Characteristics of Na–Mg double salt for high-temperature CO2 sorption

Lee, Chan Hyun; Mun, Sungyong; Lee, Ki Bong

doi:10.1016/j.cej.2014.07.082

Cited by 67 publications

(49 citation statements)

References 37 publications

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“…These two studies both emphasized the crucial function of NaNO 3 in facilitating the absorption ability of the alkali carbonate‐promoted MgO‐based absorbent. Lee et al and Min et al have also verified the CO 2 absorption ability 0.153 g of CO 2 /g of MgO–Na 2 CO 3 sorbent at 375 °C. Because the natural dolomite exists widely, Yang et al have investigated the CO 2 absorption ability of the NaNO 3 ‐modified dolomite and indicated that NaNO 3 lowers its activation temperature, which is the temperature for the first decomposition of MgCO 3 in MgCO 3 –CaCO 3 double salts.…”

Section: Introductionmentioning

confidence: 84%

Affecting mechanism of activation conditions on the performance of NaNO₃‐modified dolomite for CO₂ capture

Yang

Zhao

Xiao

2015

Asia-Pacific J Chem Eng

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The affecting mechanism of activation conditions on the performance of NaNO 3 -modified dolomites for CO 2 capture was conducted combined with the activation tests and the CO 2 absorption tests. The weight loss during activation was determined by the combined effects of the NaNO 3 content, activation temperature, and activation atmosphere, for their combined effects on the ion diffusion. Moreover, the greater weight loss during activation did not elicit a corresponding increase in CO 2 absorption ability of the activated absorbents. CO 2 absorption activity tests indicated that the sample 0.20Na-dol activated at 500°C in N 2 showed the best cyclic CO 2 absorption ability. The underlying mechanism was then analyzed based on the results of the Brunauer-Emmett-Teller, X-ray diffraction, and Raman analysis of the absorbents. The results indicated that the different CO 2 absorption abilities might be due to the two kinds of molecular arrangements between the MgO and CaCO 3 grains obtained during activation.

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Section: Introductionmentioning

confidence: 84%

Affecting mechanism of activation conditions on the performance of NaNO₃‐modified dolomite for CO₂ capture

Yang

Zhao

Xiao

2015

Asia-Pacific J Chem Eng

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“…(3). Hence, NaNO 3 is a by-product and its CO 2 adsorption is negligible as reported by Lee et al [36]. As NaNO 3 melting point is 308 C, and CO 2 sorption in this work is carried out 375 C, therefore the double salts are the compounds with significant CO 2 sorption capacity.…”

Section: Sorbent Characterisationmentioning

confidence: 56%

“…Recently, Mg based double salts significantly enhanced CO 2 uptake and reaction kinetics [36,37]. Double salts of alkali metals and magnesium carbonate can be represented by the following formula…”

mentioning

confidence: 99%

Long term and performance testing of NaMg double salts for H 2 /CO 2 separation

Motuzas

Birkett

et al. 2017

International Journal of Hydrogen Energy

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This work investigates the synthesis and performance of double salts for H 2 /CO 2 separation. A series of NaMg double salts were prepared based on xMg(NO 3) 2 : yNa 2 CO 3 : zH 2 O and characterised. The best sorbents reached CO 2 uptake of 17.9 wt% at 0.62 MPa and 375 C. The NaMg double salts preferentially sorbed CO 2 as determined by breakthrough tests. The NaMg double salts were packed in a sorbent bed and tested for H 2 /CO 2 separation at the back end of a water gas shift reactor. The space velocity had the largest impact on the performance of the sorbent bed, as increasing the space velocity from 2.16 Â 10 À3 to 9.51 Â 10 À3 s À1 sped up the breakthrough time by 84%. Increasing the feed gas pressure from 0.3 to 0.6 MPa reduced the breakthrough time by~45%. The NaMg double salt sorbents were exposed for over 1000 h of continuous temperature including 28 cycles of sorption and desorption, and proved to be stable during changes of operating conditions such as flow rates and pressures.

