scholarly journals Development of the Method for Forecasting and Calculating the Operation of Sorption Systems for Purifying the Generator Gas Based on Dolomite Use. Part I

2021 ◽  
pp. 78-90
Author(s):  
Mihail Malko ◽  
◽  
Sergey Vasilevich ◽  
Andrei Mitrofanov ◽  
Vadim Mizonov ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Reaction Products ◽  
Initial Particle ◽  
Scientific Result ◽  
Catalytic Systems ◽  
Gaseous Reaction ◽  
Direct Combustion ◽  
Static Conditions ◽  
Generator Gas

A trend towards energy diversification creates the expansion of small energy facilities that involve the production of solid fuel generator gas, rather than its direct combustion. The economic indicators of such facilities significantly depend on the efficiency of the generator gas purification. A promising sorbent for the purification of the generator gas is dolomite. When working as a sorbent, dolomite particles usually form a layer, through which the generator gas that is heating them is filtered. The objective of the study is to determine kinetic parameters of the thermal decomposition of dolomite, depending on the size of the sample. It was achieved using the thermogravimetric study of the thermal decomposition of single dolomite particles under static conditions at various temperatures. The most significant scientific result was that a dependence of the kinetic parameters of the gross reaction on the size of the initial particle is revealed, and a regression equation was proposed for its quantitative assessment. In addition, since the heat treatment process of the material was fairly long lasting, and the sizes of the particles allowed them to be referred to thermally thin bodies, it was inferred that the effect of a grain size on the reaction kinetics should be explained through the description of the evacuation process of gaseous reaction products from the material. The significance of the results of the study lies in the fact that a particle size must be considered as a factor that affects the progress of the technological process, which increases the reliability of the calculation of sorption-catalytic systems based on the use of dolomite.

scholarly journals The Kinetics of the decomposition of chloral and its catalysis by iodine

1934 ◽  
Vol 146 (857) ◽  
pp. 334-344 ◽  
Keyword(s):  
Thermal Decomposition ◽  
High Temperature ◽  
Organic Compounds ◽  
Reaction Vessel ◽  
Reaction Products ◽  
Considerable Difficulty ◽  
Gaseous Reaction ◽  
High Boiling Point ◽  
Kinetics Of ◽  
Mercury Manometer

The introduction of chlorine atoms into organic compounds causes marked changes in properties which can often be explained in terms of a displacement of electrons under the influence of the substituent. It is an interesting question how far these influences will show themselves in the kinetic behaviour of the substituted molecules. Accordingly the thermal decomposition of chloral and its catalysis by iodine have been studied. The decomposition is a homogeneous gaseous reaction which can be compared with the decomposition of acetaldehyde and propionic aldehyde. Apparatus The apparatus was of the usual type, with a silica reaction vessel heated in an electric furnace. A tube led to a capillary mercury manometer outside the furnace, and the course of the reaction was followed by observing the rate of pressure increase. In view of the relatively high boiling point of chloral it was necessary to keep all the connecting tubes heated to 80°-90° C. Considerable difficulty was experienced with the lubricants for the stop-cocks operating at this temperature. A special high temperature vapourless grease was used, but even this showed a tendency to run and foul the connecting tubes. The reaction products also tended to foul the apparatus so that frequent cleaning of the whole, including the manometer and the mercury pump, was required.

Application of Calculus Equation in Solving Thermal Decomposition Kinetics Parameters of Flame Retardant Wood

2014 ◽  
Vol 983 ◽  
pp. 190-193
Author(s):  
Cai Yun Sun ◽  
Yong Li Yang ◽  
Ming Gao
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Phosphoric Acid ◽  
Flame Retardant ◽  
Kinetic Parameters ◽  
Flame Retardancy ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Kinetics Parameters

Wood has been treated with amino resins and amino resins modified with phosphoric acid to impart flame retardancy. The thermal degradation of samples has been studied by thermogravimetry (TG) in air. From the resulting data, kinetic parameters for different stages of thermal degradation are obtained following the method of Broido. For the decomposition of wood and flame retardant wood, the activation energy is found to decrease from 122 to 72 kJmol-1.

