Investigation of the Kinetics of Sulfite Oxidation on by-Production Recovery Process in WFGD

2012 ◽  
Vol 610-613 ◽  
pp. 1980-1985 ◽  
Author(s):  
Hong Jian Xu ◽  
Shu Fang Wang ◽  
Wei Guo Pan ◽  
Rui Tang Guo

The limestone-lime washing technology is the most widely used WFGD process, which normally we adopt to control the discharge of SO2 caused by coal’s combustion. Through the research on the oxidation kinetics of sulfite in this paper, it is indicated that macroscopic chemical reaction which responses to rate of sulfite is 1/2. And the results of orthogonal test can be concluded that: to the extent influence of oxidization reaction rate, the influences of temperature is the most significant, and influences of stirred speed is nearly negligible. The optimized operation factors may be shown as that temperature is controlled at 40°C, air ventilation is at 88ml/min,pH is 4.5 and stir speed is 500 r/min.

2019 ◽  
Vol 63 (3) ◽  
pp. 100-104
Author(s):  
T. Chmela ◽  
P. Krupička

Abstract The oxidation kinetics of depleted uranium and its low-alloy molybdenum alloys (U-2wt.%Mo, U-5wt.%Mo) were measured in a moist air (75% relative humidity) at 60 and 75 ° C. Coefficients of reaction rate equations were determined for linear oxidation kinetics. In the oxidation of depleted uranium at 75 ° C, a change in reaction kinetics from linear to exponential behaviour was observed after about 2500 hours.


1979 ◽  
Vol 44 (12) ◽  
pp. 3588-3594 ◽  
Author(s):  
Vladislav Holba ◽  
Olga Volárová

The oxidation kinetics of cis-bis(ethylenediamine)isothiocyanonitrocobalt(III) ion with peroxodisulphate was investigated in the medium of 0.01 M-HClO4 in dependence on the ionic strength and temperature and the reaction products were identified. Extrapolated values of thermodynamic activation parameters were determined from the temperature dependence of the rate constants extrapolated to zero ionic strength. The distance of the closest approach was estimated for the reacting ions by evaluating the primary salt effect. To elucidate the mechanism, the influence of the cyclic polyether 18-crown-6 on the reaction rate was followed.


2013 ◽  
Vol 760 ◽  
pp. 85-94
Author(s):  
D.M.A. Khan

Plain Chromite and Ore- Coal/charcoal Compositepellets were Reduced in the CO Atmosphere between 1350°C and 1600°C in a Superkenthal Muffle Furnace. the Reaction Followed the Path of First Order Reductionkinetics and the Reduction was under Chemical Reaction Rate Control. Theactivation Energy was Calculated in the Range from 225KJ/mole to 342KJ/mole.The Insitu Carbon Present in the Composite Pellets Motivated the Gasificationreaction of Carbon and the Reduced Fe and Cr Act as the Catalysts to Propagatethe Reduction in the Forward Direction.


2011 ◽  
Vol 391-392 ◽  
pp. 1350-1353
Author(s):  
Tong Zhu ◽  
Xiao Yan Qi ◽  
Zhong Yuan Wang ◽  
Fang Yu ◽  
An An Liu ◽  
...  

This paper presented a study on the reaction kinetics of magnesium sulfite catalyzed by Catalyst TR. Used a Lib-scale Plexiglas reactor aerated by air compressors to research the oxidation process Influence by pH, catalyst concentration, aeration quantity, temperature, time, sulfate concentration. Through experiment concluded the activation energy, got the formula between reaction rate and sulfate concentration.


2021 ◽  
Author(s):  
Anton Makoveev ◽  
Pavel Procházka ◽  
Azin Shahsavar ◽  
Lukáš Kormoš ◽  
Tomáš Krajňák ◽  
...  

Abstract Self-assembly and on-surface synthesis are vital strategies used for fabricating surface-confined 1D or 2D supramolecular nanoarchitectures with atomic precision. In many systems, the resulting structure is determined by kinetics of processes involved, i.e., reaction rate, on-surface diffusion, nucleation, and growth, all of which are typically governed by temperature. However, other external factors have been only scarcely harnessed to control the on-surface chemical reaction kinetics and self-assembly. Here, we show that a low-energy electron beam can be used to steer chemical reaction kinetics and induce the growth of molecular phases unattainable by thermal annealing. The electron beam provides a well-controlled means of promoting the elementary reaction step, i.e., deprotonation of carboxyl groups. The reaction rate linearly increases with increasing electron beam energy beyond the threshold energy of 6 eV. Our results offer the novel prospect of controlling the self-assembly, enhancing the rate of reaction steps selectively, and thus altering the kinetic rate hierarchy.


2011 ◽  
Vol 239-242 ◽  
pp. 2286-2292 ◽  
Author(s):  
Hai Chuan Wang ◽  
Zhi You Liao ◽  
Yuan Chi Dong ◽  
Shi Jun Wang ◽  
Yun Zhou

The reduction rates of manganese oxide by carbon and SiC was examined by heating MnO2-carbon and MnO2-SiC mixtures in a 7-kW industrial microwave oven. The results show that the rate of the reduction increased with the amount of carbon in MnO2-carbon mixture and with SiC in MnO2-SiC mixture. The rate of the MnO2 reduction by carbon was proportional to the reaction time, and that by SiC was proportional to 2/3 power of the reaction time. The reduction was found to be controlled by chemical reaction. The reaction rate constant of the reduction of MnO2kC increased with increasing the amount of carbon in the mixtures but kSiC decreased with increasing the amount of SiC in the mixtures.


Author(s):  
M.A. Egyan ◽  

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.


2020 ◽  
Author(s):  
Camilo A. Mesa ◽  
Ludmilla Steier ◽  
Benjamin Moss ◽  
Laia Francàs ◽  
James E. Thorne ◽  
...  

<p><i>Operando</i> spectroelectrochemical analysis is used to determine the water oxidation reaction kinetics for hematite photoanodes prepared using four different synthetic procedures. Whilst these photoanodes exhibit very different current / voltage performance, their underlying water oxidation kinetics are found to be almost invariant. Lower photoanode performance was found to correlate with the observation of optical signals indicative of charge accumulation in mid-gap oxygen vacancy states, indicating these states do not contribute directly to water oxidation.</p>


2019 ◽  
Author(s):  
Milad Narimani ◽  
Gabriel da Silva

Glyphosate (GP) is a widely used herbicide worldwide, yet accumulation of GP and its main byproduct, aminomethylphosphonic acid (AMPA), in soil and water has raised concerns about its potential effects to human health. Thermal treatment processes are one option for decontaminating material containing GP and AMPA, yet the thermal decomposition chemistry of these compounds remains poorly understood. Here, we have revealed the thermal decomposition mechanism of GP and AMPA by applying computational chemistry and reaction rate theory methods. <br>


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