Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors conducted a review on the corrosion mechanisms for waste-to-energy plant boilers and existing anti-corrosion measures adopted for these boilers. They concluded that new technologies should be developed, focusing on the specific requirements of the boilers, which involves multiple corrosion mechanisms.

 

Overall, the study is a useful addition to the literature. However, it is advised that the authors improve on the rationale of the study and highlight clearly the specific future directions that would help overcome the corrosion issues for these boilers. For the latter, it is suggested to state the requirements for the anti-corrosion measures that are related to the boilers. 

 

Other comments are given below:

 

Comment #1:

Section 2 mainly focuses on the corrosion mechanisms related to waste-to-energy plant boilers. Suggest removing “Advances in the study of” in the title as they do not add any value to the message intended for this section.

 

Comment #2:

In Section 2, I would suggest adding a comparison between the different mechanisms, highlighting potentially which one would be more crucial to overcome. Providing some statistical data on the common failures would be useful.

 

Comment #3:

Please improve the resolution of Figure 8.

 

Comment #4:

Similarly, in Section 3, remove “Advances in the study of” from the section heading. Suggest going straight to the point.

 

Comment #5:

Section 3 can be improved by correlating the corrosion preventive measures with the various mechanisms discussed in Section 2. Maybe producing an infographic or diagram could be useful.

 

Comment #6:

In Section 4.2, where did the authors obtain the breakdown for the methods used to protect waste incineration boilers from corrosion in China?

 

Comment #7:

In the conclusion, the authors suggested that developing new anti-corrosion technologies should focus on introducing new coating technologies with excellent protective performance and longer service life, along with competitive production efficiency and preparation costs. However, production efficiency and preparation costs were not covered in the study. Please include whenever necessary.

Comments on the Quality of English Language

The language is acceptable. The paper would benefit from minor language editing.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript presented for evaluation concerns a review of research and the state of the art in the field of corrosion and corrosion protection in waste incineration boilers. The presented work is of a review nature and correctly presents the current state of knowledge and perspectives of ongoing research work in the field of corrosion and its control. The structure and scope of the issues covered is familiar and correct. The literature selected for the review is up-to-date and correct. As a review paper, I assess it correctly, however, I would ask you to make some additions as noted below: 

1. in the introduction, please relate the level of energy generated from waste also to the overall level of energy generated and energy consumed (also as a %).

2. If possible, please indicate how common a problem corrosion damage is due to the chemical composition (unfavourable) of the municipal waste treated in the described boilers.

3. In the paragraph concerning operational problems related to the combustion of non-normative fuels, which include waste in classic coal boilers (lines 58-75), I suggest mentioning that the significantly higher content of volatile parts in fuels of the waste type in relation to coal, especially highly carbonised or anthracite, will strongly affect the temperature fluctuations mentioned in this paragraph, which are directly related to temperature fluctuations and, as mentioned, will have a huge impact on the thermal load of the boiler piping systems. Relevant literature on the effects of volatile components on boiler operation can be referred to here.

4. Please explain the mechanism associated with fly ash fouling of pipe walls and, more specifically, the relationship between the chemical composition of fly ash (or the chemical composition of the fuel) and the degree of fouling and fouling of pipe walls (line 198-201).

5. In subsection 3.2.1, please complete the indicative ranges (%) of individual alloying elements for the coatings discussed.

6. in the conclusions, I suggest indicating that the study of the chlorine/sulphur ratio could be an important aspect of further research and development of this topic. The rest of the conclusions are correct and I have no comments on them.

Editorial comments:

1. in Table 1 the unit designation Kelvin according to the SI system - (capital letter K).

2. Corrosion resistance limit temperatures (Table 1) - I recommend converting to Kelvins to correspond with the thermal conductivity given next to it, this will make it easier for the reader to quickly calculate the minimum material layer for a given material.

3. Figures 1, 5, 6, 8, 11, 12, 15 need improvement,

4 Minor editorial corrections due to publisher requirements.

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Author,

After a careful and thorough review, my considerations are as follows:

I have reviewed your manuscript and would like to provide some feedback that could enhance the rigor and impact of your study. The investigation into the properties and performance of coatings is indeed crucial, especially when considering their microstructural characteristics and surface morphology. However, I noticed that your study lacks critical analyses that would significantly strengthen your findings and conclusions.

