title: CO2 sequestration by carbonation of steelmaking slags in an autoclave reactor.
abstract: Carbon dioxide (CO(2)) sequestration experiments using the accelerated carbonation of three types of steelmaking slags, i.e., ultra-fine (UF) slag, fly-ash (FA) slag, and blended hydraulic slag cement (BHC), were performed in an autoclave reactor. The effects of reaction time, liquid-to-solid ratio (L/S), temperature, CO(2) pressure, and initial pH on CO(2) sequestration were evaluated. Two different CO(2) pressures were chosen: the normal condition (700 psig) and the supercritical condition (1300 psig). The carbonation conversion was determined quantitatively by using thermo-gravimetric analysis (TGA). The major factors that affected the conversion were reaction time (5 min to 12h) and temperature (40-160°C). The BHC was found to have the highest carbonation conversion of approximately 68%, corresponding to a capacity of 0.283 kg CO(2)/kg BHC, in 12h at 700 psig and 160°C. In addition, the carbonation products were confirmed to be mainly in CaCO(3), which was determined by using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) to analyze samples before and after carbonation. Furthermore, reaction kinetics were expressed with a surface coverage model, and the carbon footprint of the developed technology in this investigation was calculated by a life cycle assessment (LCA).
authors: Department of Biochemistry, Taipei Medical University, Taipei, Taiwan.
authors: E-E
authors: EE
authors: Chang
authors: Shu-Yuan
authors: SY
authors: Pan
authors: Yi-Hung
authors: YH
authors: Chen
authors: Hsiao-Wen
authors: HW
authors: Chu
authors: Chu-Fang
authors: CF
authors: Wang
authors: Pen-Chi
authors: PC
authors: Chiang
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D003252:Construction Materials; D006358:Hot Temperature; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D013232:Steel
chemical_list: D013232:Steel; D002245:Carbon Dioxide; D002244:Carbon