Alternative Integrated Ethanol, Urea, and Acetic Acid Processing Routes Employing CCU: A Prospective Study through a Life Cycle Perspective

Round 1

Reviewer 1 Report

Upon reviewing your manuscript, I find that it adheres well to the standards of scientific research papers, and its overall structure and flow are commendable. However, based on the current state of the manuscript, there are several areas that require attention and response:

1.        The treatment of gaseous streams is a critical aspect to address. Their management in environmental assessments can significantly impact Global Warming Potential (GWP) results. Could you please elaborate on this?

2.        Establishing and sustaining an industrial ecosystem involving multiple agents is a pressing concern. How do you propose to address this unresolved issue?

3.        While integrated processes theoretically present advantages, are there potential challenges or limitations that might arise during their real-world implementation?

4.        The emergence of Homogeneous Ru-Based catalysts in recent years is noteworthy. However, it remains unclear if they can be extensively employed in the synthetic test paths of products. Are there discernible effects? Additionally, are there alternative catalysts available for comparison?

5.        I noticed that the utilization of CCU technology depicted in Fig. 5 is not mirrored in the modeled reactions. This discrepancy needs rectification.

6.        The manuscript frequently employs technical terms such as GWP, LCA, and PED relaxation without providing clear definitions or references. I recommend incorporating relevant definitions or citations to enhance clarity for readers.

7.        There's a formatting issue on line 114; it lacks the necessary indentation.

8.        Post line 248, the subheadings appear to be formatted incorrectly. Please review and amend as necessary.

9.        Each subheading should have a primary theme or subject. In instances where examples or cases are provided, it would be beneficial to introduce a main subject.

10.    Line 447 begins without capitalization. Kindly correct this oversight.

11.    The primary headings on line 502 seem ambiguous. Could you please clarify or rephrase for better understanding?

I hope these suggestions aid in enhancing the quality of this manuscript.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This study focused on alternative scenarios of an integrated ethanol-urea-acetic acid production process from an environmental point of view, enabling the adequacy of the proposed model compared to traditional routes. The materials were characterized carefully. According to the results,

 Environmental performance measures in the global warming potential and primary energy demand categories indicate that the integration of ethanol, urea and acetic acid production processes employing

carbon capture and usage present lower environmental impacts compared to the sum of their individualized processes that operate in the 25 productive market via conventional routes. In my opinion, this study can be help to green future, and can be published after major corrections:

1- Most of the explanations are conventional. Please emphasize the highlighted content.

1-Quality of Fig. 1 is very low.

2- On what basis are the values in Table 2 calculated?

3-The results of Table 6 should be compared with previous study.

4- Novel achievement about sustainable materials should be discussed in this study, for example A) doi: 10.1016/j.ecolind.2021.107639, B) doi: https://doi.org/10.1016/j.resconrec.2022.106740 and C) doi: 10.1142/S0192415X23500325

5- English writing need to proof by native person.

need proof

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Overall, this is a well-written manuscript presenting an interesting life cycle assessment comparing conventional and integrated production routes for ethanol, urea, and acetic acid. The methods are sound and the results are clearly presented. I have some suggestions to further strengthen the manuscript:

Major comments:

·      The introduction provides good background on the individual processes, but more context is needed on prior work integrating these processes and the knowledge gaps this study aims to address. What specifically is novel about this integrated system and LCA approach compared to previous studies?

·      The description of the alternative acetic acid production route using methanol hydrocarboxylation is unclear. More details are needed on the catalyst, operating conditions, and chemical reactions taking place.

·      For the life cycle inventory, more transparency is needed on the data sources and assumptions, especially related to the agricultural production of sugarcane feedstock.

·      The scenario development and descriptions need to be more clearly explained early in the methods section. It took me until the results to fully understand the differences between scenarios.

·      In the results, discuss trends in the impact indicators across scenarios to provide more interpretation beyond just the numeric values. For example, what drives the lower GWP and PED in S5?

·      The conclusions should better situate the findings within the broader context and literature. The implications for sustainable chemical production and process integration should be expanded.

Overall this is a solid contribution and with some revisions to address the comments above, I believe it would be suitable for publication.

·      Remove extra spaces throughout manuscript

·      Carefully proofread abstract and highlight key findings

·      Reduce the number of abbreviations where possible

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Based on the state of the revised manuscript, I recommend acceptance of this article

Reviewer 2 Report

It seems that the author has done the corrections well.