Application of the Mechanical and Pressure Drop Tests to Determine the Sintering Temperature of Coal and Biomass Ash
Round 1
Reviewer 1 Report
In my opinion manuscript ID- energies-1091215 cannot be published in present form. There are too many disadvantages. I propose to complete the manuscript and resubmit the article again. My critical remarks below:
Abstract - The author fails to emphasize the novelty and significance of the study. An abstract summarizes, usually in one paragraph of 150-250 words or less, the major aspects of the entire paper in a prescribed sequence that includes: i) the overall purpose of the study and the research problem(s) you investigated; ii) the basic design of the study; iii) major findings or trends found as a result of your analysis; and, iv) a brief summary of your interpretations and conclusions.
Graphical abstract would be very useful for the reader. It would help in understanding the authors' intentions and the scheme of the research work carried out.
The introduction deviates from the standards of scientific work. It is rather common knowledge and popular science. The chapter as it stands is more like an introduction to a student handbook than a valuable introduction to research work. It needs to be corrected and completed.
The authors should explicitly specify the novelty of their work. What progress against the most recent state-of-the-art similar studies was made in this study? Mention this in the revised manuscript sections, including abstract, introduction, and conclusions.
The introduction should show the reader more what the authors' research brings to the commonly known knowledge, which inspired them to plan and implement them, and what new they bring to science. This is completely missing and needs to be completed.
The authors did not formulate any research hypotheses. This should be the starting point for research planning. What did they expect? What were they trying to verify? Needs to be completed.
It is necessary to introduce the chapter Statistical method into the methodology. It is necessary to present with which statistical tests the significance of differences between the analyzed variables was analyzed. Without properly performed statistical analysis, the results have limited scientific value and are unreliable.
Enter the values of the standard deviations in the graphs, tables and main text. It is very important information showing the range of variability of the obtained results.
Author should also pay more attention to the practical implications of this study, outlining the challenges in the current research, future work, and recommendations. There are many problems to discuss.
Broader presentation of the shortcomings and weaknesses of the presented solutions and a stronger focus on the practical and economic aspect and the area of application is needed.
Where is the scientific discussion? Scientific discussion of the obtained results is not exist. It must be supplemented and expanded with a full comparative analysis with the currently published, current scientific works.
It is recommended to extend the comparison of the study findings under Results and Discussion with other similar published work under the results and discussion section. Currently, such a comparison is limited in this section.
The conclusions are very disappointing. The applications contain too much unnecessary information related to the purpose and methodology of the research. It needs to be corrected and changed. Correct the conclusions possibly after a statistical analysis of the research results.
Most of the literature is old and out of date. It should be replaced by more recent publications.
The English language throughout the manuscript is low quality. There are many typos, grammar errors, sentences that are too long, and phrases that are difficult to understand clearly. A deep linguistic proofreading by a native speaker is necessary.
In my opinion, the manuscript has many weaknesses. It can not be published in current form. It should be rejected and, after being rewritten, it can be placed again.
Author Response
Dear Reviewer,
Please find attached our reply to your review.
Best regards
Dorota Nowak-Woźny
Author Response File: 
Author Response.docx
Reviewer 2 Report
Slagging and fouling are major concerns during biomass combustion, because of the negative effect of ash depositions on the combustion process and device. A feasible method to predict biomass samples tendency to slag and foul, means mandatory specially when considering multifuel chambers. This work proposes two methods to determine biomass samples slagging and fouling tendency from sintering temperature, providing an objective method, not dependent on direct visual observation.
From my point of view, the idea that supports this work is worthy. The experimental section is well planned and the obtained results are useful and interesting, but there are too many troubles that make it far from reaching a minimum quality to be published. In its current form, I think it is a good idea, poorly developed. Some issues should be improved.
Firstly, a complete professional format and language review is required, there are many grammar and spelling mistakes along the text. In addition to that, some sections of the manuscript are redundant. The same ideas are expressed one after the other, i.e.: lines 83 to 87: “gravimetric method” is repeated three times. “Slagging and fouling hazards” are repeated twice in lines 161 and 163. Lines 227-231 and 232-236 mean basically the same.