Inclusion of Optical Microscopy (OM) Analysis:

OM is a fundamental technique that provides valuable insights into the microstructural features of coatings, such as grain size, phase distribution, and surface defects. Including OM analysis would allow you to present a clear and detailed view of the microstructure of the coatings under different conditions.

I recommend conducting OM analysis at various magnifications to capture the microstructural changes and any defects or irregularities that may have developed during the coating process or subsequent testing.

Inclusion of Scanning Electron Microscopy (SEM) Analysis:

SEM is essential for high-resolution imaging of the surface morphology and cross-sectional analysis of coatings. It enables the observation of fine details such as porosity, cracks, and coating-substrate interfaces that cannot be resolved by OM alone. Additionally, SEM coupled with EDS (Energy Dispersive X-ray Spectroscopy) can provide elemental mapping and composition analysis, further elucidating the quality and uniformity of the coatings.

Incorporating SEM analysis would greatly enhance your study by providing detailed images of the coating's surface and cross-section. This data could be used to correlate the microstructural features with the electrochemical and mechanical properties discussed in your manuscript.

Discussion of Microstructural Findings:

Once OM and SEM analyses are included, it is crucial to discuss how the observed microstructural characteristics relate to the performance of the coatings. For example, you could explore how surface roughness, grain size, and the presence of defects influence the corrosion resistance and overall durability of the coatings.

I recommend expanding your discussion section to include these correlations, thereby providing a more comprehensive understanding of how the microstructure affects the coating's performance.

In summary, the addition of OM and SEM analyses will significantly strengthen your manuscript by providing critical insights into the microstructural characteristics of the coatings. These analyses are not only standard in coating studies but also essential for validating the performance and quality of the coatings. I strongly encourage you to incorporate these techniques and revise your manuscript accordingly.

1. INTRODUCTION

 In Figure 1, describe the meaning of each region of the WtE boiler.

In Figures 2 and 3, insert a scale bar and increase the size of the Figure, as it is too small.

2. ADVANCES IN THE STUDY OF CORROSION MECHANISMS WITHIN WASTE-TO-ENERGY PLANT BOILERS

Insert SEM/EDS results of regions that have been affected by corrosion.

3. ADVANCES IN THE STUDY OF ANTICORROSION TECHNOLOGIES APPLIED TO WASTE-TO-ENERGY PLANT BOILERS

Present the chemical composition of the alloys shown in Table 1. In addition, present a comparison of the cost of each alloy, ordering from lowest to highest cost.

What do the authors observe in Figure 9? The caption of this figure does not agree with what is actually shown in the figure. Therefore, the authors should make the necessary corrections.

In Figure 10, insert “a”, “b” and “c”.

For each coating method, present OM and SEM images in order to provide more information about the different coating methods.

For each welding process, present the cross-section so that more information can be observed for each type of welding and coating.

4. CHALLENGES AND PROSPECTS FOR FUTURE RESEARCH

Present the keywords used in the research and which databases were used in this study. Also inform the period considered in the research.

Page 16, line 540: in the sentence “Notably, the corrosion rate curve depicted in Figure 2 is plotted” Figure 2 (page 2) presents the following caption “Thinning of the tube walls owing to the detachment of the water wall coating”. I ask that the authors make the necessary corrections, presenting the correct figure, which is not included in the manuscript.

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have responded to the comments in an acceptable manner.

Comments on the Quality of English Language

the language is acceptable and can benefit from further improvement.

Reviewer 2 Report

Comments and Suggestions for Authors

In my opinion, the manuscript submitted for evaluation, after all the previous comments have been applied, meets all the academic requirements for this type of scientific work and may be submitted for further processing and publication.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Author,

Thank you for submitting the revised manuscript and for addressing the concerns raised during the initial review. I appreciate the effort and time you have invested in making the necessary corrections to enhance the quality of your study.

 

Kind regards,

Reviewer