CO2 capture by using blended hydraulic slag cement via a slurry reactor

E. E. Chang, Ya Chun Wang, Shu Yuan Pan, Yi Hung Chen, Pen Chi Chiang

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Mitigation and adaptation are viable strategies for resolving climate change issues which may pose significant challenges to both ecosystems and human populations around the world. Aqueous carbonation is a promising process for mitigating CO2, due to the permanent storage of gaseous CO2 into carbonate precipitations (CaCO3 and/or MgCO3). In this study, aqueous carbonation of blended hydraulic slag cement (BHC) for CO2 sequestration was investigated and evaluated under various operating conditions, i.e., different reaction temperatures and CO2 concentrations, in a slurry reactor. The suspension BHC slurry was strongly alkaline (pH ~11.4) before carbonation, whereas the pH of the slurry dropped rapidly to nearly a weakly acidic solution (i.e., pH ~6.3) after introducing CO2 gas into the reactor. The results show that the maximum CO2 capture capacity was 181 g CO2 per kg BHC at a reaction time of 120 min, a CO2 concentration of 10%, and a gas flow rate of 2.5 L/min at 65°C. The reaction temperature slightly influenced the carbonation conversion of BHC, with an increasing temperature resulting in relatively higher conversion. In addition, the SEM and XRD results suggest that the BHC should be carbonated with CO2 to form CaCO3 in a slurry reactor. It was thus concluded that the CO2 could be successfully captured by the carbonation of BHC in this manner. Furthermore, the experimental data were utilized to determine the rate-limiting mechanism based on the shrinking-core model (SCM), which was validated by the observations of SEM images. The SCM results indicate that the overall carbonation reaction of BHC in a slurry reactor was controlled by the ash-layer diffusion mechanism.

Original languageEnglish
Pages (from-to)1433-1443
Number of pages11
JournalAerosol and Air Quality Research
Volume12
Issue number6
DOIs
Publication statusPublished - 2012

Fingerprint

Slag cement
Carbonation
slag
slurry
cement
Hydraulics
hydraulics
Ashes
scanning electron microscopy
Scanning electron microscopy
Forms (concrete)
temperature
Carbonates
reactor
gas flow
Climate change
carbon sequestration
Ecosystems
Temperature
Flow of gases

Keywords

  • Aqueous carbonation
  • Co Concentration
  • Reaction temperature
  • Shrinking-core model
  • Slurry reactor
  • Utilization

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution

Cite this

Chang, E. E., Wang, Y. C., Pan, S. Y., Chen, Y. H., & Chiang, P. C. (2012). CO2 capture by using blended hydraulic slag cement via a slurry reactor. Aerosol and Air Quality Research, 12(6), 1433-1443. https://doi.org/10.4209/aaqr.2012.08.0210

CO2 capture by using blended hydraulic slag cement via a slurry reactor. / Chang, E. E.; Wang, Ya Chun; Pan, Shu Yuan; Chen, Yi Hung; Chiang, Pen Chi.

In: Aerosol and Air Quality Research, Vol. 12, No. 6, 2012, p. 1433-1443.

Research output: Contribution to journalArticle

Chang, E. E. ; Wang, Ya Chun ; Pan, Shu Yuan ; Chen, Yi Hung ; Chiang, Pen Chi. / CO2 capture by using blended hydraulic slag cement via a slurry reactor. In: Aerosol and Air Quality Research. 2012 ; Vol. 12, No. 6. pp. 1433-1443.
@article{6b8b9c63608d4ccab305ebf26b24a3eb,
title = "CO2 capture by using blended hydraulic slag cement via a slurry reactor",
abstract = "Mitigation and adaptation are viable strategies for resolving climate change issues which may pose significant challenges to both ecosystems and human populations around the world. Aqueous carbonation is a promising process for mitigating CO2, due to the permanent storage of gaseous CO2 into carbonate precipitations (CaCO3 and/or MgCO3). In this study, aqueous carbonation of blended hydraulic slag cement (BHC) for CO2 sequestration was investigated and evaluated under various operating conditions, i.e., different reaction temperatures and CO2 concentrations, in a slurry reactor. The suspension BHC slurry was strongly alkaline (pH ~11.4) before carbonation, whereas the pH of the slurry dropped rapidly to nearly a weakly acidic solution (i.e., pH ~6.3) after introducing CO2 gas into the reactor. The results show that the maximum CO2 capture capacity was 181 g CO2 per kg BHC at a reaction time of 120 min, a CO2 concentration of 10{\%}, and a gas flow rate of 2.5 L/min at 65°C. The reaction temperature slightly influenced the carbonation conversion of BHC, with an increasing temperature resulting in relatively higher conversion. In addition, the SEM and XRD results suggest that the BHC should be carbonated with CO2 to form CaCO3 in a slurry reactor. It was thus concluded that the CO2 could be successfully captured by the carbonation of BHC in this manner. Furthermore, the experimental data were utilized to determine the rate-limiting mechanism based on the shrinking-core model (SCM), which was validated by the observations of SEM images. The SCM results indicate that the overall carbonation reaction of BHC in a slurry reactor was controlled by the ash-layer diffusion mechanism.",
keywords = "Aqueous carbonation, Co Concentration, Reaction temperature, Shrinking-core model, Slurry reactor, Utilization",
author = "Chang, {E. E.} and Wang, {Ya Chun} and Pan, {Shu Yuan} and Chen, {Yi Hung} and Chiang, {Pen Chi}",
year = "2012",
doi = "10.4209/aaqr.2012.08.0210",
language = "English",
volume = "12",
pages = "1433--1443",
journal = "Aerosol and Air Quality Research",
issn = "1680-8584",
publisher = "AAGR Aerosol and Air Quality Research",
number = "6",