Consecutive reactions in the thermal decomposition of phenylalkyldiazirines

1977 ◽  
Vol 55 (20) ◽  
pp. 3596-3601 ◽  
Author(s):  
Michael T. H. Liu ◽  
Barry M. Jennings
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Diazo Compounds ◽  
First Order ◽  
Temperature Range ◽  
Decomposition Reactions ◽  
Consecutive Reactions ◽  
Rate Processes ◽  
Subsequent Decomposition

The thermal decomposition of phenyl-n-butyldiazirine and of phenylmethyldiazirine in DMSO and in HOAc have been investigated over the temperature range 80–130 °C. The intermediate diazo compounds, 1-phenyl-1-diazopentane and 1-phenyldiazoethane respectively have been detected and isolated. The decomposition of phenyl-n-butyldiazirine and the subsequent decomposition of its product, 1-phenyl-1-diazopentane, are an illustration of consecutive reactions. The kinetic parameters for the isomerization and decomposition reactions have been determined. The isomerization of phenylmethyldiazirine to 1-phenyldiazoethane is first order and probably unimolecular but the kinetics for the subsequent reactions of 1-phenyldiazoethane are complicated by several competing rate processes.

Research into Thermocatalytic Propane-to-Propylene Synthesis Using Iron-Containing Composite Carbon Materials

2021 ◽  
pp. 100-114
Author(s):  
E.B. Markova ◽  
A.G. Cherednichenko ◽  
L.S. Akhmedova ◽  
Yu.M. Averina ◽  
Yu.M. Serov
Keyword(s):  
Carbon Nanotubes ◽  
Iron Oxide ◽  
Service Life ◽  
Oil And Gas ◽  
Carbon Matrix ◽  
Propane Conversion ◽  
Reaction Products ◽  
Chemical Production ◽  
Catalytic Systems ◽  
Propylene Selectivity

The development of modern thermocatalytic technologies for processing oil and gas raw materials is one of the promising areas for the advancement of chemical production. New highly efficient catalytic systems with the required technical characteristics and long service life play an essential role in solving these issues. The paper focuses on obtaining propylene by selective propane dehydrogenation. In the course of the experiments, composite iron-containing catalysts were synthesized, in which the active component is iron oxide in combination with an inert carbon matrix. FAS activated carbon and carbon nanotubes were used as the matrix. As a result of the synthesis on the catalyst surface it was possible to obtain catalytic centers that transfer electrons by changing the degree of iron oxidation when converting the starting materials into the target reaction products. Findings of research show that the obtained iron-containing catalysts significantly increase the efficiency of the process in comparison with the efficiency of thermal cracking of propane. Thus, the Fe3+/FAS catalyst showed a conversion rate of the initial reagent of 68 % and a propylene selectivity of about 42 %. Further transition to catalytic systems based on singlelayer and double-layer carbon nanotubes modified with iron oxide (Fe3+/CNTI and Fe3+/CNTII) made it possible to obtain propane conversion up to 37--40 % with a decrease in propylene selectivity to 29--30 %. Studies of the service life of the synthesized catalytic systems and the possibility of their regeneration show that, with account for the regeneration, the activity of the catalysts and the main technical characteristics of the propane-to-propylene cracking process remain unchanged for 10 working cycles

scholarly journals AN INNOVATE METHOD OF THERMOGRAVIMETRIC DATA ANALYSIS

2021 ◽  
Vol 64 (3) ◽  
pp. 24-32
Author(s):  
Mihail V. Mal’ko ◽  
Sergej V. Vasilevich ◽  
Andrey V. Mitrofanov ◽  
Vadim E. Mizonov
Keyword(s):  
Experimental Data ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Kinetic Parameters ◽  
Calculation Method ◽  
Kinetic Calculation ◽  
Pyrolysis Mechanism ◽  
Total Mass Loss ◽  
Thermogravimetric Data ◽  
Heavy Tar

The objective of the study is to examine the Coats-Redfern approximation and to propose an innovative kinetic calculation method for the complex process of the heavy tar thermal decomposition under non-isothermal process. The thermal decomposition process was examined using the thermogravimetric analysis. There are several kinetic models proposed to analyze pyrolysis mechanism in terms of the formal reaction. In this manner, the kinetic parameters of the pyrolysis process can be evaluated based on total mass loss (thermogravimetric analysis –TGA). The TGA procedures can be conducted with isothermal or non-isothermal conditions, but the experimental data obtained according to this procedure have to be transformed into appropriate correlation. The obtained results have shown that the reaction takes place within temperature range of 540 K to 700 K and the inductive period of the process is about 224 min. Kinetic parameters were estimated with using of the conventional Coats-Redfern method. A new kinetic calculation method has been designed to provide a less laboriousness of identifications procedures compared with Coats-Redfern approximation and to take into account an induction time of the process. As the outcome of this study, it was shown that the kinetic parameters estimated with using of the proposed model-fitted method gives the more appropriate correlation in comparison with the conventional Coats-Redfern method. The proposed method uses the Coats-Redfern algorithm for evaluation of the reaction mechanism, but the value of the constant rate is defined directly from experimental data on the conversion rate.

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