Kinetics of the Reaction of Solid Anhydrous Potassium Carbonate with Gaseous Sulfur Dioxide

1994 ◽  
Vol 59 (11) ◽  
pp. 2357-2374 ◽  
Author(s):  
Erich Lippert ◽  
Karel Mocek ◽  
Emerich Erdös

Results are presented of an experimental kinetic study of the heterogeneous reaction between gaseous sulfur dioxide and solid anhydrous potassium carbonate. The measurements were carried out in an all glass kinetic flow apparatus with nitrogen as the carrier gas and a fixed bed of the solid working in the differential regime at atmospheric pressure and a temperature of 423 K (150 °C). The reaction course was studied in dependence on the partial pressures of sulfur dioxide (pSO2) and water vapour (pH2O) in concentration ranges pSO2 = 13 - 430 Pa and pH2O = 0 - 2 100 Pa. In the reaction, water vapour acts as a gaseous catalyst. Based on the experimental data, the corresponding kinetic equation was found together with the numerical values of the relevant rate and equilibrium adsorption constants.

1981 ◽  
Vol 46 (13) ◽  
pp. 3166-3170 ◽  
Author(s):  
Jiří Vobiš ◽  
Karel Mocek ◽  
Emerich Erdös

The formation of sodium disulphite in a heterogeneous reaction between solid sodium sulphite and gaseous sulfur dioxide has been investigated in a fixed-bed reactor at temperatures from 40 up to 80 °C in the presence of water vapour. The partial pressure of the sulfur dioxide was in the range of 1.2 to 7.5 kPa and that of the water vapour amounted to 1.0-6.5 kPa. The study has been aimed at finding optimum conditions for the formation of the disulphite according to the final degree of conversion. It has been found that the final degree of conversion depends primarily on the content of water vapour in the gas phase and on the temperature, the reactivity of the sodium sulphite being significantly affected by the way of its preparation.


1981 ◽  
Vol 46 (10) ◽  
pp. 2281-2288 ◽  
Author(s):  
Jiří Vobiš ◽  
Karel Mocek ◽  
Emerich Erdös

The heterogeneous reaction between solid sodium carbonate and gaseous sulphur dioxide of partial pressures from 1.2 to 7.5 kPa has been investigated in a fixed-bed reactor at temperatures of 54 and 81 °C in the presence of water vapour of partial pressures from 0.30 to 1.25 kPa. An independence of the reaction course of the sulphur dioxide content in the gas phase and a linear dependence of the reaction rate on the partial pressure of water vapour were found under the above conditions. The rate equation derived previously has been simplified and the set of differential equations describing the reaction in a fixed bed has been solved. The relations obtained have been applied to an evaluation of the effective rate constant. The true rate constant has been estimated to be independent of temperature.


1991 ◽  
Vol 56 (8) ◽  
pp. 1575-1579 ◽  
Author(s):  
Jiří Vobiš ◽  
Karel Mocek ◽  
Emerich Erdös

The formation of sodium disulfite by the heterogeneous reaction of solid active sodium sulfite with gaseous sulfur dioxide in the presence of water vapour was investigated over the temperature range of 293 to 393 K at SO2. H2O and O2 partial pressures of 1.2-7.4, 1.2-6.4 and 0-11.3 kPa, respectively. The effect of the reaction time was also examined. Kinetic measurements were supplemented with the determination of the equilibrium dissociation pressure of SO2 in contact with sodium sulfite at 373.15 K. The major aim of the work was to establish the optimum conditions for attaining the maximum degree of conversion of the solid reactant to sodium disulfite. The conditions for the formation of virtually pure sodium disulfite were found.


Author(s):  
Vladimir Viktorovich Pekunov

This article examines the problem of numerical simulation of interaction between the gaseous sulfur dioxide emitted by road transport and fog in the conditions of high humidity. For this purpose, the author applies a multi-factor two-phase mathematical model, which takes into account the dynamics of turbulent main phase, dynamics and kinetics of the multi-sectional droplet phase, presence of thermal inconsistencies formed as a result of direct and diffused solar radiation in various ranges, diffusion of sulfur dioxide, and its absorption by the fog droplets. The article carries out a numerical calculation of the corresponding task within the modeling system of environmental processes AirEcology-P, which allows generating the optimal calculation code for a particular mathematical model. The proposed complex mathematical model that descries interaction between the emitted sulfur dioxide gas and the fog droplets is new; it specifies the calculation of the kinetics of droplet phase based on consideration of the additional factor of droplet fusion characteristic to fog. The submodel of the droplet phase was tested in the numerical simulation (the results were compared with the data of direct Lagrangian modeling of the composite of 1,000 droplets), indicating decent accuracy results. The article obtains the results of numerical simulation of interaction between the emitted SO2 and the droplets. The author demonstrates the self-cleaning ability of the atmosphere, the degree of which correlates with the initial concentration of the smallest droplets and the height from the surface.


1981 ◽  
Vol 46 (3) ◽  
pp. 693-700 ◽  
Author(s):  
Milan Strašák ◽  
Jaroslav Majer

The kinetics of oxidation of alkenes by thallic sulphate in aqueous solutions, involving the two reaction steps-the hydroxythallation and the dethallation - was studied, and the effect of salts on the kinetics was examined; this made it possible to specify more precisely the reaction mechanism and to suggest a qualitative model of the reaction coordinate. It was found that in homogeneous as well as in heterogeneous reaction conditions, the reaction can be accelerated appreciably by adding tetraalkylammonium salts. These salts not only operate as catalysts of the phase transfer, but also exert a significant kinetic effect, which can be explained with a simplification in terms of a stabilization of the transition state of the reaction.


1980 ◽  
Vol 45 (12) ◽  
pp. 3402-3407 ◽  
Author(s):  
Jaroslav Bartoň ◽  
Vladimír Pour

The course of the conversion of methanol with water vapour was followed on a low-temperature Cu-Zn-Cr-Al catalyst at pressures of 0.2 and 0.6 MPa. The kinetic data were evaluated together with those obtained at 0.1 MPa and the following equation for the reaction kinetics at the given conditions was derived: r = [p(CH3OH)p(H2O)]0.5[p(H2)]-1.3.


1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.


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