Mineral Carbonation for Carbon Capture and Storage CCS

Similar to the natural weathering processes, the overall reaction between a metal oxide-bearing material and C02 can be expressed as  

Nonetheless, although a steadily increasing number of research teams continue to investigate these methods, none of them has proven to be both economically and environmentally viable, due to various difficulties related to mineral carbonation. As a result, according to IEA (2008), It is unlikely that mineralization will offer an opportunity for sequestering large volumes of C02 [71]. 

When considering the reaction temperature, an increase in the temperature of a process is known to enhance the reaction rate. However, thermodynamics places restraints on the stability of carbonates, such that the temperature can be increased only to a certain (pressure-dependent) level before the formation of C02 is favored over carbonates. For example, at C02 pressures of 0.1 MPa, MgC03 is stable up to temperatures of about 673 K, whereas at 3.5 MPa C02 it is stable up to about 823 K [2]. Therefore, a simple solution of increasing the temperature (and making use 

One final detail to be noted is that magnesium silicate minerals, such as olivine and serpentine, typically contain significant amounts (in the order of 5-20 wt%) of iron oxides that can turn out to be valuable byproducts when produced in amounts too large to be overlooked by the iron- and steelmaking industries. 

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In this chapter the mineralization of carbon dioxide (C02) is addressed, from the viewpoints of (i) valuable inorganic carbonate material production and (ii) large-scale carbon capture and storage (CCS). Analogies with the natural weathering of rock and the material resources are discussed, followed by a summary of the state-of-the-art of carbonate production for the two different viewpoints mentioned. 

Many technical-chemical processes take maximum benefit of similarities with ongoing processes in Nature, with increased purity or reaction speed as the most important differences. The production of carbonates is a typical example of this, and the process of C02 mineralization for carbon capture and storage (CCS) (see Section 14.4) is in fact the accelerated version of what is known as the natural weathering of minerals. This is a combination of the interacting processes of mechanical and chemical weathering, and relevant to the current discussions are the chemical weathering processes of dissolution and hydrolysis that involve C02 [6, 7]. A dissolution equilibrium reaction that proceeds in Nature with dissolved C02 in water and calcite gives a bicarbonate solution ... 

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