Hydrogen, Ammonia and Symbiotic/Smart Fertilizer Production Using Renewable Feedstock and CO₂ Utilization through Catalytic Processes and Nonthermal Plasma with Novel Catalysts and In Situ Reactive Separation: A Roadmap for Sustainable and Innovation-Based Technology

Round 1

Reviewer 1 Report

Find attached

Comments for author File: Comments.pdf

The article is ok, but it need comprehensive formatting

Author Response

Reply to reviewers’ comments

I thank the Reviewers for reviewing this very long and multi-disciplinary manuscript.  I agree with most of the Reviewers’ comments and concerns.

I apologise for the delay in my review as it took much longer than I anticipated. The manuscript is now substantially revised and re-formated in order to connect various strands of the research. The main and justified criticism by Reviewer-2 is that it is too long even for a review paper and should be split into two which I also considered before submission but decided against it.  The reason was that would look as though there were two separate topics and it would be against the objective of the paper which is to propose an achievable sustainable technology for the manufacture of symbiotic-smart fertilizers to abate climate change; essentially replacing the Haber-Bosch process. The proposed technology would have  potential for the sustainable/small scale production of anhydrous ammonia and hydrogen for transport fuel and hydrogen production and storage.  After receiving an invitation nearly a year ago, from the publisher MDPI to submit a paper to any of their journals, I   discussed the outline, purpose and  format (including the expected length) of  my intended submission. I then proceeded with the preparation and submission of the manuscript. I hope this background is useful in allaying concerns.

Notwithstanding its length, the manuscript contains several inventions and discoveries in catalyst and gasification science/technologies which I believe are useful in the delivery of the objectives.  

Reply to Reviewer-1:

The manuscript fits within the scope of colorant Journal and is also interesting and research is impressive. However, the following shortcomings have been pointed out and need to be addressed properly for further improvement of the manuscript. They are:

• The abstract it’s too broad. The length of the abstract is commensurate with the length of the manuscript and the number of topics covered. Nevertheless, I went through it again and made some reductions.
• Can’t find the keywords. Key words are now included. 
• The way you used citation is too much, eg in line 315: As the subject is highly topical and fast developing, there are a lot of papers to review in order to provide the reader with a balanced view of the subject.  These references are subsequently cited in more specific settings in the manuscript.
• Use the high resolution pictures: The original SEM-EDS images are available. Those submitted in the text were in word file and hence were not clear.
• Figure 9 should be revised, poor arrangement. Unfortunately the data presented in the paper were acquired at different institutions and in some cases the digital data were not provided.  However, at higher magnifications, the FTIR peaks are clearly identifiable.
• In a paragraph, line 1925, 2018 and 2043 why did you underline and increase the size of some selected words? : This appears to have happened when the submitted text was transferred to MDPI’s format for review. The submitted text did not contain these underlinings.
• Line 1965, why did you use different citation style?: This was a short-hand citation style and missed in translation. It is now corrected.
• Justify the table 10: This is an important table showing the types of chemical heterogeneity in the same sample obtained through extensive EDS-analyses. These micro-domains are evaluated  in order to show the effect of combined microwave and plasma in inducing rapid phase transition on BaTiO₃ surface  which results in the acquisition of piezoelectric state which is then visually observed due to colour change from white-to-black.  Table 10 now is associated with more explanation.
• Fine a better way of presenting image 12, 14 and 17 its too scattered. : It appears that the position of some of these images have been distorted when the word document was transferred to pdf. I believe that this will not be a problem in the published form as the original images in tif. or jpg. are used.
• Line 2680-2688,and 2889=2904 remove the grey highlight background: I could not find any grey highlight in my copy when I accessed the manuscript online.
• Figure 23, kindly remove, this is not a figure: Although I agree that this is not a figure but I am not sure how I would refer to it. It is a 1-D  diagram of the earlier figure.  As I am not sure what to call it, I have not changed it.  Certainly, it is not a reaction which are examined in the following 5 reactions.
• I don’t buy the idea of using the image in your conclusion section, kindly move it to section before it. : The main purpose of this study is to make a proposal based on the extensive review and new findings. Infact, I adopted  this type of approach from the earlier publications in this current series (References 82, 83; Catalysts 2016, 6, 80; and Catalysts 2020, 10, 152) and indeed this current study is based on the proposals/future work in Reference 83.  This figure is now updated.
• In general, poor presentation of Figures and Tables: I agree that that some of the figures and tables are poorly presented. This is due to the transition from the word. file to pdf.  I am sure that in the final form of the manuscript, such presentational quality problems will not be present.

