TY - GEN
T1 - Co-utilisation of CO2 and calcium silicate-rich slags for precipitated calcium carbonate production (part II)
AU - Eloneva, Sanni
AU - Teir, Sebastian
AU - Savolahti, Jaakko
AU - Fogelholm, Carl Johan
AU - Zevenhoven, Ron
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2007
Y1 - 2007
N2 - Production of commercial calcium carbonate from calcium silicate-rich slag is an attractive concept for reducing CO2 emissions. In order for this calcium carbonate to be marketable it has to be very pure, requiring separation of calcium from the slag prior to carbonation. In this study, a process concept that produces relatively pure calcium carbonate from slag is presented. It uses an aqueous solution of acetic acid to dissolve blast furnace slag, followed by removal of residues and evaporation of the acid to produce acetate, which is then dissolved in water before CO2 is introduced. The alkalinity of the solution is raised by addition of sodium hydroxide, which causes calcium to precipitate as calcium carbonate. The fate of other elements released from the slag during the process was studied as well. It was found that while Si, Ti and Zr can be separated by facilitating gel formation, Al, V, Mn, Fe, and Ba require additional separation methods to produce pure calcium carbonate. The process also requires additional measures for preventing sulphuric vapour emissions. The economical feasibility of the proposed process was also investigated. The evaporation step was found to be expensive, unless the process could be integrated with a waste heat source. Recovery of the sodium acetate solution, a by-product of the carbonation step, was also considered necessary for the process to be economically feasible.
AB - Production of commercial calcium carbonate from calcium silicate-rich slag is an attractive concept for reducing CO2 emissions. In order for this calcium carbonate to be marketable it has to be very pure, requiring separation of calcium from the slag prior to carbonation. In this study, a process concept that produces relatively pure calcium carbonate from slag is presented. It uses an aqueous solution of acetic acid to dissolve blast furnace slag, followed by removal of residues and evaporation of the acid to produce acetate, which is then dissolved in water before CO2 is introduced. The alkalinity of the solution is raised by addition of sodium hydroxide, which causes calcium to precipitate as calcium carbonate. The fate of other elements released from the slag during the process was studied as well. It was found that while Si, Ti and Zr can be separated by facilitating gel formation, Al, V, Mn, Fe, and Ba require additional separation methods to produce pure calcium carbonate. The process also requires additional measures for preventing sulphuric vapour emissions. The economical feasibility of the proposed process was also investigated. The evaporation step was found to be expensive, unless the process could be integrated with a waste heat source. Recovery of the sodium acetate solution, a by-product of the carbonation step, was also considered necessary for the process to be economically feasible.
KW - Acetic acid
KW - Blast furnace slag
KW - CO utilisation
KW - Mineral carbonation
UR - http://www.scopus.com/inward/record.url?scp=84870337551&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84870337551
T3 - ECOS 2007 - Proceedings of the 20th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems
SP - 1389
EP - 1396
BT - ECOS 2007 - Proceedings of the 20th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems
A2 - Mirandola, Alberto
A2 - Arnas, Ozer
A2 - Lazzaretto, Andrea
PB - Universita degli Studi di Padova
T2 - 20th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2007
Y2 - 25 June 2007 through 28 June 2007
ER -