Accès libre

Evaluation of CO2 adsorption capacity with a nano-CaO synthesized by chemical combustion/ball milling

Francisco Granados-Correa
Francisco Granados-Correa
 et 
Melania Jiménez-Reyes
Melania Jiménez-Reyes
   | 23 oct. 2022
Materials Science-Poland's Cover Image
À propos de cet article
Article précédent
Article suivant
Citez
Publié en ligne: 23 oct. 2022
Pages: 257 - 269
Reçu: 01 juil. 2022
Accepté: 03 sept. 2022
DOI: https://doi.org/10.2478/msp-2022-0024
Mots clés
© 2022 Francisco Granados-Correa et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

XRD diffraction pattern of the nano-CaO adsorbent.Note: XRD, X-ray diffraction
XRD diffraction pattern of the nano-CaO adsorbent.Note: XRD, X-ray diffraction

Fig. 2

SEM micrograph of Cao adsorbent at 5000× and EDS analysis.Notes: EDS, electron diffraction scattering; SEM, scanning electron microscopy
SEM micrograph of Cao adsorbent at 5000× and EDS analysis.Notes: EDS, electron diffraction scattering; SEM, scanning electron microscopy

Fig. 3

Determination of pore-size distribution by the BJH method.Notes: BJH, Barrett-Joyner-Halenda
Determination of pore-size distribution by the BJH method.Notes: BJH, Barrett-Joyner-Halenda

Fig. 4

Kinetic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures and 1 atm pressure.Notes: Linear plots of the pseudo-second-order model: t/qt = 0.11t + 0.004 (25°C); t/qt = 0.099t + 0.02 (50°C); t/qt = 0.089t + 0.05 (75°C); R2 = 0.9. qt = the amount of CO2 adsorbed at time t; R2, correlation coefficient
Kinetic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures and 1 atm pressure.Notes: Linear plots of the pseudo-second-order model: t/qt = 0.11t + 0.004 (25°C); t/qt = 0.099t + 0.02 (50°C); t/qt = 0.089t + 0.05 (75°C); R2 = 0.9. qt = the amount of CO2 adsorbed at time t; R2, correlation coefficient

Fig. 5

Kinetic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures under 1 atm pressure.Notes: Linear plots correspond to the intraparticle diffusion kinetic model. (1) qt = 7.1√t, qt = 0.73√t+6.2 (R2 = 0.94), and qe = 9.2 (25°C). (2) qt = 7.7√t, qt = 0.86√t+6.7 (R2 = 0.96), and qe = 10.3 (50°C). (3) qt = 7.72√t, qt = 0.86√t+6.7 (R2 = 0.97), and qe = 10.9 (75°C). qe, the amount of CO2 adsorbed at equilibrium; qt = the amount of CO2 adsorbed at time t; R2, correlation coefficient
Kinetic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures under 1 atm pressure.Notes: Linear plots correspond to the intraparticle diffusion kinetic model. (1) qt = 7.1√t, qt = 0.73√t+6.2 (R2 = 0.94), and qe = 9.2 (25°C). (2) qt = 7.7√t, qt = 0.86√t+6.7 (R2 = 0.96), and qe = 10.3 (50°C). (3) qt = 7.72√t, qt = 0.86√t+6.7 (R2 = 0.97), and qe = 10.9 (75°C). qe, the amount of CO2 adsorbed at equilibrium; qt = the amount of CO2 adsorbed at time t; R2, correlation coefficient

Fig. 6

Isotherm data of CaO adsorption onto nano-CaO adsorbent, at different temperatures.Notes: Linear equations of the Langmuir model: (1) PCO2/qe = 0.093 PCO2 +0.045 (R2 = 0.996) (25°C). (2) PCO2/qe = 0.088 PCO2 +0.031 (R2 = 0.998) (50°C). (3) PCO2/qe = 0.080 PCO2 +0.024 (R2 = 0.998) (75°C). PCO2, pressure of the adsorbed gas CO2; qe is the maximum adsorption capacity of CO2 at equilibrium; R2, correlation coefficient
Isotherm data of CaO adsorption onto nano-CaO adsorbent, at different temperatures.Notes: Linear equations of the Langmuir model: (1) PCO2/qe = 0.093 PCO2 +0.045 (R2 = 0.996) (25°C). (2) PCO2/qe = 0.088 PCO2 +0.031 (R2 = 0.998) (50°C). (3) PCO2/qe = 0.080 PCO2 +0.024 (R2 = 0.998) (75°C). PCO2, pressure of the adsorbed gas CO2; qe is the maximum adsorption capacity of CO2 at equilibrium; R2, correlation coefficient

Fig. 7

Thermodynamic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures under 1 atm pressure.Notes: Linear plot of the van’t Hoff modified equation: ln KL = −3917 (1/T) + 12.2 (R2 = 0.9). KL, the Langmuir isotherm constant; R2, correlation coefficient
Thermodynamic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures under 1 atm pressure.Notes: Linear plot of the van’t Hoff modified equation: ln KL = −3917 (1/T) + 12.2 (R2 = 0.9). KL, the Langmuir isotherm constant; R2, correlation coefficient

Fig. 8

Thermodynamic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures under 1 atm pressure.Notes: Linear plot of the Arrhenius equation: ln kV = 8830 (1/T) – 26.9 (R2 = 0.93). kv, the velocity constant; R2, correlation coefficient
Thermodynamic data of CaO adsorption onto nano-CaO adsorbent, at different temperatures under 1 atm pressure.Notes: Linear plot of the Arrhenius equation: ln kV = 8830 (1/T) – 26.9 (R2 = 0.93). kv, the velocity constant; R2, correlation coefficient

Kinetic parameters evaluated for the process of CO2 adsorption onto the nano-CaO adsorbent at different temperatures

Models Parameters Temperature
25°C 50°C 75°C
Pseudo-first-order model k1 (/min) 0.24 0.58 0.13
qmax (mmol/g) 4.59 3.81 5.27
R2 0.78 0.58 0.74
Pseudo-second-order model k2 (/min) 3.41 1.4 0.20
qmax (mmol/g) 9.02 10.08 11.02
R2 0.9999 0.9996 0.9998
Elovich α (mmol/g) 176.8 122.1 41.2
β (mmol/g) 1.00 1.16 1.40
R2 0.48 0.50 0.59
Intraparticle diffusion

Step 1 (0 < t < 1 min)

Step 2 (1 < t < 10 min)

 		qe (mmol/g) 7.56 8.33 8.53
kip1 (mmol/g min1/2) 4.36 4.81 4.92
R2 0.87 0.85 0.90
qe (mmol/g) 3.38 3.51 4.64
kip2 (mmol/g min1/2) 0.87 0.90 1.19
R2 0.995 0.94 0.94

Summarized linear isotherm parameters for CO2 adsorption on nano-CaO adsorbent at the temperatures of 25°C, 50°C, and 75°C and at pressures of 1 atm, 5 atm, 10 atm, and 15 atm for each temperature

Temperature (°C) Langmuir constants Freundlich constants
qmax (mmol/g) KL (/atm) R2 KF (mmol/g [atm]1/n) 1/n R2
25 10.74 0.48 0.996 0.111 0.049 0.78
50 11.31 0.35 0.998 0.099 0.022 0.75
75 12.55 0.31 0.998 0.091 0.009 0.88
eISSN:
2083-134X
Langue:
Anglais
Périodicité:
4 fois par an
Sujets de la revue:
Materials Sciences, other, Nanomaterials, Functional and Smart Materials, Materials Characterization and Properties
RSS Feed de la revue