Characterization of calcium carbonates used in wet flue gas desulphurization processes

Drăgan, Simion; Ozunu, Alexandru

doi:10.2478/s11532-012-0068-4

Cited by 15 publications

(12 citation statements)

References 6 publications

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“…It can be assumed that small particles completely reacted at this time and the size of the large particles is decisive. On the other hand, there is only a slight correlation between the reaction rate and the specifi c surface area of the samples, which is in accordance with the published data (Ahlbeck et al, 1993;Ahlbeck et al, 1995;Ukawa et al, 1993;Wallin and Bjerle, 1989;Dragan and Ozunu, 2012;Claudio A. Carleti G., 2015). Good correlation of the reaction rate and the particle size indicates that the infl uence of aragonite and vaterite is not crucial for the initial reaction rate.…”

Section: Resultssupporting

confidence: 91%

“…Calcium carbonate precipitated during the reaction of gypsum with CO 2 and ammonia may show different reactivity, mainly due to the different crystallographic modifi cation of calcium carbonate. A comparison of the reactivity and properties of limestone and calcium carbonate precipitate consisting of calcite was presented by Dragan and Ozunu (2012). Reactivity strongly depends on the particle size, the difference between the limestone and calcium carbonate precipitate was negligible.…”

Section: Introductionmentioning

confidence: 99%

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Reactivity of calcium carbonate prepared from flue gas desulfurization gypsum

Jurišová

Danielik

Fellner

et al. 2019

Acta Chimica Slovaca

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Reactivity of various calcium carbonate samples for flue gas desulfurization was tested. Two groups of CaCO3 samples were considered; natural limestone containing calcite phase dominantly and samples prepared by the conversion of gypsum with ammonium and carbon dioxide (precipitated CaCO3) containing different amounts of calcite, aragonite and vaterite. Reactivity of precipitated calcium carbonate depends primarily on the particle size, similarly as in case of industrial samples. The initial reaction rate was comparable with the industrial limestones for samples with the average particle size lower than 15 μm. However, the conversion of laboratory samples was significantly higher after 5 min of the reaction. Phase composition of the precipitated calcium carbonate has a minor but noticeable impact on the reactivity. The presence of vaterite slightly increased the reactivity, which is in accordance with its lower compact structure in comparison with calcite and aragonite. Unexpected effect of the increased content of aragonite, which is the most compact phase in comparison with calcite and vaterite, was observed. If calcium carbonate contains up to approximately 30 % of aragonite the reactivity increases, which can be explained by the SEM pictures showing agglomerate composition with relatively high specific surface. At higher contents of aragonite, the reactivity decreases. All the obtained results proved the suitability of precipitated CaCO3 prepared from flue gas desulfurization gypsum to be recycled in the flue gas desulfurization process.

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Section: Resultssupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Reactivity of calcium carbonate prepared from flue gas desulfurization gypsum

Jurišová

Danielik

Fellner

et al. 2019

Acta Chimica Slovaca

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“…Several different flue gas desulfurization (FGD) technologies have been developed for this aim. This is the main reason why the issue of flue-gas desulfurization has become very topical and is the theme of numerous researches in this field [5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Macrokinetic investigations of dry flue-gas desulfurization process using TGA technique

Drăgan¹

2018

Studia UBB Chemia

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In this paper, a kinetic study about of dry flue-gas desulfurization process was investigated. Experimental thermogravimetric measurements, employing a CAHN TG-121 system, have been performed on the reaction of sulfur dioxide and oxygen with calcined limestone. The conversions versus time of calcined limestone, ranging in particle size from 25 to 450 μm, were measured over the temperature range 973-1173 K and a gas rate of 0.046 m/s. The influence of kinetic parameters on the sulfation process has been tracked. A significant influence is the temperature at which the sulfation and the size of the adsorbent granules are achieved. Processing the experimental results in lnkI,II-T-1 coordinates allowed the determination of the activation energy and the establishment of the corresponding mechanisms. The results, Ea>42 KJ/mol for the both indicate that the sulfation process is carried out according to the macrokinetic mass transformation model, only for small granules of the solid with dp <25 μm and temperatures T> 973 K) are the limiting ones the process. At higher granulations of the solid particles, the activation energy values Ea<<42 kJ/mol, emphasizes that limitative of the global process are the inner/outer diffusion phenomena shown that the sulfation process follows the transfer macrokinetic model.

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“…A great prospect is the SO 2 absorption process into dolomite suspension thus reducing the amount of gypsum due to the fact that part of the sulfur is recovered as MgSO 4 , compound with many practical uses [9].…”

Section: Introductionmentioning

confidence: 99%

“…The kinetic study of the SO 2 chemisorption process into dolomitebrucite suspensions revealed that the global process takes place according to the shrinking core model without crust or according to the unreacted core model with crust formation of the reaction products [9][10]. In the temperature range T = 293-333K and the suspension concentration C = 5-15% limitative steps of the global absorption process are the diffusional processes.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of sulfur dioxide absorption into carbonate suspensions with sulfites addition

Drăgan¹

2017

Studia UBB Chemia

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ABSTRACT. This paper presents the experimental results obtained by sulfur dioxide chemisorption into carbonate suspension with sulfites addition at different temperatures and concentration of the absorbent suspension. Presence of sulfites in the absorbent suspension has a positive influence on the global rate of the absorption process. The acceleration of SO2 chemisorption process in the absorbent suspension containing MeSO3 -MeCO3 is determined by the higher concentration of ions in the liquid phase resulted from higher solubility of MeSO3 comparative with MeCO3. The addition of MeSO3 at a concentration of 10% in the composition of the absorbent suspension determines a significant decrease of the time required for obtaining a high conversion.

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Characterization of calcium carbonates used in wet flue gas desulphurization processes

Cited by 15 publications

References 6 publications

Reactivity of calcium carbonate prepared from flue gas desulfurization gypsum

Reactivity of calcium carbonate prepared from flue gas desulfurization gypsum

Macrokinetic investigations of dry flue-gas desulfurization process using TGA technique

Experimental study of sulfur dioxide absorption into carbonate suspensions with sulfites addition

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