds, it was found that WSP is 7%, PS 2% and HMC 0.5%. In the study of the obtained samples by IR spectroscopy, characteristic absorption peaks of Glc, Gal, Ara, Man, Xyl, and Rha are formed.

Askarov R. Ibrokhim, Isakov Khayatulla, Mukhammedov B. Saidmurod

The article presents the results of physical and chemical tests to confirm the composition and individuality of the complex compound of biogenic metallic copper acetate salt of furfurolidendiurea with high fungicidal and stimulating properties, obtained on the basis of local raw materials. IR-spectroscopic, Mass-spectroscopic, scanning electron microscopic and thermal analyzes were used.

O. I. Radjabov, A. S. Turaev, I. D. Gulmanov, A. Yu. Otajanov, L. B. Azimova

The article presents the results of obtaining dry collagen from cattle skins with the preservation of the original fibrous structure. The physicochemical parameters of the obtained collagen are determined. It has been shown that collagen with a preserved native structure, as well as collagen solutions, must be stored at a temperature of 15-25°C. Based on the obtained collagen, the composition of the injection form was developed, in which the collagen content is a maximum of 18%. Microscopic studies have established that collagen in the injection solution retains its native fibrillar structure. As a result of morphological studies, it was found that the injection solution of collagen does not cause an allergic reaction, does not sensitize the body, does not cause a pronounced inflammatory reaction, and gradually resolves, which indicates the safety of its use.

Fozilbek Khudoynazarov, Suvankul Nurmanov, Yuldosh Yakubov

The secondary product of acetylene production from methane pyrolysis was purified from soluble salts and oxides by acidic, alkaline and thermal treatment of carbon black, processing. Differential heat, isotherm, thermokinetics and entropy of benzene adsorption in acetylene black carbon were studied using the adsorption-calorimetric method at a temperature of 303 K. The mechanism of adsorption of molecules and the type and number of formed ion-molecular complexes were determined. The adsorption isotherm was characterized by a three-dimensional mathematical equation of the volumetric saturation theory of micro-pores from the initial field to the saturation field.

Dilmurod A. Ergashev, Shokhida Sh. Khamdamova

The process of conversion of 37.14% of solutions of calcium and magnesium chlorides with sodium chlorate at 50, 75, and 90°C with the evaporation of conversion solutions was studied. The activation energies of the process and the order and rate constant of the conversion reaction were determined depending on the temperature, time and conditions of the processes. The order of the process of conversion of calcium and magnesium chlorides with sodium chlorate is equal to one. This is confirmed by the fact that the conversion rate constant, calculated from experimental data, remains almost constant for each temperature. Straight Line Dependency from also indicates the first order of the process of conversion of calcium and magnesium chlorides with sodium chlorate. The conversion rate constant increases with increasing temperature. Its temperature dependence obeys the Arrhenius law. To establish the values of the conversion rate constant for different temperatures, the constants for 37.14% solutions of calcium chloride by the Arrhenius equation and the equation for the dependence of lgK on 1/T were derived. This is confirmed by the linear graphical dependence of lgK on 1/T. The expediency of carrying out the conversion process with evaporation at a temperature of 100°C.

Mutembei Peterson Kugeria, Fidelis Ngugi

The mineral data from Kenya shows several deposits of low grade titanium yet the country has been importing titanium products. Some regions of Tharaka Nithi County contain titanium minerals. These deposits have never been earmarked for extraction because the common extraction methods known are expensive. Titanium minerals are known to occur mixed with iron minerals. The objective of this study was concentrating titanium from low grade ores using carbonized biomass. The samples were obtained from the selected deposits in Maragwa location in Tharaka Nithi County. The samples were obtained from 30 cm depth and labelled level A and further one-meter depth and labelled level B. The samples were then dried at 105°C for 9 hours and later ground to 60.0 meshes (250 microns) using a ball mill. Titanium in the ore was concentrated using carbonized biomass at 800-900°C. The analyses of the minerals for the mineralogical and chemical composition were done using X-ray Diffraction Spectroscopy (XRD), X-ray Fluorescence Spectroscopy (XRF) and Atomic Absorption Spectroscopy (AAS). The mean composition of rutile was found to be 0.77±0.16% before concentration and 1.84±0.24 after concentration. The results show that rutile improved with a range of about 1.0 to 2.5% in all the deposits.

Abrekova N. N., Mahmudov S. D., Beknazarova N. S., Turaboev Sh. M., Sagdullaev B. T.

In the present work, chemical immobilization of levofloxacin into macromolecules of a synthetic polymer, polyvinylpyrrolidone, was carried out. By varying the molar ratio of PVP: levofloxacin in the reaction medium, polymer complexes were obtained in which the quantitative content of the drug was 12.3-38.5%. The structure of the synthesized polymer compounds was confirmed by IR and UV spectroscopy, and the molecular characteristics of the reaction products were also calculated. The kinetics of cleavage of levofloxacin from polyvinylpyrrolidone macromolecules at pH 2.0 and 7.4 was studied. According to data the most optimal is the use of an antibacterial complex with a molar ratio of PVP and levofloxacin respectively is 1:0.5.

F. Z. Burkhev, H. H. Kushiev, T. A. Djuraev

The article presents heavy pyrolysis oil (black, pungent-smelling poisonous liquid) formed as a result of pyrolysis of natural gas and containing polycyclic aromatic ring hydrocarbons (PAH) for the growth and development of plants and for physiologically active substances important in industrial production. indene and naphthalene were thermally fractionated. The obtained substances were quantified on Prominence-i LC-2030C 3D Plus (Shimadzu) using standard (Sigma Aldrich) samples by High Efficiency Liquid Chromatography (HELC) method. According to the results of the study, pyrolysis oil contains 9.21% indene, and 23 - 25% naphthalene, and due to the crystalline structure of the separated naphthalene, as a result of re-fractionation obtained pure naphthalene with a purity of 98.4%. The fractionation of pyrolysis oil, which is an additional product, has created a raw material base for the production of new types of import-substituting products.