Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript "Energy-saving and detailed techno-economic assessment of the CO2 avoided cost for emerging designs of a solvent-based CO2 capture facility" addresses a relevant topic with the potential to contribute to the field of carbon capture technologies. However, in the introduction, while it provides adequate context, it does not include a comparison with other existing CO2 capture technologies; and in the discussion, a better comparison with previously reported works is necessary.

1. All acronyms used throughout the article must be accompanied by their full expressions upon first occurrence:

• ACEE in line 18
• CAPEX and OPEX, in line 59 (note, in this sense, in lines 84 and 85, only CAPEX and OPEX should appear here)
• FGC and LVC in line 65
• DOE/NETL in line 97
• AIC, MRS, and SIH in line 101
• NPV in line 107
• Please review the entire text.

2. In lines 77, 196, 209, 211, 224, 232, 375, review the way CO2 is written.
3. It would be helpful to include, in the introduction, a comparison between the solvents discussed and other carbon capture technologies (such as calcium looping process; cryogenic separation, membrane separation; solid adsorbents, and hybrid processes), considering criteria like energy efficiency, cost, environmental impact, and technological maturity. A comparative figure or table could support the contextualization of the chosen approach.
4. A short analysis of the applicability of solvents across different industrial sectors (e.g., energy, cement, and chemical) could enhance the practical relevance of the study.
5. Table 1: it is not necessary to repeat the units next to the values. Only the numeric values need to be displayed.
6. Figure 3: Why does the absorber packing diameter have a greater impact on CO2 capture rate compared to the packing height?
7. Table 2: it is not necessary to repeat the units next to the values.
8. Table 2: How do the optimization results affect the performance or feasibility of the proposed design?
9. The "hydrodynamic" study and/or characteristics should be explained in the discussion of figure 6.
10. Figure 6 should be improved.
11. Table 3 and Table 4: it is not necessary to repeat the units next to the values.
12. Figure 8: How does the inclusion of CO2 transportation and storage costs affect the levelized cost of electricity (LCOE) of the proposed configuration compared to those found in the literature?
13. Figure 9: What is the impact of the avoided CO2 cost on the economic feasibility of the proposed configuration compared to other mitigation alternatives?
14. In References, review the way CO2 is written.
15. In conclusions: What are the main technical and operational challenges that still limit the large-scale implementation of these innovative solutions? In other words, what can be done in the future.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents a techno-economic evaluation of two process intensification configurations—Flue Gas Compression (FGC) and Lean Vapor Compression (LVC)—for post-combustion CO₂ capture in NGCC power plants. A validated Aspen Plus simulation model was developed, benchmarked against commercial systems, and used for sensitivity and cost analyses. The study compares energy savings, capital costs, LCOE, and CO₂ avoided costs, concluding that LVC offers better economic performance than FGC.

 

1. The solvent formulation of Cansolv is proprietary, how do the authors justify that flue gas velocity alone is sufficient for validating the simulation model against commercial technologies?
2. The simulated design is significantly larger than commercial plants (e.g., seven times larger than Cansolv). How do the authors address uncertainties or scale-up limitations when extrapolating design and cost performance?
3. The study highlights reboiler duty reductions with FGC and LVC. Could the authors elaborate on how auxiliary energy penalties (e.g., blower/compressor duty) were accounted for in the total energy balance?
4. The cost evaluation follows ACEE class 4 methodology with a ±15–30% accuracy. How sensitive are the final LCOE and CO₂ avoided cost values to uncertainties in capital and operating cost assumptions?
5. The study compares LVC and FGC with literature-reported upgrades such as MRS, AIC, and SIH. How do differences in boundary conditions and assumptions (e.g., fuel type, flue gas composition, capture rate) affect the fairness of these comparisons?
6. The conclusions suggest that LVC is a promising option for NGCC integration. Have the authors considered potential operability challenges (e.g., transient load changes, solvent degradation, or integration with plant heat recovery systems) that may affect the long-term feasibility?

Author Response

"Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have made substantial changes based on the comments, and it can now be accepted for publication. However, minor revisions are required to improve clarity and coherence: 

1. In the introduction, particularly lines 40 to 64 and 69 to 96: bibliographic references should be added to reinforce the context and validate the scientific claims.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The revised version of the manuscript will be accept. 

Author Response

No additional revisions required by the reviewer