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1.
Подробнее
24
N94
Nurdillayeva, R. N.
Dissolution of stanless steel in sodium chloride solution at polarization by non-stationary current. [Текст] / R. N. Nurdillayeva // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 75-81
ББК 24
Рубрики: chemistry
Кл.слова (ненормированные):
stainless steel -- titanium electrode -- alternating current -- iron (II) ions -- chromium (III)ions -- current density -- and current efficiency
Аннотация: Stainless steel is in great demand due to its mechanical strength, heat resistance, and resistance to corrosive environments. This article presents the result of a study of the electrochemical dissolution behavior of a stainless steel electrode (12X18H10T) at polarization by 50 Hz alternating current in a neutral medium (NaCl). Preliminary experiments have shown that the main processes do not take place when two stainless steel electrodes are polarized with an alternating current. It was observed that by the polarization of the “stainless steel – titanium” pair electrodes with alternating current, the alloy is intensively dissolved with the formation of iron (II) and chromium (III) ions. This is due to the "valve" properties of the oxide layer formed on the surface of the titanium electrode. A change in the value of the current density of the titanium and steel electrodes significantly affects the process of electrochemical dissolution of the alloy. At high current densities, the dissolution rate of the alloy decreases due to the deterioration of the current correcting properties of titanium. With an increase in the electrolyte concentration, the current efficiency is reduced as salt passivation occurs. A maximum value of the current efficiency of dissolution of stainless steel was observed at a current frequency of 50 Hz. High frequencies of the alternating current do not provide an adjustable duration of the anodic half-cycle for the oxidation reaction due to the frequent change of half-cycles of the alternating current. It was observed that increasing the temperature of the electrolyte reduces the current efficiency of the electrochemical dissolution of stainless steel electrodes. The effects of main electrochemical parameters on the electrolysis process have been investigated, and the optimal conditions of the alloy dissolution were established (іТі = 60 kA/m2, іSS = 800 A/m2, [NaCl] = 2.0 M, t = 30, ν = 50 Hz.).
Держатели документа:
WKU
Доп.точки доступа:
Sauirbay, Zh.G.
Bayeshov, A.B.
N94
Nurdillayeva, R. N.
Dissolution of stanless steel in sodium chloride solution at polarization by non-stationary current. [Текст] / R. N. Nurdillayeva // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 75-81
Рубрики: chemistry
Кл.слова (ненормированные):
stainless steel -- titanium electrode -- alternating current -- iron (II) ions -- chromium (III)ions -- current density -- and current efficiency
Аннотация: Stainless steel is in great demand due to its mechanical strength, heat resistance, and resistance to corrosive environments. This article presents the result of a study of the electrochemical dissolution behavior of a stainless steel electrode (12X18H10T) at polarization by 50 Hz alternating current in a neutral medium (NaCl). Preliminary experiments have shown that the main processes do not take place when two stainless steel electrodes are polarized with an alternating current. It was observed that by the polarization of the “stainless steel – titanium” pair electrodes with alternating current, the alloy is intensively dissolved with the formation of iron (II) and chromium (III) ions. This is due to the "valve" properties of the oxide layer formed on the surface of the titanium electrode. A change in the value of the current density of the titanium and steel electrodes significantly affects the process of electrochemical dissolution of the alloy. At high current densities, the dissolution rate of the alloy decreases due to the deterioration of the current correcting properties of titanium. With an increase in the electrolyte concentration, the current efficiency is reduced as salt passivation occurs. A maximum value of the current efficiency of dissolution of stainless steel was observed at a current frequency of 50 Hz. High frequencies of the alternating current do not provide an adjustable duration of the anodic half-cycle for the oxidation reaction due to the frequent change of half-cycles of the alternating current. It was observed that increasing the temperature of the electrolyte reduces the current efficiency of the electrochemical dissolution of stainless steel electrodes. The effects of main electrochemical parameters on the electrolysis process have been investigated, and the optimal conditions of the alloy dissolution were established (іТі = 60 kA/m2, іSS = 800 A/m2, [NaCl] = 2.0 M, t = 30, ν = 50 Hz.).
Держатели документа:
WKU
Доп.точки доступа:
Sauirbay, Zh.G.
Bayeshov, A.B.
2.
Подробнее
35
R24
Rasulov, S. R.
Development of effective catalysts for processing C3-C4 Hydrocarbons. [Текст] / S. R. Rasulov, G. R. Mustafayeva // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 87-93
ББК 35
Рубрики: chemical Technology
Кл.слова (ненормированные):
refinery gases -- 3-C4 hydrocarbons -- zeolite-containing catalyst -- modifiers -- reaction-regeneration cycles.
Аннотация: The aim of the article is to study the effect of preparation and activation methods of a modified zeolite-containing catalyst on the activity and stability of catalytic properties displayed by it during the conversion of C3-C4 hydrocarbons. During the experiment, the industrial cracking catalyst OMNIKAT, which is a zeolite in the sodium form, was used as the initial one. Zinc, gallium, and REE (rare earth elements) were sequentially applied to decationized samples of this catalyst by ion exchange, impregnation, and dry mechanical mixing, and the effect of these methods on the catalytic properties of the zeolite-containing catalyst was observed. As a result of a comparative analysis of the regularities of aromatization of C3-C4hydrocarbons, it was found that the mechanical mixing method is the most preferable, since it provides the best process performance.
Держатели документа:
WKU
Доп.точки доступа:
Mustafayeva, G.R.
R24
Rasulov, S. R.
Development of effective catalysts for processing C3-C4 Hydrocarbons. [Текст] / S. R. Rasulov, G. R. Mustafayeva // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 87-93
Рубрики: chemical Technology
Кл.слова (ненормированные):
refinery gases -- 3-C4 hydrocarbons -- zeolite-containing catalyst -- modifiers -- reaction-regeneration cycles.
Аннотация: The aim of the article is to study the effect of preparation and activation methods of a modified zeolite-containing catalyst on the activity and stability of catalytic properties displayed by it during the conversion of C3-C4 hydrocarbons. During the experiment, the industrial cracking catalyst OMNIKAT, which is a zeolite in the sodium form, was used as the initial one. Zinc, gallium, and REE (rare earth elements) were sequentially applied to decationized samples of this catalyst by ion exchange, impregnation, and dry mechanical mixing, and the effect of these methods on the catalytic properties of the zeolite-containing catalyst was observed. As a result of a comparative analysis of the regularities of aromatization of C3-C4hydrocarbons, it was found that the mechanical mixing method is the most preferable, since it provides the best process performance.
Держатели документа:
WKU
Доп.точки доступа:
Mustafayeva, G.R.
Page 1, Results: 2