**2. Carbon dioxide capture**

the life on earth during nighttime. However, the increased concentrations of GHGs, par-

Global warming refers to the increase in the average global temperatures, mostly noticeable in the melting of ice caps in polar regions and the rising of sea levels. Specifically, the green-

allow this gas to absorb and emit infrared radiation at wavelengths of 4.26 and 14.99 μm, respectively [1, 4]. On the other hand, ocean acidification refers to the ongoing decrease in

oceans and seas forming carbonic acids to achieve chemical equilibrium. Consequently, the

toward neutrality or even acidity in the long term, hence affecting the life cycles of marine

Several international conventions and governmental protocols have been formulated to

*Change*, and *the Intergovernmental Panel on Climate Change*. To date, there is no universal agreement on these laws, and many countries and industries do not abide by these conventions. Therefore, immediate actions and solutions are demanded to circumvent the potential influ-

controlled by reducing the energy intensity, limiting the carbon intensity, or by improving

source of energy. Thus, there is an urgent need to develop economically feasible and efficient processes for capturing, separating, storing, sequestering, and utilizing the continuous CO2

emissions and technologies used in CCS and CCU.

emissions on the climate. In general, the total CO2

sequestration. In the short term, carbon-based fossil fuels will persist to be the main

ions are leading to decrease the pH of earth water from slightly basic conditions

emissions such as *The Kyoto Protocol*, *the UN Framework Convention on Climate* 

the pH of water in seas and oceans. About 30–40% of the anthropogenic CO2

organisms and the subsequent food chains [5].

4 Carbon Dioxide Chemistry, Capture and Oil Recovery

, are believed to cause drastic changes such as global warming and ocean

relies on its asymmetric stretching and bending vibrational modes, which

are dissolved in

emission can be

ticularly CO2

acidification [3].

house effect of CO<sup>2</sup>

formed H+

reduce the CO2

the CO2

ence of the yet high CO2

**Figure 1.** Major sources of CO2

Carbon dioxide capture technologies involve the processes of producing relatively high purity stream of CO2 for transport and storage, since most CO2 emissions from electricity generation and industries are released as flue gas (4–14% by volume CO<sup>2</sup> ). Storage of flue gas is possible in principle by compression to a pressure typically higher than 10 MPa, thus requiring a huge amount of energy aside from the large volumes produced that can rapidly fill the storage reservoirs. Therefore, carbon capture and storage (CCS) technologies represent an economic solution for storage of flue gases [4, 8].

Three methods are known for capturing CO2 in combustion systems of fossil fuels, namely *postconversion capture*, *preconversion capture*, and *oxy-fuel combustion* (**Figure 1**).
