A Comparison of Feedstock from Agricultural Biomass and Face Masks for the Production of Biochar through Co-Pyrolysis

Round 1

Reviewer 1 Report

The authors presented a manuscript related to utilizing face masks waste as a biomass for energy generation. Overall, the topic is interested and the manuscript is well written and organized.

My comments are below:

1.      Introduction is too poor. The authors have to summarize the related biomass published studies. Particularly, the usage of waste in energy generation.

2.      The authors must point out the novelty of this work clearly. The authors must summarize the previous research work and point out clearly which knowledge they added to this manuscript. Therefore, please improve my introduction greatly.

3.      The figures’ quality is too poor please draw again and improve it.

Moderate editing of English language required

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors,

The manuscript is devoted to the current problem of recycling disposable medical masks. Pyrolysis of medical masks together with biomass waste was chosen as a processing method.

There are several questions about the submitted manuscript.

Many works are devoted to this topic and there are review articles:

1. Wee, M. X. J., Chin, B. L. F., Saptoro, A. et al. A review on co-pyrolysis of agriculture biomass and disposable medical face waste mask for green fuel production: recent advances and thermo-kinetic models. Front. Chem. Sci. Eng. 17, 1141–1161 (2023). https://doi.org/10.1007/s11705-022-2230-7

2. Yousef S, Eimontas J, Stasiulaitiene I, Zakarauskas K, Striūgas N. Pyrolysis of all layers of surgical mask waste as a mixture and its life-cycle assessment. Sustainable Production and Consumption, 2022, 32: 519–531

3. Johansson, A.-C., et al., Co-pyrolysis of woody biomass and plastic waste in both analytical and pilot scale. Journal of Analytical and Applied Pyrolysis, 2018. 134: p. 102-113.

1. What makes your work unique?

2. You indicate that the best pyrolysis mode is not higher than 400C, however, the recommendations of the World Health Organization and other researchers indicate that for medical waste the temperature should be above 1400C (a medical face mask is this type of waste). You will never be able to use contaminated biochar for industrial applications.

“The disposal of medical waste with pneumonia epidemic in other ways should pay attention to ensure the disposal effect. The temperature in the cement kiln is about 1400 °C, which can completely extinguish the new coronavirus. It has the characteristics of high disposal efficiency, no secondary pollution, high safety, and resource utilization, and it is one of the effective methods of COVID-19 medical waste treatment.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8619950/

Su M, Wang Q, Li R. How to Dispose of Medical Waste Caused by COVID-19? A Case Study of China. Int J Environ Res Public Health. 2021 Nov 19;18(22):12127. doi: 10.3390/ijerph182212127. PMID: 34831883; PMCID: PMC8619950.

3. The installation diagram and pyrolysis modes are not provided. What is the loading volume of raw materials? How were the raw materials mixed (mill, knives, etc.)? Why pyrolysis 60 minutes? What is the yield of coal and gases? and others.

4. How was the coal analyzed? What installation? How was the sample collected?

5. If the mask is made of polyvinyl chloride, what to do with the remaining chlorine? How do you plan to identify the composition of the masks?

6. Where is this data? “Then the by-products will be sent for characterization. The bio-oil and biochar pro-232 duced from the co-pyrolysis experiments would be characterized to determine their phys-233 ical and chemical properties. The characterization includes analyzing the composition, 234 heating value, viscosity, and density of the bio-oil. The experimental data would be ana-235 lyzed statistically on one final potential sample. Should there be no significant improvement-236 ments in the yield, the parameters will have to be re-evaluated and the optimization will 237 need to be done again.”

7. Where is the data on the influence of the ratio of biomass waste and medical masks on the composition of coal, product yield, and others?

8. In conclusion, you need to provide specific facts related to question 7.

You have submitted materials to the conference. Will these data be published in another journal? Will there be duplication of materials? Please provide the data sent to the conference.

TAN EE SANN; Co-Pyrolysis Of Biomass With Face Mask: A New Alternative For Energy Production; Pyroasia Symposium 2023; ; 10 May 2023; Conference Proceedings; Indexing In Progress

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

In this manuscript, authors considered co-pyrolysis of biomass with a waste face mask. Although the issue of the study itself is highly scientifically interesting and deals with current problems with waste disposal, the manuscript has numerous shortcomings. In the first place is the structure of the manuscript itself. English and typos must be corrected.

1. In the introduction part, give an overview of the applied method, and the results so far and point out why to use co-pyrolysis instead of pyrolysis of single waste. Give a summary of the applied methodology at the end of the introductory part and not as a separate part.

2. Material preparation, the pyrolysis procedure itself, and all applied characterization methods should be placed in part 2-Materials and methods. Explain in detail all used methods and techniques and refer to relevant standards and previous studies. All this has been done several times so it is necessary to cite the relevant publications.

3. The biggest complaint of the whole study - Through the results, only the results for masks and biomass are given, where are the results for biochars?

4. It is necessary to add the results for the biochars obtained from each separate material, and then their co-biochars, and then compare all the obtained results. Highlight the conclusion.

5. Add standard deviations for results and compare with literature.

Revision of English is necessary.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have done a good job of improving the quality of the article and have responded to all comments. I believe that the manuscript can be accepted in its current form.

Reviewer 3 Report

Manuscript can be considered for publication.