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“…found that a CaO–MgO sorbent with MgO content of 31.5–38.7 wt% should be good to improve the cyclic capture activity of a CaO sorbent. At elevated temperatures, alkali metal carbonates (K 2 CO 3 , Na 2 CO 3 , and Cs 2 CO 3 ) are added into MgO, and these composite sorbents possess considerable CO 2 sorption capacities and good cycling stability . Moreover, MgO has also been applied to low temperature CO 2 capture in the presence of water vapor.…”

Section: Introductionmentioning

confidence: 99%

“…At elevated temperatures, alkali metal carbonates (K 2 CO 3 , Na 2 CO 3 , and Cs 2 CO 3 ) are added into MgO, and these composite sorbents possess considerable CO 2 sorption capacities and good cycling stability. 26,30,31 Moreover, MgO has also been applied to low temperature CO 2 capture in the presence of water vapor. The MgO/γ -Al 2 O 3 sorbents prepared by Li et al and Zhang et al, with different methods exhibited a considerable CO 2 sorption capacity at low temperatures.…”

Section: Introductionmentioning

confidence: 99%

Understanding the CO₂ sorption mechanisms of the MgO‐doped Na‐based sorbent at low temperatures

Cai

et al. 2019

Greenhouse Gases

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Using a solid Na‐based sorbent is one potential option to decrease CO2 emission in coal‐fired power plants, and the CO2 sorption reactivity of Na2CO3/γ‐Al2O3 sorbent was improved by mechanically doping MgO into Na2CO3/γ‐Al2O3 in our previous study while the mechanism was not clear. In this paper, the CO2 sorption/desorption mechanisms of the promising MgO‐doped Na‐based sorbent prepared by the two‐step incipient wetness impregnation method were studied using a fixed‐bed reactor, together with characterizations of X‐ray fluorescence, nitrogen adsorption apparatus, field emission scanning electron microscopy, X‐ray diffraction, and thermogravimetric analyzer coupled with Fourier transform infrared spectrometer (TG‐FTIR). Also, the sorption behaviors were well described with Avrami's fractional‐order kinetic model. Results demonstrated that MgO not only dispersed on γ‐Al2O3 but entered γ‐Al2O3’s lattice, leading to the formation of Mg‐Al mixed oxides for CO2 sorption. In addition, a new phase Mg6Al2CO3(OH)16·4H2O was produced during the CO2 sorption process, which plays a crucial role in facilitating the conversion of Na2CO3 to NaHCO3. The CO2 sorption capacity of MgO‐doped Na‐based sorbents is presumably determined by the trade‐off between microstructure and active component dispersion. The knowledge gained about the promotion mechanism of MgO provides fundamental direction for the synthesis of Mg–Al mixed oxides, supported with the developed microstructure for CO2 sorption enhancement of Na‐based sorbents. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

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Characteristics of Na–Mg double salt for high-temperature CO2 sorption

Cited by 67 publications

References 37 publications

Affecting mechanism of activation conditions on the performance of NaNO₃‐modified dolomite for CO₂ capture

Affecting mechanism of activation conditions on the performance of NaNO₃‐modified dolomite for CO₂ capture

Long term and performance testing of NaMg double salts for H 2 /CO 2 separation

Understanding the CO₂ sorption mechanisms of the MgO‐doped Na‐based sorbent at low temperatures

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Characteristics of Na–Mg double salt for high-temperature CO2 sorption

Cited by 67 publications

References 37 publications

Affecting mechanism of activation conditions on the performance of NaNO3‐modified dolomite for CO2 capture

Affecting mechanism of activation conditions on the performance of NaNO3‐modified dolomite for CO2 capture

Long term and performance testing of NaMg double salts for H 2 /CO 2 separation

Understanding the CO2 sorption mechanisms of the MgO‐doped Na‐based sorbent at low temperatures

Contact Info

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Affecting mechanism of activation conditions on the performance of NaNO₃‐modified dolomite for CO₂ capture

Affecting mechanism of activation conditions on the performance of NaNO₃‐modified dolomite for CO₂ capture

Understanding the CO₂ sorption mechanisms of the MgO‐doped Na‐based sorbent at low temperatures