Economic metrics of different PCC process configurations with MEA and MDEA

Fig. 5 and Fig. 6 present the cost estimations, performed using APEA, for the studied cases with MEA and a-MDEA, respectively. This analysis shows that by introducing process modifications to the base case configuration, energy savings (i.e., reduction in steam required) can be achieved, as demonstrated by decreasing annual OPEX values. However, moving towards advanced complex configurations with more process modifications increases the capital investment required, as shown by the increasing CAPEX values.”

Fig. 5

Fig. 5. Economic metrics of different PCC process configurations with MEA solvent.

Fig. 6

Fig. 6. Economic metrics of different PCC process configurations with a-MDEA solvent.

“Figs. 5 and 6 reveal that, as expected, the CAPEX is higher for the a-MDEA configurations because a bigger absorber with a larger diameter is required to obtain the same capture rate of 90%. A bigger absorber also means more packing in the column, and consequently, a higher cost. At the same time, OPEX and total annualized expenditure values, which include CAPEX and OPEX (i.e., TOTEX), are lower for a-MDEA configurations due to less energy demand for solvent regeneration. Therefore, in terms of total annualized costs, a-MDEA configurations are more economically attractive.

Among the different simulated cases, the combination of AIC and LVR had the lowest OPEX and TOTEX for both solvents. This is a direct result of lower steam consumption in the reboiler and hence less utility consumption. A more detailed economic analysis is essential to choose the best scenario among the proposed process modifications. Moreover, decision making requires knowledge about the availability of steam and electricity in the area as well as the indirect CO2 emissions associated with electricity consumption in the capture plant. Furthermore, an investigation should be performed on possible heat integration scenarios and synergies between the carbon capture unit and the host plant (typically chosen from a large CO2 emitting industry). It should be concluded that the implementation of these process modifications on a pilot-scale, in a demonstration plant and eventually in a large-scale capture plant integrated with a host plant is essential to ensure of the efficacy of the potential savings.”

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