Bibliography is obsolete. There are just a couple of references published in the last five years. In lines 67 to 69 it is stated that there have been previously published several “unprecise” works regarding sintering temperature determination, but no reference is provided. A deep state of the art summary should be provided, or at least some references must back that statement.
Line 133. I think figure 2 refers to pressure test instead to mechanical test setup.
Line 136, what do authors refer to with “technical analysis”?
Line 151. Volatile parts?
Lines 157 and 158. Lover?
Section 3; samples analysis, a routine experiment that is not the main section of this work, is explained in full detail, while the body of the work, such are mechanical and pressure drop tests are explained just in a few lines. This discussion must be improved.
Figures 3b and 4b provide no new information. The sintering temperature determination procedure is also explained in the text, and the same information can be provided in figures 3a and 4a.
Author Response
Dear Reviewer,
Please find attached our reply to your review.
Best regards
Dorota Nowak-Woźny
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript entitled “Biomass utilization for energy purposes in comparison with the coal from Polish mines – mechanical and pressure drop test for assessing the slagging and fouling exploitation hazards” presents an interesting study of the methodologies used for ash quality verification. However, some extensive improvements must be done before the its publication.
Dear Authors,
First of all, I highly recommend you to rephrase the title of the manuscript, because it does not match to the results you had presented.
Secondly, please highlight the novelty of your study. It has been shown extremely briefly in the introduction and therefore it's getting clear on the end of your manuscript.
The methodology was presented precisely, except giving an explanation what can we understand by cm from tab. 2? An equation should be given.
In the results section, you are describing the proximate and ultimate analysis of used feedstock, mainly by comparing one to another. In my opinion, the comparison should be done to data available in the literature. Were the results similar to others same kind? What with the ashes? Were the data similar?
Moreover, tab.1. is not the main approch of the research, I would consider tab. 2. as a main source of interesting data (giving some chemical explanations about the ash phenomena behaviour at high temperatures) but it has not been discussed at all... 'The composition of the tested materials’ ash is present in the table 2.'
Fig. 3 b) - I advice placing it in the methodology. Is the temp. 975C in the midpoint between the last 2 data obtained? Same with Fig. 4. b) - please clarify is the temp. 942C corresponding the highest value of the drop pressure obtained in every case?
The discussion has to be improved considering the chemical composition (as mentioned above). There is no need to mention all of the results in the text, if they are already given in the table.
I suggest giving a linear trend equation and R2 coefficient in Fig.5, then the dependence would more visible.
Best.
Author Response
Dear Reviewer,
Please find attached our reply to your review.
Best regards
Dorota Nowak-Woźny
Author Response File: Author Response.docx
Reviewer 4 Report
Reviewer’s comments on manuscript energies 1091215
The presented manuscript is an experimental study on coal and biomass ash sintering temperature estimation by mechanical and pressure drop tests. It is envisioned that those methods could be applied in industry due to their robustness and simplicity. Such work is relevant for Energies journal and this study has potential to be a fine paper after a major revision. Generally, it is the Introduction and Results and Discussion part that should mostly benefit from it. An update of references is recommended and a few more should be included, broadening the study background. Citing in bulk should be avoided. Past studies presenting methods relevant to this study should be paid more credit. Results and Discussion part should be enriched, to better link the presented methods results with chemical composition of ash. Language level can be improved.
I recommend major revision of this manuscript.
Detailed manuscript assessment and list of queries:
Language: Is generally acceptable with some typing errors. Some sentences though seen to be incomplete (line 29, 231). Please perform a careful proofreading and consult with a native English speaker.
Title is too long, try to shorten it. If nothing else, “exploitation” should be omitted as it does not fit there. Keywords are relevant with respect to manuscript content.
Both study objectives and content are in line with aims and scope of Energies journal.
