Differential thermal analysis studies on the kinetics of crystallization of calcium tungstate from solutions in sodium tungstate melts

1979 ◽  
Vol 16 (1) ◽  
pp. 27-34 ◽  
Author(s):  
B. N. Roy ◽  
S. Appalasami
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Sodium Tungstate ◽  
Calcium Tungstate ◽  
Kinetics Of Crystallization ◽  
Kinetics Of

Zeolites Fit For A Crown: Probing Host-Guest Interactions with Thermogravimetric Methods

2018 ◽  
Author(s):  
Asel Sartbaeva ◽  
Paul R. Raithby ◽  
Remi Castaing ◽  
Antony Nearchou
Keyword(s):  
Mass Spectrometry ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Petrochemical Industry ◽  
Rational Use ◽  
New Methodologies ◽  
First Time ◽  
Kinetics Of

Through a combination of thermogravimetry, mass spectrometry and differential thermal analysis, we demonstrate for the first time that all four zeolites show experimental differences in their host-guest interactions with 18C6. In addition, we have estimated the kinetics of 18C6 decomposition, which is a technique that has not been applied to zeolites previously. Using these findings as a toolkit, a more rational use of OSDAs can be utilised to prepare designer zeolites. Furthermore, the new methodologies presented herein can be applied to current zeolites, such as MFI-type zeolites used in the petrochemical industry.

Kinetics of temperature-programmed reactivation of a hydrodesulphurization catalyst

1983 ◽  
Vol 48 (12) ◽  
pp. 3340-3355 ◽  
Author(s):  
Pavel Fott ◽  
Pavel Šebesta
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thin Layer ◽  
Kinetic Parameters ◽  
Diffusion Region ◽  
Reaction Heat ◽  
Gaseous Products ◽  
Temperature Programmed ◽  
Kinetics Of

The kinetic parameters of reactivation of a carbonized hydrodesulphurization (HDS) catalyst by air were evaluated from combined thermogravimetric (TG) and differential thermal analysis (DTA) data. In addition, the gaseous products leaving a temperature-programmed reactor with a thin layer of catalyst were analyzed chromatographically. Two exothermic processes were found to take part in the reactivation, and their kinetics were described by 1st order equations. In the first process (180-400 °C), sulphur in Co and Mo sulphides is oxidized to sulphur dioxide; in the second process (300-540 °C), in which the essential portion of heat is produced, the deposited carbon is oxidized to give predominantly carbon dioxide. If the reaction heat is not removed efficiently enough, ignition of the catalyst takes place, which is associated with a transition to the diffusion region. The application of the obtained kinetic parameters to modelling a temperature-programmed reactivation is illustrated on the case of a single particle.

Kinetics Study on Controlled Crystallization of a Ca2ZnSi2O7 Phase in Materials Obtained from Vitrification of Metallurgical Slag and Recycled Soda Lime Glass

2010 ◽  
Vol 68 ◽  
pp. 114-119 ◽  
Author(s):  
Erika Iveth Cedillo González ◽  
Juan Jacobo Ruiz Valdés ◽  
Anabel Álvarez Méndez
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Soda Lime ◽  
Exothermic Peak ◽  
Metallurgical Slag ◽  
Isothermal Kinetics ◽  
Soda Lime Glass ◽  
Structural Applications ◽  
Minor Peak ◽  
Kinetics Of

Non isothermal kinetics of a glass obtained from a mixture of 59 wt % of metallurgical slag and 41 wt % of soda lime recycled glass was studied by differential thermal analysis (DTA), x-ray diffraction (XRD) and scanning electron microscopy (SEM). The curves of differential thermal analysis revealed the presence of two exothermic peaks, a major peak at 810 °C and a minor peak at 1085 °C. DRX revealed that the first exothermic peak corresponds to the formation of hardystonite, Ca2ZnSi2O7 and aegirine, NaFe3+Si2O6, while the second minor peak corresponds to the formation of zinc ferrite, ZnFe2O4. The activation energy of the crystallization, <em>Ea</em>, was calculated with the Kissinger equation from DTA data, obtained at different heating rates. In addition, the particle size effect on the kinetics of crystallization was studied. The Avrami factor, <em>n,</em> was calculated with Augis-Bennett method. The values of obtained<em> Ea</em> increase with bigger particle sizes and also the value of n, indicating that for small particles the superficial crystallization mechanism is predominant, while bulk mechanism is preferential on large particles. Obtained materials are suitable for some structural applications.

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