OPTIMUM CONDITIONS DETERMINATION OF METHYL METHACRYLATE OBTAINING OVER TUNGSTEN-CONTAINING CATALYST

Y . V . D m y t r u k Postgraduate student* Е-mail: yulia.nu.lp@gmail.com V . V . I v a s i v PhD* Е-mail: el.spectre.x@gmail.com R . V . N e b e s n y i PhD* Е-mail: nebesnyi@lp.edu.ua S . V . M a y k o v a PhD, associate professor Food Technologies and Restaurant Business Department Lviv Institute of Economy and Tourism Mentsynskogo str., 8, Lviv, Ukraine, 79008 Е-mail: svitl-maykova@yandex.ru *Technology of Organic Products Department Lviv Polytechnic National University S. Bandery str., 12, Lviv, Ukraine, 79013 Досліджено процес одержання метилметакрилату альдольною конденсацією метилпропіонату з формальдегідом на B2O3– –P2O5–WO3/SiO2 каталізаторі в газовій фазі. Встановлено вплив додавання метанолу в реакційну суміш на побічну реакцію гідролізу естерів. Визначено оптимальні умови (температура, час контакту) здійснення процесу конденсації метилпропіонату з формальдегідом в присутності даного каталізатора Ключові слова: метилметакрилат, метакрилова кислота, метилпропіонат, формальдегід, каталізатор, гетерогенний каталіз, альдольна конденсація


OPTIMUM CONDITIONS DETERMINATION OF METHYL METHACRYLATE OBTAINING OVER TUNGSTEN-CONTAINING CATALYST (p. 4-7)
Yuliia Dmytruk, Volodymyr Ivasiv, Roman Nebesnyi, Svitlana Maykova The main common methods of methyl methacrylate producing are acetoncyanohydrin method and oxidation of isobutylene and tert-butanol. Because of the significant drawbacks of these methods, it is important to develop new, alternative ways of methyl methacrylate obtaining, one of which could be aldol condensation of methyl propionate with formaldehyde in the gas phase. The actual task for today is to find out effective catalysts for this process.
For this aim, methyl propionate condensation with formaldehyde was studied in the presence of B 2 O 3 -P 2 O 5 -WO 3 /SiO 2 catalyst, which previously has showed high activity in the condensation of propionic acid with formaldehyde to methacrylic acid. The paper also investigates the influence of methanol on the side reaction of methyl propionate hydrolysis; it was found that adding methanol causes a slight increase in MMA selectivity, but the yield of unsaturated products decreases, and therefore adding methanol to the reaction mixture for the MP condensation with FA over B 2 O 3 -P 2 O 5 -WO 3 /SiO 2 catalyst is impractical. The optimum conditions for MP condensation with FA, namely temperature 653 K and contact time 12 s were found. Under these conditions, in the presence of B 2 O 3 -P 2 O 5 -WO 3 /SiO 2 catalyst with an atomic ratio of components B:P:W 3:1:0.6 respectively total yield of MMA and MAA was 31.91 % while their total selectivity was 32.3 %.
Keywords: methyl methacrylate, methacrylic acid, methyl propionate, formaldehyde, catalyst, heterogeneous catalysis, aldol condensation. Experience in using low cement alumina-magnesia castables, containing spinel-forming reagents, in monolithic ladle linings identified their significant advantages in terms of thermomechanical properties, corrosion resistance and slag resistance. A particular feature of these castables is the synthesis of «in situ» magnesium aluminate spinel at high operating temperatures, which provides increased operational lifetime of the lining.

References
The microsilica influence on the phase constitution of the composite mixture, containing calcium aluminate cement and spinelforming reagents -calcined alumina and sintered periclase after firing at 1700 о C was investigated in the paper. It was found that as a result of the interaction of cement calcium aluminates with microsilica, fusible compounds -anorthite and helenite that, at increased microsilica content, impair physical and technical properties of the composite are formed. It was determined that the ratio of spinelforming reagents and content of the silica-containing material in a matrix component of alumina-magnesia castables is a more important factor of the synthesis of high-melting-point crystalline phases than the microsilica content. Directed regulation of the phase constitution of the matrix component of alumina-magnesia castables by adjusting the grain-size composition of spinel-forming reagents and their optimal ratio will ensure achieving a set of the given physical and technical characteristics of concrete and increasing the operational lifetime of monolithic ladle linings.

A STUDY OF THE EFFECT OF IRON (III) COMPOUNDSON OXIDATION OF IRON (II) IONS BY ATMOSPHERIC OXYGEN (p. 13-17) Victor Yavorskiy, Yaroslav Kalymon, Olga Rubaу
Deferrisation of groundwater has been performed by many methods whose choice depends on the form in which iron (Fe) compounds exist in water and on its chemical composition. A number of published studies have proved that the iron (III) compounds'sediment used in the filtering substrate has a catalytic effect on the oxidation process. The same property of iron (III) compounds'sedimentis observed in the sediment layerresulting from contact purification of water. However, in the case of filtering, due to the large-size granules of the filter substrate, the specific surface area of the autocatalytic layer is small, which significantly reduces the system performance. In the schemes of contact filtering with held-up sediment, the area of the phases' contact increases, but there is a need for strict observance of the speed of the water flow and an extended contact time (45 min.). Therefore, our tasks were to increase the active contact area of the catalyst pellicle of the iron (III) sediment and to reduce the time ofthe contact between water and the held-upsediment.
Deferrisation was carried out in a horizontal absorber bucket of dispersants,in which intensive dispersion significantly increases the area of the phases' contact in the system. Thus, if the pH of water was 6.4 to 7.8 and the temperature was 291 K,the achieved deferrisation was highly efficient, with low concentration of iron (III) compounds in the volume of the researched water in the process of dispersion-0.02 and 0.05 mol Fe 3+ /m 3 . The time of the contact between the purified water and the compounds of the sediment was 15 to 80 sec, depending on the pH of the water and the dose of the applied iron (III) compounds.
The obtained results can serve as a basis for the development of a resource and energy saving technology of groundwater deferrising with recirculation of the newly formed sediment.