Introduction – literature survey: Most of the literature is of older date. Please try to include newer relevant information sources as well. Please avoid citing in bulk (line 41): either reduce the references or link them to the subject of your study one by one. Please provide a broader background and discuss in a separate paragraph the sources and abundance of the considered biomass, its current use and what beneficial outcomes (maybe negative ones as well) could result from its use as fuel (diverting it from its current use). Please try to give more credit to past studies related to methods used for ash sintering temperature prediction – lines 66-72 are insufficient in this sense; this will help you to highlight the relevance for more robust methods / development of the existing ones. Thereby, objectives of your work gain more support and the scientific relevance of your paper increases.
Line 29: please explain what you meant by “…knowledge of the biomass ash…”.
Materials and methods part is well-written. Statement about the statistics of experimental result should be included.
Results and discussion part should be enriched/improved:
- Table 2: include the slagging and fouling propensity assessment via suitable indicators (see papers by Baxter or Pronobis as inspiration).
- Try to avoid extensive description of data/trends visible from the presented Tables/Figures
- Lines 203-205 and 248-250 contain identical information, please rationalize the description of the data
- Line 226: should be Figure 5? In addition, please support the relevance of Figure 5 by longer discussion (is just one sentence currently), or remove it as it contains data from table 3.
- Discussion about accuracy / repeatability of measurements should be improved. Do Figures/Tables contain data from just one experimental run or are the values averages from multiple experiments?
- Lines 205 and 228: please list references for the mentioned methods
- Please enrich the discussion by linking the results of the mechanical and pressure drop tests with chemical composition of ash. You highlight the ash composition as crucial factor when considering ash slagging/fouling propensity at the very beginning of the manuscript (line 26-29). A brief comparison with the findings of Vassilev or other researchers would increase the value of this study. Maybe you can get inspiration from a recent review paper (https://doi.org/10.3390/pr9010100).
Conclusions: please modify it according to the contentual changes you perform in manuscript revision.
Abstract: Please include key quantitative results of comparison with other methods (Leitz, ASTM).
Author Response
Dear Reviewer,
Please find attached our reply to your review.
Best regards
Dorota Nowak-Woźny
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Thanks for improving the manuscript. In my opinion manuscript can be publish in present form. Congratulations
Author Response
Dear reviewer,
thank you for your time and valuable comments that allowed us to improve the article.
Yours sincerely
Dorota Nowak-Woźny
Reviewer 2 Report
the new manuscript was deeply reviewed. I think in its current for is suitable for publication
Author Response
Dear Reviewer,
thank you for your time and valuable comments that allowed us to improve the article.
Yours sincerely
Dorota Nowak-Woźny
Reviewer 3 Report
Dear Authors,
thank you for your answers. I find the manuscript significantly improved and now suitable for further processing.
Best.
Author Response
Dear Reviewer,
thank you for your time and valuable comments that allowed us to improve the article.
Yours sincerely
Dorota Nowak-Woźny
Reviewer 4 Report
Reviewer´s comments on revised manuscript energies 1091215
The revised submission has improved visibly, compared to the previous one. My comments and suggestions were answered thoroughly, and several manuscript parts were substantially changed or completely rewritten. This helped the manuscript objectives to be stated more clearly and study results and related discussion are written in a systematic manner. Inclusion of various slagging and fouling indices and the related discussion is interesting, and it improved the value of this study.
Substantial manuscript improvement can be documented and only few minor issues remain to be dealt with (listed below). As a result, a minor revision should suffice to fix the last weak spots and a fine study will be a result.
List of remaining queries:
Abstract is quite long and could be rationalized. The last sentence “But it needs more study.” is not a standard concluding sentence in an abstract; please rephrase it. Please consult Energies guide for authors, typically 200 to 300 words are the upper limit for abstract length.
Language level has improved sufficiently. Yet, please check the newly added/reformulated text for unclear formulations and typing errors.
Formatting: Please check the bold text (lines 96-104) – is bold necessary? Please separate Part 2 headings from the previous text. Please separate subheading for part 3.2 from the previous text. Please check and refer to all equations in text (especially equations (6) and (7)).
Figure 4: Please check and translate the text in Polish.
References: please add DOIs wherever available.
Author Response
Dear Reviewer,
thank you for your time and valuable comments that allowed us to improve the article.
Yours sincerely
Dorota Nowak-Woźny
Author Response File: 
Author Response.pdf
