:Post-combustion carbon capture in a power plant (Source: Smit et al., 2014)
The approach is considered economically advantageous since the plant doesn’t require any redesign and the carbon capture is added as an accessory. However, the shortcoming of the approach is that it consumes a significant amount of electricity, thereby reducing the overall power generated by the facility. The primary alternative to this is the pre-combustion carbon capture technique illustrated in figure 9 below.
Figure 9: Pre-combustion carbon capture in a power plant (Smit et al., 2014)
With the pre-combustion technique, coal is burned with pure oxygen rather than air which is comprised of different gases. As a result, carbon dioxide and water are released as the only by-products. The water is thereafter condensed and carbon dioxide easily separated from the gas mixture (Smit et al., 2014). The main shortcoming of the precombustion approach is that to separate oxygen from the air, cryogenic separations are required which are expensive and highly energy-intensive. Furthermore, the adoption of the system requires a complete re-design of the power plant, which implies additional costs (Soares, 2014).
Thirdly, researchers such as Lima et al. (2020) further advocate for the adoption of renewable energy as an alternative to non-renewable fossil fuels in a bid to facilitate the reduction of GHG emissions. The researchers reveal that in Brazil, renewable energy sources such as wind and solar have grown significantly, with a target of 20GW power generation being set for wind energy by 2024. Bansal et al. (2018) also report that in India, non-renewable energy contributes to 65% of the energy demand in the country. This results in a significant GHG emissions due to the use of coal in power plants. However, the country has invested significantly in renewable energy with the primary focus on solar in a move to reduce the level of greenhouse gases emitted.