Base Case CO2 Capture Cost

Estimates of CO₂ capture cost for all the base cases in this study are presented in Table 15. These values are in line with the literature results. According to reference [31], CO₂ capture costs for post-combustion CO₂ capture processes are in the range of EUR 50/tCO₂ to EUR 128/tCO₂. A decade ago, reference [65] reported a range of EUR 60/tCO₂ to EUR 90/tCO₂ for the power industry. Meanwhile, a range of USD 48/tCO₂ to USD 111/tCO₂ (i.e., EUR 41/tCO₂ to EUR 95/tCO₂) was reported by [35] specifically for post-combustion CO₂ capture from NGCC power plant’s exhaust gas.

In their study, Roussanaly et al. [66] estimated a CO₂ capture cost of EUR 63.2/tCO₂ (cost year of 2014) for a solvent-based CO₂ capture from a cement plant’s flue gas. For the cost year of 2016, Ali et al. [31] estimated the capture cost for a similar cement flue gas CO₂ capture system to be EUR 62.5/tCO₂. These literature capture costs are close to the capture cost in this work for the STHXs systems, though the cost years are different.

These results revealed that using the PHE in a standard post-combustion CO₂ capture process will lead to 4.4% reduction in carbon capture cost. A CO₂ capture cost reduction of approximately 3% will be achieved if the lean vapour compression is implemented instead. These are significant cost reductions, since over 1 million tons of CO₂ and over 630,000 CO₂ are captured in the NGCC system and the cement system, respectively.

The costs based on actual CO₂ emissions reduction (CO₂ avoided cost) from the cement plant were also estimated for the FTS-STHX, FH-STHX and PHE capture scenarios. They are EUR 87.5/tCO₂, EUR 87.7/tCO₂ and EUR 73.7/tCO₂, respectively, for the cement flue gas’ standard of CO₂ capture process. For the lean vapour recompression cement flue gas process, the costs are EUR 77.4/tCO₂, EUR 77.6/tCO₂ and EUR 75.2/tCO₂ for the FTS-STHX, FH-STHX and PHE capture systems, respectively. The CO₂ avoided cost values reported in the literature for the MEA capture systems ranges widely from EUR 75/tCO₂ to EUR 170/tCO₂. A CO₂ avoided cost of EUR 95.2/tCO₂ was estimated by [67], while reference [68] estimated EUR 81.9/tCO₂. Li et al. [29] reported an avoided cost of EUR 86.4/tCO₂. A CO₂ avoided cost of EUR 83/tCO₂ was estimated by [66]. For a closely related system, EUR 80/tCO₂ was recently estimated by [52].

The analysis of CO₂ actual emissions reduction is given in Figure 6. Steam and electricity are assumed to be generated from natural gas with CO₂ emissions of 0.18 kg of CO₂ emitted per kWh (thermal). The lean vapour compression (LVC) has better CO₂ emissions reduction performance due to the reduction in reboiler heat consumption from 3.89 GJ/tCO₂ to equivalent heat (reboiler heat and compressor work) of 3.28 GJ/tCO₂ (see Table 11 and Table 13).