Tuning the dissolution kinetics of wollastonite via chelating agents for CO2 sequestration with integrated synthesis of precipitated calcium carbonates

Abstract

Carbon mineralization has recently received much attention as one of the most promising options for CO2 sequestration. The engineered weathering of silicate minerals as a means of permanent carbon storage has unique advantages such as the abundance of naturally occurring calcium and magnesium-bearing minerals and the formation of environmentally-benign and geologically stable solids via a thermodynamically favored carbonation reaction. However, several challenges need to be overcome to successfully deploy carbon mineralization on a large scale. In particular, the acceleration of the rate-limiting mineral dissolution step along with process optimization is essential to ensure the economic feasibility of the proposed carbon storage technology. In this study, the effect of various types of chelating agents on the dissolution rate of calcium-bearing silicate mineral, wollastonite, was explored to accelerate its weathering rate. It was found that chelating agents such as acetic acid and gluconic acid significantly improved the dissolution kinetics of wollastonite even at a much diluted concentration of 0.006 M by complexing with calcium in the mineral matrix. Calcium extracted from wollastonite was then reacted with a carbonate solution to form precipitated calcium carbonate (PCC), while tuning the particle size and the morphological structure of PCC to mimic commercially available PCC-based filler materials.

Calcium Carbonate Precipitation for CO2 Storage and Utilization: A Review of the Carbonate Crystallization and Polymorphism

“…The anhydrous crystalline polymorphs of CaCO3 strongly depend on the synthesis variables such as temperature, pressure, pH of the solution, reaction time, degree of supersaturation, ion concentration and ratio, ionic strength, stirring, type and concentration of additives, and feeding order (Tai and Chen, 1998;Jung et al, 2000;García-Carmona et al, 2003a,b;Shen et al, 2006;Meldrum and Cölfen, 2008;Chen and Xiang, 2009;Fuchigami et al, 2009;Ren et al, 2011;Chu et al, 2013;Zhao et al, 2013;Jiang et al, 2014;Ševčík et al, 2015;Chang et al, 2017). Although the formation of CaCO3 can be achieved by a simple precipitation reaction between Ca 2+ and CO 3 2− ions, the controllable formation of a specific polymorph of CaCO3 is still a practical challenge.…”

“…In the dissolution step, various additives including strong acids (i.e., HCl, HNO3, and H2SO4) Lin et al, 2008;Bobicki et al, 2012), organic acids (i.e., acetic acid, formic acid, succinic acid, oxalic acid, etc.) (Park et al, 2003;Park and Fan, 2004;Bałdyga et al, 2010;Zhao et al, 2013), salts, and alkali solution and ligands (Maroto-Valer et al, 2005;Jarvis et al, 2009;Lackner, 2009, 2011) have been investigated to date. Although the extraction efficiencies are promising, the use of such strong acids may provoke significant energy penalties associated with their recovery Olajire, 2013;Sanna et al, 2014).…”

“…It has been reported that the formation behavior of each polymorph is affected by synthesis factors including pH, temperature, concentration, and ratio of carbonate and calcium ions, additives, stirring, reaction time, etc. (Zhao et al, 2013;Chang et al, 2017). In this review, we present a summary of current knowledge and recent investigations involving mechanistic studies on the formation of the precipitated CaCO3 and the influences of the synthesis factors on the polymorphs.…”

Connecting the Morphological and Crystal Structural Changes during the Conversion of Lithium Hydroxide Monohydrate to Lithium Carbonate Using Multi-Scale X-ray Scattering Measurements

“…While various earth-abundant calcium and magnesium silicates have been extensively investigated for the permanent storage of CO 2 [3][4][5]7,11,12] given their availability in nature [13][14][15], there is an increasing interest in the scalable synthesis of alternative carbonates such as lithium carbonates. Lithium carbonate is the end-product of the carbonation of lithium hydroxide, a highly reactive sorbent for CO 2 capture in spacecraft and submarines.…”

Commentary: Ex Situ Aqueous Mineral Carbonation

“…Predicting the fate of CO2 injected into geological formations containing these rocks and minerals and developing chemical processes for converting CO2 to carbonates require a fundamental understanding of the kinetics of mineral carbonation and the corresponding morphological changes in materials. Thus, more recent studies have focused on understanding the carbon mineralization behavior via direct carbonation (Bonfils et al, 2012;Gadikota et al, 2014a;Eikeland et al, 2015) and indirect carbonation, which involves the dissolution of minerals (Park et al, 2003;Park and Fan, 2004;Hänchen et al, 2006;Prigiobbe et al, 2009;Gadikota et al, 2014b), formation of carbonates (Ferrini et al, 2009;Saldi et al, 2009Saldi et al, , 2012Cheng and Li, 2010;Bénézeth et al, 2011;Zhao et al, 2013;Fricker and Park, 2014;Swanson et al, 2014), and the corresponding morphological changes in materials (Hövelmann et al, 2012;Olsson et al, 2012;Gadikota et al, 2014a). The effects of sodium and ammonium salts and Si-, Mg-, and Ca-targeting chelating agents on enhancing mineral carbonation behavior has been investigated (Bonfils et al, 2012;Highfield et al, 2012;Declercq et al, 2013;Zhao et al, 2013;Gadikota et al, 2014a,b;Ghoorah et al, 2014).…”