title: Reaction mechanism for the aqueous-phase mineral carbonation of heat-activated serpentine at low temperatures and pressures in flue gas conditions.
abstract: Mineral carbonation is known as one of the safest ways to sequester CO2. Nevertheless, the slow kinetics and low carbonation rates constitute a major barrier for any possible industrial application. To date, no studies have focused on reacting serpentinite with a relatively low partial pressure of CO2 (pCO2) close to flue gas conditions. In this work, finely ground and heat-treated serpentinite [Mg3Si2O5(OH)4] extracted from mining residues was reacted with a 18.2 vol % CO2 gas stream at moderate global pressures to investigate the effect on CO2 solubility and Mg leaching. Serpentinite dissolution rates were also measured to define the rate-limiting step. Successive batches of gas were contacted with the same serpentinite to identify surface-limiting factors using scanning electron microscopy (SEM) analysis. Investigation of the serpentinite carbonation reaction mechanisms under conditions close to a direct flue gas treatment showed that increased dissolution rates could be achieved relative to prior work, with an average Mg dissolution rate of 3.55 × 10(-11) mol cm(-2) s(-1). This study provides another perspective of the feasibility of applying a mineral carbonation process to reduce industrial greenhouse gas (GHG) emissions from large emission sources.
authors.affiliation: Institut National de la Recherche Scientifique (Centre Eau, Terre et Environnement), Université du Québec , 490 rue de la Couronne, Quebec, Quebec G1K 9A9, Canada.
authors.forename: Louis-César
authors.initials: LC
authors.lastname: Pasquier
authors.forename: Guy
authors.initials: G
authors.lastname: Mercier
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Blais
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Cecchi
authors.forename: Sandra
authors.initials: S
authors.lastname: Kentish
mesh_terms: D017632:Asbestos, Serpentine / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D003080:Cold Temperature; D005740:Gases / Q000737:chemistry*; D006358:Hot Temperature; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000737:chemistry*; D008906:Mining; D011312:Pressure; D014867:Water / Q000737:chemistry*
chemical_list: D017632:Asbestos, Serpentine; D005740:Gases; D008903:Minerals; D014867:Water; D002245:Carbon Dioxide