Efficient Fractionation of Green Bamboo Using an Integrated Hydrothermal–Deep Eutectic Solvent Pretreatment for Its Valorization

Round 1

Reviewer 1 Report

Page 2 line 58

Added references:

It is generally acknowledged that lignin can’t be easily deconstructed by hydrothermal pretreatment [18], whereas deep eutectic solvent (DES) can easily dissolve lignin [20], this effect has been documented in various reviews (Amesho et al. 2022, Jablonsky et al. 2018, Sharma et al. 2022, Yiin et al. 2022,).

 

Amesho, K. T., Lin, Y. C., Mohan, S. V., Halder, S., Ponnusamy, V. K., & Jhang, S. R. (2022). Deep eutectic solvents in the transformation of biomass into biofuels and fine chemicals: A review. Environmental Chemistry Letters, 1-48.

 

Jablonsky, M.; Skulcova, A.; Malvis, A.; Sima, J. Extraction of value-added components from food industry based and agro-forestbiowastes by deep eutectic solvents. J. Biotechnol. 2018, 282, 46–66. doi: 10.1016/j.jbiotec.2018.06.349.

 

Sharma, V., Tsai, M. L., Chen, C. W., Sun, P. P., Patel, A. K., Singhania, R. R., ... & Dong, C. D. (2022). Deep eutectic solvents as promising pretreatment agents for sustainable lignocellulosic biorefineries: A review. Bioresource Technology, 127631.

 

Yiin, C.L., bin Odita, E., Lock, S.S.M., Cheah, K.W., Chan, Y.H., Wong, M.K., Chin, B.L.F., Quitain, A.T., Loh, S.K. and Yusup, S., 2022. A review on potential of green solvents in hydrothermal liquefaction (HTL) of lignin. Bioresource Technology, p.128075.

 

Do not use the term DES, your system is not eutectic, it needs to be replaced Low-Temperature Transition Mixtures” or term “DES-like mixtures”

Recent years of research and development have brought frequently used terms for new types of green solvents to the lexicon of scientists. This can lead to terminological inaccuracies. In particular, different names are being used for the same types of solvents: Deep Eutectic Solvents (DES); Natural Deep Eutectic Solvents; Low-Transition Temperature Mixtures; Low-Melting Mixtures. It would, therefore, be appropriate to eliminate certain inaccuracies and to use simplification, which means using the general term “Low-Temperature Transition Mixtures” or introducing the term “DES-like mixtures”. (Jablonský and Šima, 2022)

Jablonský, M.; Šima, J. Is it correct to name DESs deep eutectic solvents? Bioresources 2022, 17, 3880–3882. DOI: 10.15376/biores.17.3.3880-3882.

 

it is necessary to improve the quality of fig. 2, or divide them

It would be appropriate to add information about the mechanism of action of choline chloride and lactic acid during hydrothermal treatment. What causes the agent, what degrades, what is the mechanism (from the literature but also from the data of the lignin analysis in your study, what is split, what bonds or groups)

 

page 11 line 335-337

Contrary to CR yield and cellulose retention, lignin removal exhibits a decreasing trend with the increasing run number, which is probably related to the decrease in acidity of DES [52].

It would be appropriate to expand it more and to support it with other works

Your acidity does not increasing Figure 2 (fig 2g pH from 4.6 to approx. 3.5, or fig 2), pH decreasing but acidity rises

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Reviewer 2 Report

The manuscript reports a chemical treatment of green bamboo to isolate hemicellulose and lignin using hydrothermal treatment combined with a deep eutectic solvent. My points of concern are as follows:

1. What are the High and low-Temperature impacts during hydrothermal treatment?

2. By what method was the concentration of xylose determined?

3. Figures 2g,h,i are not much clear.

4. SAED pattern is required in support of figure 3b. and crystallinity data.

5. 

 

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Reviewer 3 Report

Congratulations for your complete and thorough study, just some suggestions for underline your work:

- at the end of introduction, the aims of your work could be better expressed by answering the questions: why is important to fractionate the lignocellulose? Which are the applications of your work in the future? how does your results could be valued forward?

- the conclusions could be better expressed if you use short and clear cut  statements, presenting the main results and their importance for the field.

Pay attention! in rows 227, 304, 381 some statements begin with And which it is not corectly

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