Investigation of Pyrolysis/Gasification Process Conditions and Syngas Production with Metal Catalysts Using Waste Bamboo Biomass: Effects and Insights

Round 1

Reviewer 1 Report

 

The manuscript is clear and concise, but it could benefit from a bit more detail and context to help the reader understand the significance of the findings. Here are some comments and suggestions:

1.     The abstract states that the primary objective is to examine catalytic behaviors, but it doesn't explicitly mention the context or why this examination is important. Consider adding a brief statement about the significance of studying these catalytic behaviors or the broader goal of the research.

2.     The abstract mentions that K₂CO₃ demonstrated the most favorable catalytic impact, but it would be beneficial to include some quantitative results or percentages to indicate the extent of improvement in char yield and tar reduction. This would make the findings more concrete.

3.     In the introduction section, it would be helpful to include more specific citations for claims and findings related to previous research. This adds credibility to your introduction and allows readers to explore these studies for further details. Fill those gaps by adding 10.1016/j.seta.2023.103346 and 10.1016/j.rser.2019.109477, and more citations to this section.

4.     I suggest that the result trends should be compared with more existing literatures; this is to ensure that they offer expected outcomes.

5.     In the conclusion section, emphasize why your study is important and how it adds to the existing body of knowledge in biomass gasification. Be cautious about repeating information already presented in the results and discussion sections. Instead, focus on summarizing and synthesizing the key points.

Author Response

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Reviewer 2 Report

 

In this manuscript the authors presented a manuscript regarding investigation of Pyrolysis/Gasification Process Conditions and  Syngas Production with Metal Catalysts Through Waste Bamboo Biomass. The authors presented good topic related to the catalyst research area. The manuscript is written and organized well. The authors included several types of analysis. I can recommend this article for the publication in sustainability after a major revision.  My comments below: 1. Introduction is too messy and must be written again carefully. The recent results related to this topic must be included along with stating clearly the novelty of this work.  2. Please improve the schematics in Fig 1 and 2, too poor and not clear.  3. References formatting is wrong.  4. Please add more scientific information to support your results. In my opinion, the current state of manuscript now looks like an experimental report rather than an academic article. 

Extensive editing of English language required

Author Response

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Reviewer 3 Report

The paper by Wang group reported about the syn gas production from waste bamboo biomass. Although the work is interesting, yet some defects are noticed, which should be rectified before publications. Please see my comments.

1.  There are little to discuss on the process about several pyrolysis process for biomass gasification reactions  and so on. Authors should kindly notice the issue and rectify such errors.

2. Besides, Figure 1 has no sense, so rectify  the figure.

3. Authors should cite several recent papers on biomass conversion issues to make the manuscript more readability and appropriate to the readers: As for example:

ChemistrySelect, 2023, 8 (33), e202204680;  ACS Sustainable Chemistry & Engineering 2021, 9 (37), 12431-12460.

4. Did the authors showed any GC-MS analysis of the gaseous mixture obtained from the pyrolysis process?

5. The explanation in line 174-176 is not clear  and authors are requested to kindly look into this matter. How they could predict about the crystallinity of the char produced. Did they perform xrd analysis or such similar experiments. What about the metal percentage and other impurities in the mixture after charing? What  is the effect of Ca-based catalyst as compared to others and please clarify it bit.

6. In line 251, how the authors optimize a 5% loading of catalyst showing a faster maximum reaction rate.

7. Whether the authors noticed any liquid product ?

8. Conclusions should be precise. The effect of potassium on decreasing the tar yield is also required proper justifications as compared to other catlysts.

NA

Author Response

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Reviewer 4 Report

1.      Abstract is not highlights the work methodology, provide aim, methodology and results

2. Introduction part is not quite enough, add a para on bamboo related studies with reference

3.      Author can include https://doi.org/10.1002/er.7062 , https://doi.org/10.1016/j.biteb.2020.100465 , https://doi.org/10.1016/j.biombioe.2023.106705, https://doi.org/10.1016/j.indcrop.2022.115986 and discuss

4.      Novelty statement needs to be more clear and reflect the concept of manuscript

5.      Check spelling and grammar mistakes

6.      Table 2 and 3, can be removed and data can be incorporated in the text

7.      Conclusion needs to be rewritten, highlight the important outcomes and how this addressed SDGs

8. what is the end factor of metal residue in char produced from gasification process, how it will be processed

9. How do lignin degradation confronts the yield of syngas

1.      Abstract is not highlights the work methodology, provide aim, methodology and results

2. Introduction part is not quite enough, add a para on bamboo related studies with reference

3.      Author can include https://doi.org/10.1002/er.7062 , https://doi.org/10.1016/j.biteb.2020.100465 , https://doi.org/10.1016/j.biombioe.2023.106705, https://doi.org/10.1016/j.indcrop.2022.115986 and discuss

