Carbon dioxide sequestration process for the cement industry.

• KCl and CaCl 2 were extracted using pure water and HCl solutions at various concentrations, respectively, from industrial cement kiln dust. • For the membrane electrolysis, higher anolyte/lower catholyte concentrations, and higher temperature are appropriate for KOH production. • The CO 2 capture-mineralization was tested by measurement of CO 2 removal efficiency depending on the Ca/CO 2 ratio and gas retention time. Due to the significant amount of CO 2 released from the cement industry, a CO 2 sequestration process suitable for cement-manufacturing plants is required to reduce greenhouse gas emission and to mitigate global warming. In the present study, a new overall process of CO 2 treatment is proposed for the cement industry that includes the extraction of KCl and CaCl 2 from the cement by-products, KCl membrane electrolysis for KOH formation, and CO 2 capture-mineralization using the extracted KOH and CaCl 2. For this three-step process, various experiments were conducted to determine how the results varied in relation to experimental conditions and to find the most suitable conditions for process operation. The KCl and CaCl 2 were extracted using pure water and HCl solutions at various concentrations, respectively, from industrial cement kiln dust. KCl membrane electrolysis was carried out to measure the electrochemical performance in relation to the KCl or KOH concentration, temperature, and applied current density. The single process of CO 2 capture-mineralization was tested by measurement of the CO 2 removal efficiency in relation to variation of the Ca/CO 2 ratio and gas retention time. In addition, the purity of the CaCO 3 produced was evaluated in relation to the Ca/CO 2 ratio, and the CO 2 removal efficiency was examined over time on stream. [ABSTRACT FROM AUTHOR]