CO2 Concentration Essay

One of the most widely studied mitigation options for reducing concentration of CO2 in atmosphere involves injecting it into the ocean at great depths, where the gaseous CO2 reacts to form carbonic acid (H2CO3) as shown in equation (2.1). This equation shows various forms of CO2 as it is dissolved in the water (brine). Depending on the pH of the solution, either forms of CO2 may be observed (CO2 (aq), 〖"HCO" 〗_"3" ^"-" , 〖"CO" 〗_"3" ^"2-" ). There are two ways for storing CO2 in ocean, either directly injected into the oceans or injected beneath ocean floor at a depth greater than 3000 meters and several hundred meters of marine sediment. The downside of this method is it endangers the marine life by as its pH alters as CO2 dissolves in water. The long-lasting impacts of direct CO2 injection into the ocean on ecosystems over large ocean areas and long-time scales have not been sufficiently studied to certify the safe implementation of this method.
CO2 (g) + H2O (l) ↔ CO2 (aq) ↔ H2CO3 (aq) ↔ HCO3- + H+ ↔ CO2 + 2H+ (2.1) (Qanbari et al., 2011)
2.2.2 Mineral …show more content…
Carbonation can take place either in situ or ex situ (Azdarpour et al., 2014). One major benefit of CO2 sequestration by mineral carbonation is that CO2 remains environmentally benign and virtually permanently trapped in the form of carbonated minerals by using abundant mineral resources such as Mg-silicates. In addition to benefits of mineral carbonation, this option is the only CO2 sequestration option where large underground reservoirs do not exist and ocean storage of CO2 is not feasible. The major drawback of this method is slow rate of reactions. Therefore attempts are being made to speed up the carbonation reaction using various methods such as additives, heating and pressurizing the carbonation