Synthesis of aluminum oxides from the products of the rapid thermal decomposition of hydrargillite in a centrifugal flash reactor: II. Physicochemical properties of the products obtained by the centrifugal thermal activation of hydrargillite

2007 ◽  
Vol 48 (1) ◽  
pp. 153-161 ◽  
Author(s):  
Yu. Yu. Tanashev ◽  
E. M. Moroz ◽  
L. A. Isupova ◽  
A. S. Ivanova ◽  
G. S. Litvak ◽  
...  
Author(s):  
A. Legrouri

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.


2016 ◽  
Vol 89 (5) ◽  
pp. 683-689 ◽  
Author(s):  
E. V. Ovchinnikova ◽  
L. A. Isupova ◽  
I. G. Danilova ◽  
V. V. Danilevich ◽  
B. A. Chumachenko

Polyhedron ◽  
2013 ◽  
Vol 65 ◽  
pp. 110-121 ◽  
Author(s):  
Pavel S. Koroteev ◽  
Zhanna V. Dobrokhotova ◽  
Andrey B. Ilyukhin ◽  
Nikolay N. Efimov ◽  
Denis I. Kirdyankin ◽  
...  

Author(s):  
Ольга Валентиновна Гребенникова ◽  
Александрина Михайловна Сульман

D-глюконовая кислота является широко потребляемым продуктом в пищевой и фармацевтической промышленностях. Данная работа посвящена разработке биокатализатора окисления D-глюкозы до D-глюконовой кислоты. Биокаталитические системы были выполнены на основе глюкозооксидазы, иммобилизованной на магнитоотделяемые мезопористые оксиды SiO и AlO, которые были синтезированы путем образования наночастиц магнетита в порах оксидов кремния и алюминия в результате термического разложения нитрата железа, инкорпорированного пропиткой. В работе подобраны оптимальные значения рН и температуры, при которых синтезированные биокатализаторы способны работать. Произведена сравнительная характеристика работы биокаталитических систем по сравнению с нативной формой глюкозооксидазы. D-gluconic acid is a widely consumed product in the food and pharmaceutical industries. This work is devoted to the development of a biocatalyst for the oxidation of D-glucose to D-gluconic acid. Biocatalytic systems were based on hycose oxidase immobilized on magnetically detachable mesoporous oxides SiO and AlO, which were synthesized by the formation of magnetite nanoparticles in the pores of silicon and aluminum oxides as a result of thermal decomposition of iron nitrate incorporated by impregnation. In this work, the optimal pH and temperature values were selected, at which the synthesized biocatalysts are able to work. A comparative characteristic of the work of biocatalytic systems in comparison with the native form of glucose oxidase has been made.


2020 ◽  
Vol 42 (4) ◽  
pp. 50-58
Author(s):  
T.V. Korinchevska ◽  
V.A. Mykhailyk

The article considers the effect of the granulometric composition of pine wood sawdust and granulation modes on the thermal decomposition of biofuel. Mechanical activation and thermal activation of raw materials before pressing were used in the study. Thermal decomposition of granular fuel was carried out by the methods of thermogravimetry and differential thermal analysis. The temperature ranges of dehydration, thermal decomposition of organic and mineral substances, moisture and ash content of the fuel have been determined. The rates of thermal decomposition of organic substances in granular fuel were also determined. The thermal effects of thermal decomposition of the granule samples were compared. It is registered that the equilibrium moisture content of granules obtained after thermal activation of the raw material is lower than that for granules made by cold pressing. This is indirect evidence of their increased density. It has been determined that most of the heat of thermal decomposition of organic substances in granular fuels is released in the high-temperature period at a decomposition rate of 1,12 to 1,37 % dry matter per minute. It was revealed that the thermal effect of thermal decomposition of granules depends on the fractional composition of the ground raw materials. This may be due to the difference in the chemical composition of the fractions. The analysis of obtained results made it possible to determine that the mechanical activation of raw materials increases the average rate of granule decomposition, and thermal activation reduces it. That is, the mechanical activation of raw materials has a positive effect on the thermal decomposition process. Grinding wood sawdust to particles smaller than 0,2 mm can lead to partial destruction of complex macromolecular compounds (hemicellulose, cellulose and lignin). Thus, this leads to a decrease in the degree of intermolecular interaction and intensification of the decomposition process.


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