Current Status and Development Trend of Research on Polymer-Based Kinetic Inhibitors for Natural Gas Hydrates

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. What particular chemical features of polyvinylpyrrolidone (PVP) and polyvinylcaprolactam (PVCap) contribute to their efficiency as kinetic hydrate inhibitors?

2. The importance of binding energy in the performance of kinetic hydrate inhibitors needs to be discussed. What is the relationship between binding energy and the efficacy of hydrate inhibition?

3. The perturbation suppression mechanism has several limits in its ability to prevent hydrate formation. Future study should focus on overcoming these limitations.

4. The layer mass transfer obstruction mechanism has a unique impact on the diffusion rates of guest molecules in hydrate formation.

5. The adsorption and spatial blockage processes differ between PVP and PVCap in several ways. What are the practical consequences of these differences?

6. The goal of molecular simulation approaches in studying the inhibitory effects of kinetic hydrate inhibitors is to provide a comprehensive knowledge of the molecular interactions and dynamics involved in inhibiting the formation of hydrates. How might these strategies be more effectively employed in future studies?

7. The biodegradability of polymer inhibitors such as PVP and PVCap presents certain obstacles. To solve these issues, several solutions can be employed. The significance of assessing the environmental impact of kinetic hydrate inhibitors lies in the need to understand their potential effects on the environment. To foster the development of more environmentally friendly alternatives, certain measures may be implemented.

8. What are the practical consequences of the discoveries on particle adhesion processes in terms of preventing pipeline blockages? How might this information be utilised in practical situations?

9. Analyse the possibility of integrating kinetic inhibitors with thermodynamic inhibitors. What are the advantages and disadvantages of implementing such a method?

10. How do the results of this study contrast with prior studies on hydrate inhibition mechanisms?

11. What novel perspectives does this study offer?The study aims to identify the primary elements that impact the efficacy of hydration inhibition in field applications and determine how these aspects might be optimised based on the study's findings.

12. The comprehension of the memory impact of hydrates is crucial for the advancement of efficient inhibitors. What are the differences between PVP and PVCap in terms of mitigating this effect?

13. What are the recommended areas for further research based on the findings of the study? What is the most effective way to prioritise these areas in order to tackle the most crucial difficulties in hydration inhibition?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The review “Current Status and Development Trend of Research on Polymer-Based Kinetic Inhibitors for Natural Gas Hydrates” is devoted to the development of new and effective inhibitors of natural gas hydrates. According to the authors, the review systematically reviews recent research advances and development trends of KHIs for natural gas hydrates. The reviewer agrees with this idea, since 26 pages of the review covers a significant number of publications, and quite recent ones (as a percentage of the total volume 33). The text is written in scientific language, but is easy to read and will be understandable to Polymers readers. The authors were able to present a qualitative analysis of publications, starting with the history of the use of KHIs, uploading forecasts and recommendations for their safe and effective use. But there are several recommendations that need to be followed.

List of recommendations:

1. Figure 1. There is no explanation in the caption NGHs.

2. Figure 5. There is a recommendation to remove the figure, since a large number of more complex polymers are discussed in the review, and also for the first time the PVP formula appears in Figure 4.

3. Lines 126-129. In the sentence about “This series of studies...” it is necessary to cite several publications on this topic.

4. Section 3. Structural Composition Classification of Natural Gas Hydrate Kinetic Inhibitors. I recommend that authors think about how to present the so-called “zero” period in the history of the development of KHIs.

Line 361 and throughout the text are recommended to check: the designation KHIs must be entered once.

5. Lines 361-367. It is recommended to determine how “classification” and categorization relate to each other.” It is necessary to clarify, since the Polymer publication is specialized in polymer chemistry.

6. The most complex section is 4. Mechanism of Inhibition of Hydrate Generation by Kinetic Inhibitors of Natural 445 Gas Hydrates, which describes five mechanisms. It is recommended to ensure an even number of citations when describing each mechanism. For example, in subsection 4.1 there are only two recent links (140 and 141), in subsection 4.2 there are many more from 142 to 150, and so on...

7. Section 5. Conclusions and Outlook. It is recommended to work on the conclusion as it is written too vaguely for such a good review.

Author Response

Please see the attachment.

Author Response File: Author Response.docx