Acetone is a valuable chemical product. It can be obtained by oxidative dehydrogenation of isopropyl alcohol, oxidation of propylene, decomposition of acetic acid and ethyl alcohol, oxidation of cymene and others. Among the known processes for the production of acetone, the most promising is the synthesis by hydration of acetylene in the presence of catalysts. The advantage of this method is the possibility of carrying out the process in existing plants for the production of acetic aldehyde. On the other hand, the process of simultaneously producing acetaldehyde and acetone under the influence of multifunctional catalysts and carrying out the process using flexible technology is promising. The vapor-phase hydration of acetylene with the formation of acetone on polyfunctional catalysts was studied. Process parameters are found that provide acetone with high selectivity and acetylene conversion. At present, acetic aldehyde is mainly obtained by two methods - hydration of acetylene and oxidation of ethylene. The process of hydration of acetylene to acetic aldehyde in the presence of catalysts has been studied quite well. Numerous catalysts have been proposed for this process. Among the known catalysts for hydration of acetylene to acetic aldehyde, the most active was the cadmium calcium phosphate catalyst (CCF), which is recommended for industrial use. However, cadmium calcium phosphate catalyst is not without drawbacks. The average yield of acetaldehyde in one pass of acetylene does not exceed 7.0%. The CCF catalyst is very sensitive to temperature changes, its service life before regeneration does not exceed 72-76 hours. Keywords: acetone, propylene, hydration process, catalyst, crosslinking, multifunctional properties.

The technologies associated with the use of a membrane bioreactor (MBR) are becoming one of the dynamically developing directions in the wastewater disposal system. However, a certain part of the used design of membrane units are exposed to mechanical contamination, which significantly impairs their performance. This is especially noticeable when working at wastewater treatment plants, where the required degree of preliminary cleaning from solid mechanical particles and suspended solids is not provided. The purpose of the work was to improve the process of post-treatment of urban wastewater and protect the membrane element of the installation from clogging with coarse impurities and wear, with an overestimated concentration of suspended solids. The essence of the improved membrane technology of wastewater treatment consists in the preliminary capture of heavy and suspended particles with a size of more than 0.03 microns in a hydrocyclone, followed by water treatment in a chamber of a membrane bioreactor of modern design. The operating conditions of the membranes were determined by the operating modes and parameters of the bioreactor, in particular, by the degree of formation of colloidal compounds in it, which adversely affect the permeability. The density of the initial water varied within 1.059-1.078 g/cm³, and the content of solid particles was up to 0.3 mm. The activated sludge was filtered under vacuum on a Buchner funnel through a thin layer of cotton wool and gauze. During the tests, the indicators for capturing suspended solids were 5.0-9.0 mg/dm³, whereas, when working without a hydrocyclone, they were equal to 27-30 mg/dm³. The maximum performance of the hydrocyclone is provided at an inlet pressure of 225-300 kPa, and the pressure loss in the hydrocyclone chamber is 7.9-9.0 kPa. It was established that additional preparation of waste water for the post-treatment process using a hydrocyclone increases the cleaning capacity of membrane elements by reducing the load of accumulation of coarse impurities on the membrane surface.

The influence of a complex application of both plasticizing and air-entraining effects on concrete with polycarboxylate ether superplasticizer (PCE), air-entraining admixture (AIR), or an anti-foaming agent (AF) is analyzed in this paper with considerations for on the air content, workability, flexural and compressive strength, and freezing–thawing resistance of hardened cement mixtures. The effect of the complex behavior of PCE, AIR, and AF on the porosity of hardened cement mortar (HCM) and freezing–thawing resistance was investigated; freezing–thawing resistance prediction methodology for plasticized mortar was also evaluated. The results presented in the article demonstrate the beneficial influence of entrained air content on consistency and stability of cement mortar, closed porosity, and durability of concrete. Freezing–thawing factor KF depending on porosity parameters can be used for freezing–thawing resistance prediction. With both plasticizing (decrease in the water–cement ratio) and air-entraining effects (increase in the amount of entrained air content), the frost resistance of concrete increases, scaling decreases exponentially, and it is possible to obtain great frost resistance for cement-based material.

For the catalytic hydro chlorination of acetylene in the vapor phase based on local raw materials for the Zola-gel technology, we selected an active and high-performance catalyst (ZnCl2)x*(FeCl3)y*(CuCl2)z and also under the influence of various factors (partial pressure, temperature, ratio of reagent properties, contact time, catalyst concentration) the yield and reaction rate were studied with the participation of the selected catalyst. Based on the results obtained, a kinetic equation was proposed that satisfies the reaction, its adequacy is estimated, and a scheme of the reaction mechanism and the basis on the kinetic model are proposed. Because of studying the influence of the mass transfer coefficient on the process productivity and the influence of other factors, the technological parameters of the catalytic flocculants of vinyl chloride and the chloroprene extraction reactor of acetylene were calculated and the main indicators of the compatibility of technological capabilities of environmental and economic factors were substantiated. The successful development of the production of VC from ethylene was associated with the search for a cheaper hydrocarbon feed than acetylene. Analysis of the structure of the cost price of VC obtained by various methods shows that the acetylene method gives the highest cost, with acetylene accounting for about 90%. However, the world hydrocarbon price environment is constantly changing. In the future, it is possible to increase prices for oil and gas raw materials, the convergence of prices for acetylene and ethylene, and the latter may lose its main advantage in this regard.

During the construction of concrete structures of small cross-sections, the release of heat during cement hardening has no harmful effects. With the increasing temperature of the hardening cement mass, the rate of cement hydration increases. This increases the rate of release of its heat of hydration of cement. The consequence of the accelerated process of hydration of the binder is a more intensive increase in the strength of cement stone than in the case of hardening under normal conditions. This fact is widely used in practice for the intensification of the hardening of concrete. When structures with small cross-sections are being built, the heat released during hardening is relatively quickly transferred to the surrounding space and does not cause a significant increase in temperature. In structures made of massive concrete (with a large cross-section), this heat is stored in the interior of the array for a long time, which causes a rather large rise in temperature and its slow drop. This is due to the fact that heat transfer to the external environment is hampered here by the considerable thickness of the massif and the rapid rate of concreting, mechanized laying of large masses of concrete. As a result, a temperature difference is created between the internal and external parts of the structure and harmful internal stresses arise that can cause cracking in the hardened concrete. This leads to a violation of its solidity. The faster cement hydrates, the sooner and more heat is released. The types of cements with a high content of tricalcium silicate and aluminate emit more heat and rather than types of cement with a high content of dicalcium silicate and tetra-calcium aluminoferrite. However, the latter has a lower strength. The increase in strength resulting from the hydration process is inevitably associated with the release of heat into the environment