Evaluating CO₂ Desorption Activity of Tri-Solvent MEA + EAE + AMP with Various Commercial Solid Acid Catalysts

Round 1

Reviewer 1 Report

Main question addressed by the research: The work addresses Evaluating CO2 desorption activity of tri-solvent MEA+EAE+AMP with various commercial solid acid catalysts.

Originality and relevance of the topic: The topic is relevant to the field and it considers a suitable research gap.
Added value of the paper:  The manuscript takes into account the study of the desorption performance, desorption factor and heat duty, however the main purpose of it is not clearly stated. The paper should include what aspects are critical for these assessments and clearly explain why they are analysing those and why they are needed at the end of the Introduction.

Quality of figures: Good and easy to follow.
Specific improvements for the paper to be considered:

1. Section 2 describes the "coordinative effect". Could this be explained further?
2. Scheme 1 is unclear because of overlapping.
3. What would be the optimal conditions for this study?
4. The conclusions are weak and they would need more elaboration so they clearly match the results.

Author Response

See attach file.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is about the desorption methods of CO2 which is a hot topic since the captured CO2 in sorbents should be desorbed properly. However, I found many errors and disorganization in the manuscript, and I do not feel it is ready for publication. 

The English is not well written.

The introduction should cover the CO2 capture advances as well in a proper mode. Some recent advances should be discussed such as: Inorg. Chem. 2020, 59, 16, 11223–11227, Energy Environ. Sci. 2018, 11 (5), 1062– 1176; ACS Appl. Mater. Interfaces 2015, 7 (12), 6792– 6802.

The figures are not well prepared, they should be revised. 

Some equations are messed up. It should be revised. 

The title is not easy to understand, avoid any types of Abbreviations.

Give some presentation from what you use as sorbent.

Author Response

See attach file.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have replied to the comments based on the comments I had paused them in the first round of the review. I think it can be pulished in the current format after this revision, although it can be improved more and more.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The manuscript “Evaluating CO2 desorption activity of tri-solvent MEA+EAE+AMP with various commercial solid acid catalysts" by Zhang et al. reports the use of tri-solvent and commercial solid acid catalysts for CO2 desorption activity. The authors report that this combination has not been reported previously and novel. Overall, the article is well written has quite importance in CO2 capture field. Although, the presented results merely shows the performance of this combination without much scientific insights. Neither there is clear discussion about the catalyst role, active site etc. This seems to be more technological article that could be published in highly specialised engineering journal. I find article has value however it does not fit very well with the Catalysts, perhaps appealing to the engineering readers.

Reviewer 2 Report

Main question addressed by the research: The work evaluates CO2 desorption activity of tri-solvent MEA+EAE+AMP with various commercial solid acid catalysts .
Originality and relevance of the topic: The topic is relevant to the field and it considers a suitable model (research gap) So there is a novel aspect for this manuscript, however this novelty should be highlighted within the introduction and the abstract.
Added value of the paper:  The manuscript takes into account the study of the tri-solvent and commercial catalysts, however the main purpose and justification of them are not clearly stated. The paper should include clearly why they are analysing those and why they are needed. 

Quality of figures: figures are clear, but figure captions are confusing and formatting of figures should be improved as for removal of outline and consistency for all of them.
Specific improvements for the paper to be considered:

1. Abstract is too short and general. It should summarize the main findings and applications of the paper. What is the percentage increase or benefit in terms of heat duty? And DF? Not clear about the main findings and contributions in absolute values.
2. Scheme 2 is not readable and more explanations are needed within the main text.
3. Issues with figures and the readability of the legend. Discussion of the figures is weak. Why is there a change within the desorption factor? And in the heat duty? References should be provided for this change. Is there a relationship with the activation energy of the catalysts?
4. What are the optimal conditions for this case? 
5. The conclusions are poor and they would need more elaboration so they clearly match the results. Main findings are summarised briefly. They would need absolute values and clear contributions of everything achieved.

Reviewer 3 Report

Reviewer comments

1. In the abstract, you mentioned that ''The 0.2+1+3 mol/L MEA+EAE+AMP with HND-8 held minimized Heat Duty (H) and biggest Desorption Factor (DF) among the rest combinations''. You need to highlight how much heat duty decreased and the changes in desorption factor in the abstract.
2. Did you study the cyclic capacity for the applied catalyst? if not, you need to study their stability if yes, where are the results.
3. Based on your results presented in Figure 1. (a-e). The CO2 desorption profiles of MEA+EAE+AMP with and without catalysts added you did your test for different periods why? It should be for the same period to compare their performances ideally.
4. The author needs to add two figures, one as a schematic diagram of the batch reactor and the other one as graphical abstract.
5. In the revised manuscript author needs to provide a table to list a review of studies for the catalytic CO₂ desorption process in the amine-based solution.
6. To ensure the accuracy and reliability of the obtained data, the amounts of CO2 desorbed need to be conducted in triplicate or need to study it in both in the gas phase and compared with the liquid loading method.
7. The manuscript is not well written; a native English speaker's proof needs to be conducted to make the final paper organized and easy to follow.
8. Why did you select desorption time for 3h and less than 3h in some tests? What if experiments run for a longer time? More explanation should be made.
9. More details are required about how the measurement and characterizations were performed?