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.

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.

scholarly journals An Overview of Thermal Analysis of Polymers

2017 ◽  
Vol 3 (1) ◽  
pp. 36-54
Author(s):  
DR Hardy Chan Sze On
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Kinetic Parameters ◽  
Physical Meaning ◽  
Thermomechanical Analysis ◽  
Special Focus ◽  
Modes Of Operation ◽  
Polymer Reaction

This article presents an up-to-date overview of the application of thermoanalytical methods in the study of polymers with special focus on thermogravimetry, differential thermal analysis, diferential scening calorimetry and thermomechanical analysis. The working principles behind the variouse thermoanalytical methods together with modes of operation are described. Their usefulness in the characterisation of polymers is cowered comprehensively with examples cited in the litearture. The question of validity of data obtained from thermokinetic studies of polymers is examined and it is felt that the kinetic parameters generated carry little physical meaning about the kinetic of the polymer reaction.

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.

scholarly journals Contamination Studies on Mollusk Shell Samples

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Tomasz Goslar ◽  
Mieczysław F Pazdur
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Solid State ◽  
Carbon Exchange ◽  
Laboratory Contamination ◽  
Mollusk Shell

A series of shell samples has been studied to determine the magnitude and mechanisms of carbon exchange between shells and their environment. Laboratory contamination experiments included the storing of shell samples in acid and calcareous environments of different 14C concentrations as well as studies of carbon exchange in the course of thermal recrystallization in solid state in an atomosphere of carbon dioxide. The applicability of differential thermal analysis to studies of the structure and texture of shells is discussed.

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