Carbon dioxide sequestration as stable carbonate minerals – environmental barriers

Abstract

This paper considers the major environ-

MINERAL TRAPPING OF CO2VIA OIL SHALE ASH AQUEOUS CARBONATION: CONTROLLING MECHANISM OF PROCESS RATE AND DEVELOPMENT OF CONTINUOUS-FLOW REACTOR SYSTEM

“…As the water penetrates into the surface pores, heat of hydration is released which exerts internal expansive forces in the lime-containing particles (the molar volumes of Ca(OH) 2 and CaO are 33.078 and 16.79 mL/mol, respectively [24]) and causes them to fracture and disintegrate (Fig. 5a,b) [21].…”

“…Because of the high share of minerals present in oil shale, large amounts of ash are produced (45-47% of oil shale burnt, dry mass basis) and deposited in openair ash ponds. Depending on the combustion technology, ash contains from 10 to 25% free Ca and Mg oxides and thereby it can be considered a CO 2 binder even under natural weathering conditions [21]. On the other hand, the ash is rich in free lime as the most active component, and because of that it requires stabilization to assure safe landfilling or further use.…”

“…CO 2 emissions could be decreased by reducing the usage of fossil energy sources, improving energy efficiency and/or by more intensive implementation of carbon capture and storage (CCS) technologies. CO 2 sequestration by mineral carbonation, considering both natural minerals [1,2] and alkali wastes [3][4][5] as CO 2 sorbents, is a prospective option.…”

“…CO 2 emissions could be decreased by reducing the usage of fossil energy sources, improving energy efficiency and/or by more intensive implementation of carbon capture and storage (CCS) technologies. CO 2 sequestration by mineral carbonation, considering both natural minerals [1,2] and alkali wastes [3][4][5] as CO 2 sorbents, is a prospective option.Carbonation of minerals is similar to natural rock weathering and involves permanent storage of CO 2 under the thermodynamically stable form of calcium and magnesium carbonates [6]. Mg-and Ca-rich silicates such as olivine, serpentine, talc and wollastonite are available worldwide and have * Corresponding author: e-mail maiuibu@staff.ttu.ee…”

Effects of CO2 Bubble Size, CO2 Flow Rate and Calcium Source on the Size and Specific Surface Area of CaCO3 Particles

“…This method originated from a process for producing precipitated CaCO3 [8]. Although this chemical reaction is simple and well known, as pointed out by Haywood et al [9], some consideration of the reaction rate and efficiency of metal extraction is needed to realize a successful CO2 fixation method. Ca(OH)2 or CaO (the dehydrated form of Ca(OH)2) is the calcined form of CaCO3 (formed by dissociation of CO2 when heated above 900 K).…”