Reviewer 2 Report

In my opinion, the present work, despite valuable in some parts, cannot be accepted in the present form. The manuscript is too long even for a review, and it can be more suitable as a chapter of a book. Too many different topics are presented, from plasma technology to gasification, which are not well presented in terms of sinergy. The quality of the figures (specially the ones related to GC and IR spectra) is low. I suggest a global revision of the paper prioir to further consideration, maybe dividing it into different parts and submitted separately.

Minor editing of English language required

Author Response

Reply to reviewers’ comments

I thank the Reviewers for reviewing this very long and multi-disciplinary manuscript.  I agree with most of the Reviewers’ comments and concerns.

I apologise for the delay in my review as it took much longer than I anticipated. The manuscript is now substantially revised and re-formated in order to connect various strands of the research. The main and justified criticism by Reviewer-2 is that it is too long even for a review paper and should be split into two which I also considered before submission but decided against it.  The reason was that would look as though there were two separate topics and it would be against the objective of the paper which is to propose an achievable sustainable technology for the manufacture of symbiotic-smart fertilizers to abate climate change; essentially replacing the Haber-Bosch process. The proposed technology would have  potential for the sustainable/small scale production of anhydrous ammonia and hydrogen for transport fuel and hydrogen production and storage.  After receiving an invitation nearly a year ago, from the publisher MDPI to submit a paper to any of their journals, I   discussed the outline, purpose and  format (including the expected length) of  my intended submission. I then proceeded with the preparation and submission of the manuscript. I hope this background is useful in allaying concerns.

Notwithstanding its length, the manuscript contains several inventions and discoveries in catalyst and gasification science/technologies which I believe are useful in the delivery of the objectives.  

Reply to Reviewer-2

Reviewer’s Comments: In my opinion, the present work, despite valuable in some parts, cannot be accepted in the present form. The manuscript is too long even for a review, and it can be more suitable as a chapter of a book. Too many different topics are presented, from plasma technology to gasification, which are not well presented in terms of sinergy. The quality of the figures (specially the ones related to GC and IR spectra) is low. I suggest a global revision of the paper prioir to further consideration, maybe dividing it into different parts and submitted separately.

Reply: I have already explained the reasons for the length and scope of this study as well as the quality of some of the figures.  It is true that it is not a “single topic” presentation and hence has great difficulties to make it highly comprehensible.  Nevertheless, as the objective of the study itself is highly multi-disciplinary, I believe that the outcome matches the scope and significance of the technology it describes and proposes for implementation. This study is “application guided” and requires expertise on several disciplines and experience in industrial scale operations as well as in plant design and  technology transfer. If no such “unusual” studies are undertaken, so much good science and engineering research would be wasted instead of being implemented in dealing with important global issues such as global warming which this study addresses.  In this respect, with due respect, I  disagree with the ratings of 3 as regards the significance of the work, its scientific rigour and its coverage of related/previous work especially with some 400 references; although this is not a review paper but an original search with several granted patents providing the background of the study.   I believe a single paper covering all aspects of a technology proposal is more useful than several papers covering specific aspects.  This opinion is based on my long experience on industrial/academic research, technology transfer and industrial/laboratory plant desing.

Round 2

Reviewer 2 Report

I thank the author for the response, which clarified some unclear points. To be honest, I remain sceptical with regards to the length of the manuscript, but I trust the author and the editorial board on such decision. 

I suggest to add in the introduction a kind of "guide for reading", helping the reader to go through this massive work, and explaining in a better way also the decision for which such format was chosen.

Author Response

Thank you again for your comments and suggestion as regards adding a guide section to make it easier to nevegate through the paper.  This is now done and highlighted at the beginning of Introduction under the heading "Scope and Structure".  The following alterations were also made:

1. The abstract was shortened.
2. "Visual Abstract" added
3. Figures 2, 22 and 25 were replaced by good quality images
4. Full text and the references were checked for errors.

I am now satisfied that the paper has been fully revised to my satisfaction and I hope the reviewers share this view. 

Author Response File: Author Response.docx