4.      Novelty statement needs to be more clear and reflect the concept of manuscript

5.      Check spelling and grammar mistakes

6.      Table 2 and 3, can be removed and data can be incorporated in the text

7.      Conclusion needs to be rewritten, highlight the important outcomes and how this addressed SDGs

8. what is the end factor of metal residue in char produced from gasification process, how it will be processed

9. How do lignin degradation confronts the yield of syngas

Author Response

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Reviewer 5 Report

The authors proposed a novel Investigation of Pyrolysis/Gasification Process Conditions and Syngas Production with Metal Catalysts Through Waste Bamboo Biomass: Effects and Insights. The design of the experiments and characterization analysis were reasonable, which explained the primary objective of this study was to examine the catalytic behaviors exhibited by diverse metal catalysts. Overall, this manuscript is written and organized well. After carefully reviewing this manuscript, there are some improvements also needed to be made before the manuscript could be accepted.

1. The K-loaded moso in this Table 1 has no description of the preparation method. As well, it is recommended to do an elemental analysis to compare the K-loaded moso before and after the reaction.

2. In fact, the catalytic activity of NiO decreases at high temperatures, and it is not recommended to state directly that Ni metal has less effect on the gasification temperature.

3. The formula at Line304 is incorrectly expressed.

4. In section 3.1.4, it is suggested to do a comparison experiment with lower loadings, just two sets of data are not enough to prove that 5% is the ideal ratio, so there needs to be a trend to explain it further.

5. The thermal decomposition of K₂CO₃ also produces a portion of CO₂. does it have an effect on the experimental results of Fig.8 Syngas volume? Were other K-containing catalysts tested, such as the KCL chemical.

6. It is suggested that the authors add a statistical graph of the amount of syngas for different K doses, which would better illustrate the point that loading K elements is beneficial for the experiment.

Author Response

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Reviewer 6 Report

Dear Authors

The work is typical - no new concepts for the pyrolysis and gasification process. There is a lack of balance and kinetic analysis of both processes - a thermobalance is an excellent tool for such analysis. The role of catalysts is not underststend - please refer to the definition of a catalyst.

My comments on the work:

1. The last paragraph "Introduction" - please complete the scope and purpose of the work, write why this topic is important, and what is expected from the mentioned additions.
   2. Gas flow rate, e.g. 100 ml/min, sample heating rate 10 C/min - why such values were adopted.
   3. What was the gasifying agent during gasification or how was the exothermic gasification process defined. What was the fuel/gasification agent ratio?
   4. It should be justified why the tests were carried out in the temperature range up to 600 C and up to 1000 C.
   5. How do the authors justify the adoption of a catalyst/raw material ratio of 0.1 and 0.05
   6. Why are the process parameters shown in section 2.3 different from those in section 2.2.
   7. If there is no change in mass from T = 600 C, why is the pyrolysis process carried out up to 1000 C? Please explain.
   8. There is no information on the use of catalysts in Fig. 2
   9. Fig. 2 does not include the method of collecting gas samples for the chromatograph
   10. Line 136 – H2O appears – in what form and why was H2O used. There was no talk about this before.
   11. What is the relationship between reactions 1-4 and the studied processes (the chemical mechanism presented is very simplified.
   12. Equation 5-7 requires explanation, including the role of the catalyst - what this is all about. Can the additives used be called catalysts according to their definition?
   13. Why did the Authors not refer to other catalysts as they did to K2CO3 in equations 5-7.
   14. In the Conclusions, the Authors did not refer to the process effects of the catalysis used in the case of gasification and pyrolysis. It has not been commented that the catalyst (reactions 5-7) is actively involved in the process - how is this possible.

Regards

Reviewer

Author Response

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Round 2

Reviewer 1 Report

All of the reviewers' comments have been thoroughly addressed by the authors. Consequently, the manuscript is now suitable for acceptance and publication.

Author Response

Dear reviewer 1

Thank you very much for your advice and valuable comments.

Reviewer 2 Report

I think that the authors have adequately addressed most of my comments. Therefore, I recommend this manuscript for publication.

Minor editing of English language required

Author Response

Dear reviewer 2

Thank you very much for your advice and valuable comments. With your reasonable comments, we have revised the manuscript. We would like to show the answer for each comment as possible. Please review these parts again. Thank you very much with my heart.

Reviewer 6 Report

Dear Authors

Thank you for the discussion.  It is still not clear why the fuel/CO2 ratio cannot be specified for solid bed.

Why is K2CO3 a catalyst if it takes part in the reaction - this is how my intentions should have been understood.

Regards

Reviewer

Author Response

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