An Approach towards the Conversion of Biomass Feedstocks into Biofuel Using a Zeolite Socony Mobil-5-Based Catalysts via the Hydrothermal Liquefaction Process: A Review
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe author wrote a comphensive short review of hydrothermal liquefaction process via ZSM-5 catalyst, and this review was well-organized and quite unique, it's strongly recommend to be published as soon as possible. I only have some simple comments about the statements and presentations in this review.
1. The topic was limited in ZSM-5 zeolite, and gave a brief summarization of advantages of ZSM-5 on this field, but it's of necessity to enhance the overview to the zeolites not just ZSM-5 on HTL process from the perspective of acidity, confinement effect, morphology and etc.
2. The author used ZSM-5 catalyst in the title, but the discussed catalysts is metal modified or loaded ZSM-5 catalysts. it's not inappropriate.
3. Please provide a new figure to clear illustrate the reaction process in this review for attracting the interest of reader.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis manuscript reviews recent literature on the conversion of biomass to biofuel via hydrothermal liquefaction using zeolite HZSM-5 as a catalyst. This topic has attracted significant interest during the last couple of decades in the context of sustainable development based on the use of renewable feedstocks.
The review is well written in a logical manner, with a competent selection of the relevant material mostly published in the last decade. In my view, it will be interesting for the readership of this journal, especially serving as a good and timely introduction to the important area of conversion of biomass to biofuel via catalytic hydrothermal liquefaction. Therefore, I recommend the acceptance of this manuscript for publication in Catalysts.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors
The following review discusses an approach towards the conversion of biomass feedstocks into biofuel using ZSM-5 catalyst via hydrothermal liquefaction (HTL) process. The article brings an interesting discussion, however, there many comments that authors are invited to address before considering the review for publication:
The main new addition of this review article is not clear, what is the new contribution that the authors are tying to present in this review article? This should be clearly stated in the introduction section.
Figure 1 and figure 2 have been copied from other papers, authors are required to ask for a copyright.
Page 3, line 81, “…………and pyrolysis because liquefaction is a potential method for turning raw materials into liquid……..”. replace the word liquefaction by “it”, you should refer to HTL.
Page 3, line 86. The paragraph starts with “The use of a catalyst during thermochemical……” please provide a reference
Page 3, line 105, “The unique function of different heterogeneous catalysts can change product yields and selectivity”. Please add the word “process” before selectivity.
The authors have discussed the advantages of heterogenous catalyst over the homogeneous catalysts in two sections, namely 2.4.1. and 1. Please don’t repeat the same information. In section 2.4.1. it is advised to write more about the advantages of zeolite rather than wring the advantages of heterogenous catalysts that already discussed in the introduction section.
It is suggested to add the following related paper to the reference list when you write about the advantages of heterogenous catalysts “Synthesis and characterization of new bifunctional SnZrSi oxide catalysts for biodiesel production”.
Section 2, the authors report the differences between four thermochemical processes namely, combustion, gasification, pyrolysis and HTL. I highly suggest constructing a new table shows the advantages and disadvantages of every process.
What are the key properties that future developments in hydrothermal liquefaction (HTL) catalysts should focus on?
Out of 36 references, no 2023 reference is cited. Please provide UpToDate recent references.
Page 4, line 148, please subscript the numbers in chemical formulas, such as H2O, and CO2. Please revise the whole paper accordingly.
Page 10, section 5. Why do you call this section “patents” and not “acknowledgment”. In addition, you wrote “This research was funded by the National Research Foundation, grant number 138079”. In which county the word national refer?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors have solved the comments of reviewer. I suggest publication.
