Thin-film versus slurry-phase carbonation of steel slag: CO2 uptake and effects on mineralogy

Baciocchi, Renato; Costa, Giulia; Gianfilippo, Martina Di; Polettini, Alessandra; Pomi, Raffaella; Stramazzo, A.

doi:10.1016/j.jhazmat.2014.09.016

Cited by 98 publications

(64 citation statements)

References 44 publications

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“…The slight differences in the preparation and final particle size of the samples tested in the two types of carbonations tests was due to the fact that the two routes were investigated in two distinct laboratories, equipped with different milling and sieving devices. Anyhow, this difference is not expected to significantly affect the obtained results, since the composition and mineralogy as well as CO2 reactivity of the same type of slag milled <150 μm or sieved <125 μm showed to be quite similar (as indicated by the results of thin-film route experiments performed on BOF samples milled at 150 μm, Baciocchi et al, 2015). The elemental composition of the four BOF slag samples is reported in Table 1.…”

Section: Methodsmentioning

confidence: 83%

“…Based on the results of previous investigations (Baciocchi et al, 2011(Baciocchi et al, , 2015, a liquid to solid ratio (L/S) of 5 l/kg, operating temperature of 100°C and total pressure of 10 bar were selected. The thin-film route carbonation tests were carried out on BOF slag samples c and d in a pressurized stainless steel reactor placed in a water bath for temperature control.…”

Section: Methodsmentioning

confidence: 99%

“…Steel manufacturing plants are the typical examples of industrial sites in which relevant flows of both CO2 and alkaline industrial residues are generated and therefore represent one of the potentially most interesting contexts for the application of accelerated carbonation. Several studies have shown that a number of different types of steel slag present a significant reactivity with CO2, allowing to achieve, for specific process routes and operating conditions, relevant CO2 uptakes (Huijgen et al, 2005;Baciocchi et al, 2010Baciocchi et al, , 2015Uibu et al, 2011;Chang et al, 2012;Santos et al, 2013a,b). Furthermore, several types of residues generated in steel manufacturing plants, such as Basic Oxygen Furnace (BOF), Electric Arc Furnace (EAF), and argon oxygen decarburization (AOD) slag, are typically not valorized and generally landfilled, or employed only for low-end applications, owing for their significant content of free calcium and magnesium (hydr)oxides that may result in poor volumetric stability and hence in a low technical performance in construction applications (Morone et al, 2014).…”

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confidence: 99%

“…Specifically, with regard to the latter, significant CO2 uptakes in reasonable timeframes were achieved via the slurry-phase route using residues with a fine particle size (typically below 100 μm), obtained either by milling or simple sieving of the material, and operating the carbonation reactor at enhanced temperature and CO2 pressure (Huijgen et al, 2005;Chang et al, 2012;Santos et al, 2013a,b;Baciocchi et al, 2015). It should be noted, however, that in a recent study, milder operating conditions were shown to be effective employing a proper lixiviant (ammonium chloride) to enhance calcium dissolution (Mattila et al, 2014).…”

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confidence: 99%

“…It should be noted, however, that in a recent study, milder operating conditions were shown to be effective employing a proper lixiviant (ammonium chloride) to enhance calcium dissolution (Mattila et al, 2014). Besides, promising results in terms of CO2 uptake (even if lower than those attained through the former route) have been achieved also via the thin-film (or wet) route (Baciocchi et al, 2011(Baciocchi et al, , 2015Santos et al, 2013b;Morone et al, 2014), which is operated at lower temperature and CO2 pressure and also presents the advantage of not generating a liquid by-product that necessitates suitable management and treatment.…”

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confidence: 99%

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Accelerated Carbonation of Steel Slags Using CO2 Diluted Sources: CO2 Uptakes and Energy Requirements

et al. 2016

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This work presents the results of carbonation experiments performed on Basic Oxygen Furnace (BOF) steel slag samples employing gas mixtures containing 40 and 10% CO2 vol. simulating the gaseous effluents of gasification and combustion processes respectively, as well as 100% CO2 for comparison purposes. Two routes were tested, the slurry-phase (L/S = 5 l/kg, T = 100°C and Ptot = 10 bar) and the thin-film (L/S = 0.3-0.4 l kg, T = 50°C and Ptot = 7-10 bar) routes. For each one, the CO2 uptake achieved as a function of the reaction time was analyzed and on this basis, the energy requirements associated with each carbonation route and gas mixture composition were estimated considering to store the CO2 emissions of a medium size natural gas fired power plant (20 MW). For the slurry-phase route, maximum CO2 uptakes ranged from around 8% at 10% CO2, to 21.1% (BOF-a) and 29.2% (BOF-b) at 40% CO2 and 32.5% (BOF-a) and 40.3% (BOF-b) at 100% CO2. For the thin-film route, maximum uptakes of 13% (BOF-c) and 19.5% (BOF-d) at 40% CO2, and 17.8% (BOF-c) and 20.2% (BOF-d) at 100% were attained. The energy requirements of the two analyzed process routes appeared to depend chiefly on the CO2 uptake of the slag. For both process route, the minimum overall energy requirements were found for the tests with 40% CO2 flows (i.e., 1400 − 1600 MJ / t CO for the slurry-phase and 2 2220 0 -/ 255 MJ t CO for the thin-film route).

