Liquefied Natural Gas (LNG) as a Transitional Choice Replacing Marine Conventional Fuels (Heavy Fuel Oil/Marine Diesel Oil), towards the Era of Decarbonisation
Round 1
Reviewer 1 Report
In terms of content, Authors in this article want to prove that LNG is a good choice as a transition fuel, especially in sea transport, which was discussed in detail in the article. Is it proven from the results obtained? In my opinion, partially. The article requires deep editorial corrections, mainly graphic. I expect the Authors to emphasize the importance of LNG as a transitional fuel, as it is known that at the present time the importance of this fuel has increased significantly.
Main comments:
1) In title of article "L.N.G" should be changed on "LNG". Also all title, I think, should be reconsidered:
"Liquefied natural gas (LNG) as transitional choice among alternative fuels" will be better.
2) In line 14 liquid natural gas should be changed to liquefied natural gas
3) Table 1 should be improved - it is illegible, edges are missing
4) In line 177 unit "g/kW h" should be corrected
5) Table 2 - incorrect style of references
6) Table 3 - it should be improved - table is illegible
7) All abbreviations like HFO etc. should be described in text, where they are marked or at the end of article before the references
8) Equation 2 in line 206 should be corrected in context of subscriptions
9) Figure 3 should be improved because the numbers make the tightly arranged labels in the chart unreadable
10) The green series in Figure 3 chart is not necessary
11) Units in Figure 3 should be corrected, there is: tn/y it would be better: tonne/yr
12) Table 5 should be on the same page. Table is poorly legible. Edges are needed.
13) Figures 7 and 9 are too small. They should be corrected.
14) Figures 8 and 10 should be improved.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This study investigates the potential of LNG as an alternative fuel in reducing GHG emissions in the marine sector. This is a hot topic recently and attract a lot of attention. But the language of this paper is poor, and the authors didn’t pay enough attention to the details (e.g., typos, fonts are not constant, and section titles are duplicated). Basic English grammar needs to be checked throughout the manuscript. This paper needs extensive revision before pushing to be published.
1. The title “L.N.G a transitional choice among alternative fuels” should be revised to indicate that this study focused on the marine sector.
2. The abstract needs to be modified. Major findings or conclusions should be mentioned in the abstract.
3. Line 14: After defining Liquefied natural gas as LNG when it first showed up, use “LNG” to keep it constant throughout the paper.
4. Line 35: I don’t see much contribution that comes from Figure 1. The source of the data is a bit out of date (2017). The information in Figure 1 can be easily converted to one or two sentences conveying the “ongoing” targets/goals of SOx emission reduction. More recent numbers on the progress of SOx emission reductions or reduction goals would provide more valuable context.
5. Line 38-47: the context is so poorly conveyed. The narratives must be rewritten.
6. Line 61: “…will take effect in 2021” change the tense since it’s already 2022.
7. Line 63: “During the Coronavcirus disease 219 epidemic,” what does “219” mean?
8. Line 74: “ECAs” should be in the full name when it showed up the first time.
9. Line 73-119: I am not sure what are the major points that the authors tried to convey. The “storyline” is confusing. The main idea should be emphasized in the first sentence of each paragraph and the logic can be explained in detail in the following sentences.
10. Line 120-141: some of the content in this paragraph should go to the “Methodology” section and the details/configuration of the case studies should be well described in this section.
11. Figure 4 and Figure 5 should be combined as one figure, and the two figures are shown as panels (a) and (b). Add similar panel labels for figures 6, 8, and 10.
12. The third section is “Results and Discussion” so the fourth section should be “Conclusions and Implications”. The contributions, limitations, and implications of this study should be discussed more in this section.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
I recommend acceptance after major revision. Please see my detailed comments below
Abstract: Please edit the abstract to make it more coherent. Also, please avoid acronyms in the abstract, or completely define what HFO and MDO means?
Figure 1: In the figure legend, describe what different colored lines mean.
Table 4: Where is the reference for table 4?
Please improve the quality of all figures.
Section 3 and Section 4 are both named as results and discussion. Section 4 should be conclusion.
I would also recommend citing the following latest articles on SOx and NOx mitigation.
Zhang, Z., Su, X., Jin, Y., Zhu, Z. and Lin, T., 2022. Research on energy recovery through hydraulic turbine system in marine desulfurization application. Sustainable Energy Technologies and Assessments, 51, p.101912.
Valluri, S. and Kawatra, S.K., 2021. Simultaneous removal of CO2, NOx and SOx using single stage absorption column. Journal of Environmental Sciences, 103, pp.279-287.
Zhao, J., Wei, Q., Bi, D., Liu, L., Wang, S. and Ren, X., 2022. A brand new two-phase wet oxidation absorption system for the simultaneous removal of SO2 and NOX from simulated marine exhaust gas. Chemosphere, 307, p.135830.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The incorrect uploaded file does not correspond to the previous version of the article.
Author Response
thanks
Reviewer 2 Report
A wrong file has been uploaded. The revised manuscript is not available for review.
Author Response
thanks
Reviewer 3 Report
Accept
Author Response
Dear Review ,
Thank you for your reviewing comments in the paper and your useful and constructive feedback, that helped us in improve the overall quality.
Round 3
Reviewer 1 Report
Many of my first substantive comments are included in revised version of manuscript. Unfortunately, the article still needs strong editorial improvements and in my opinion cannot be published until it looks like a solid scientific paper according to MDPI manuscript templates.
Author Response
Dear Review,
Thank you for your reviewing comments in the paper and your useful and constructive feedback, that helped us in improve the overall quality.
The following are our replies to your commentary.
The authors followed the comments from each reviewer resulting in significant text changes of the paper. The structure of the text, figures and tables have been modified in many points to comply with the MDPI manuscript templates. Please accept the changes and proceed with publishing the paper.
Please check the revised version through attachment.
Reviewer 2 Report
The authors revised the manuscript according to most of the comments. But they didn't mention the new line numbers of the corresponding content, it's hard to locate the revised content in the new version of the manuscript.
There is no need to add "(by author)" in the caption of the figures if the figures are made by the authors. If a figure is referred from literature, just add the citation number for it.
Author Response
Dear Review ,
Thank you for your reviewing comments in the paper and your useful and constructive feedback, that helped us in improve the overall quality.
The following are our replies to your commentary.
The authors followed the comments from each reviewer resulting in significant text changes of the paper. The structure of the text, figures and tables have been modified in many points to comply with the MDPI manuscript templates. Please accept the changes and proceed with publishing the paper.
Please check the revised version through attachment.