}

TY - JOUR

T1 - CO2 capture by using blended hydraulic slag cement via a slurry reactor

AU - Chang, E. E.

AU - Wang, Ya Chun

AU - Pan, Shu Yuan

AU - Chen, Yi Hung

AU - Chiang, Pen Chi

PY - 2012

Y1 - 2012

N2 - Mitigation and adaptation are viable strategies for resolving climate change issues which may pose significant challenges to both ecosystems and human populations around the world. Aqueous carbonation is a promising process for mitigating CO2, due to the permanent storage of gaseous CO2 into carbonate precipitations (CaCO3 and/or MgCO3). In this study, aqueous carbonation of blended hydraulic slag cement (BHC) for CO2 sequestration was investigated and evaluated under various operating conditions, i.e., different reaction temperatures and CO2 concentrations, in a slurry reactor. The suspension BHC slurry was strongly alkaline (pH ~11.4) before carbonation, whereas the pH of the slurry dropped rapidly to nearly a weakly acidic solution (i.e., pH ~6.3) after introducing CO2 gas into the reactor. The results show that the maximum CO2 capture capacity was 181 g CO2 per kg BHC at a reaction time of 120 min, a CO2 concentration of 10%, and a gas flow rate of 2.5 L/min at 65°C. The reaction temperature slightly influenced the carbonation conversion of BHC, with an increasing temperature resulting in relatively higher conversion. In addition, the SEM and XRD results suggest that the BHC should be carbonated with CO2 to form CaCO3 in a slurry reactor. It was thus concluded that the CO2 could be successfully captured by the carbonation of BHC in this manner. Furthermore, the experimental data were utilized to determine the rate-limiting mechanism based on the shrinking-core model (SCM), which was validated by the observations of SEM images. The SCM results indicate that the overall carbonation reaction of BHC in a slurry reactor was controlled by the ash-layer diffusion mechanism.

AB - Mitigation and adaptation are viable strategies for resolving climate change issues which may pose significant challenges to both ecosystems and human populations around the world. Aqueous carbonation is a promising process for mitigating CO2, due to the permanent storage of gaseous CO2 into carbonate precipitations (CaCO3 and/or MgCO3). In this study, aqueous carbonation of blended hydraulic slag cement (BHC) for CO2 sequestration was investigated and evaluated under various operating conditions, i.e., different reaction temperatures and CO2 concentrations, in a slurry reactor. The suspension BHC slurry was strongly alkaline (pH ~11.4) before carbonation, whereas the pH of the slurry dropped rapidly to nearly a weakly acidic solution (i.e., pH ~6.3) after introducing CO2 gas into the reactor. The results show that the maximum CO2 capture capacity was 181 g CO2 per kg BHC at a reaction time of 120 min, a CO2 concentration of 10%, and a gas flow rate of 2.5 L/min at 65°C. The reaction temperature slightly influenced the carbonation conversion of BHC, with an increasing temperature resulting in relatively higher conversion. In addition, the SEM and XRD results suggest that the BHC should be carbonated with CO2 to form CaCO3 in a slurry reactor. It was thus concluded that the CO2 could be successfully captured by the carbonation of BHC in this manner. Furthermore, the experimental data were utilized to determine the rate-limiting mechanism based on the shrinking-core model (SCM), which was validated by the observations of SEM images. The SCM results indicate that the overall carbonation reaction of BHC in a slurry reactor was controlled by the ash-layer diffusion mechanism.

KW - Aqueous carbonation

KW - Co Concentration

KW - Reaction temperature

KW - Shrinking-core model

KW - Slurry reactor

KW - Utilization

UR - http://www.scopus.com/inward/record.url?scp=84874992158&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84874992158&partnerID=8YFLogxK

U2 - 10.4209/aaqr.2012.08.0210

DO - 10.4209/aaqr.2012.08.0210

M3 - Article

AN - SCOPUS:84874992158

VL - 12

SP - 1433

EP - 1443

JO - Aerosol and Air Quality Research

JF - Aerosol and Air Quality Research

SN - 1680-8584

IS - 6

ER -