THE STUDY OF PHYSICOCHEMICAL PROPERTIES OF THE SEDIMENTARY CHALK SURFACE OF DOMESTIC DEPOSITS (p. 17-22) Dmytro Arshynnikov, Valentyn Sviderskiy
The physicochemical properties of the surface of sedimentary chalk deposits in Ukraine were studied, quantification of wettability in static cycles (water) with sinters (water and xylene) compared to chemically precipitated chalk and some imported varieties of calcite was presented. The importance of the role of mineralogical composition and content of adsorbed water in the process of implementation of polar and nonpolar wetting liquids is shown.
The effect of specific surface area, particle morphology, pore structure, surface energy state and variety of sedimentary varieties on the wetting process and adsorption activity with respect to water and oil was evaluated. Analysis of the importance of the role of chemically deposited chalk in the above-mentioned processes was also conducted. The influence of hydrophobication of calcium carbonates on sedimentary chalk, for example, the possibility of a fundamental change in the physicochemical properties of the surface was analyzed. Future possibilities for use of natural sedimentary chalk in the finished building materials suitable for various functional applications were identified.

USE OF THE ADMIXTURE CONSISTING OF PRODUCTS OF PROCESSED POLYMER FRACTION OF MUNICIPAL SOLID WASTE AS A CEMENT HARDENING ACCELERATOR (p. 23-29) Anna Fleysher, Volodymyr Tokarchuk, Valentin Sviderskiy
Increasing quality and durability requirements of concrete and reinforced concrete products lead to the growth of quality requirements not only of the main raw materials but also additional, for example, admixtures. Therefore, many effective admixtures, which have a negative impact on the quality of concrete are taken out of use. These include calcium chloride, which causes corrosion of concrete reinforcement. Hence, developing and introducing new admixtures that would combine high main effect and the lack of negative impact on the concrete quality is reasonable.
The influence of the experimental admixture DOR № 1 on physical and mechanical properties of the cement and the formation rate of bound water in the hardening of the latter was investigated. The admixture DOR № 1 is the product of the processed polymer fraction of municipal solid waste and consists of amides and ammonium salts of the terephthalic acid.
It was found that the admixture DOR № 1 accelerates cement setting and hardening under normal and low temperatures, but has a selective efficiency, which depends on the admixture concentration, cement type and temperature conditions. Cement hardening acceleration occurs due to increased solubility of clinker minerals, which in turn increases the formation rate of the gel-like phase, calcium ions and accelerates crystallization of calcium hydrosilicates, which increases cement strength.
The results confirm the possibility of using the admixture DOR № 1 as a cement setting and hardening accelerator. The admixture can be used for concreting under different temperatures.
Keywords: admixture, cement setting and hardening accelerator, polymer fraction of municipal solid waste, compressive strength, hydration rate, amount of bound water.

DESIGN OF GASOLINE VAPOR EJECTION CONDENSATOR FROM VAPOR AND GAS MIXTURES (p. 29-37) Michail Kologrivov, Vitalii Buzovskiy
The calculation method of the ejection apparatus, which operates with flammable and explosive vapor-gas flow is considered. Calculation of the apparatus is performed without prior experimental research of the operation with gasoline vapor. The calculation method is based on two models. The first Pazhi-Galustov model is theoretical, the second Andreev model uses similarity criteria. The Stefan formula, as applied to the polar coordinate system was derived, which has allowed to give a more rigorous description of the mass transfer mechanisms at the droplet interface. The results of Andreev E.I., obtained for the nozzle chambers of air conditioners were used for deriving the heat-mass transfer intensity equation according to the first model by numerical simulation. The approach, which has allowed to develop recommendations for a constructive design of the ejection apparatus for condensing gasoline vapors without dangerous experimental research was proposed. In particular, the numerical experiment has shown that in order to reduce materials consumption, the length of the apparatus is advisable to be no more than 1.5 m, and the ratio of mass flows of brine and vaporgas mixture, providing the necessary gasoline vapor recovery degree must be at least 5:1.
Keywords: ejection heat exchanger, heat-mass transfer, convective and molecular diffusion, mathematical model. temperatures of 393-433 K by changes in the amine concentration over time was investigated, based on which the rate constants, activation energy and entropy were calculated. Using a kinetic firstorder reaction model, the estimated thermodynamic parameters, changes in the amine concentration over time were calculated and compared with the experimental values. Analysis of variance between concentrations indicates that the amine concentration can be used for the sunflower oil amidation reaction control only at the initial stage. This is caused by the fact that both nitrogen and oxygen-containing products that also react with amine are formed in the oil amidation.
initiators on the yield and physicochemical properties of cooligomers obtained, namely bromine number, softening temperature, color and molecular weight. For that, surface-active properties of emulsifiers used were thoroughly studied, the surface tension isotherm for the given emulsifiers (sodium stearate and oleate, emulsifier E-30) was obtained. To determine the optimal emulsifier concentration, the critical micelle concentration (CMC) and surface tension at the point corresponding to the CMC was defined. It was found that the emulsifier amount increase to the CMC point promotes the yield enhancement (up to 17.8 wt%) and improves the physicochemical properties of the product.