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Section: Methodsmentioning

confidence: 83%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Accelerated Carbonation of Steel Slags Using CO2 Diluted Sources: CO2 Uptakes and Energy Requirements

et al. 2016

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Carbonation of BOF Slag in a Rotary Kiln Reactor in View of the Scale‐Up of the Wet Route Process

Librandi

Costa

Stendardo

et al. 2019

Env Prog and Sustain Energy

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Carbonation of alkaline residues represents a potentially interesting technique for permanently storing in solid form CO2 contained in flue gas, syngas or biogas, as well as for the valorization of the residues. In particular, the wet carbonation route requires a low amount of water, does not generate wastewater and can be exploited to produce aggregates. The efficacy of this route has been demonstrated at laboratory scale. In view of its scale‐up, this study was aimed at evaluating the performance of a wet‐route carbonation process applied to Basic Oxygen Furnace (BOF) steel slag employing an operating procedure that could be adopted also at demonstrative or full scale. Dry residues were directly fed by a loading hopper into a rotary kiln reactor, in which gas containing 40% CO2 and steam were flown through. During the experiments, the flow and composition of the gas phase were continuously monitored, allowing to calculate the amount of CO2 captured from the gas phase and to compare it with the CO2 uptake of the solid product. In addition, the leaching behavior of the treated slag was assessed. The results of the tests were close to those obtained in previous experiments performed with pre‐humidified BOF slag, both with the same reactor used in this study and at laboratory scale; this suggests that this more automated wet‐route process could be employed for demonstration or full scale tests. The set up still needs to be optimized to obtain a product with physical and technical properties suitable for use as aggregate. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13140, 2019

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Energetic assessment of CO₂ sequestration through slurry carbonation of steel slag: a factorial study

et al. 2016

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An assessment of the energetic requirements of slurry‐phase accelerated carbonation for CO2 sequestration using steelmaking slag was conducted. The results of dedicated lab‐scale carbonation experiments in which the CO2 sequestration yield of basic oxygen furnace slag was investigated at different operating conditions were used for the energy requirement calculations. The operating variables of the process and the associated values adopted were total gas pressure, temperature, and CO2 concentration in the gas phase. The energy duties of the slurry‐phase carbonation layout were calculated for the different unit operations, which included slag milling, mixing, slurry pumping, heating, CO2 compression, solid/liquid separation, and CO2 capture (when required). The estimated energy requirements were found to lie in the range 980−6300 MJ t−1 CO2 sequestered, where the lower end of the range was associated with the use of diluted CO2. In all cases, the use of a concentrated CO2 flow proved largely energetically unfavorable over the use of diluted gas streams, since the energy duty of the required CO2 capture stage by far overcame the benefits associated with improved sequestration yields at increased CO2 concentrations in the gas phase. The calculated energy requirements were also processed to derive a second‐order model accounting for the main effects and interactions between the operating variables of the carbonation process. The model developed is meant to predict the expected energy demand of the carbonation process under different operating conditions and to define the optimal combination of these in terms of the energetic profile of the process itself. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.

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Thin-film versus slurry-phase carbonation of steel slag: CO2 uptake and effects on mineralogy

Cited by 98 publications

References 44 publications

Accelerated Carbonation of Steel Slags Using CO2 Diluted Sources: CO2 Uptakes and Energy Requirements

Accelerated Carbonation of Steel Slags Using CO2 Diluted Sources: CO2 Uptakes and Energy Requirements

Carbonation of BOF Slag in a Rotary Kiln Reactor in View of the Scale‐Up of the Wet Route Process

Energetic assessment of CO₂ sequestration through slurry carbonation of steel slag: a factorial study

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Thin-film versus slurry-phase carbonation of steel slag: CO2 uptake and effects on mineralogy

Cited by 98 publications

References 44 publications

Accelerated Carbonation of Steel Slags Using CO2 Diluted Sources: CO2 Uptakes and Energy Requirements

Accelerated Carbonation of Steel Slags Using CO2 Diluted Sources: CO2 Uptakes and Energy Requirements

Carbonation of BOF Slag in a Rotary Kiln Reactor in View of the Scale‐Up of the Wet Route Process

Energetic assessment of CO2 sequestration through slurry carbonation of steel slag: a factorial study

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Energetic assessment of CO₂ sequestration through slurry carbonation of steel slag: a factorial study