Kinetics of the reaction between the solid sodium carbonate and the gaseous sulphur dioxide. IV. Effect of the gas phase composition and of temperature in an integral fixed-bed reactor

1970 ◽  
Vol 35 (1) ◽  
pp. 154-164 ◽  
Author(s):  
J. Mareček ◽  
K. Mocek ◽  
E. Erdös
1983 ◽  
Vol 48 (12) ◽  
pp. 3500-3507 ◽  
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös

The rate of reaction of the anhydrous sodium carbonate with the hydrogen chloride and its mixture with sulphur dioxide was measured in an integral fixed-bed reactor. Reactivity of the active sodium carbonate towards the hydrogen chloride is lower as compared with its reactivity towards the sulphur dioxide. A relationship was found between the reactivity of the solid and the way of its preparation. The inactive form of the sodium carbonate is inactive towards both the sulphur dioxide and the hydrogen chloride. The active form of the sodium carbonate exhibits towards the hydrogen chloride a reactivity which is by orders of magnitude higher than that of the inactive form. The variation of the ratio of partial pressures of the hydrogen chloride and the sulphur dioxide in the reaction with the sodium carbonate does not affect significantly the total degree of the solid conversion, which attained a value of 65% in laboratory experiments. The degree of gas purification from the acid components did not fall under a value of 99% up to a solid conversion of about 50% at a mean gas contact time of about 10-2 s.


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.


1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.


2014 ◽  
Vol 53 (49) ◽  
pp. 19145-19158 ◽  
Author(s):  
Miloslav Hartman ◽  
Karel Svoboda ◽  
Michael Pohořelý ◽  
Michal Šyc ◽  
Siarhei Skoblia ◽  
...  

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Xiaoxiao Meng ◽  
Wei Zhou ◽  
Emad Rokni ◽  
Honghua Zhao ◽  
Rui Sun ◽  
...  

This research investigated the effects of the specific primary (under-fire) air flowrate (m˙air) on the combustion behavior of a 50–50 wt % blend of raw corn straw (CS) and raw pinewood wastes in a fixed-bed reactor. This parameter was varied in the range of 0.079–0.226 kg m−2 s−1, which changed the overall combustion stoichiometry from air-lean (excess air coefficient λ = 0.73) to air-rich (excess air coefficient λ = 1.25) and affected the combustion efficiency and stability as well as the emissions of hazardous pollutants. It was observed that by increasing m˙air, the ignition delay time first increased and then decreased, the average bed temperatures increased, both the average flame propagation rates and the fuel burning rates increased, and the combustion efficiencies also increased. The emissions of CO as well as those of cumulative gas phase nitrogen compounds increased, the latter mostly because of increasing HCN, while those of NO were rather constant. The emissions of HCl decreased but those of other chlorine-containing species increased. The effect of m˙air on the conversion of sulfur to SO2 was minor. By considering all of the aforesaid factors, a mildly overall air-rich (fuel-lean) (λ = 1.04) operating condition can be suggested for corn-straw/pinewood burning fixed-bed grate-fired reactors.


2020 ◽  
Vol 10 (24) ◽  
pp. 8962
Author(s):  
Mohammad Reza Ghaani ◽  
Satoshi Takeya ◽  
Niall J. English

There have been studies on gas-phase promoter facilitation of H2-containing clathrates. In the present study, non-equilibrium molecular dynamics (NEMD) simulations were conducted to analyse hydrogen release and uptake from/into propane planar clathrate surfaces at 180–273 K. The kinetics of the formation of propane hydrate as the host for hydrogen as well as hydrogen uptake into this framework was investigated experimentally using a fixed-bed reactor. The experimental hydrogen storage capacity propane hydrate was found to be around 1.04 wt% in compare with the theoretical expected 1.13 wt% storage capacity of propane hydrate. As a result, we advocate some limitation of gas-dispersion (fixed-bed) reactors such as the possibility of having un-reacted water as well as limited diffusion of hydrogen in the bulk hydrate.


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