Synthesis of nesquehonite by reaction of gaseous CO2 with Mg chloride solution: Its potential role in the sequestration of carbon dioxide

Sequestering CO2 by Mineralization into Useful Nesquehonite-Based Products

“…Precipitation is mainly done by mixing an aqueous solution of Mg salts, e.g., MgCl2, with an aqueous solution of NaHCO3 and/or Na2CO3 (Kloprogge et al, 2003;Haenchen et al, 2008;Case et al, 2011;Ma and Yoon, 2013). NaHCO3/ Na2CO3 solutions would be obtained when NaOH is used for the dissolution of CO2 into an aqueous solution but other bases such as aqueous ammonia solutions have been also used (Ferrini et al, 2009;De Vito et al, 2012). The physical chemistry of the precipitation of MHCH phases has been much studied and it appears that metastability is widespread among the precipitated products (Dell and Weller, 1959;Bender and Sprague, 1965;Langmuir, 1965;Davies and Bubela, 1973;Canterford et al, 1984;Haenchen et al, 2008;Hopkinson et al, 2008Hopkinson et al, , 2012Case et al, 2011;Ballirano et al, 2013).…”

Reject Brines from Desalination as Possible Sources for Environmental Technologies

“…If a supply of the appropriate cations can be assured, such carbonation reactions offer virtually unlimited capacity and the promise of safe, permanent storage of CO 2 . This idea was first proposed by Seifritz in 1990. There is little risk of unexpected release of CO 2 back to the atmosphere, because the resulting carbonates are thermodynamically stable (Ballirano et al, 2010;Ferrini et al, 2009). The process occurs naturally on a small scale during the weathering of rocks (Robertson, 2004), and has been shown to be important locally in ultrabasic and ophiolitic complexes (Hansen et al, 2005).…”

“…In this case, the precipitation of carbonates of Ca and Mg proceeds much faster than if the cations are locked in a silicate structure. The source of such a process could be a brine www.intechopen.com (Ferrini et al, 2009) or even seawater. There is an advantage in focusing on Mg, because a greater weight proportion of CO 2 is found in Mg carbonates than in Ca carbonates.…”

“…There are serious problems with that approach: the reaction kinetics for magnesium silicates tends to be too slow, and environmental concerns are associated with mining and processing very large amounts of magnesium-bearing rocks. Our group has recently described a carbonation process involving the reaction of gaseous CO 2 with a magnesium chloride solution producing a hydrated carbonate stable at Earth surface conditions (Ferrini et al, 2009). Additional experiments intended to simulate more closely the reject brines that are industrially available have been performed to explore the influence of the salinity on the carbonation process.…”

Carbonate mineral paragenesis and reaction kinetics in the system MgO–CaO–CO 2 –H 2 O in presence of chloride or nitrate ions at near surface ambient temperatures

“…Hopkinson et al, 2012). Various combinations of the methods described above also exist including pH adjustments of the solutions (e.g., Ferrini et al, 2009;Ballirano et al, 2010). Salts commonly employed include chloride, nitrate and hydroxides.…”