Synergistic Effect on the Non-Oxygenated Fraction of Bio-Oil in Thermal Co-Pyrolysis of Biomass and Polypropylene at Low Heating Rate
Round 1
Reviewer 1 Report
1- Introduction section, other actual application of biomass in different fields of study, such as catalyses, metal or polymer matrix composite, advanced ceramics, etc. should be mentioned. The authors are recommended to read and use the following publications or other recent studies in this field to strengthen their introduction:
"Development of metal-matrix composites from industrial/agricultural waste materials and their derivatives", Critical Reviews in Environmental Science and Technology, 2016, 46 (2), 143-208. "Eco-fabrication of hierarchical porous silica monoliths by ice-templating of rice husk ash", Green Chemistry, 2017, 19 (1), 188-195. "Bilayer graded Al/B4C/rice husk ash composite: Wettability behavior, thermo-mechanical, and electrical properties", Journal of Composite Materials, 2018, 52 (27), 3745-3758. "Improving the Interfacial Reaction Between Cristobalite Silica from Rice Husk and Al–Mg–Si by CVD-Si 3 N 4 Deposition", Waste and Biomass Valorization, 2019, DOIhttps://doi.org/10.1007/s12649-019-00706-w.
2- Figure 3, please change the position of labels and increase the size of the text in the figure.
3- There is no explanation for Figures 6 and 7 in the text.
4- Figure 11, please change the scale of Y axis, so the changes can be seen.
5- Please introduce the NMR equipment in the experimental section.
6- Please elaborate more the conclusion section.
7- English of the text should be revised carefully.
Author Response
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Author Response.pdf
Reviewer 2 Report
The manuscript is not written well. The flow and structure of writing are messy and need substantial changes. I suggest the authors should read while the paper again to modify the issues and inconsistencies. The language has problem in several parts of the manuscript which needs to be checked by an expert person. I suggest resubmitting the manuscript after changes.
Overall, the paper is too long and needs to be reduced to fewer pages.
The introduction is too long and there is much extra information. The novelty of the research should be written at the end of the introduction, not in the middle.
What Table 1 shows? is there any reason to show the information like this?
Figure 2 captions should be merged as a one. Figure 2 b needs changes as there is no Y and X axis.
Figure 6 captions should be merged. There is no explanation for Figure 6 in the text.
Figure 7 captions should be merged. There is no explanation for Figure 7 in the text.
The conclusion is weak and needs to be enriched by more results.
References: The numbers are too much. There are many old references which should be deleted and some of them should be updated to 2018-2020. I suggest deleting all the non-indexed papers from the reference list.
Author Response
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Reviewer 3 Report
In the paper, the authors reported the different behaviors during pyrolysis of mixture of polypropene and biomass with various composition. The temperature of different regime, FTIR and NMR were comprehensively used to probe this process. Whereas the authors attempts to solve an interesting scientific problem in the field of pyrolysis process, there are several issued to be addressed before the paper is suitable for publication on Processes.
1) The authors mentioned that the triplicated experiments have been carried out at feed compositions of 0, 50% and 100% PP. Please report the these results in the supporting information to show the error of the experiments.
2) From lines 182 to 188, the authors explained the negative synergistic effectat 12.5% PP feed by the high composition of hydroxyl radicals. This is not rigorous. The production of non-polar fraction involves not only hydroxyl radical generation but other steps. The variation observed in Figure 2 is the result of the complicated reaction network but not caused by a single step.
3) The authors cited Bandara's work (reference 44) to conclude that there were negligible convective heat transfer in regimes 1. However, Bandara was using biomass particle size of 300 micron. In this work, Biomass particles with diameter of 300 - 2380 micron meters. There can be up to an order of magnitude of difference of particle size. Please comment on what will happen for biomass particles with size of 2380 micron meter.
4) FTIR provide important experimental support to the conclusion of this work. Please add the experimental details of IR experiments in the Experimental section. In addition, please quantify the area of peaks at 3337 cm-1 to prove the points.
Author Response
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Reviewer 4 Report
Dear Authors,
I have completed my review on your manuscript.
I believe that it is sufficiently novel to be published. Nevertheless, it still holds some parts that should be improved. For instance, I think that in the introduction or discussion you should emphasize more the significance for practice/industry. Then, I think that you should check carefully the English and also the format. Some parts need to be redistributed between the sections. I have provided some comments on the text.
Best regards,
Reviewer.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The revised manuscript still needs improvements. The English of whole the manuscript needs to be checked by a native especially the results and discussion part. Some of the comments didn't respond and then I suggest major revision.
Added information at the beginning of the abstract should be revised. Some of the sentences are in the present form and some of them in past tense. I suggest making all to the past tense as the research is finished.
The introduction should be summarized. There is much extra information in this section.
The old Table 1 is emoved but the explanation is still in the text.
The caption of Figure 1 should be merged.
Figure 2 style is not good and the X and Y axis not visible. Please check and re-draw.
There are no explanations for Figures 6 and 7.
The paper still is too big and needs to be summarized. I suggest deleting all the comparisons with old studies in the discussion section.
The information for reference 2 is incomplete.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
The authors have addressed the majority of the questions except the questions regarding the IR.
Please clearly state whether the transition mode is used and how the sample was prepared. Table 1 shows that the intensities of the OH and CO IR features decrease with increasing PP content. This makes sense since OH and CO features originate from the biomass content. With increasing PP content and decreasing biomass content, the Oh and CO features are expected to decrease. But it is not a strong evidence that "by increasing PP composition in the feed, carbohydrates present at early stage of co-pyrolysis much reduced as the bed reached 300 C", which was stated in lines 431 and 432 in the revised manuscript.
Author Response
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